fix: recalculate passes when station position changes

Use combine(selectedIds, stationPosition) in SatelliteRepo.initRepository
so that passes are recalculated on either satellite selection change or
station position change. StateFlow already emits distinct values.

.github/copilot-instructions.md

@@ -0,0 +1,5 @@
+# GitHub Copilot Instructions
+
+Read `AGENTS.md` first, then `CLAUDE.md`.
+
+`AGENTS.md` contains the architecture, module boundaries, implementation details, conventions, and gotchas.

.github/dependabot.yml

@@ -0,0 +1,6 @@
+version: 2
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"

.github/workflows/release.yml

@@ -16,59 +16,64 @@ jobs:
       contents: write
     steps:
       - name: Checkout Repository
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
 
       - name: Setup Java
         uses: actions/setup-java@v5
         with:
           distribution: 'temurin'
-          java-version: '17'
+          java-version: '21'
 
       - name: Setup Gradle
-        uses: gradle/actions/setup-gradle@v5
+        uses: gradle/actions/setup-gradle@v6
 
       - name: Assemble Artifacts
-        run: |
-          ./gradlew assembleRelease
-          ./gradlew bundleRelease
+        run: ./gradlew assembleRelease bundleRelease
 
       - name: Sign APK
-        uses: r0adkll/sign-android-release@v1
-        id: sign_apk
-        with:
-          releaseDirectory: app/build/outputs/apk/release
-          signingKeyBase64: ${{ secrets.KEY_STORE }}
-          keyStorePassword: ${{ secrets.KEY_STORE_PASSWORD }}
-          alias: ${{ secrets.KEY_ALIAS }}
-          keyPassword: ${{ secrets.KEY_PASSWORD }}
-        env:
-          BUILD_TOOLS_VERSION: "36.0.0"
+        run: |
+          echo "${{ secrets.KEY_STORE }}" | base64 -d > keystore.jks
+          APK=$(find app/build/outputs/apk/release -name "*.apk" | head -1)
+          BUILD_TOOLS=$(ls -d ${ANDROID_HOME}/build-tools/*/ | sort -V | tail -1)
+          ${BUILD_TOOLS}apksigner sign \
+            --ks keystore.jks \
+            --ks-pass pass:${{ secrets.KEY_STORE_PASSWORD }} \
+            --ks-key-alias ${{ secrets.KEY_ALIAS }} \
+            --key-pass pass:${{ secrets.KEY_PASSWORD }} \
+            --out app/build/outputs/apk/release/look4sat.apk \
+            "$APK"
+          rm keystore.jks
 
       - name: Sign Bundle
-        uses: r0adkll/sign-android-release@v1
-        id: sign_bundle
-        with:
-          releaseDirectory: app/build/outputs/bundle/release
-          signingKeyBase64: ${{ secrets.KEY_STORE }}
-          keyStorePassword: ${{ secrets.KEY_STORE_PASSWORD }}
-          alias: ${{ secrets.KEY_ALIAS }}
-          keyPassword: ${{ secrets.KEY_PASSWORD }}
-        env:
-          BUILD_TOOLS_VERSION: "36.0.0"
-
-      - name: Rename Artifacts
         run: |
-          mv ${{steps.sign_apk.outputs.signedReleaseFile}} app/build/outputs/apk/release/look4sat.apk
-          mv ${{steps.sign_bundle.outputs.signedReleaseFile}} app/build/outputs/apk/release/look4sat.aab
+          echo "${{ secrets.KEY_STORE }}" | base64 -d > keystore.jks
+          AAB=$(find app/build/outputs/bundle/release -name "*.aab" | head -1)
+          jarsigner -verbose -sigalg SHA256withRSA -digestalg SHA-256 \
+            -keystore keystore.jks \
+            -storepass ${{ secrets.KEY_STORE_PASSWORD }} \
+            -keypass ${{ secrets.KEY_PASSWORD }} \
+            "$AAB" ${{ secrets.KEY_ALIAS }}
+          rm keystore.jks
 
-      - name: Deploy Bundle
-        uses: r0adkll/upload-google-play@v1
+      - name: Setup Ruby
+        uses: ruby/setup-ruby@v1
         with:
-          serviceAccountJsonPlainText: ${{secrets.SERVICE_ACCOUNT_JSON}}
-          packageName: com.rtbishop.look4sat
-          releaseFiles: app/build/outputs/apk/release/look4sat.aab
-          track: production
-          whatsNewDirectory: fastlane/metadata/android/en-US/whatsnew
+          ruby-version: '3.4'
+
+      - name: Deploy Bundle to Google Play
+        run: |
+          gem install multi_json
+          gem install fastlane --no-document
+          AAB=$(find app/build/outputs/bundle/release -name "*.aab" | head -1)
+          echo '${{ secrets.SERVICE_ACCOUNT_JSON }}' > service_account.json
+          fastlane supply \
+            --aab "$AAB" \
+            --json_key service_account.json \
+            --package_name com.rtbishop.look4sat \
+            --track production \
+            --skip_upload_images true \
+            --skip_upload_screenshots true \
+          rm service_account.json
 
       - name: Create Release
         run: |

.gitignore

@@ -1,6 +1,9 @@
 # Built application files
 *.ap_
 
+# Hermes AI plans and metadata
+.hermes/
+
 # Files for the ART/Dalvik VM
 *.dex
 
@@ -15,6 +18,7 @@ out/
 # Gradle files
 .gradle/
 build/
+.cxx/
 
 # Local configuration file (sdk path, etc)
 local.properties

AGENTS.md

@@ -0,0 +1,122 @@
+# Look4Sat AI Agent Instructions
+
+This is the canonical project guide for all AI assistants working on Look4Sat.
+All assistant-specific files (`CLAUDE.md`, `.github/copilot-instructions.md`) point here.
+
+---
+
+## Project Overview
+
+Look4Sat is an open-source, fully offline Android satellite tracker and pass predictor. It tracks 9000+ active
+satellites using TLE/OMM data from Celestrak/SatNOGS, calculates orbital positions via SGP4/SDP4 models, and displays
+passes relative to the user's location. Features include polar radar visualization, SSTV image decoding, satellite
+ground track mapping, and pass predictions up to 10 days ahead. No ads, no tracking, no network required after initial
+data download.
+
+## Architecture
+
+**MVI (Model-View-Intent)** with unidirectional data flow:
+- `State` data class → exposed via `StateFlow` from ViewModel
+- `Action` sealed interface → user intents dispatched to ViewModel's `onAction()`
+- Jetpack Compose UI observes state and recomposes reactively
+
+**Clean Architecture layers:**
+
+| Module               | Responsibility                                                      |
+|----------------------|---------------------------------------------------------------------|
+| `app`                | Entry point. Aggregates all modules                                 |
+| `core:data`          | Android library. Room DB, OkHttp networking, repo implementations   |
+| `core:domain`        | Pure Kotlin (JVM). Orbital math (SGP4/SDP4), models, repo contracts |
+| `core:presentation`  | Android library. Compose theme, shared UI components, NavKeys       |
+| `feature:map`        | OSMDroid map with ground tracks                                     |
+| `feature:passes`     | Pass predictions and upcoming events                                |
+| `feature:radar`      | Polar radar view of satellite positions, SSTV image decoding        |
+| `feature:satellites` | Satellite list, filtering, selection                                |
+| `feature:settings`   | User preferences                                                    |
+
+- `feature:*` modules depend only on `core:domain` + `core:presentation`. Features never depend on each other.
+
+## Build & Run
+
+```shell
+# Debug build
+./gradlew assembleDebug
+
+# Release build (minified, shrunk resources)
+./gradlew assembleRelease
+
+# Run tests
+./gradlew test
+```
+
+- **Min SDK**: 24 | **Target SDK**: 36 | **JDK**: 17
+- **Gradle**: Uses version catalog (`gradle/libs.versions.toml`) + convention plugins in `build-logic/`
+
+## Key Libraries
+
+- **Compose** (BOM 2026.05.01) + Material3 Adaptive
+- **Navigation3** (type-safe, uses `@Serializable` NavKeys)
+- **Room** (KSP code generation) for local satellite/TLE storage
+- **OkHttp** 5.x for TLE downloads
+- **OSMDroid** for map rendering
+- **Kotlin Serialization** for navigation args and data parsing
+- **Coroutines** + `StateFlow` for async/reactive patterns
+
+## Conventions
+
+- **Minimal dependencies**: Avoid adding libraries when a simple manual solution exists. Fewer deps = less maintenance.
+- **DI**: Manual — ViewModels use companion `factory()` methods with `IMainContainer` interface.
+- **Navigation**: Type-safe Compose Navigation3 with `@Serializable` data classes as nav keys.
+- **State naming**: `<Feature>State` data class + `<Feature>Action` sealed interface per feature.
+- **No feature-to-feature deps**: All cross-feature communication goes through core layers.
+- **Localization**: 7 languages (en, es, ru, si, tr, uk, zh).
+
+## Data Formats & Migration
+
+**TLE vs. OMM/CSV format:**
+
+Look4Sat supports both TLE and OMM (Orbit Mean-Elements Message) formats for backward compatibility:
+
+- **TLE format**: Traditional 3-line element format (deprecated). NORAD catalog numbers are 5-digit integers, which
+  are running out of space. Celestrak has signaled that TLE format will eventually be phased out.
+- **OMM/CSV format**: The future standard. CSV files contain the same orbital parameters as TLE but use ISO 8601
+  timestamps and support larger NORAD IDs. Celestrak and SatNOGS already provide OMM data in CSV format.
+
+**Current implementation:**
+- `DataParser.kt` handles both `parseTLEStream()` and `parseCSVStream()` seamlessly
+- TLE data is downloaded from configured sources and stored in Room database
+- When downloading satellite data, the app automatically detects format and parses accordingly
+- Both formats produce identical `OrbitalData` objects, ensuring transparent format switching
+
+**Migration path:**
+As NORAD catalog space becomes constrained, OMM/CSV will become the primary format. Look4Sat is already positioned
+to handle this transition without code changes — existing users can continue using TLE files while new sources
+transition to OMM/CSV automatically.
+
+## Code Style
+
+- Prefer **short, focused functions** — single responsibility, easy to read.
+- **Exceptions**: Composable functions and math-heavy algorithms (SGP4/SDP4) may be longer.
+- Strict code style — no dead code, no unused imports, consistent formatting.
+
+## Roadmap
+
+- **KMP migration**: `core:domain` is to become a fully shareable KMM module. Keep it pure Kotlin/JVM.
+
+## Gotchas
+
+- Orbital math lives in `core:domain/predict/` — it's dense vector math (SGP4/SDP4). Tread carefully.
+- TLE/OMM data must be refreshed weekly for accurate predictions (satellite orbits decay). TLE format is legacy and
+  will eventually be deprecated in favor of OMM/CSV as NORAD catalog numbers approach the 5-digit limit.
+- SSTV decoding in `feature:radar` is experimental; image quality depends on signal strength during satellite pass.
+- `build-logic/convention/` contains all shared Gradle configuration — edit there, not in individual modules.
+- ProGuard is enabled for release builds — don't add reflection-based libs or any other dependencies without asking.
+
+## Copilot Working Mode: Code-Only
+
+- Default to code changes only. Provide explanations in chat only.
+- If documentation seems useful, ask first before creating files.
+- Do NOT create any `.md` documentation files unless explicitly requested.
+- Do NOT add README, guides, summaries, migration notes, or how-to files unless asked.
+- Prefer minimal diffs focused on requested implementation.
+- Default validation is static checks (`get_errors`). Do NOT run Gradle compile/test tasks unless explicitly requested.

CLAUDE.md

@@ -0,0 +1,5 @@
+# CLAUDE.md
+
+Read `AGENTS.md` first, then follow the instructions there.
+
+`AGENTS.md` contains the architecture, module boundaries, implementation details, conventions, and gotchas.

README.md

@@ -1,35 +1,26 @@
-# Look4Sat: Satellite tracker
+# Look4Sat-BA7OPF
 
-[![Look4Sat CI](https://github.com/rt-bishop/Look4Sat/actions/workflows/release.yml/badge.svg)](https://github.com/rt-bishop/Look4Sat/actions/workflows/release.yml)
+[![Release](https://img.shields.io/github/v/release/atsunatsu/Look4Sat)](https://github.com/atsunatsu/Look4Sat/releases)
 
-[<img src="https://play.google.com/intl/en_gb/badges/static/images/badges/en_badge_web_generic.png" alt="Get it on Google Play" height="80">](https://play.google.com/store/apps/details?id=com.rtbishop.look4sat)
-[<img src="https://fdroid.gitlab.io/artwork/badge/get-it-on.png" alt="Get it on F-Droid" height="80">](https://f-droid.org/packages/com.rtbishop.look4sat/)
+**BA7OPF 定制版** — 基于 [rt-bishop/Look4Sat](https://github.com/rt-bishop/Look4Sat) 的业余无线电卫星追踪器，增加了线性卫星频率计算器等功能。
 
-### Radio satellite tracker and pass predictor for Android, inspired by Gpredict
+## 本仓库特色功能
 
-<p float="left">
-<img src="fastlane/metadata/android/en-US/images/phoneScreenshots/1.png" width="192"/>
-<img src="fastlane/metadata/android/en-US/images/phoneScreenshots/2.png" width="192"/>
-<img src="fastlane/metadata/android/en-US/images/phoneScreenshots/3.png" width="192"/>
-<img src="fastlane/metadata/android/en-US/images/phoneScreenshots/4.png" width="192">
-</p>
+- **线性卫星转发器频率计算器** — 在雷达页的 Calculator 标签页中，支持 TX/RX 双向多普勒频率计算，以及下行频率偏移（offset）输入，方便操作带偏移的线性卫星
+- **CW 解码器** — 集成 Morse Expert 解码引擎，支持瀑布图、实时解码文本
+- **Passband 模式** — 支持通过位置滑块（Passband）自动计算 TX/RX 频率，避免切换时跳变
+- **中文界面优化** — 翻译修正、UI 布局调整
 
-### Track satellite passes with ease!
+## 上游仓库
 
-Thanks to [Celestrak](https://celestrak.com/) and [SatNOGS](https://satnogs.org/) you have access to over 9000 active satellites.\
-You can search the entire database by NORAD Catalog Number or the satellite's name.
+本仓库是 [rt-bishop/Look4Sat](https://github.com/rt-bishop/Look4Sat) 的分支，上游仓库的原始功能包括：
 
-Orbital positions and passes are calculated relative to your location.\
-To get reliable data make sure to set the station position via the app Settings.
+- 基于 Celestrak / SatNOGS 数据的 9000+ 活跃卫星追踪
+- SGP4/SDP4 轨道预测，10 天过境预报
+- 极坐标雷达图、地面轨迹图
+- SSTV 图像解码
+- 无广告、无跟踪、完全离线
 
-The application is built using Kotlin, Coroutines, Jetpack Compose and Navigation.\
-It is now and always will be completely ad-free and open-source.
+## 许可证
 
-## Main features:
-
-*  Predicting satellite positions and passes for up to 10 days
-*  Showing the list of currently active and upcoming satellite passes
-*  Showing the active pass progress, polar trajectory and transceivers info
-*  Showing the satellite positional data, footprint and ground track on the map
-*  Custom TLE satellite data import is available via Three Line Element .txt files
-*  Offline first: calculations are made offline. Weekly TLE data update is recommended.
+GNU General Public License v3.0。详见 [LICENSE](LICENSE)。

app/build.gradle.kts

@@ -1,3 +1,24 @@
 plugins {
     alias(libs.plugins.convention.applicationPlugin)
 }
+
+android {
+    namespace = libs.versions.packageName.get()
+    defaultConfig {
+        applicationId = "cn.ba7opf.look4sat"
+        ndk { abiFilters.add("armeabi-v7a") }
+    }
+    signingConfigs {
+        create("release") {
+            storeFile = file(System.getProperty("user.home") + "/my-release-key.jks")
+            storePassword = "look4sat123"
+            keyAlias = "look4sat"
+            keyPassword = "look4sat123"
+        }
+    }
+    buildTypes {
+        release {
+            signingConfig = signingConfigs.getByName("release")
+        }
+    }
+}

app/src/main/AndroidManifest.xml

@@ -2,6 +2,7 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android">
 
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
+    <uses-permission android:name="android.permission.ACCESS_LOCAL_NETWORK" />
     <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
     <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
     <uses-permission
@@ -11,21 +12,33 @@
     <uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />
     <uses-permission android:name="android.permission.BLUETOOTH_SCAN" />
     <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.RECORD_AUDIO" />
 
     <application
         android:name=".MainApplication"
+        android:allowBackup="false"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
+        android:networkSecurityConfig="@xml/network_security_config"
         android:roundIcon="@mipmap/ic_launcher_round">
 
         <activity
             android:name=".MainActivity"
             android:exported="true"
+            android:screenOrientation="portrait"
             android:theme="@style/Theme.Look4Sat.SplashScreen">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
+<!--            <intent-filter android:autoVerify="true">-->
+<!--                <action android:name="android.intent.action.VIEW" />-->
+<!--                <category android:name="android.intent.category.DEFAULT" />-->
+<!--                <category android:name="android.intent.category.BROWSABLE" />-->
+<!--                <data android:scheme="https" />-->
+<!--                <data android:host="github.com" />-->
+<!--                <data android:pathPattern="/rt-bishop/Look4Sat/passes.*" />-->
+<!--            </intent-filter>-->
         </activity>
 
         <meta-data

app/src/main/java/com/rtbishop/look4sat/MainActivity.kt

@@ -19,12 +19,21 @@ package com.rtbishop.look4sat
 
 import android.content.Context
 import android.content.res.Configuration
+import android.graphics.ColorMatrix
+import android.graphics.ColorMatrixColorFilter
+import android.graphics.Paint
 import android.os.Bundle
+import android.view.View
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
 import androidx.core.splashscreen.SplashScreen.Companion.installSplashScreen
+import androidx.lifecycle.lifecycleScope
+import com.rtbishop.look4sat.core.domain.repository.IContainerProvider
 import com.rtbishop.look4sat.core.presentation.MainTheme
+import kotlinx.coroutines.flow.distinctUntilChanged
+import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.launch
 
 class MainActivity : ComponentActivity() {
 
@@ -38,8 +47,37 @@ class MainActivity : ComponentActivity() {
         installSplashScreen()
         enableEdgeToEdge()
         super.onCreate(savedInstanceState)
+        observeNightFilterState()
         setContent {
             MainTheme(isDarkTheme = true) { MainScreen() }
         }
     }
+
+    private fun observeNightFilterState() {
+        val mainContainer = (applicationContext as IContainerProvider).getMainContainer()
+        lifecycleScope.launch {
+            mainContainer.settingsRepo.otherSettings
+                .map { it.stateOfNightMode }
+                .distinctUntilChanged()
+                .collect { nightMode -> applyNightFilter(nightMode) }
+        }
+    }
+
+    private fun applyNightFilter(enabled: Boolean) {
+        if (enabled) {
+            val nightMatrix = ColorMatrix(
+                floatArrayOf(
+                    1f, 0f, 0f, 0f, 0f,   // R → R
+                    0f, 0f, 0f, 0f, 0f,   // G → 0
+                    0f, 0f, 0f, 0f, 0f,   // B → 0
+                    0f, 0f, 0f, 1f, 0f    // A → A
+                )
+            )
+            window.decorView.setLayerType(View.LAYER_TYPE_HARDWARE, Paint().apply {
+                colorFilter = ColorMatrixColorFilter(nightMatrix)
+            })
+        } else {
+            window.decorView.setLayerType(View.LAYER_TYPE_NONE, null)
+        }
+    }
 }

app/src/main/java/com/rtbishop/look4sat/MainScreen.kt

@@ -25,6 +25,10 @@ import androidx.compose.animation.core.rememberInfiniteTransition
 import androidx.compose.animation.core.tween
 import androidx.compose.animation.fadeIn
 import androidx.compose.animation.fadeOut
+import androidx.compose.animation.scaleIn
+import androidx.compose.animation.scaleOut
+import androidx.compose.animation.slideInHorizontally
+import androidx.compose.animation.slideOutHorizontally
 import androidx.compose.animation.togetherWith
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
@@ -32,6 +36,7 @@ import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
@@ -39,11 +44,14 @@ import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Scaffold
 import androidx.compose.material3.Text
 import androidx.compose.material3.adaptive.navigationsuite.NavigationSuiteDefaults
 import androidx.compose.material3.adaptive.navigationsuite.NavigationSuiteScaffold
 import androidx.compose.material3.adaptive.navigationsuite.NavigationSuiteType
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
@@ -55,151 +63,219 @@ import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
+import androidx.lifecycle.ViewModelStoreOwner
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import androidx.lifecycle.viewmodel.compose.viewModel
+import androidx.lifecycle.viewmodel.navigation3.rememberViewModelStoreNavEntryDecorator
 import androidx.navigation3.runtime.entryProvider
 import androidx.navigation3.runtime.rememberNavBackStack
+import androidx.navigation3.runtime.rememberSaveableStateHolderNavEntryDecorator
 import androidx.navigation3.ui.NavDisplay
 import com.rtbishop.look4sat.core.domain.repository.IContainerProvider
+import com.rtbishop.look4sat.core.domain.repository.MutualPassData
+import com.rtbishop.look4sat.core.presentation.DeeplinkResolver
+import com.rtbishop.look4sat.core.presentation.ElevationThresholds
+import com.rtbishop.look4sat.core.presentation.LocalElevationThresholds
+import com.rtbishop.look4sat.core.presentation.RadarDestination
 import com.rtbishop.look4sat.core.presentation.Screen
 import com.rtbishop.look4sat.core.presentation.hasEnoughHeight
 import com.rtbishop.look4sat.core.presentation.hasEnoughWidth
 import com.rtbishop.look4sat.feature.map.MapDestination
+import com.rtbishop.look4sat.feature.mutual.MutualScreen
+import com.rtbishop.look4sat.feature.mutual.MutualViewModel
 import com.rtbishop.look4sat.feature.passes.PassesDestination
 import com.rtbishop.look4sat.feature.radar.RadarDestination
-import com.rtbishop.look4sat.feature.radiocontrol.RadioControlDestination
 import com.rtbishop.look4sat.feature.satellites.SatellitesDestination
 import com.rtbishop.look4sat.feature.settings.SettingsDestination
 
 @Composable
-fun MainScreen() {
+fun NavRoot(deeplink: String? = null) {
+    val rootBackStack = rememberNavBackStack(Screen.Passes)
+    val deeplinkResolver = DeeplinkResolver()
+    LaunchedEffect(deeplink) {
+        deeplink?.let {
+            val destination = deeplinkResolver.resolve(it) // rootBackStack.clear()
+            rootBackStack.add(destination)
+        }
+    }
+    val navigateBack: () -> Unit = { rootBackStack.removeLastOrNull() }
+    val slideInTransition = slideInHorizontally(initialOffsetX = { it }) togetherWith scaleOut(targetScale = 0.9f)
+    val slideOutTransition = scaleIn(initialScale = 0.9f) togetherWith slideOutHorizontally(targetOffsetX = { it })
+    NavDisplay(
+        modifier = Modifier.fillMaxSize(),
+        backStack = rootBackStack,
+        onBack = navigateBack,
+        transitionSpec = { slideInTransition },
+        popTransitionSpec = { slideOutTransition },
+        predictivePopTransitionSpec = { slideOutTransition },
+        entryDecorators = listOf(
+            rememberSaveableStateHolderNavEntryDecorator(), // Required for saving Compose state per entry
+            rememberViewModelStoreNavEntryDecorator() // Required for ViewModel scoping per entry
+        ),
+        entryProvider = entryProvider {
+            entry<Screen.Passes> { MainScreen(navigateToRadar = { rootBackStack.add(RadarDestination) }) }
+            entry<RadarDestination> {
+                Scaffold { innerPadding ->
+                    RadarDestination(navigateUp = navigateBack)
+                    innerPadding.calculateTopPadding()
+                }
+            }
+        }
+    )
+}
+
+@Composable
+fun MainScreen(navigateToRadar: () -> Unit = {}) {
     val backStack = rememberNavBackStack(Screen.Passes)
     val currentKey = backStack.lastOrNull()
-    val navigateBack: () -> Unit = { backStack.removeAt(backStack.size - 1) }
+    val navigateBack: () -> Unit = { backStack.removeLastOrNull() }
     val fadeTransition = fadeIn(animationSpec = tween(350)) togetherWith fadeOut(animationSpec = tween(350))
-    val navItems = listOf(Screen.Satellites, Screen.Passes, Screen.Radar(), Screen.Map, Screen.Settings)
+    val navItems = listOf(Screen.Satellites, Screen.Passes, Screen.Radar, Screen.Mutual, Screen.Map, Screen.Settings)
 
     val context = LocalContext.current
     val container = (context.applicationContext as IContainerProvider).getMainContainer()
     val trackingState by container.radioTrackingService.state.collectAsStateWithLifecycle()
+    val otherSettings by container.settingsRepo.otherSettings.collectAsStateWithLifecycle()
+    // Activity-scoped so the mutual query results survive navigation to Radar and back
+    val mutualViewModel: MutualViewModel = viewModel(
+        viewModelStoreOwner = context as ViewModelStoreOwner,
+        factory = MutualViewModel.factory(container)
+    )
 
-    NavigationSuiteScaffold(
-        navigationSuiteItems = {
-            navItems.forEach { screen ->
-                val isSelected = when (currentKey) {
-                    is Screen.Satellites -> screen is Screen.Satellites
-                    is Screen.Passes -> screen is Screen.Passes
-                    is Screen.Radar -> screen is Screen.Radar
-                    is Screen.Map -> screen is Screen.Map
-                    is Screen.Settings -> screen is Screen.Settings
-                    else -> false
-                }
-                item(
-                    icon = { Icon(painterResource(screen.iconResId), stringResource(screen.titleResId)) },
-                    label = { Text(stringResource(screen.titleResId)) },
-                    selected = isSelected,
-                    onClick = {
-                        if (isSelected) return@item
-                        while (backStack.size > 1) backStack.removeAt(backStack.size - 1)
-                        if (screen !is Screen.Passes) backStack.add(screen)
-                    }
-                )
-            }
-        },
-        navigationSuiteColors = NavigationSuiteDefaults.colors(
-            navigationRailContainerColor = MaterialTheme.colorScheme.surfaceContainer
-        ),
-        layoutType = when {
-            !hasEnoughHeight() && hasEnoughWidth() -> NavigationSuiteType.NavigationRail
-            !hasEnoughWidth() -> NavigationSuiteType.ShortNavigationBarCompact
-            else -> NavigationSuiteType.ShortNavigationBarMedium
-        }
+    CompositionLocalProvider(
+        LocalElevationThresholds provides ElevationThresholds(
+            low = otherSettings.lowElevation,
+            high = otherSettings.highElevation
+        )
     ) {
-        Column {
-            NavDisplay(
-                backStack = backStack,
-                modifier = Modifier.weight(1f),
-                onBack = navigateBack,
-                transitionSpec = { fadeTransition },
-                popTransitionSpec = { fadeTransition },
-                predictivePopTransitionSpec = { fadeTransition },
-                entryProvider = entryProvider {
-                    entry<Screen.Satellites> {
-                        SatellitesDestination(navigateUp = navigateBack)
+        NavigationSuiteScaffold(
+            navigationSuiteItems = {
+                navItems.forEach { screen ->
+                    val isSelected = when (currentKey) {
+                        is Screen.Satellites -> screen is Screen.Satellites
+                        is Screen.Passes -> screen is Screen.Passes
+                        is Screen.Radar -> screen is Screen.Radar
+                        is Screen.Mutual -> screen is Screen.Mutual
+                        is Screen.Map -> screen is Screen.Map
+                        is Screen.Settings -> screen is Screen.Settings
+                        else -> false
                     }
-                    entry<Screen.Passes> {
-                        PassesDestination { catNum, aosTime ->
-                            backStack.add(Screen.Radar(catNum, aosTime))
+                    item(
+                        icon = { Icon(painterResource(screen.iconResId), stringResource(screen.titleResId)) },
+                        label = { Text(stringResource(screen.titleResId)) },
+                        selected = isSelected,
+                        onClick = {
+                            if (isSelected) return@item
+                            while (backStack.size > 1) backStack.removeAt(backStack.size - 1)
+                            if (screen !is Screen.Passes) backStack.add(screen)
                         }
-                    }
-                    entry<Screen.Radar> { route ->
-                        RadarDestination(
-                            catNum = route.catNum,
-                            aosTime = route.aosTime,
-                            navigateUp = navigateBack,
-                            navigateToRadioControl = { catNum, aosTime ->
-                                backStack.add(Screen.RadioControl(catNum, aosTime))
-                            }
-                        )
-                    }
-                    entry<Screen.RadioControl> { route ->
-                        RadioControlDestination(
-                            catNum = route.catNum,
-                            aosTime = route.aosTime,
-                            navigateUp = navigateBack
-                        )
-                    }
-                    entry<Screen.Map> {
-                        MapDestination()
-                    }
-                    entry<Screen.Settings> {
-                        SettingsDestination()
-                    }
+                    )
                 }
-            )
-            // Radio tracking status banner
-            if (trackingState.isActive) {
-                val infiniteTransition = rememberInfiniteTransition(label = "trackingPulse")
-                val alpha by infiniteTransition.animateFloat(
-                    initialValue = 1f, targetValue = 0.4f,
-                    animationSpec = infiniteRepeatable(
-                        animation = tween(1000, easing = LinearEasing),
-                        repeatMode = RepeatMode.Reverse
-                    ), label = "pulseAlpha"
-                )
-                Row(
-                    verticalAlignment = Alignment.CenterVertically,
-                    modifier = Modifier
-                        .fillMaxWidth()
-                        .background(MaterialTheme.colorScheme.primaryContainer)
-                        .clickable {
-                            val pass = trackingState.currentPass
-                            if (pass != null) {
-                                backStack.add(Screen.RadioControl(pass.catNum, pass.aosTime))
+            },
+            navigationSuiteColors = NavigationSuiteDefaults.colors(
+                navigationRailContainerColor = MaterialTheme.colorScheme.surfaceContainer
+            ),
+            layoutType = when {
+                !hasEnoughHeight() && hasEnoughWidth() -> NavigationSuiteType.NavigationRail
+                !hasEnoughWidth() -> NavigationSuiteType.ShortNavigationBarCompact
+                else -> NavigationSuiteType.ShortNavigationBarMedium
+            }
+        ) {
+            Column {
+                NavDisplay(
+                    backStack = backStack,
+                    modifier = Modifier.weight(1f),
+                    onBack = navigateBack,
+                    transitionSpec = { fadeTransition },
+                    popTransitionSpec = { fadeTransition },
+                    predictivePopTransitionSpec = { fadeTransition },
+                    entryDecorators = listOf(
+                        // Required for saving Compose state per entry
+                        rememberSaveableStateHolderNavEntryDecorator(),
+                        // Required for ViewModel scoping per entry
+                        rememberViewModelStoreNavEntryDecorator()
+                    ),
+                    entryProvider = entryProvider {
+                        entry<Screen.Satellites> {
+                            SatellitesDestination(navigateUp = navigateBack)
+                        }
+                        entry<Screen.Passes> {
+                            PassesDestination { catNum, aosTime ->
+                                container.setMutualPassData(MutualPassData())
+                                container.satelliteRepo.selectPass(catNum, aosTime)
+                                backStack.add(Screen.Radar)
+//                            navigateToRadar()
                             }
                         }
-                        .padding(horizontal = 12.dp, vertical = 6.dp)
-                ) {
-                    Box(
+                        entry<Screen.Radar> {
+                            RadarDestination(navigateUp = navigateBack)
+                        }
+                        entry<Screen.Map> {
+                            MapDestination()
+                        }
+                        entry<Screen.Mutual> {
+                            MutualScreen(
+                                viewModel = mutualViewModel,
+                                navigateUp = navigateBack,
+                                navigateToRadar = { catNum, aosTime, pass ->
+                                    container.setMutualPassData(pass ?: MutualPassData())
+                                    container.satelliteRepo.selectPass(catNum, aosTime)
+                                    backStack.add(Screen.Radar)
+                                }
+                            )
+                        }
+                        entry<Screen.Settings> {
+                            SettingsDestination()
+                        }
+                    }
+                )
+                // Radio tracking status banner
+                if (trackingState.isActive) {
+                    val infiniteTransition = rememberInfiniteTransition(label = "trackingPulse")
+                    val alpha by infiniteTransition.animateFloat(
+                        initialValue = 1f, targetValue = 0.4f,
+                        animationSpec = infiniteRepeatable(
+                            animation = tween(1000, easing = LinearEasing),
+                            repeatMode = RepeatMode.Reverse
+                        ), label = "pulseAlpha"
+                    )
+                    Row(
+                        verticalAlignment = Alignment.CenterVertically,
                         modifier = Modifier
-                            .size(8.dp)
-                            .clip(CircleShape)
-                            .background(Color(0xFF4CAF50).copy(alpha = alpha))
-                    )
-                    Spacer(modifier = Modifier.width(8.dp))
-                    Text(
-                        text = "Tracking: ${trackingState.currentPass?.name ?: ""}",
-                        fontSize = 13.sp,
-                        fontWeight = FontWeight.Medium,
-                        color = MaterialTheme.colorScheme.onPrimaryContainer,
-                        modifier = Modifier.weight(1f)
-                    )
-                    val txOk = if (trackingState.txConnected) "TX" else ""
-                    val rxOk = if (trackingState.rxConnected) "RX" else ""
-                    Text(
-                        text = listOf(txOk, rxOk).filter { it.isNotBlank() }.joinToString("/"),
-                        fontSize = 12.sp,
-                        color = MaterialTheme.colorScheme.onPrimaryContainer
-                    )
+                            .fillMaxWidth()
+                            .background(MaterialTheme.colorScheme.primaryContainer)
+                            .clickable {
+                                val pass = trackingState.currentPass
+                                if (pass != null) {
+                                    container.setMutualPassData(MutualPassData())
+                                    container.satelliteRepo.selectPass(pass.catNum, pass.aosTime)
+                                    backStack.add(Screen.Radar)
+                                }
+                            }
+                            .padding(horizontal = 12.dp, vertical = 6.dp)
+                    ) {
+                        Box(
+                            modifier = Modifier
+                                .size(8.dp)
+                                .clip(CircleShape)
+                                .background(Color(0xFF4CAF50).copy(alpha = alpha))
+                        )
+                        Spacer(modifier = Modifier.width(8.dp))
+                        Text(
+                            text = "Tracking: ${trackingState.currentPass?.name ?: ""}",
+                            fontSize = 13.sp,
+                            fontWeight = FontWeight.Medium,
+                            color = MaterialTheme.colorScheme.onPrimaryContainer,
+                            modifier = Modifier.weight(1f)
+                        )
+                        val txOk = if (trackingState.txConnected) "TX" else ""
+                        val rxOk = if (trackingState.rxConnected) "RX" else ""
+                        Text(
+                            text = listOf(txOk, rxOk).filter { it.isNotBlank() }.joinToString("/"),
+                            fontSize = 12.sp,
+                            color = MaterialTheme.colorScheme.onPrimaryContainer
+                        )
+                    }
                 }
             }
         }

app/src/main/res/xml/network_security_config.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<network-security-config>
+    <base-config cleartextTrafficPermitted="true" />
+</network-security-config>

build-logic/convention/src/main/java/com/rtbishop/look4sat/convention/ApplicationPlugin.kt

@@ -32,9 +32,9 @@ internal class ApplicationPlugin : Plugin<Project> {
             implementation(project(":core:domain"))
             implementation(project(":core:presentation"))
             implementation(project(":feature:map"))
+            implementation(project(":feature:mutual"))
             implementation(project(":feature:passes"))
             implementation(project(":feature:radar"))
-            implementation(project(":feature:radiocontrol"))
             implementation(project(":feature:satellites"))
             implementation(project(":feature:settings"))
             implementation(libs.androidx.core.splashscreen)

build.gradle.kts

@@ -8,5 +8,6 @@ plugins {
 }
 
 tasks.register("clean", Delete::class.java) {
+    description = "Cleans the build directory"
     delete(rootProject.layout.buildDirectory)
 }

core/data/src/main/AndroidManifest.xml

@@ -2,6 +2,7 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android">
 
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
+    <uses-permission android:name="android.permission.ACCESS_LOCAL_NETWORK" />
     <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
     <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
     <uses-permission
@@ -11,5 +12,6 @@
     <uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />
     <uses-permission android:name="android.permission.BLUETOOTH_SCAN" />
     <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.RECORD_AUDIO" />
 
 </manifest>

core/data/src/main/java/com/rtbishop/look4sat/core/data/framework/Ft817CatProtocol.kt

@@ -17,6 +17,9 @@
  */
 package com.rtbishop.look4sat.core.data.framework
 
+import java.util.Locale
+import kotlin.math.roundToLong
+
 object Ft817CatProtocol {
 
     const val CMD_SET_FREQ: Byte = 0x01
@@ -50,7 +53,7 @@ object Ft817CatProtocol {
     fun encodeFrequencyBcd(frequencyHz: Long): ByteArray {
         val freq10Hz = frequencyHz / 10
         val bcd = ByteArray(4)
-        val digits = String.format("%08d", freq10Hz)
+        val digits = String.format(Locale.US, "%08d", freq10Hz)
         for (i in 0 until 4) {
             val high = digits[i * 2] - '0'
             val low = digits[i * 2 + 1] - '0'
@@ -78,8 +81,8 @@ object Ft817CatProtocol {
      * 67.0 Hz → 670 (in 0.1 Hz) → BCD [0x06, 0x70]
      */
     fun encodeCtcssToneBcd(toneHz: Double): ByteArray {
-        val tone01Hz = (toneHz * 10).toLong()
-        val digits = String.format("%04d", tone01Hz)
+        val tone01Hz = (toneHz * 10).roundToLong()
+        val digits = String.format(Locale.US, "%04d", tone01Hz)
         val bcd = ByteArray(2)
         for (i in 0 until 2) {
             val high = digits[i * 2] - '0'
@@ -95,7 +98,7 @@ object Ft817CatProtocol {
     }
 
     fun buildSetModeCommand(mode: String): ByteArray? {
-        val modeByte = MODE_TO_BYTE[mode.uppercase()] ?: return null
+        val modeByte = MODE_TO_BYTE[mode.uppercase(Locale.US)] ?: return null
         return byteArrayOf(modeByte, 0x00, 0x00, 0x00, CMD_SET_MODE)
     }
 

core/data/src/main/java/com/rtbishop/look4sat/core/data/framework/Ft817Controller.kt

@@ -29,6 +29,7 @@ import kotlinx.coroutines.withContext
 import java.io.InputStream
 import java.io.OutputStream
 import java.util.UUID
+import kotlin.time.Duration.Companion.milliseconds
 
 class Ft817Controller(
     private val bluetoothManager: BluetoothManager,
@@ -39,10 +40,12 @@ class Ft817Controller(
     private val sppId: UUID = UUID.fromString("00001101-0000-1000-8000-00805f9b34fb")
     private val ioMutex = Mutex()
     private val commandDelayMs = 200L
+    private val maxAckReadFailures = 3
 
     private var socket: BluetoothSocket? = null
     private var outputStream: OutputStream? = null
     private var inputStream: InputStream? = null
+    private var ackReadFailureCount = 0
 
     override var isConnected: Boolean = false
         private set
@@ -57,6 +60,7 @@ class Ft817Controller(
             socket = btSocket
             outputStream = btSocket.outputStream
             inputStream = btSocket.inputStream
+            ackReadFailureCount = 0
             isConnected = true
             Log.i(tag, "Connected to $deviceAddress")
             true
@@ -79,6 +83,7 @@ class Ft817Controller(
                 inputStream = null
                 outputStream = null
                 socket = null
+                ackReadFailureCount = 0
                 isConnected = false
                 Log.i(tag, "Disconnected from $deviceAddress")
             }
@@ -112,8 +117,8 @@ class Ft817Controller(
         ioMutex.withLock {
             val sent = sendCommand(Ft817CatProtocol.buildReadFreqModeCommand())
             if (!sent) return@withContext null
-            delay(commandDelayMs)
-            val response = readResponse(5) ?: return@withContext null
+            delay(commandDelayMs.milliseconds)
+            val response = readResponse() ?: return@withContext null
             Ft817CatProtocol.parseReadResponse(response)
         }
     }
@@ -127,44 +132,76 @@ class Ft817Controller(
     }
 
     private suspend fun sendCommand(bytes: ByteArray): Boolean {
-        return try {
-            outputStream?.write(bytes) ?: return false
-            outputStream?.flush()
-            delay(commandDelayMs)
-            true
-        } catch (e: Exception) {
-            Log.e(tag, "Send error: ${e.message}")
-            isConnected = false
-            false
+        return withContext(Dispatchers.IO) {
+            try {
+                outputStream?.write(bytes) ?: return@withContext false
+                outputStream?.flush()
+                delay(commandDelayMs.milliseconds)
+                true
+            } catch (e: Exception) {
+                Log.e(tag, "Send error: ${e.message}")
+                isConnected = false
+                false
+            }
         }
     }
 
     /** Send command and read the 1-byte ACK response (0x00 = OK). */
     private suspend fun sendCommandWithAck(bytes: ByteArray): Boolean {
         if (!sendCommand(bytes)) return false
-        return try {
-            val ack = inputStream?.read() ?: return false
-            ack == 0x00
-        } catch (e: Exception) {
-            Log.e(tag, "ACK read error: ${e.message}")
-            true // command was sent, ACK read failed - continue anyway
+        return withContext(Dispatchers.IO) {
+            try {
+                val ack = inputStream?.read() ?: run {
+                    ackReadFailureCount = 0
+                    isConnected = false
+                    return@withContext false
+                }
+                if (ack < 0) {
+                    ackReadFailureCount = 0
+                    Log.i(tag, "ACK stream closed by remote device")
+                    isConnected = false
+                    return@withContext false
+                }
+                ackReadFailureCount = 0
+                ack == 0x00
+            } catch (e: Exception) {
+                ackReadFailureCount += 1
+                Log.w(tag, "ACK read error (${ackReadFailureCount}/$maxAckReadFailures): ${e.message}")
+                if (ackReadFailureCount >= maxAckReadFailures) {
+                    Log.e(tag, "Too many ACK read errors, marking radio disconnected")
+                    isConnected = false
+                    false
+                } else {
+                    true // Command was sent, treat transient ACK read failures as best-effort
+                }
+            }
         }
     }
 
-    private fun readResponse(length: Int): ByteArray? {
-        return try {
-            val buffer = ByteArray(length)
-            var read = 0
-            while (read < length) {
-                val count = inputStream?.read(buffer, read, length - read) ?: return null
-                if (count < 0) return null
-                read += count
+    private suspend fun readResponse(): ByteArray? {
+        return withContext(Dispatchers.IO) {
+            try {
+                val responseSize = 5
+                val buffer = ByteArray(responseSize)
+                var read = 0
+                while (read < responseSize) {
+                    val count = inputStream?.read(buffer, read, responseSize - read) ?: run {
+                        isConnected = false
+                        return@withContext null
+                    }
+                    if (count < 0) {
+                        Log.i(tag, "Response stream closed by remote device")
+                        isConnected = false
+                        return@withContext null
+                    }
+                    read += count
+                }
+                buffer
+            } catch (e: Exception) {
+                Log.e(tag, "Read error: ${e.message}")
+                isConnected = false
+                null
             }
-            buffer
-        } catch (e: Exception) {
-            Log.e(tag, "Read error: ${e.message}")
-            isConnected = false
-            null
         }
     }
 }

core/data/src/main/java/com/rtbishop/look4sat/core/data/framework/Ic705Controller.kt

@@ -0,0 +1,364 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.data.framework
+
+import android.bluetooth.BluetoothManager
+import android.bluetooth.BluetoothSocket
+import android.util.Log
+import com.rtbishop.look4sat.core.domain.repository.IRadioController
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
+import kotlinx.coroutines.withContext
+import java.io.InputStream
+import java.io.OutputStream
+import java.util.UUID
+
+/**
+ * Icom IC-705 CI-V controller over Bluetooth SPP.
+ *
+ * The IC-705 emits broadcast frames continuously (band scope, UTC, signal
+ * level, …).  A reply to any command we send may therefore be buried in
+ * that noise.  All response reads drain up to [ACK_TIMEOUT_MS] and scan the
+ * entire accumulated buffer for the frame we expect rather than assuming
+ * the very next byte is the response.
+ */
+class Ic705Controller(
+    private val bluetoothManager: BluetoothManager,
+    private val deviceAddress: String
+) : IRadioController {
+
+    private val tag = "IC705"
+    private val sppId: UUID = UUID.fromString("00001101-0000-1000-8000-00805f9b34fb")
+    private val ioMutex = Mutex()
+
+    /** Time budget (ms) to wait for a response amid broadcast noise. */
+    private val ACK_TIMEOUT_MS = 500L
+    /** Polling interval while draining the input buffer. */
+    private val POLL_INTERVAL_MS = 20L
+    /** Small pause after writing a command before reading the response. */
+    private val WRITE_SETTLE_MS = 50L
+
+    private var socket: BluetoothSocket? = null
+    private var outputStream: OutputStream? = null
+    private var inputStream: InputStream? = null
+
+    override var isConnected: Boolean = false
+        private set
+
+    // ── Connection ──────────────────────────────────────────────────────────
+
+    override suspend fun connect(): Boolean = withContext(Dispatchers.IO) {
+        if (isConnected) return@withContext true
+        if (deviceAddress.isBlank()) return@withContext false
+        try {
+            val device  = bluetoothManager.adapter.getRemoteDevice(deviceAddress)
+            val btSocket = device.createInsecureRfcommSocketToServiceRecord(sppId)
+            btSocket.connect()
+            socket       = btSocket
+            outputStream = btSocket.outputStream
+            inputStream  = btSocket.inputStream
+            isConnected  = true
+            // Enter VFO mode — frequency/mode commands return FA if the radio
+            // is in memory-channel mode. Safe to send regardless of current state.
+            Log.i(tag, "Connected to $deviceAddress — entering VFO mode")
+            val vfoCmd = IcomCivProtocol.buildEnterVfoModeCommand()
+            Log.d(tag, "CMD enterVfoMode → ${IcomCivProtocol.toHex(vfoCmd)}")
+            ioMutex.withLock { sendAndWaitAck(vfoCmd) }
+            true
+        } catch (e: Exception) {
+            Log.e(tag, "Connect error: ${e.message}")
+            isConnected = false
+            false
+        }
+    }
+
+    override suspend fun disconnect() {
+        withContext(Dispatchers.IO) {
+            try {
+                inputStream?.close()
+                outputStream?.close()
+                socket?.close()
+            } catch (e: Exception) {
+                Log.e(tag, "Disconnect error: ${e.message}")
+            } finally {
+                inputStream  = null
+                outputStream = null
+                socket       = null
+                isConnected  = false
+                Log.i(tag, "Disconnected from $deviceAddress")
+            }
+        }
+    }
+
+    // ── IRadioController – standard operations ──────────────────────────────
+
+    override suspend fun setFrequency(frequencyHz: Long): Boolean = withContext(Dispatchers.IO) {
+        Log.d(tag, "setFrequency: ${frequencyHz}Hz")
+        ioMutex.withLock {
+            val cmd = IcomCivProtocol.buildSetFreqCommand(frequencyHz)
+            Log.d(tag, "CMD setFreq → ${IcomCivProtocol.toHex(cmd)}")
+            sendAndWaitAck(cmd)
+        }
+    }
+
+    override suspend fun setMode(mode: String): Boolean = withContext(Dispatchers.IO) {
+        val cmd = IcomCivProtocol.buildSetModeCommand(mode) ?: run {
+            Log.w(tag, "setMode: unknown mode '$mode'")
+            return@withContext false
+        }
+        Log.d(tag, "setMode: $mode")
+        Log.d(tag, "CMD setMode → ${IcomCivProtocol.toHex(cmd)}")
+        ioMutex.withLock { sendAndWaitAck(cmd) }
+    }
+
+    override suspend fun setCtcssMode(enabled: Boolean): Boolean = withContext(Dispatchers.IO) {
+        Log.d(tag, "setCtcssMode: $enabled")
+        val cmd = IcomCivProtocol.buildCtcssModeCommand(enabled)
+        Log.d(tag, "CMD ctcssMode → ${IcomCivProtocol.toHex(cmd)}")
+        ioMutex.withLock { sendAndWaitAck(cmd) }
+    }
+
+    override suspend fun setCtcssTone(toneHz: Double): Boolean = withContext(Dispatchers.IO) {
+        Log.d(tag, "setCtcssTone: ${toneHz}Hz")
+        val cmd = IcomCivProtocol.buildSetCtcssToneCommand(toneHz)
+        Log.d(tag, "CMD ctcssTone → ${IcomCivProtocol.toHex(cmd)}")
+        ioMutex.withLock { sendAndWaitAck(cmd) }
+    }
+
+    override suspend fun readFrequencyAndMode(): Pair<Long, String>? = withContext(Dispatchers.IO) {
+        ioMutex.withLock {
+            val cmd = IcomCivProtocol.buildReadFreqCommand()
+            Log.d(tag, "CMD readFreq → ${IcomCivProtocol.toHex(cmd)}")
+            val payload = sendAndReadResponse(cmd, IcomCivProtocol.CMD_READ_FREQ) ?: return@withContext null
+            // Read-freq reply payload: [cmd byte already stripped by parseResponse] [5 freq bytes] [mode] [filter]
+            IcomCivProtocol.parseFreqModePayload(payload).also {
+                if (it != null) Log.d(tag, "readFreqMode: ${it.first}Hz, ${it.second}")
+                else Log.w(tag, "readFreqMode: parse failed, payload=${IcomCivProtocol.toHex(payload)}")
+            }
+        }
+    }
+
+    override suspend fun pttOn(): Boolean = withContext(Dispatchers.IO) {
+        Log.w(tag, "pttOn: not used for IC-705")
+        true
+    }
+
+    override suspend fun pttOff(): Boolean = withContext(Dispatchers.IO) {
+        Log.w(tag, "pttOff: not used for IC-705")
+        true
+    }
+
+    // ── IRadioController – IC-705 extended operations ───────────────────────
+
+    /** Select the band for [frequencyHz] via CMD 0x1A sub 0x00 (band stacking register). */
+    override suspend fun setBand(frequencyHz: Long): Boolean = withContext(Dispatchers.IO) {
+        val cmd = IcomCivProtocol.buildBandSelectCommand(frequencyHz) ?: run {
+            Log.w(tag, "setBand: no band code for ${frequencyHz}Hz — skipping")
+            return@withContext false
+        }
+        Log.d(tag, "CMD setBand (${frequencyHz}Hz) → ${IcomCivProtocol.toHex(cmd)}")
+        ioMutex.withLock { sendAndWaitAck(cmd) }
+    }
+
+    /** Select VFO-A (main/RX) or VFO-B (sub/TX). */
+    override suspend fun setVfo(vfoA: Boolean): Boolean = withContext(Dispatchers.IO) {
+        val cmd = if (vfoA) IcomCivProtocol.buildSelectVfoACommand()
+                  else      IcomCivProtocol.buildSelectVfoBCommand()
+        Log.d(tag, "CMD selectVFO${if (vfoA) "A" else "B"} → ${IcomCivProtocol.toHex(cmd)}")
+        ioMutex.withLock { sendAndWaitAck(cmd) }
+    }
+
+    /**
+     * Enable or disable SPLIT mode (TX on sub-VFO while listening on main VFO).
+     */
+    override suspend fun setSplitMode(enabled: Boolean): Boolean = withContext(Dispatchers.IO) {
+        val cmd = IcomCivProtocol.buildSplitModeCommand(enabled)
+        Log.d(tag, "CMD split ${if (enabled) "ON" else "OFF"} → ${IcomCivProtocol.toHex(cmd)}")
+        ioMutex.withLock { sendAndWaitAck(cmd) }
+    }
+
+    /**
+     * Set the frequency of the **currently active** VFO (CMD 0x25 sub 0x00).
+     * In split mode the radio automatically switches active VFO on PTT, so
+     * always writing to the active VFO is the correct strategy.
+     */
+    override suspend fun setWorkingFrequency(frequencyHz: Long): Boolean = withContext(Dispatchers.IO) {
+        Log.d(tag, "setWorkingFrequency (0x25/00): ${frequencyHz}Hz")
+        val cmd = IcomCivProtocol.buildSetWorkingFreqCommand(frequencyHz)
+        Log.d(tag, "CMD setWorkingFreq → ${IcomCivProtocol.toHex(cmd)}")
+        ioMutex.withLock { sendAndWaitAck(cmd) }
+    }
+
+    /**
+     * Set TX VFO frequency via CMD 0x25 sub 0x01 (unselected VFO).
+     * Sent every tracking cycle in split mode alongside [setWorkingFrequency].
+     */
+    override suspend fun setTxVfoFrequency(frequencyHz: Long): Boolean = withContext(Dispatchers.IO) {
+        Log.d(tag, "setTxVfoFrequency (0x25/01): ${frequencyHz}Hz")
+        val cmd = IcomCivProtocol.buildSetUnselectedVfoFreqCommand(frequencyHz)
+        Log.d(tag, "CMD setTxVfoFreq → ${IcomCivProtocol.toHex(cmd)}")
+        ioMutex.withLock { sendAndWaitAck(cmd) }
+    }
+
+    /**
+     * Read the frequency of the currently active VFO (CMD 0x25 sub 0x00).
+     * Used for tuning detection in split mode.
+     */
+    override suspend fun readWorkingFrequency(): Long? = withContext(Dispatchers.IO) {
+        ioMutex.withLock {
+            val cmd = IcomCivProtocol.buildReadWorkingFreqCommand()
+            Log.d(tag, "CMD readWorkingFreq → ${IcomCivProtocol.toHex(cmd)}")
+            val payload = sendAndReadResponse(cmd, IcomCivProtocol.CMD_SELECTED_VFO_FREQ) ?: return@withContext null
+            // Response payload: [sub] [5 freq bytes] — CMD byte already stripped by parseResponse
+            Log.d(tag, "readWorkingFreq: got ${payload.size} bytes: ${IcomCivProtocol.toHex(payload)}")
+            if (payload.size < 6) {
+                Log.w(tag, "readWorkingFreq: payload too short (${payload.size} bytes)")
+                return@withContext null
+            }
+            val freqBcd = payload.sliceArray(1..5)
+            val freq = IcomCivProtocol.decodeFrequencyBcd(freqBcd)
+            Log.d(tag, "readWorkingFreq: ${freq}Hz")
+            freq
+        }
+    }
+
+    /**
+     * Read the frequency of the inactive/TX VFO (CMD 0x25 sub 0x01).
+     * Used for tuning detection in split mode.
+     */
+    override suspend fun readTxVfoFrequency(): Long? = withContext(Dispatchers.IO) {
+        ioMutex.withLock {
+            val cmd = IcomCivProtocol.buildReadTxVfoFreqCommand()
+            Log.d(tag, "CMD readTxVfoFreq → ${IcomCivProtocol.toHex(cmd)}")
+            val payload = sendAndReadResponse(cmd, IcomCivProtocol.CMD_SELECTED_VFO_FREQ) ?: return@withContext null
+            // Response payload: [sub] [5 freq bytes] — CMD byte already stripped by parseResponse
+            Log.d(tag, "readTxVfoFreq: got ${payload.size} bytes: ${IcomCivProtocol.toHex(payload)}")
+            if (payload.size < 6) {
+                Log.w(tag, "readTxVfoFreq: payload too short (${payload.size} bytes)")
+                return@withContext null
+            }
+            val freqBcd = payload.sliceArray(1..5)
+            val freq = IcomCivProtocol.decodeFrequencyBcd(freqBcd)
+            Log.d(tag, "readTxVfoFreq: ${freq}Hz")
+            freq
+        }
+    }
+
+    // ── Internal I/O helpers ────────────────────────────────────────────────
+
+    /**
+     * Write [cmd] to the radio and drain the input stream for up to
+     * [ACK_TIMEOUT_MS], looking for an OK/NG acknowledgement frame.
+     */
+    private suspend fun sendAndWaitAck(cmd: ByteArray): Boolean {
+        if (!write(cmd)) return false
+        delay(WRITE_SETTLE_MS)
+        val buf = drainWithTimeout(ACK_TIMEOUT_MS)
+        val ok  = IcomCivProtocol.containsAck(buf)
+        if (!ok) Log.w(tag, "ACK not found in ${buf.size} bytes: ${IcomCivProtocol.toHex(buf)}")
+        return ok
+    }
+
+    /**
+     * Write [cmd] to the radio and drain the input stream for up to
+     * [ACK_TIMEOUT_MS], scanning for a response frame carrying [expectCmd].
+     * Returns the payload bytes of that frame, or null on timeout/error.
+     */
+    private suspend fun sendAndReadResponse(cmd: ByteArray, expectCmd: Byte): ByteArray? {
+        if (!write(cmd)) return null
+        delay(WRITE_SETTLE_MS)
+        val buf      = drainWithTimeout(ACK_TIMEOUT_MS)
+        val response = IcomCivProtocol.parseResponse(buf, expectCmd)
+        if (response == null) {
+            Log.w(tag, "No response for cmd 0x${String.format("%02X", expectCmd.toInt() and 0xFF)} " +
+                    "in ${buf.size} bytes: ${IcomCivProtocol.toHex(buf)}")
+        }
+        return response?.payload
+    }
+
+    /**
+     * Drain whatever bytes the radio has buffered within a [timeoutMs] window.
+     * Exits early as soon as a complete CI-V frame addressed to us is present
+     * in the buffer (i.e., FE FE E0 A4 … FD), so we don't waste the remaining
+     * timeout on responses that already arrived.
+     */
+    private suspend fun drainWithTimeout(timeoutMs: Long): ByteArray {
+        val result   = mutableListOf<Byte>()
+        val deadline = System.currentTimeMillis() + timeoutMs
+        val stream   = inputStream ?: return ByteArray(0)
+        while (System.currentTimeMillis() < deadline) {
+            try {
+                val available = stream.available()
+                if (available > 0) {
+                    val chunk = ByteArray(available)
+                    val read  = stream.read(chunk)
+                    if (read > 0) {
+                        result.addAll(chunk.take(read))
+                        // Exit early once we have a complete frame for us
+                        if (hasCompleteFrameForUs(result)) break
+                    }
+                } else {
+                    delay(POLL_INTERVAL_MS)
+                }
+            } catch (e: Exception) {
+                Log.e(tag, "Drain error: ${e.message}")
+                isConnected = false
+                break
+            }
+        }
+        return result.toByteArray()
+    }
+
+    /**
+     * Returns true if [buf] contains a complete CI-V frame addressed to the
+     * controller (FE FE [ADDR_CTRL] [ADDR_IC705] … FD).
+     * CI-V data bytes cannot be 0xFD, so the first 0xFD after the header is
+     * always the frame terminator.
+     */
+    private fun hasCompleteFrameForUs(buf: List<Byte>): Boolean {
+        var i = 0
+        while (i < buf.size - 4) {
+            if (buf[i]     == IcomCivProtocol.PREAMBLE    &&
+                buf[i + 1] == IcomCivProtocol.PREAMBLE    &&
+                buf[i + 2] == IcomCivProtocol.ADDR_CTRL   &&
+                buf[i + 3] == IcomCivProtocol.ADDR_IC705
+            ) {
+                for (k in i + 4 until buf.size) {
+                    if (buf[k] == IcomCivProtocol.END_OF_MSG) return true
+                }
+                return false  // header found but no FD yet
+            }
+            i++
+        }
+        return false
+    }
+
+    private fun write(bytes: ByteArray): Boolean {
+        return try {
+            outputStream?.write(bytes)
+            outputStream?.flush()
+            true
+        } catch (e: Exception) {
+            Log.e(tag, "Write error: ${e.message}")
+            isConnected = false
+            false
+        }
+    }
+}

core/data/src/main/java/com/rtbishop/look4sat/core/data/framework/IcomCivProtocol.kt

@@ -0,0 +1,352 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.data.framework
+
+import java.util.Locale
+
+/**
+ * Icom CI-V protocol encoder/decoder for the IC-705.
+ *
+ * Frame structure:
+ *   FE FE <DEST> <SRC> <CMD> [<SUB>] [<DATA...>] FD
+ *
+ * IC-705 default CI-V address : 0xA4
+ * Controller (us) address     : 0xE0
+ */
+object IcomCivProtocol {
+
+    // ── Framing constants ──────────────────────────────────────────────────
+    const val PREAMBLE: Byte      = 0xFE.toByte()
+    const val END_OF_MSG: Byte    = 0xFD.toByte()
+    const val ACK_OK: Byte        = 0xFB.toByte()
+    const val ACK_NG: Byte        = 0xFA.toByte()
+
+    // ── Address constants ──────────────────────────────────────────────────
+    /** Default CI-V address of the IC-705. */
+    const val ADDR_IC705: Byte    = 0xA4.toByte()
+    /** Default CI-V address of the controller (us). */
+    const val ADDR_CTRL: Byte     = 0xE0.toByte()
+
+    // ── Command bytes ──────────────────────────────────────────────────────
+    /** Read operating frequency (main VFO). */
+    const val CMD_READ_FREQ: Byte           = 0x03
+    /** Set operating frequency (main VFO). */
+    const val CMD_SET_FREQ: Byte            = 0x05
+    /** Set operating mode. */
+    const val CMD_SET_MODE: Byte            = 0x06
+    /** Select VFO / memory. */
+    const val CMD_SELECT_VFO: Byte          = 0x07
+    /**
+     * Select operating mode (VFO vs memory-channel).
+     * Sub 0x00 = VFO mode. Must be sent after connect if the radio is in
+     * memory-channel mode — frequency/mode commands return FA until it is.
+     */
+    const val CMD_SELECT_OP_MODE: Byte      = 0x08
+    /** Set repeater duplex / SPLIT. */
+    const val CMD_DUPLEX_SPLIT: Byte        = 0x0F
+    /** Band stacking register / band select (sub 0x00 = select, data = BCD band number). */
+    const val CMD_BAND_SELECT: Byte         = 0x1A
+    /** Read/write CTCSS tone frequency. */
+    const val CMD_CTCSS_TONE: Byte          = 0x1B
+    /** Read/write misc settings (used for enabling CTCSS encode). */
+    const val CMD_MISC_SETTING: Byte        = 0x16
+    /** Read/write selected-VFO frequency (cmd 0x25). */
+    const val CMD_SELECTED_VFO_FREQ: Byte   = 0x25
+
+    // ── Sub-command bytes ──────────────────────────────────────────────────
+    /** Sub for CMD_SELECT_VFO: select VFO-A (main). */
+    const val SUB_VFO_A: Byte   = 0x00
+    /** Sub for CMD_SELECT_VFO: select VFO-B (sub). */
+    const val SUB_VFO_B: Byte   = 0x01
+    /** Sub for CMD_DUPLEX_SPLIT: simplex / split OFF. */
+    const val SUB_SPLIT_OFF: Byte = 0x00
+    /** Sub for CMD_DUPLEX_SPLIT: SPLIT ON. */
+    const val SUB_SPLIT_ON: Byte  = 0x01
+    /** Sub for CMD_SELECTED_VFO_FREQ: selected (active) VFO frequency. */
+    const val SUB_SELECTED_VFO: Byte = 0x00
+    /** Sub for CMD_SELECTED_VFO_FREQ: unselected (inactive / TX in split) VFO frequency. */
+    const val SUB_UNSELECTED_VFO: Byte = 0x01
+    /** Sub for CMD_MISC_SETTING: CTCSS/DTCS tone squelch. */
+    const val SUB_CTCSS_SETTING: Byte = 0x42.toByte()
+
+    // ── Mode bytes ────────────────────────────────────────────────────────
+    /** Maps mode strings (upper-case) → IC-705 mode bytes. */
+    val MODE_TO_BYTE: Map<String, Byte> = mapOf(
+        "LSB"    to 0x00,
+        "USB"    to 0x01,
+        "AM"     to 0x02,
+        "CW"     to 0x03,
+        "RTTY"   to 0x04,
+        "FM"     to 0x05,
+        "WFM"    to 0x06,
+        "CW-R"   to 0x07,
+        "RTTY-R" to 0x08,
+        "DV"     to 0x12,
+        "AFSK"   to 0x05  // AFSK uses FM modulation
+    )
+
+    val BYTE_TO_MODE: Map<Byte, String> = MODE_TO_BYTE.entries.associate { it.value to it.key }
+
+    // ── Frequency BCD encoding ─────────────────────────────────────────────
+
+    /**
+     * Encode a frequency in Hz to the IC-705's 5-byte BCD format.
+     *
+     * The IC-705 uses 5 bytes, LSB pair first, with 1 Hz resolution.
+     * Example: 145,500,000 Hz → "0145500000" → pairs LSB→MSB:
+     *   [00, 00, 50, 45, 01]
+     */
+    fun encodeFrequencyBcd(frequencyHz: Long): ByteArray {
+        val digits = String.format(Locale.US, "%010d", frequencyHz)
+        val bcd = ByteArray(5)
+        for (i in 0 until 5) {
+            // digits are MSB first; we want pair index 0 = LSB pair
+            val pairIndex = 4 - i
+            val high = digits[pairIndex * 2] - '0'
+            val low  = digits[pairIndex * 2 + 1] - '0'
+            bcd[i] = ((high shl 4) or low).toByte()
+        }
+        return bcd
+    }
+
+    /**
+     * Decode 5-byte BCD frequency (LSB pair first) to Hz.
+     */
+    fun decodeFrequencyBcd(bcd: ByteArray): Long {
+        // Build digit string MSB→LSB by reversing the byte order
+        var freqHz = 0L
+        for (i in 4 downTo 0) {
+            val b    = bcd[i].toInt() and 0xFF
+            val high = b shr 4
+            val low  = b and 0x0F
+            freqHz   = freqHz * 100 + high * 10 + low
+        }
+        return freqHz
+    }
+
+    /**
+     * Encode a CTCSS tone (Hz, e.g. 67.0) to 2-byte BCD (0.1 Hz resolution).
+     * 67.0 → 670 (tenths of Hz) → BCD bytes [0x06, 0x70].
+     */
+    fun encodeCtcssToneBcd(toneHz: Double): ByteArray {
+        val tone01 = (toneHz * 10).toLong()
+        val digits = String.format(Locale.US, "%04d", tone01)
+        return byteArrayOf(
+            ((digits[0] - '0') shl 4 or (digits[1] - '0')).toByte(),
+            ((digits[2] - '0') shl 4 or (digits[3] - '0')).toByte()
+        )
+    }
+
+    // ── Message builders ───────────────────────────────────────────────────
+
+    /** Wrap payload bytes in a CI-V frame: FE FE DEST SRC ... FD. */
+    private fun frame(vararg payload: Byte): ByteArray {
+        return byteArrayOf(PREAMBLE, PREAMBLE, ADDR_IC705, ADDR_CTRL) +
+                payload +
+                byteArrayOf(END_OF_MSG)
+    }
+
+    /** Set operating frequency via CMD 0x05 (main VFO). */
+    fun buildSetFreqCommand(frequencyHz: Long): ByteArray {
+        return frame(CMD_SET_FREQ, *encodeFrequencyBcd(frequencyHz))
+    }
+
+    /**
+     * Set selected-VFO frequency via CMD 0x25 sub 0x00.
+     * This updates whichever VFO is currently active (RX or TX after split).
+     */
+    fun buildSetWorkingFreqCommand(frequencyHz: Long): ByteArray {
+        return frame(CMD_SELECTED_VFO_FREQ, SUB_SELECTED_VFO, *encodeFrequencyBcd(frequencyHz))
+    }
+
+    /**
+     * Set unselected-VFO frequency via CMD 0x25 sub 0x01.
+     * In split mode while PTT is pressed the IC-705 makes VFO-B active, so
+     * this command targets VFO-A (the RX VFO) — and vice-versa when in RX.
+     * Use this to update the TX VFO when PTT is on.
+     */
+    fun buildSetUnselectedVfoFreqCommand(frequencyHz: Long): ByteArray {
+        return frame(CMD_SELECTED_VFO_FREQ, SUB_UNSELECTED_VFO, *encodeFrequencyBcd(frequencyHz))
+    }
+
+    /** Read operating frequency (CMD 0x03). */
+    fun buildReadFreqCommand(): ByteArray = frame(CMD_READ_FREQ)
+
+    /** Read selected (active) VFO frequency (CMD 0x25 sub 0x00). */
+    fun buildReadWorkingFreqCommand(): ByteArray = frame(CMD_SELECTED_VFO_FREQ, SUB_SELECTED_VFO)
+
+    /** Read unselected (inactive/TX in split) VFO frequency (CMD 0x25 sub 0x01). */
+    fun buildReadTxVfoFreqCommand(): ByteArray = frame(CMD_SELECTED_VFO_FREQ, SUB_UNSELECTED_VFO)
+
+    /**
+     * Select band via CMD 0x1A sub 0x00.
+     * Band codes are BCD-numbered: 1=160m, 2=80m, …, 9=10m, 0x10=6m, 0x11=2m, 0x12=70cm, 0x13=23cm.
+     * Returns null if [frequencyHz] doesn't fall in a known amateur band.
+     */
+    fun buildBandSelectCommand(frequencyHz: Long): ByteArray? {
+        val code = bandCodeForFrequency(frequencyHz) ?: return null
+        return frame(CMD_BAND_SELECT, 0x00, code)
+    }
+
+    /**
+     * Map a frequency in Hz to the IC-705 band stacking register code.
+     * Codes are BCD (band number in decimal expressed as hex nibbles).
+     */
+    fun bandCodeForFrequency(frequencyHz: Long): Byte? = when {
+        frequencyHz in 1_800_000L     ..1_999_999L     -> 0x01 // 160 m
+        frequencyHz in 3_500_000L     ..3_999_999L     -> 0x02 // 80 m
+        frequencyHz in 7_000_000L     ..7_299_999L     -> 0x03 // 40 m
+        frequencyHz in 10_100_000L    ..10_149_999L    -> 0x04 // 30 m
+        frequencyHz in 14_000_000L    ..14_349_999L    -> 0x05 // 20 m
+        frequencyHz in 18_068_000L    ..18_167_999L    -> 0x06 // 17 m
+        frequencyHz in 21_000_000L    ..21_449_999L    -> 0x07 // 15 m
+        frequencyHz in 24_890_000L    ..24_989_999L    -> 0x08 // 12 m
+        frequencyHz in 28_000_000L    ..29_699_999L    -> 0x09 // 10 m
+        frequencyHz in 50_000_000L    ..53_999_999L    -> 0x10 // 6 m  (BCD 10)
+        frequencyHz in 144_000_000L   ..147_999_999L   -> 0x11 // 2 m  (BCD 11)
+        frequencyHz in 420_000_000L   ..449_999_999L   -> 0x12 // 70 cm (BCD 12)
+        frequencyHz in 1_240_000_000L ..1_299_999_999L -> 0x13 // 23 cm (BCD 13)
+        else -> null
+    }
+
+    /** Set operating mode (CMD 0x06). Filter byte is omitted — radio uses its default filter for the mode. */
+    fun buildSetModeCommand(mode: String): ByteArray? {
+        val modeByte = MODE_TO_BYTE[mode.uppercase(Locale.US)] ?: return null
+        return frame(CMD_SET_MODE, modeByte)
+    }
+
+    /** Select VFO-A (CMD 0x07 sub 0x00). */
+    fun buildSelectVfoACommand(): ByteArray = frame(CMD_SELECT_VFO, SUB_VFO_A)
+
+    /** Select VFO-B (CMD 0x07 sub 0x01). */
+    fun buildSelectVfoBCommand(): ByteArray = frame(CMD_SELECT_VFO, SUB_VFO_B)
+
+    /**
+     * Enter VFO operating mode (CMD 0x08 sub 0x00).
+     * Sent after connect — if the radio is in memory-channel mode frequency
+     * and mode commands return FA until this is issued.
+     */
+    fun buildEnterVfoModeCommand(): ByteArray = frame(CMD_SELECT_OP_MODE, 0x00)
+
+    /** Enable or disable SPLIT mode (CMD 0x0F). */
+    fun buildSplitModeCommand(enable: Boolean): ByteArray {
+        val sub = if (enable) SUB_SPLIT_ON else SUB_SPLIT_OFF
+        return frame(CMD_DUPLEX_SPLIT, sub)
+    }
+
+    /**
+     * Enable/disable CTCSS encode (CMD 0x16 sub 0x42).
+     * 0x01 = CTCSS encoder ON, 0x00 = OFF.
+     */
+    fun buildCtcssModeCommand(enabled: Boolean): ByteArray {
+        val value: Byte = if (enabled) 0x01 else 0x00
+        return frame(CMD_MISC_SETTING, SUB_CTCSS_SETTING, value)
+    }
+
+    /**
+     * Set CTCSS tone frequency (CMD 0x1B sub 0x00).
+     */
+    fun buildSetCtcssToneCommand(toneHz: Double): ByteArray {
+        val bcd = encodeCtcssToneBcd(toneHz)
+        return frame(CMD_CTCSS_TONE, 0x00, *bcd)
+    }
+
+    // ── Response parsing ───────────────────────────────────────────────────
+
+    /**
+     * Find and parse a complete CI-V response frame from a buffer.
+     *
+     * Returns the bytes between "FE FE E0 A4 <CMD>" and FD, or null if no
+     * complete frame was found. The search is tolerant of interleaved
+     * broadcast traffic.
+     *
+     * @param buf       bytes accumulated from the radio
+     * @param expectCmd the command byte we are looking for in the reply, or
+     *                  null to accept any command response from the radio
+     */
+    fun parseResponse(buf: ByteArray, expectCmd: Byte?): ParsedResponse? {
+        var i = 0
+        while (i < buf.size - 5) {
+            // Look for FE FE preamble
+            if (buf[i] != PREAMBLE || buf[i + 1] != PREAMBLE) { i++; continue }
+            val dest = buf[i + 2]
+            val src  = buf[i + 3]
+            val cmd  = buf[i + 4]
+            // We only care about frames addressed to us from the radio
+            if (dest != ADDR_CTRL || src != ADDR_IC705) { i++; continue }
+            // Find the terminating FD
+            val fdIdx = buf.indexOf(END_OF_MSG, startIndex = i + 5)
+            if (fdIdx < 0) break  // incomplete frame, wait for more data
+            val payload = buf.copyOfRange(i + 5, fdIdx)
+            if (expectCmd == null || cmd == expectCmd) {
+                return ParsedResponse(cmd, payload, fdIdx + 1)
+            }
+            i = fdIdx + 1
+        }
+        return null
+    }
+
+    private fun ByteArray.indexOf(b: Byte, startIndex: Int): Int {
+        for (k in startIndex until size) if (this[k] == b) return k
+        return -1
+    }
+
+    /**
+     * Check whether a buffer contains an OK acknowledgement (FB FD) from
+     * the radio. Tolerates broadcast noise before the ACK.
+     */
+    fun containsAck(buf: ByteArray): Boolean {
+        var i = 0
+        while (i < buf.size - 5) {
+            if (buf[i] != PREAMBLE || buf[i + 1] != PREAMBLE) { i++; continue }
+            val dest = buf[i + 2]
+            val src  = buf[i + 3]
+            val cmd  = buf[i + 4]
+            if (dest != ADDR_CTRL || src != ADDR_IC705) { i++; continue }
+            // Skip to FD
+            val fdIdx = buf.indexOf(END_OF_MSG, startIndex = i + 5)
+            if (fdIdx < 0) break
+            if (cmd == ACK_OK) return true
+            if (cmd == ACK_NG) return false
+            i = fdIdx + 1
+        }
+        return false
+    }
+
+    /**
+     * Parse frequency + mode from a CMD_READ_FREQ reply payload.
+     * Payload layout after stripping command byte: [5 freq bytes] [mode byte] [filter byte]
+     */
+    fun parseFreqModePayload(payload: ByteArray): Pair<Long, String>? {
+        if (payload.size < 6) return null
+        val freqHz = decodeFrequencyBcd(payload.copyOfRange(0, 5))
+        val mode   = BYTE_TO_MODE[payload[5]] ?: return null
+        return freqHz to mode
+    }
+
+    /** Hex dump of bytes, useful for debug logging. */
+    fun toHex(bytes: ByteArray): String =
+        bytes.joinToString(" ") { String.format(Locale.US, "%02X", it.toInt() and 0xFF) }
+
+    data class ParsedResponse(
+        val cmd: Byte,
+        val payload: ByteArray,
+        /** Index in the source buffer immediately after the FD terminator. */
+        val nextOffset: Int
+    )
+}

core/data/src/main/java/com/rtbishop/look4sat/core/data/framework/RadioTrackingService.kt

@@ -19,8 +19,10 @@ package com.rtbishop.look4sat.core.data.framework
 
 import android.bluetooth.BluetoothManager
 import android.util.Log
+import com.rtbishop.look4sat.core.domain.model.RadioControlSettings
 import com.rtbishop.look4sat.core.domain.model.SatRadio
 import com.rtbishop.look4sat.core.domain.predict.OrbitalPass
+import com.rtbishop.look4sat.core.domain.predict.SPEED_OF_LIGHT
 import com.rtbishop.look4sat.core.domain.repository.IRadioController
 import com.rtbishop.look4sat.core.domain.repository.IRadioTrackingService
 import com.rtbishop.look4sat.core.domain.repository.ISatelliteRepo
@@ -29,6 +31,7 @@ import com.rtbishop.look4sat.core.domain.repository.RadioTrackingState
 import com.rtbishop.look4sat.core.domain.utility.TransponderMapper
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Job
+import kotlinx.coroutines.currentCoroutineContext
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
@@ -44,6 +47,8 @@ class RadioTrackingService(
 ) : IRadioTrackingService {
 
     private val tag = "RadioTracking"
+    /** Delay between each step of the split-mode init sequence (ms). */
+    private val INIT_STEP_DELAY_MS = 200L
     private val _state = MutableStateFlow(RadioTrackingState())
     override val state: StateFlow<RadioTrackingState> = _state
 
@@ -51,227 +56,427 @@ class RadioTrackingService(
     private var rxController: IRadioController? = null
     private var trackingJob: Job? = null
 
+    // ── Connection ──────────────────────────────────────────────────────────
+
     override suspend fun connectRadios() {
-        // Disconnect old controllers if any
         txController?.disconnect()
         rxController?.disconnect()
 
-        // Read current addresses from settings
         val rcSettings = settingsRepo.radioControlSettings.value
-        val txAddr = rcSettings.txRadioAddress
-        val rxAddr = rcSettings.rxRadioAddress
+        val txAddr     = rcSettings.txRadioAddress
+        val rxAddr     = rcSettings.rxRadioAddress
+        val isIcom     = rcSettings.radioModel == RadioControlSettings.MODEL_ICOM_IC705
+        val isSplit    = isIcom && rcSettings.splitMode
 
-        Log.i(tag, "Connecting TX=$txAddr RX=$rxAddr")
+        Log.i(tag, "connectRadios model=${rcSettings.radioModel} split=$isSplit TX=$txAddr RX=$rxAddr")
 
-        if (txAddr.isBlank() && rxAddr.isBlank()) {
-            _state.update { it.copy(errorMessage = "No radio addresses configured. Set them in Settings → FT-817.") }
-            return
-        }
-
-        val tx = Ft817Controller(bluetoothManager, txAddr)
-        val rx = Ft817Controller(bluetoothManager, rxAddr)
-        txController = tx
-        rxController = rx
-
-        _state.update { it.copy(errorMessage = null) }
-        val txOk = if (txAddr.isNotBlank()) tx.connect() else false
-        val rxOk = if (rxAddr.isNotBlank()) rx.connect() else false
-        _state.update {
-            it.copy(
-                txConnected = txOk,
-                rxConnected = rxOk,
-                errorMessage = when {
-                    !txOk && !rxOk -> "Could not connect to TX and RX radios"
-                    !txOk -> "Could not connect to TX radio ($txAddr)"
-                    !rxOk -> "Could not connect to RX radio ($rxAddr)"
-                    else -> null
-                }
-            )
+        if (isSplit) {
+            // Single-radio split mode: only TX slot is used
+            if (txAddr.isBlank()) {
+                _state.update { it.copy(errorMessage = "No radio address configured in Settings") }
+                return
+            }
+            val tx = makeController(isIcom, txAddr)
+            txController = tx
+            rxController = null
+            _state.update { it.copy(errorMessage = null) }
+            val txOk = tx.connect()
+            _state.update {
+                it.copy(
+                    txConnected = txOk,
+                    rxConnected = false,
+                    errorMessage = if (!txOk) "Could not connect to radio ($txAddr)" else null
+                )
+            }
+            Log.i(tag, "IC-705 split mode connected: txOk=$txOk")
+        } else {
+            if (txAddr.isBlank() && rxAddr.isBlank()) {
+                _state.update { it.copy(errorMessage = "No radio addresses configured in Settings") }
+                return
+            }
+            val tx = makeController(isIcom, txAddr)
+            val rx = makeController(isIcom, rxAddr)
+            txController = tx
+            rxController = rx
+            _state.update { it.copy(errorMessage = null) }
+            val txOk = if (txAddr.isNotBlank()) tx.connect() else false
+            val rxOk = if (rxAddr.isNotBlank()) rx.connect() else false
+            _state.update {
+                it.copy(
+                    txConnected = txOk,
+                    rxConnected = rxOk,
+                    errorMessage = when {
+                        !txOk && !rxOk -> "Could not connect to TX and RX radios"
+                        !txOk          -> "Could not connect to TX radio ($txAddr)"
+                        !rxOk          -> "Could not connect to RX radio ($rxAddr)"
+                        else           -> null
+                    }
+                )
+            }
+            Log.i(tag, "Dual-radio connected: txOk=$txOk rxOk=$rxOk")
         }
     }
 
+    private fun makeController(isIcom: Boolean, address: String): IRadioController =
+        if (isIcom) Ic705Controller(bluetoothManager, address)
+        else        Ft817Controller(bluetoothManager, address)
+
     override suspend fun disconnectRadios() {
         stopTracking()
         txController?.disconnect()
         rxController?.disconnect()
         txController = null
         rxController = null
-        _state.update {
-            it.copy(
-                txConnected = false,
-                rxConnected = false,
-                isActive = false
-            )
-        }
+        _state.update { it.copy(txConnected = false, rxConnected = false, isActive = false) }
     }
 
+    // ── Tracking ────────────────────────────────────────────────────────────
+
     override fun startTracking(pass: OrbitalPass, transponder: SatRadio, txBaseFreqHz: Long?) {
         _state.update {
             it.copy(
-                isActive = true,
-                currentPass = pass,
-                selectedTransponder = transponder,
-                txBaseFrequencyHz = txBaseFreqHz
+                isActive             = true,
+                currentPass          = pass,
+                selectedTransponder  = transponder,
+                txBaseFrequencyHz    = txBaseFreqHz
             )
         }
         trackingJob?.cancel()
-        trackingJob = appScope.launch {
-            // Set modes on both radios at tracking start
-            val tx = txController
-            val rx = rxController
-            val txMode = transponder.uplinkMode
-            val rxMode = transponder.downlinkMode
-                ?: transponder.uplinkMode?.let {
-                    TransponderMapper.mapUplinkModeToDownlinkMode(it, transponder.isInverted)
-                }
-            if (tx != null && tx.isConnected && txMode != null) {
-                tx.setMode(txMode)
-                Log.i(tag, "TX mode set to $txMode")
-            }
-            if (rx != null && rx.isConnected && rxMode != null) {
-                rx.setMode(rxMode)
-                Log.i(tag, "RX mode set to $rxMode")
-            }
-            // Set CTCSS if FM
-            if (txMode?.uppercase() == "FM") {
-                _state.value.ctcssTone?.let { tone ->
-                    tx?.setCtcssTone(tone)
-                    tx?.setCtcssMode(true)
-                }
-            }
-            _state.update { it.copy(txMode = txMode, rxMode = rxMode) }
 
-            var lastSetTxFreq = 0.0
-            var lastSetRxFreq = 0.0
-            var tuningRadio = "" // "", "tx", or "rx" - which radio the user is tuning
-            var lastReadFreq = 0L
-            var stableCount = 0
+        val rcSettings = settingsRepo.radioControlSettings.value
+        val isIcom     = rcSettings.radioModel == RadioControlSettings.MODEL_ICOM_IC705
+        val isSplit    = isIcom && rcSettings.splitMode
 
-            while (isActive) {
-                val currentState = _state.value
-                if (!currentState.isActive) break
-
-                val satPass = currentState.currentPass ?: break
-                val xpdr = currentState.selectedTransponder ?: break
-                var txBaseFreq = currentState.txBaseFrequencyHz
-                val stationPos = settingsRepo.stationPosition.value
-                val timeNow = System.currentTimeMillis()
-
-                val pos = satelliteRepo.getPosition(satPass.orbitalObject, stationPos, timeNow)
-                val tx = txController
-                val rx = rxController
-                val hasUplink = txBaseFreq != null
-                val c = com.rtbishop.look4sat.core.domain.predict.SPEED_OF_LIGHT
-                val v = pos.distanceRate * 1000.0
-
-                if (tuningRadio.isNotEmpty()) {
-                    // --- User is tuning: keep reading, wait for stabilization ---
-                    val radio = if (tuningRadio == "tx") tx else rx
-                    if (radio != null && radio.isConnected) {
-                        val readResult = radio.readFrequencyAndMode()
-                        if (readResult != null) {
-                            val (freq, _) = readResult
-                            if (kotlin.math.abs(freq - lastReadFreq) <= 20) {
-                                stableCount++
-                            } else {
-                                stableCount = 0
-                                lastReadFreq = freq
-                            }
-                            // Stable for 2 reads → user stopped turning
-                            if (stableCount >= 2) {
-                                if (tuningRadio == "tx" && txBaseFreq != null) {
-                                    val newBase = (freq.toDouble() * c / (c + v)).toLong()
-                                    if (newBase > 0) {
-                                        txBaseFreq = newBase
-                                        _state.update { it.copy(txBaseFrequencyHz = newBase) }
-                                        Log.i(tag, "TX tuning done → base=$newBase")
-                                    }
-                                } else if (tuningRadio == "rx") {
-                                    val rxNominal = (freq.toDouble() * c / (c - v)).toLong()
-                                    val newTxBase = TransponderMapper.mapDownlinkToUplink(rxNominal, xpdr)
-                                    if (newTxBase != null && newTxBase > 0) {
-                                        txBaseFreq = newTxBase
-                                        _state.update { it.copy(txBaseFrequencyHz = newTxBase) }
-                                        Log.i(tag, "RX tuning done → txBase=$newTxBase")
-                                    }
-                                }
-                                tuningRadio = ""
-                                stableCount = 0
-                                lastSetTxFreq = 0.0
-                                lastSetRxFreq = 0.0
-                            }
-                        }
-                    }
-                } else {
-                    // --- Normal tracking: read, detect changes, command ---
-
-                    // TX dial feedback
-                    if (hasUplink && tx != null && tx.isConnected && lastSetTxFreq > 0.0) {
-                        val readResult = tx.readFrequencyAndMode()
-                        if (readResult != null) {
-                            val (actualTxFreq, _) = readResult
-                            if (kotlin.math.abs(actualTxFreq - lastSetTxFreq) >= 20.0) {
-                                tuningRadio = "tx"
-                                lastReadFreq = actualTxFreq
-                                stableCount = 0
-                                Log.i(tag, "TX tuning detected (read=$actualTxFreq, lastSet=$lastSetTxFreq)")
-                            }
-                        }
-                    }
-
-                    // RX dial feedback (only if TX not tuning)
-                    if (tuningRadio.isEmpty() && rx != null && rx.isConnected && lastSetRxFreq > 0.0) {
-                        val readResult = rx.readFrequencyAndMode()
-                        if (readResult != null) {
-                            val (actualRxFreq, _) = readResult
-                            if (kotlin.math.abs(actualRxFreq - lastSetRxFreq) >= 20.0) {
-                                tuningRadio = "rx"
-                                lastReadFreq = actualRxFreq
-                                stableCount = 0
-                                Log.i(tag, "RX tuning detected (read=$actualRxFreq, lastSet=$lastSetRxFreq)")
-                            }
-                        }
-                    }
-                }
-
-                // Compute Doppler-corrected frequencies
-                val txRadioFreq = txBaseFreq?.let { pos.getUplinkFreq(it) }
-                val rxBaseFreq = if (txBaseFreq != null) {
-                    TransponderMapper.mapUplinkToDownlink(txBaseFreq, xpdr)
-                } else {
-                    xpdr.downlinkLow
-                }
-                val rxRadioFreq = rxBaseFreq?.let { pos.getDownlinkFreq(it) }
-
-                // Command radios (only when not tuning)
-                if (tuningRadio.isEmpty()) {
-                    if (tx != null && tx.isConnected && txRadioFreq != null) {
-                        tx.setFrequency(txRadioFreq)
-                        lastSetTxFreq = txRadioFreq.toDouble()
-                    }
-                    if (rx != null && rx.isConnected && rxRadioFreq != null) {
-                        rx.setFrequency(rxRadioFreq)
-                        lastSetRxFreq = rxRadioFreq.toDouble()
-                    }
-                }
-
-                _state.update {
-                    it.copy(
-                        txConnected = tx?.isConnected ?: false,
-                        rxConnected = rx?.isConnected ?: false,
-                        txFrequencyHz = txRadioFreq,
-                        rxFrequencyHz = rxRadioFreq,
-                        azimuth = Math.toDegrees(pos.azimuth),
-                        elevation = Math.toDegrees(pos.elevation),
-                        distance = pos.distance
-                    )
-                }
-
-                delay(1000)
-            }
+        if (isSplit) {
+            trackingJob = appScope.launch { runSplitTracking(transponder, txBaseFreqHz) }
+        } else {
+            trackingJob = appScope.launch { runDualRadioTracking(transponder, txBaseFreqHz) }
         }
     }
 
+    // ── Dual-radio tracking (Yaesu or two IC-705s) ──────────────────────────
+
+    private suspend fun runDualRadioTracking(transponder: SatRadio, initialTxBaseFreqHz: Long?) {
+        val tx = txController
+        val rx = rxController
+
+        // Initial setup: set band/mode/CTCSS on both radios
+        val txMode = transponder.uplinkMode
+        val rxMode = transponder.downlinkMode
+            ?: transponder.uplinkMode?.let {
+                TransponderMapper.mapUplinkModeToDownlinkMode(it, transponder.isInverted)
+            }
+
+        Log.i(tag, "DualRadio start: txMode=$txMode rxMode=$rxMode")
+
+        if (tx != null && tx.isConnected && txMode != null) {
+            Log.d(tag, "Setting TX mode: $txMode")
+            tx.setMode(txMode)
+        }
+        if (rx != null && rx.isConnected && rxMode != null) {
+            Log.d(tag, "Setting RX mode: $rxMode")
+            rx.setMode(rxMode)
+        }
+        if (txMode?.uppercase() == "FM") {
+            _state.value.ctcssTone?.let { tone ->
+                Log.d(tag, "Setting CTCSS: ${tone}Hz")
+                tx?.setCtcssTone(tone)
+                tx?.setCtcssMode(true)
+            }
+        }
+        _state.update { it.copy(txMode = txMode, rxMode = rxMode) }
+
+        var lastSetTxFreq = 0.0
+        var lastSetRxFreq = 0.0
+        var tuningRadio   = ""
+        var lastReadFreq  = 0L
+        var stableCount   = 0
+
+        while (currentCoroutineContext().isActive) {
+            val currentState = _state.value
+            if (!currentState.isActive) break
+
+            val satPass = currentState.currentPass ?: break
+            val xpdr    = currentState.selectedTransponder ?: break
+            var txBaseFreq = currentState.txBaseFrequencyHz
+            val stationPos = settingsRepo.stationPosition.value
+            val pos = satelliteRepo.getPosition(satPass.orbitalObject, stationPos, System.currentTimeMillis())
+            val txNow = txController
+            val rxNow = rxController
+            val v = pos.distanceRate * 1000.0
+
+            if (tuningRadio.isNotEmpty()) {
+                val radio = if (tuningRadio == "tx") txNow else rxNow
+                if (radio != null && radio.isConnected) {
+                    val read = radio.readFrequencyAndMode()
+                    if (read != null) {
+                        val (freq, _) = read
+                        if (kotlin.math.abs(freq - lastReadFreq) <= 20) stableCount++
+                        else { stableCount = 0; lastReadFreq = freq }
+                        if (stableCount >= 2) {
+                            if (tuningRadio == "tx" && txBaseFreq != null) {
+                                val newBase = (freq.toDouble() * SPEED_OF_LIGHT / (SPEED_OF_LIGHT + v)).toLong()
+                                if (newBase > 0) {
+                                    txBaseFreq = newBase
+                                    _state.update { it.copy(txBaseFrequencyHz = newBase) }
+                                    Log.i(tag, "TX tuning done → base=$newBase")
+                                }
+                            } else if (tuningRadio == "rx") {
+                                val rxNominal = (freq.toDouble() * SPEED_OF_LIGHT / (SPEED_OF_LIGHT - v)).toLong()
+                                val newTxBase = TransponderMapper.mapDownlinkToUplink(rxNominal, xpdr)
+                                if (newTxBase != null && newTxBase > 0) {
+                                    txBaseFreq = newTxBase
+                                    _state.update { it.copy(txBaseFrequencyHz = newTxBase) }
+                                    Log.i(tag, "RX tuning done → txBase=$newTxBase")
+                                }
+                            }
+                            tuningRadio   = ""
+                            stableCount   = 0
+                            lastSetTxFreq = 0.0
+                            lastSetRxFreq = 0.0
+                        }
+                    }
+                }
+            } else {
+                // Detect manual dial changes
+                if (txBaseFreq != null && txNow != null && txNow.isConnected && lastSetTxFreq > 0.0) {
+                    val read = txNow.readFrequencyAndMode()
+                    if (read != null && kotlin.math.abs(read.first - lastSetTxFreq) >= 20.0) {
+                        tuningRadio  = "tx"
+                        lastReadFreq = read.first
+                        stableCount  = 0
+                        Log.i(tag, "TX tuning detected (read=${read.first}, lastSet=$lastSetTxFreq)")
+                    }
+                }
+                if (tuningRadio.isEmpty() && rxNow != null && rxNow.isConnected && lastSetRxFreq > 0.0) {
+                    val read = rxNow.readFrequencyAndMode()
+                    if (read != null && kotlin.math.abs(read.first - lastSetRxFreq) >= 20.0) {
+                        tuningRadio  = "rx"
+                        lastReadFreq = read.first
+                        stableCount  = 0
+                        Log.i(tag, "RX tuning detected (read=${read.first}, lastSet=$lastSetRxFreq)")
+                    }
+                }
+            }
+
+            val txRadioFreq = txBaseFreq?.let { pos.getUplinkFreq(it) }
+            val rxBaseFreq  = if (txBaseFreq != null) {
+                TransponderMapper.mapUplinkToDownlink(txBaseFreq, xpdr)
+            } else xpdr.downlinkLow
+            val rxRadioFreq = rxBaseFreq?.let { pos.getDownlinkFreq(it) }
+
+            if (tuningRadio.isEmpty()) {
+                if (txNow != null && txNow.isConnected && txRadioFreq != null) {
+                    txNow.setFrequency(txRadioFreq)
+                    lastSetTxFreq = txRadioFreq.toDouble()
+                }
+                if (rxNow != null && rxNow.isConnected && rxRadioFreq != null) {
+                    rxNow.setFrequency(rxRadioFreq)
+                    lastSetRxFreq = rxRadioFreq.toDouble()
+                }
+            }
+
+            _state.update {
+                it.copy(
+                    txConnected  = txNow?.isConnected ?: false,
+                    rxConnected  = rxNow?.isConnected ?: false,
+                    txFrequencyHz = txRadioFreq,
+                    rxFrequencyHz = rxRadioFreq,
+                    azimuth      = Math.toDegrees(pos.azimuth),
+                    elevation    = Math.toDegrees(pos.elevation),
+                    distance     = pos.distance
+                )
+            }
+            delay(1000)
+        }
+    }
+
+    // ── IC-705 split-radio tracking ─────────────────────────────────────────
+
+    private suspend fun runSplitTracking(transponder: SatRadio, initialTxBaseFreqHz: Long?) {
+        val radio = txController ?: return
+        if (!radio.isConnected) return
+
+        val txMode = transponder.uplinkMode
+        val rxMode = transponder.downlinkMode
+            ?: transponder.uplinkMode?.let {
+                TransponderMapper.mapUplinkModeToDownlinkMode(it, transponder.isInverted)
+            }
+
+        // Compute nominal base frequencies
+        val txCenter = when {
+            transponder.uplinkLow != null && transponder.uplinkHigh != null ->
+                (transponder.uplinkLow!! + transponder.uplinkHigh!!) / 2
+            transponder.uplinkLow != null -> transponder.uplinkLow!!
+            else -> null
+        }
+        val rxNominal = if (txCenter != null) {
+            TransponderMapper.mapUplinkToDownlink(txCenter, transponder)
+        } else transponder.downlinkLow
+
+        val txBase = initialTxBaseFreqHz ?: txCenter
+        Log.i(tag, "IC-705 split setup: txBase=${txBase}Hz rxNominal=${rxNominal}Hz txMode=$txMode rxMode=$rxMode")
+
+        // ── Initial setup sequence ──────────────────────────────────────────
+        // Sequence per IC-705: explicitly select VFO, then band → freq → mode.
+        // ACK from each command gates the next — no fixed delays needed.
+
+        // VFO-A = RX (downlink)
+        Log.d(tag, "Split init: selecting VFO-A for RX (downlink)")
+        radio.setVfo(vfoA = true)
+        if (rxNominal != null) {
+            Log.d(tag, "Split init: VFO-A band for ${rxNominal}Hz")
+            radio.setBand(rxNominal)
+            Log.d(tag, "Split init: VFO-A freq=${rxNominal}Hz")
+            radio.setFrequency(rxNominal)
+        }
+        if (rxMode != null) {
+            Log.d(tag, "Split init: VFO-A mode=$rxMode")
+            radio.setMode(rxMode)
+        }
+
+        // VFO-B = TX (uplink)
+        Log.d(tag, "Split init: selecting VFO-B for TX (uplink)")
+        radio.setVfo(vfoA = false)
+        if (txBase != null) {
+            Log.d(tag, "Split init: VFO-B band for ${txBase}Hz")
+            radio.setBand(txBase)
+            Log.d(tag, "Split init: VFO-B freq=${txBase}Hz")
+            radio.setFrequency(txBase)
+        }
+        if (txMode != null) {
+            Log.d(tag, "Split init: VFO-B mode=$txMode")
+            radio.setMode(txMode)
+        }
+        if (txMode?.uppercase() == "FM") {
+            val tone = _state.value.ctcssTone
+            if (tone != null) {
+                Log.d(tag, "Split init: CTCSS=${tone}Hz")
+                radio.setCtcssTone(tone)
+                radio.setCtcssMode(true)
+            } else {
+                radio.setCtcssMode(false)
+            }
+        }
+
+        // Enable SPLIT on VFO-A (return display to RX VFO first)
+        Log.d(tag, "Split init: returning to VFO-A, then enabling SPLIT mode")
+        radio.setVfo(vfoA = true)
+        radio.setSplitMode(enabled = true)
+
+        _state.update { it.copy(txMode = txMode, rxMode = rxMode, txBaseFrequencyHz = txBase) }
+        Log.i(tag, "IC-705 split init done — entering tracking loop")
+
+        // ── Tracking loop with tuning detection ─────────────────────────────
+        var lastSetTxFreq = 0.0
+        var lastSetRxFreq = 0.0
+        var tuningRadio   = ""  // "tx" or "rx" when manual tuning detected
+        var lastReadFreq  = 0L
+        var stableCount   = 0
+
+        while (currentCoroutineContext().isActive) {
+            val currentState = _state.value
+            if (!currentState.isActive) break
+
+            val satPass = currentState.currentPass ?: break
+            val xpdr    = currentState.selectedTransponder ?: break
+            var txBaseFreq = currentState.txBaseFrequencyHz
+            val stationPos = settingsRepo.stationPosition.value
+            val pos = satelliteRepo.getPosition(satPass.orbitalObject, stationPos, System.currentTimeMillis())
+            val v = pos.distanceRate * 1000.0
+
+            if (tuningRadio.isNotEmpty()) {
+                // User is tuning — wait for frequency to stabilize
+                val readFreq = if (tuningRadio == "tx") radio.readTxVfoFrequency() else radio.readWorkingFrequency()
+                if (readFreq != null) {
+                    if (kotlin.math.abs(readFreq - lastReadFreq) <= 20) stableCount++
+                    else { stableCount = 0; lastReadFreq = readFreq }
+
+                    if (stableCount >= 2) {
+                        // Frequency stable — reverse-calculate base frequency
+                        if (tuningRadio == "tx" && txBaseFreq != null) {
+                            val newBase = (readFreq.toDouble() * SPEED_OF_LIGHT / (SPEED_OF_LIGHT + v)).toLong()
+                            if (newBase > 0) {
+                                txBaseFreq = newBase
+                                _state.update { it.copy(txBaseFrequencyHz = newBase) }
+                                Log.i(tag, "Split TX tuning done → base=$newBase")
+                            }
+                        } else if (tuningRadio == "rx") {
+                            val rxNominal = (readFreq.toDouble() * SPEED_OF_LIGHT / (SPEED_OF_LIGHT - v)).toLong()
+                            val newTxBase = TransponderMapper.mapDownlinkToUplink(rxNominal, xpdr)
+                            if (newTxBase != null && newTxBase > 0) {
+                                txBaseFreq = newTxBase
+                                _state.update { it.copy(txBaseFrequencyHz = newTxBase) }
+                                Log.i(tag, "Split RX tuning done → txBase=$newTxBase")
+                            }
+                        }
+                        tuningRadio   = ""
+                        stableCount   = 0
+                        lastSetTxFreq = 0.0
+                        lastSetRxFreq = 0.0
+                    }
+                }
+            } else {
+                // Detect manual dial changes
+                if (txBaseFreq != null && lastSetTxFreq > 0.0) {
+                    val readTx = radio.readTxVfoFrequency()
+                    if (readTx != null && kotlin.math.abs(readTx - lastSetTxFreq) >= 20.0) {
+                        tuningRadio  = "tx"
+                        lastReadFreq = readTx
+                        stableCount  = 0
+                        Log.i(tag, "Split TX tuning detected (read=${readTx}, lastSet=$lastSetTxFreq)")
+                    }
+                }
+                if (tuningRadio.isEmpty() && lastSetRxFreq > 0.0) {
+                    val readRx = radio.readWorkingFrequency()
+                    if (readRx != null && kotlin.math.abs(readRx - lastSetRxFreq) >= 20.0) {
+                        tuningRadio  = "rx"
+                        lastReadFreq = readRx
+                        stableCount  = 0
+                        Log.i(tag, "Split RX tuning detected (read=${readRx}, lastSet=$lastSetRxFreq)")
+                    }
+                }
+            }
+
+            // Determine Doppler-corrected frequencies
+            val txRadioFreq = txBaseFreq?.let { pos.getUplinkFreq(it) }
+            val rxBaseCalc  = if (txBaseFreq != null) {
+                TransponderMapper.mapUplinkToDownlink(txBaseFreq, xpdr)
+            } else xpdr.downlinkLow
+            val rxRadioFreq = rxBaseCalc?.let { pos.getDownlinkFreq(it) }
+
+            if (radio.isConnected && tuningRadio.isEmpty()) {
+                // Update both VFOs every cycle — no PTT polling needed.
+                // 0x25/00 = active (RX) VFO, 0x25/01 = inactive (TX) VFO.
+                if (rxRadioFreq != null) {
+                    Log.d(tag, "Split loop RX (0x25/00): ${rxRadioFreq}Hz")
+                    radio.setWorkingFrequency(rxRadioFreq)
+                    lastSetRxFreq = rxRadioFreq.toDouble()
+                }
+                if (txRadioFreq != null) {
+                    Log.d(tag, "Split loop TX (0x25/01): ${txRadioFreq}Hz")
+                    radio.setTxVfoFrequency(txRadioFreq)
+                    lastSetTxFreq = txRadioFreq.toDouble()
+                }
+            }
+
+            _state.update {
+                it.copy(
+                    txConnected   = radio.isConnected,
+                    rxConnected   = false,  // single radio
+                    txFrequencyHz = txRadioFreq,
+                    rxFrequencyHz = rxRadioFreq,
+                    azimuth       = Math.toDegrees(pos.azimuth),
+                    elevation     = Math.toDegrees(pos.elevation),
+                    distance      = pos.distance
+                )
+            }
+            delay(1000)
+        }
+    }
+
+    // ── Other IRadioTrackingService methods ─────────────────────────────────
+
     override fun stopTracking() {
         trackingJob?.cancel()
         trackingJob = null
@@ -288,7 +493,6 @@ class RadioTrackingService(
                     TransponderMapper.mapUplinkModeToDownlinkMode(it, transponder.isInverted)
                 }
             rxMode?.let { rx?.setMode(it) }
-
             if (transponder.uplinkMode?.uppercase() == "FM") {
                 _state.value.ctcssTone?.let { tone ->
                     tx?.setCtcssTone(tone)
@@ -302,21 +506,17 @@ class RadioTrackingService(
             transponder.uplinkLow != null -> transponder.uplinkLow!!
             else -> null
         }
-        // Show nominal frequencies immediately
         val rxNominal = if (txCenter != null) {
             TransponderMapper.mapUplinkToDownlink(txCenter, transponder)
-        } else {
-            // Downlink-only transponder (beacon etc.) - use downlink directly
-            transponder.downlinkLow
-        }
+        } else transponder.downlinkLow
         _state.update {
             it.copy(
                 selectedTransponder = transponder,
-                txBaseFrequencyHz = txCenter,
-                txFrequencyHz = txCenter,
-                rxFrequencyHz = rxNominal,
-                txMode = transponder.uplinkMode,
-                rxMode = transponder.downlinkMode
+                txBaseFrequencyHz   = txCenter,
+                txFrequencyHz       = txCenter,
+                rxFrequencyHz       = rxNominal,
+                txMode              = transponder.uplinkMode,
+                rxMode              = transponder.downlinkMode
                     ?: transponder.uplinkMode?.let { m ->
                         TransponderMapper.mapUplinkModeToDownlinkMode(m, transponder.isInverted)
                     }
@@ -353,5 +553,4 @@ class RadioTrackingService(
         }
         _state.update { it.copy(txMode = txMode, rxMode = rxMode) }
     }
-
 }

core/data/src/main/java/com/rtbishop/look4sat/core/data/injection/MainContainer.kt

@@ -1,15 +1,32 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
 package com.rtbishop.look4sat.core.data.injection
 
 import android.bluetooth.BluetoothManager
 import android.content.Context
-import android.hardware.Sensor
 import android.hardware.SensorManager
+import android.hardware.display.DisplayManager
 import android.location.LocationManager
-import android.view.WindowManager
 import androidx.room.Room
 import com.rtbishop.look4sat.core.data.database.Look4SatDb
 import com.rtbishop.look4sat.core.data.framework.BluetoothReporter
 import com.rtbishop.look4sat.core.data.framework.Ft817Controller
+import com.rtbishop.look4sat.core.data.framework.Ic705Controller
 import com.rtbishop.look4sat.core.data.framework.NetworkReporter
 import com.rtbishop.look4sat.core.data.framework.RadioTrackingService
 import com.rtbishop.look4sat.core.data.repository.DatabaseRepo
@@ -20,7 +37,10 @@ import com.rtbishop.look4sat.core.data.repository.SettingsRepo
 import com.rtbishop.look4sat.core.data.source.LocalSource
 import com.rtbishop.look4sat.core.data.source.RemoteSource
 import com.rtbishop.look4sat.core.data.usecase.AddToCalendar
+import com.rtbishop.look4sat.core.data.usecase.AudioCapture
+import com.rtbishop.look4sat.core.data.usecase.SaveImage
 import com.rtbishop.look4sat.core.data.usecase.ShowToast
+import com.rtbishop.look4sat.core.domain.model.RadioControlSettings
 import com.rtbishop.look4sat.core.domain.repository.IDatabaseRepo
 import com.rtbishop.look4sat.core.domain.repository.IMainContainer
 import com.rtbishop.look4sat.core.domain.repository.IRadioController
@@ -30,15 +50,21 @@ import com.rtbishop.look4sat.core.domain.repository.ISatelliteRepo
 import com.rtbishop.look4sat.core.domain.repository.ISelectionRepo
 import com.rtbishop.look4sat.core.domain.repository.ISensorsRepo
 import com.rtbishop.look4sat.core.domain.repository.ISettingsRepo
+import com.rtbishop.look4sat.core.domain.repository.MutualPassData
 import com.rtbishop.look4sat.core.domain.source.ILocalSource
 import com.rtbishop.look4sat.core.domain.source.IRemoteSource
 import com.rtbishop.look4sat.core.domain.usecase.IAddToCalendar
+import com.rtbishop.look4sat.core.domain.usecase.IAudioCapture
+import com.rtbishop.look4sat.core.domain.usecase.ISaveImage
 import com.rtbishop.look4sat.core.domain.usecase.IShowToast
 import com.rtbishop.look4sat.core.domain.utility.DataParser
 import kotlinx.coroutines.CoroutineExceptionHandler
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
 import okhttp3.OkHttpClient
 
 class MainContainer(private val context: Context) : IMainContainer {
@@ -55,10 +81,21 @@ class MainContainer(private val context: Context) : IMainContainer {
         RadioTrackingService(appScope, manager, satelliteRepo, settingsRepo)
     }
 
+    private val _mutualPassData = MutableStateFlow(MutualPassData())
+    override val mutualPassData: StateFlow<MutualPassData> = _mutualPassData.asStateFlow()
+
+    override fun setMutualPassData(data: MutualPassData) {
+        _mutualPassData.value = data
+    }
+
     override fun provideAddToCalendar(): IAddToCalendar = AddToCalendar(context)
 
     override fun provideShowToast(): IShowToast = ShowToast(context)
 
+    override fun provideAudioCapture(): IAudioCapture = AudioCapture()
+
+    override fun provideSaveImage(): ISaveImage = SaveImage(context)
+
     override fun provideBluetoothReporter(): IReporter {
         val manager = context.getSystemService(Context.BLUETOOTH_SERVICE) as BluetoothManager
         val rc = settingsRepo.rcSettings.value
@@ -82,22 +119,31 @@ class MainContainer(private val context: Context) : IMainContainer {
     }
 
     override fun provideTxRadioController(): IRadioController {
-        val manager = context.getSystemService(Context.BLUETOOTH_SERVICE) as BluetoothManager
-        val address = settingsRepo.radioControlSettings.value.txRadioAddress
-        return Ft817Controller(manager, address)
+        val manager  = context.getSystemService(Context.BLUETOOTH_SERVICE) as BluetoothManager
+        val settings = settingsRepo.radioControlSettings.value
+        val address  = settings.txRadioAddress
+        return if (settings.radioModel == RadioControlSettings.MODEL_ICOM_IC705) {
+            Ic705Controller(manager, address)
+        } else {
+            Ft817Controller(manager, address)
+        }
     }
 
     override fun provideRxRadioController(): IRadioController {
-        val manager = context.getSystemService(Context.BLUETOOTH_SERVICE) as BluetoothManager
-        val address = settingsRepo.radioControlSettings.value.rxRadioAddress
-        return Ft817Controller(manager, address)
+        val manager  = context.getSystemService(Context.BLUETOOTH_SERVICE) as BluetoothManager
+        val settings = settingsRepo.radioControlSettings.value
+        val address  = settings.rxRadioAddress
+        return if (settings.radioModel == RadioControlSettings.MODEL_ICOM_IC705) {
+            Ic705Controller(manager, address)
+        } else {
+            Ft817Controller(manager, address)
+        }
     }
 
     override fun provideSensorsRepo(): ISensorsRepo {
         val manager = context.getSystemService(Context.SENSOR_SERVICE) as SensorManager
-        val sensor = manager.getDefaultSensor(Sensor.TYPE_ROTATION_VECTOR)
-        val window = context.getSystemService(Context.WINDOW_SERVICE) as WindowManager
-        return SensorsRepo(manager,sensor,window)
+        val displayManager = context.getSystemService(DisplayManager::class.java)
+        return SensorsRepo(manager, displayManager)
     }
 
     private fun provideDatabaseRepo(): IDatabaseRepo {

core/data/src/main/java/com/rtbishop/look4sat/core/data/repository/DatabaseRepo.kt

@@ -40,57 +40,55 @@ class DatabaseRepo(
     private val settingsRepo: ISettingsRepo
 ) : IDatabaseRepo {
 
-    private companion object {
-        val tleTypes = setOf("Amsat", "R4UAB", "Other")
-        val zippedTleTypes = setOf("McCants", "Classified")
-    }
+    private val customSourceType = "Other"
 
-    override suspend fun updateTLEFromFile(uri: String) = withContext(dispatcher) {
+    override suspend fun updateTLEFromFile(uri: String): Int = withContext(dispatcher) {
+        var importedCount = 0
         remoteSource.getFileStream(uri)?.let { stream ->
-            val entries = dataParser.parseTLEStream(stream)
+            val entries = parseSatelliteStream(uri, unwrapIfZipped(uri, stream))
             localSource.insertEntries(entries)
-            settingsRepo.setSatelliteTypeIds("Other", entries.map { it.catnum })
+            settingsRepo.setSatelliteTypeIds(customSourceType, entries.map { it.catnum })
+            importedCount = entries.size
         }
         setUpdateSuccessful(System.currentTimeMillis())
+        importedCount
     }
 
-    override suspend fun updateTransceiversFromFile(uri: String) = withContext(dispatcher) {
-        remoteSource.getFileStream(uri)
-            ?.let { dataParser.parseJSONStream(it) }
-            ?.takeIf { it.isNotEmpty() }
-            ?.let {
-                localSource.deleteRadios()
-                localSource.insertRadios(it)
-            }
+    override suspend fun updateTransceiversFromFile(uri: String): Int = withContext(dispatcher) {
+        var importedCount = 0
+        remoteSource.getFileStream(uri)?.let { stream ->
+            val transceivers = dataParser.parseJSONStream(unwrapIfZipped(uri, stream))
+            localSource.insertRadios(transceivers)
+            importedCount = transceivers.size
+        }
         setUpdateSuccessful(System.currentTimeMillis())
+        importedCount
     }
 
     override suspend fun updateFromRemote() = withContext(dispatcher) {
         val dataSourcesSettings = settingsRepo.dataSourcesSettings.value
         val tleUrls = buildMap {
             putAll(Sources.satelliteDataUrls)
-            if (dataSourcesSettings.useCustomTLE) put("Other", dataSourcesSettings.tleUrl)
-        }.filterValues { it.isNotEmpty() }
-
-        val radioUrls = buildList {
-            add(Sources.RADIO_DATA_URL)
-            if (dataSourcesSettings.useCustomTransceivers) add(dataSourcesSettings.transceiversUrl)
-        }
-
+            if (dataSourcesSettings.useCustomTLE) put(customSourceType, dataSourcesSettings.tleUrl)
+        }.filterValues { it.isNotBlank() }
+        val radioUrls = buildMap {
+            putAll(Sources.transceiversDataUrls)
+            if (dataSourcesSettings.useCustomTransceivers) put(customSourceType, dataSourcesSettings.transceiversUrl)
+        }.filterValues { it.isNotBlank() }
         // launch all network requests concurrently
-        val tleJobs = tleUrls.map { (type, url) -> async { type to remoteSource.getNetworkStream(url) } }
-        val radioJobs = radioUrls.map { url -> async { remoteSource.getNetworkStream(url) } }
-
-        // parse satellite data
-        val importedEntries = tleJobs.awaitAll().flatMap { (type, stream) ->
-            stream?.let { parseSatelliteStream(type, it) }.orEmpty().also { satellites ->
-                settingsRepo.setSatelliteTypeIds(type, satellites.map { it.catnum })
+        val tleJobs = tleUrls.values.map { url -> async { url to remoteSource.getNetworkStream(url) } }
+        val radioJobs = radioUrls.values.map { url -> async { url to remoteSource.getNetworkStream(url) } }
+        // parse fetched data concurrently and associate with types
+        val importedEntries = tleJobs.awaitAll().flatMap { (url, stream) ->
+            val type = tleUrls.entries.find { it.value == url }?.key ?: customSourceType
+            stream?.let { parseSatelliteStream(url, unwrapIfZipped(url, it)) }.orEmpty().also { entries ->
+                settingsRepo.setSatelliteTypeIds(type, entries.map { it.catnum })
             }
         }
-
-        // parse radio data
-        val importedRadios = radioJobs.awaitAll().filterNotNull().flatMap { dataParser.parseJSONStream(it) }
-
+        val importedRadios = radioJobs.awaitAll().flatMap { (url, stream) ->
+            stream?.let { dataParser.parseJSONStream(unwrapIfZipped(url, it)) }.orEmpty()
+        }
+        // insert parsed data into the database
         localSource.insertEntries(importedEntries)
         localSource.insertRadios(importedRadios)
         setUpdateSuccessful(System.currentTimeMillis())
@@ -102,10 +100,31 @@ class DatabaseRepo(
         setUpdateSuccessful(0L)
     }
 
-    private suspend fun parseSatelliteStream(type: String, stream: InputStream): List<OrbitalData> = when (type) {
-        in tleTypes -> dataParser.parseTLEStream(stream)
-        in zippedTleTypes -> dataParser.parseTLEStream(ZipInputStream(stream).apply { nextEntry })
-        else -> dataParser.parseCSVStream(stream)
+    private suspend fun parseSatelliteStream(url: String, stream: InputStream): List<OrbitalData> {
+        val bufferedStream = stream.buffered()
+        return when {
+            hasCsvHint(url) || looksLikeCsv(bufferedStream) -> dataParser.parseCSVStream(bufferedStream)
+            else -> dataParser.parseTLEStream(bufferedStream)
+        }
+    }
+
+    private fun hasCsvHint(url: String): Boolean {
+        return url.contains("FORMAT=csv", ignoreCase = true) ||
+            url.endsWith(".csv", ignoreCase = true) ||
+            url.endsWith(".csv.zip", ignoreCase = true)
+    }
+
+    private fun looksLikeCsv(stream: InputStream): Boolean {
+        if (!stream.markSupported()) return false
+        stream.mark(4096)
+        val preview = ByteArray(4096)
+        val length = stream.read(preview)
+        stream.reset()
+        if (length <= 0) return false
+        val line = preview.decodeToString(0, length).lineSequence().firstOrNull()?.trim().orEmpty()
+        return line.contains("OBJECT_NAME", ignoreCase = true) ||
+            line.contains("NORAD_CAT_ID", ignoreCase = true) ||
+            line.count { it == ',' } >= 4
     }
 
     private suspend fun setUpdateSuccessful(timestamp: Long) {
@@ -113,4 +132,7 @@ class DatabaseRepo(
             DatabaseState(localSource.getRadiosTotal(), localSource.getEntriesTotal(), timestamp)
         )
     }
+
+    private fun unwrapIfZipped(url: String, stream: InputStream): InputStream =
+        if (url.endsWith(".zip", ignoreCase = true)) ZipInputStream(stream).apply { nextEntry } else stream
 }

core/data/src/main/java/com/rtbishop/look4sat/core/data/repository/SatelliteRepo.kt

@@ -34,8 +34,10 @@ import kotlinx.coroutines.coroutineScope
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.withContext
+import java.util.TimeZone
 
 class SatelliteRepo(
     private val dispatcher: CoroutineDispatcher,
@@ -52,14 +54,33 @@ class SatelliteRepo(
     private val _satellites = MutableStateFlow<List<OrbitalObject>>(emptyList())
     override val satellites: StateFlow<List<OrbitalObject>> = _satellites
 
+    private val _selectedPass = MutableStateFlow(0 to 0L)
+    override val selectedPass: StateFlow<Pair<Int, Long>> = _selectedPass
+
+    override fun selectPass(catNum: Int, aosTime: Long) {
+        _selectedPass.value = catNum to aosTime
+    }
+
     override suspend fun getRadiosWithId(id: Int) = localStorage.getRadiosWithId(id)
 
     override suspend fun initRepository() = withContext(dispatcher) {
-        settingsRepo.selectedIds.collect { selectedIds ->
-            _satellites.update { localStorage.getEntriesWithIds(selectedIds) }
-            val (_, hoursAhead, minElevation, modes) = settingsRepo.passesSettings.value
-            calculatePasses(System.currentTimeMillis(), hoursAhead, minElevation, modes)
-        }
+        combine(
+            settingsRepo.selectedIds,
+            settingsRepo.stationPosition
+        ) { selectedIds, _ -> selectedIds }
+            .collect { selectedIds ->
+                _satellites.update { localStorage.getEntriesWithIds(selectedIds) }
+                val settings = settingsRepo.passesSettings.value
+                calculatePasses(
+                    time = System.currentTimeMillis(),
+                    hoursAhead = settings.hoursAhead,
+                    minElevation = settings.minElevation,
+                    aosStartMinute = settings.aosStartMinute,
+                    aosEndMinute = settings.aosEndMinute,
+                    invertAosTimeWindow = settings.invertAosTimeWindow,
+                    modes = settings.selectedModes
+                )
+            }
     }
 
     override suspend fun getPosition(sat: OrbitalObject, pos: GeoPos, time: Long): OrbitalPos {
@@ -98,7 +119,15 @@ class SatelliteRepo(
         }
     }
 
-    override suspend fun calculatePasses(time: Long, hoursAhead: Int, minElevation: Double, modes: List<String>) {
+    override suspend fun calculatePasses(
+        time: Long,
+        hoursAhead: Int,
+        minElevation: Double,
+        aosStartMinute: Int,
+        aosEndMinute: Int,
+        invertAosTimeWindow: Boolean,
+        modes: List<String>
+    ) {
         _isCalculating.value = true
         // Normalize to the start of the current minute so that coarse 60-second stepping
         // in getLeoPass always begins from the same phase, producing stable AOS/LOS times
@@ -123,7 +152,12 @@ class SatelliteRepo(
             val newPasses = ArrayList<OrbitalPass>()
             for (list in passLists) {
                 for (pass in list) {
-                    if (pass.losTime > time && pass.aosTime < timeFuture && pass.maxElevation > minElevation) {
+                    if (
+                        pass.losTime > time
+                        && pass.aosTime < timeFuture
+                        && pass.maxElevation > minElevation
+                        && (pass.isDeepSpace || isAosInRange(pass.aosTime, aosStartMinute, aosEndMinute, invertAosTimeWindow))
+                    ) {
                         newPasses.add(pass)
                     }
                 }
@@ -135,21 +169,39 @@ class SatelliteRepo(
         _isCalculating.value = false
     }
 
+    private fun isAosInRange(
+        aosTime: Long,
+        aosStartMinute: Int,
+        aosEndMinute: Int,
+        invertAosTimeWindow: Boolean
+    ): Boolean {
+        val offsetMillis = TimeZone.getDefault().getOffset(aosTime).toLong()
+        val localMillis = Math.floorMod(aosTime + offsetMillis, 24L * 60L * 60L * 1000L)
+        val aosMinute = (localMillis / 60_000L).toInt()
+        val inRange = if (aosStartMinute <= aosEndMinute) {
+            aosMinute in aosStartMinute..aosEndMinute
+        } else {
+            aosMinute >= aosStartMinute || aosMinute <= aosEndMinute
+        }
+        return if (invertAosTimeWindow) !inRange else inRange
+    }
+
     private fun OrbitalObject.getPasses(pos: GeoPos, time: Long, hours: Int): List<OrbitalPass> {
         val passes = mutableListOf<OrbitalPass>()
         val endDate = time + hours * 60L * 60L * 1000L
         val quarterOrbitMin = (this.data.orbitalPeriod / 4.0).toInt()
+        val decayed = this.data.hasDecayed(time)
         var startDate = time
         var shouldRewind = true
         var lastAosDate: Long
         var count = 0
         if (this.willBeSeen(pos)) {
             if (this.data.isDeepSpace) {
-                passes.add(getGeoPass(this, pos, time))
+                passes.add(getGeoPass(this, pos, time, decayed))
             } else {
                 do {
                     if (count > 0) shouldRewind = false
-                    val pass = getLeoPass(this, pos, startDate, shouldRewind)
+                    val pass = getLeoPass(this, pos, startDate, shouldRewind, decayed)
                     lastAosDate = pass.aosTime
                     passes.add(pass)
                     startDate = pass.losTime + (quarterOrbitMin * 3) * 60L * 1000L
@@ -160,17 +212,17 @@ class SatelliteRepo(
         return passes
     }
 
-    private fun getGeoPass(sat: OrbitalObject, pos: GeoPos, time: Long): OrbitalPass {
+    private fun getGeoPass(sat: OrbitalObject, pos: GeoPos, time: Long, decayed: Boolean): OrbitalPass {
         val satPos = sat.getPosition(pos, time)
         val aos = time - 24 * 60L * 60L * 1000L
         val los = time + 24 * 60L * 60L * 1000L // val tca = (aos + los) / 2
         val az = satPos.azimuth.toDegrees().round(1)
         val elev = satPos.elevation.toDegrees().round(1)
         val alt = satPos.altitude
-        return OrbitalPass(aos, az, los, az, alt.toInt(), elev, sat)
+        return OrbitalPass(aos, az, los, az, alt.toInt(), elev, sat, hasDecayed = decayed)
     }
 
-    private fun getLeoPass(sat: OrbitalObject, pos: GeoPos, time: Long, rewind: Boolean): OrbitalPass {
+    private fun getLeoPass(sat: OrbitalObject, pos: GeoPos, time: Long, rewind: Boolean, decayed: Boolean): OrbitalPass {
         val quarterOrbitMin = (sat.data.orbitalPeriod / 4.0).toInt()
         var calendarTimeMillis = time
         var elevation: Double
@@ -234,6 +286,6 @@ class SatelliteRepo(
         val alt = tcaPos.altitude
 
         val elev = maxElevation.toDegrees().round(1)
-        return OrbitalPass(aos, aosAz, los, losAz, alt.toInt(), elev, sat)
+        return OrbitalPass(aos, aosAz, los, losAz, alt.toInt(), elev, sat, hasDecayed = decayed)
     }
 }

core/data/src/main/java/com/rtbishop/look4sat/core/data/repository/SensorsRepo.kt

@@ -22,8 +22,9 @@ import android.hardware.Sensor
 import android.hardware.SensorEvent
 import android.hardware.SensorEventListener
 import android.hardware.SensorManager
+import android.hardware.display.DisplayManager
+import android.view.Display
 import android.view.Surface
-import android.view.WindowManager
 import com.rtbishop.look4sat.core.domain.predict.GeoPos
 import com.rtbishop.look4sat.core.domain.predict.RAD2DEG
 import com.rtbishop.look4sat.core.domain.repository.ISensorsRepo
@@ -31,13 +32,16 @@ import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlin.math.round
 
+private const val SMOOTHING_FACTOR = 0.15f
+private const val SENSOR_RATE_US = 16_000
+
 class SensorsRepo(
     private val sensorManager: SensorManager,
-    private val sensor: Sensor?,
-    private val windowManager: WindowManager
-) : SensorEventListener, ISensorsRepo {
+    private val displayManager: DisplayManager?
+) : ISensorsRepo, SensorEventListener {
 
-    private val _orientation = MutableStateFlow(Pair(0f, 0f))
+    private val _sensorData = MutableStateFlow(Pair(0f, 0f))
+    private val sensor: Sensor? = sensorManager.getDefaultSensor(Sensor.TYPE_ROTATION_VECTOR)
     private val rotationMatrix = FloatArray(9)
     private val tempMatrix = FloatArray(9)
     private val orientationValues = FloatArray(3)
@@ -45,11 +49,7 @@ class SensorsRepo(
     private var smoothPitch = 0f
     private var hasInitialReading = false
 
-    companion object {
-        private const val SMOOTHING_FACTOR = 0.15f
-    }
-
-    override val orientation: StateFlow<Pair<Float, Float>> = _orientation
+    override val sensorData: StateFlow<Pair<Float, Float>> = _sensorData
 
     override fun getMagDeclination(geoPos: GeoPos, time: Long): Float {
         return GeomagneticField(
@@ -62,7 +62,7 @@ class SensorsRepo(
 
     override fun enableSensor() {
         hasInitialReading = false
-        sensor?.let { sensorManager.registerListener(this, it, 8000) }
+        sensor?.let { sensorManager.registerListener(this, it, SENSOR_RATE_US) }
     }
 
     override fun disableSensor() = sensorManager.unregisterListener(this)
@@ -70,16 +70,11 @@ class SensorsRepo(
     override fun onAccuracyChanged(sensor: Sensor, accuracy: Int) = Unit
 
     override fun onSensorChanged(event: SensorEvent) {
-        if (event.sensor == sensor) updateOrientation(event.values)
+        if (event.sensor.type == Sensor.TYPE_ROTATION_VECTOR) handleSensorEvent(event)
     }
 
     private fun getDisplayRotation(): Int {
-        return try {
-            @Suppress("DEPRECATION")
-            windowManager.defaultDisplay.rotation
-        } catch (_: Exception) {
-            Surface.ROTATION_0
-        }
+        return displayManager?.getDisplay(Display.DEFAULT_DISPLAY)?.rotation ?: Surface.ROTATION_0
     }
 
     private fun remapForRotation(rotation: Int) {
@@ -101,30 +96,23 @@ class SensorsRepo(
         if (remapped) System.arraycopy(tempMatrix, 0, rotationMatrix, 0, 9)
     }
 
-    private fun updateOrientation(rotationVector: FloatArray) {
-        SensorManager.getRotationMatrixFromVector(rotationMatrix, rotationVector)
+    private fun handleSensorEvent(event: SensorEvent) {
+        SensorManager.getRotationMatrixFromVector(rotationMatrix, event.values)
         remapForRotation(getDisplayRotation())
         SensorManager.getOrientation(rotationMatrix, orientationValues)
-        val azimuth = (orientationValues[0] * RAD2DEG).toFloat()
+        val azimuth = normalizeAzimuth((orientationValues[0] * RAD2DEG).toFloat())
         val pitch = (orientationValues[1] * RAD2DEG).toFloat()
-        val magneticAzimuth = (azimuth + 360f) % 360f
-
         if (!hasInitialReading) {
-            smoothAzimuth = magneticAzimuth
+            smoothAzimuth = azimuth
             smoothPitch = pitch
             hasInitialReading = true
         } else {
-            smoothAzimuth = lowPassAngle(smoothAzimuth, magneticAzimuth)
+            smoothAzimuth = lowPassAngle(smoothAzimuth, azimuth)
             smoothPitch = lowPass(smoothPitch, pitch)
         }
-
-        _orientation.value = Pair(
-            round(smoothAzimuth * 10) / 10,
-            round(smoothPitch * 10) / 10
-        )
+        _sensorData.value = Pair(round(smoothAzimuth * 10) / 10, round(smoothPitch * 10) / 10)
     }
 
-    /** Standard exponential low-pass filter. */
     private fun lowPass(previous: Float, current: Float): Float {
         return previous + SMOOTHING_FACTOR * (current - previous)
     }
@@ -135,9 +123,10 @@ class SensorsRepo(
      */
     private fun lowPassAngle(previous: Float, current: Float): Float {
         var delta = current - previous
-        // Normalise delta into the range (-180, 180]
         while (delta > 180f) delta -= 360f
         while (delta <= -180f) delta += 360f
-        return (previous + SMOOTHING_FACTOR * delta + 360f) % 360f
+        return normalizeAzimuth(previous + SMOOTHING_FACTOR * delta)
     }
+
+    private fun normalizeAzimuth(value: Float): Float = (value + 360f) % 360f
 }

core/data/src/main/java/com/rtbishop/look4sat/core/data/repository/SettingsRepo.kt

@@ -54,6 +54,9 @@ class SettingsRepo(
     private val keyFilterShowDeepSpace = "filterShowDeepSpace"
     private val keyFilterHoursAhead = "filterHoursAhead"
     private val keyFilterMinElevation = "filterMinElevation"
+    private val keyFilterAosStartMinute = "filterAosStartMinute"
+    private val keyFilterAosEndMinute = "filterAosEndMinute"
+    private val keyFilterAosInvert = "filterAosInvert"
     private val keyNumberOfRadios = "numberOfRadios"
     private val keyNumberOfSatellites = "numberOfSatellites"
     private val keyRotatorAddress = "rotatorAddress"
@@ -72,6 +75,7 @@ class SettingsRepo(
     private val keyStateOfSweep = "stateOfSweep"
     private val keyStateOfUtc = "stateOfUtc"
     private val keyStateOfLightTheme = "stateOfLightTheme"
+    private val keyStateOfNightMode = "stateOfNightMode"
     private val keyStationAltitude = "stationAltitude"
     private val keyStationLatitude = "stationLatitude"
     private val keyStationLongitude = "stationLongitude"
@@ -80,6 +84,9 @@ class SettingsRepo(
     private val keyUpdateTimestamp = "updateTimestamp"
     private val keyShouldSeeWarning = "shouldSeeWarning"
     private val keyShouldSeeWhatsNew = "shouldSeeWhatsNew_v$appVersionName"
+    private val keySstvMode = "sstvMode"
+    private val keyLowElevation = "lowElevation"
+    private val keyHighElevation = "highElevation"
     private val keyUseCustomTle = "useCustomTle"
     private val keyUseCustomTransceivers = "useCustomTransceivers"
     private val keyTleUrl = "tleUrl"
@@ -111,8 +118,8 @@ class SettingsRepo(
     }
 
     private fun getSelectedTypes(): List<String> {
-        val typesString = preferences.getString(keySelectedTypes, null)
-        if (typesString.isNullOrEmpty()) return listOf("Amateur")
+        val typesString = preferences.getString(keySelectedTypes, "Amateur")
+        if (typesString.isNullOrEmpty()) return emptyList()
         return typesString.split(separatorComma)
     }
     //endregion
@@ -125,6 +132,9 @@ class SettingsRepo(
         putBoolean(keyFilterShowDeepSpace, settings.showDeepSpace)
         putInt(keyFilterHoursAhead, settings.hoursAhead)
         putLong(keyFilterMinElevation, settings.minElevation.toRawBits())
+        putInt(keyFilterAosStartMinute, settings.aosStartMinute)
+        putInt(keyFilterAosEndMinute, settings.aosEndMinute)
+        putBoolean(keyFilterAosInvert, settings.invertAosTimeWindow)
         putString(keySelectedModes, settings.selectedModes.joinToString(separatorComma))
         _passesSettings.value = settings
     }
@@ -133,9 +143,20 @@ class SettingsRepo(
         val showDeepSpace = preferences.getBoolean(keyFilterShowDeepSpace, true)
         val hoursAhead = preferences.getInt(keyFilterHoursAhead, 24)
         val minElevation = Double.fromBits(preferences.getLong(keyFilterMinElevation, 16.0.toRawBits()))
+        val aosStartMinute = preferences.getInt(keyFilterAosStartMinute, 0).coerceIn(0, 23 * 60 + 59)
+        val aosEndMinute = preferences.getInt(keyFilterAosEndMinute, 23 * 60 + 59).coerceIn(0, 23 * 60 + 59)
+        val invertAosTimeWindow = preferences.getBoolean(keyFilterAosInvert, false)
         val selectedModesString = preferences.getString(keySelectedModes, null)
         val selectedModes = selectedModesString?.split(separatorComma)?.sorted() ?: emptyList()
-        return PassesSettings(showDeepSpace, hoursAhead, minElevation, selectedModes)
+        return PassesSettings(
+            showDeepSpace,
+            hoursAhead,
+            minElevation,
+            aosStartMinute,
+            aosEndMinute,
+            invertAosTimeWindow,
+            selectedModes
+        )
     }
     //endregion
 
@@ -329,8 +350,12 @@ class SettingsRepo(
                 putBoolean(keyStateOfSweep, new.stateOfSweep)
                 putBoolean(keyStateOfUtc, new.stateOfUtc)
                 putBoolean(keyStateOfLightTheme, new.stateOfLightTheme)
+                putBoolean(keyStateOfNightMode, new.stateOfNightMode)
                 putBoolean(keyShouldSeeWarning, new.shouldSeeWarning)
                 putBoolean(keyShouldSeeWhatsNew, new.shouldSeeWhatsNew)
+                putString(keySstvMode, new.sstvMode)
+                putLong(keyLowElevation, new.lowElevation.toRawBits())
+                putLong(keyHighElevation, new.highElevation.toRawBits())
             }
             new
         }
@@ -342,8 +367,12 @@ class SettingsRepo(
         stateOfSweep = preferences.getBoolean(keyStateOfSweep, true),
         stateOfUtc = preferences.getBoolean(keyStateOfUtc, false),
         stateOfLightTheme = preferences.getBoolean(keyStateOfLightTheme, false),
+        stateOfNightMode = preferences.getBoolean(keyStateOfNightMode, false),
         shouldSeeWarning = preferences.getBoolean(keyShouldSeeWarning, true),
-        shouldSeeWhatsNew = preferences.getBoolean(keyShouldSeeWhatsNew, true)
+        shouldSeeWhatsNew = preferences.getBoolean(keyShouldSeeWhatsNew, true),
+        sstvMode = preferences.getString(keySstvMode, null) ?: "Auto",
+        lowElevation = Double.fromBits(preferences.getLong(keyLowElevation, 15.0.toRawBits())),
+        highElevation = Double.fromBits(preferences.getLong(keyHighElevation, 45.0.toRawBits()))
     )
     //endregion
 
@@ -377,6 +406,7 @@ class SettingsRepo(
     private val keyTxRadioName = "txRadioName"
     private val keyRxRadioName = "rxRadioName"
     private val keyRadioBaudRate = "radioBaudRate"
+    private val keyRadioSplitMode = "radioSplitMode"
 
     private val _radioControlSettings = MutableStateFlow(getRadioControlSettings())
     override val radioControlSettings: StateFlow<RadioControlSettings> = _radioControlSettings
@@ -390,18 +420,20 @@ class SettingsRepo(
             putString(keyTxRadioName, settings.txRadioName)
             putString(keyRxRadioName, settings.rxRadioName)
             putInt(keyRadioBaudRate, settings.baudRate)
+            putBoolean(keyRadioSplitMode, settings.splitMode)
         }
         _radioControlSettings.value = settings
     }
 
     private fun getRadioControlSettings(): RadioControlSettings = RadioControlSettings(
         enabled = preferences.getBoolean(keyRadioControlEnabled, false),
-        radioModel = preferences.getString(keyRadioModel, null) ?: "Yaesu FT-817/818",
+        radioModel = preferences.getString(keyRadioModel, null) ?: RadioControlSettings.MODEL_YAESU_FT817,
         txRadioAddress = preferences.getString(keyTxRadioAddress, null) ?: "",
         rxRadioAddress = preferences.getString(keyRxRadioAddress, null) ?: "",
         txRadioName = preferences.getString(keyTxRadioName, null) ?: "TX Radio",
         rxRadioName = preferences.getString(keyRxRadioName, null) ?: "RX Radio",
-        baudRate = preferences.getInt(keyRadioBaudRate, 4800)
+        baudRate = preferences.getInt(keyRadioBaudRate, 4800),
+        splitMode = preferences.getBoolean(keyRadioSplitMode, false)
     )
     //endregion
 }

core/data/src/main/java/com/rtbishop/look4sat/core/data/source/LocalSource.kt

@@ -74,7 +74,6 @@ class LocalSource(private val look4SatDao: Look4SatDao) : ILocalSource {
     }
 
     override suspend fun insertRadios(radios: List<SatRadio>) {
-        look4SatDao.deleteRadios()
         look4SatDao.insertRadios(radios.toFrameworkRadios())
     }
 

core/data/src/main/java/com/rtbishop/look4sat/core/data/source/RemoteSource.kt

@@ -24,6 +24,7 @@ import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.withContext
 import okhttp3.OkHttpClient
 import okhttp3.Request
+import java.io.ByteArrayInputStream
 import java.io.InputStream
 
 class RemoteSource(
@@ -45,7 +46,10 @@ class RemoteSource(
     override suspend fun getNetworkStream(url: String): InputStream? = withContext(dispatcher) {
         try {
             val networkRequest = Request.Builder().url(url).build()
-            httpClient.newCall(networkRequest).execute().body.byteStream()
+            httpClient.newCall(networkRequest).execute().use { response ->
+                if (!response.isSuccessful) return@withContext null
+                ByteArrayInputStream(response.body.bytes())
+            }
         } catch (exception: Exception) {
             println("RemoteSource network stream exception: $exception")
             null

core/data/src/main/java/com/rtbishop/look4sat/core/data/usecase/AudioCapture.kt

@@ -0,0 +1,63 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.data.usecase
+
+import android.media.AudioFormat
+import android.media.AudioRecord
+import android.media.MediaRecorder
+import androidx.annotation.RequiresPermission
+import com.rtbishop.look4sat.core.domain.usecase.IAudioCapture
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.currentCoroutineContext
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.flow.flowOn
+import kotlinx.coroutines.isActive
+
+class AudioCapture : IAudioCapture {
+
+    override val sampleRate: Int = 44100
+
+    private val channelConfig = AudioFormat.CHANNEL_IN_MONO
+    private val audioFormat = AudioFormat.ENCODING_PCM_FLOAT
+    private val bufferSize = AudioRecord.getMinBufferSize(sampleRate, channelConfig, audioFormat)
+        .coerceAtLeast(sampleRate) // at least 1 second buffer
+
+    @RequiresPermission(android.Manifest.permission.RECORD_AUDIO)
+    override fun audioFlow(): Flow<FloatArray> = flow {
+        val recorder = AudioRecord(
+            MediaRecorder.AudioSource.MIC,
+            sampleRate,
+            channelConfig,
+            audioFormat,
+            bufferSize * 4 // bytes for float
+        )
+        try {
+            recorder.startRecording()
+            val chunkSize = sampleRate / 10 // ~100ms chunks
+            val buffer = FloatArray(chunkSize)
+            while (currentCoroutineContext().isActive) {
+                val read = recorder.read(buffer, 0, chunkSize, AudioRecord.READ_BLOCKING)
+                if (read > 0) emit(if (read == chunkSize) buffer.copyOf() else buffer.copyOfRange(0, read))
+            }
+        } finally {
+            recorder.stop()
+            recorder.release()
+        }
+    }.flowOn(Dispatchers.IO)
+}

core/data/src/main/java/com/rtbishop/look4sat/core/data/usecase/SaveImage.kt

@@ -0,0 +1,84 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.data.usecase
+
+import android.content.ContentValues
+import android.content.Context
+import android.graphics.Bitmap
+import android.os.Build
+import android.os.Environment
+import android.provider.MediaStore
+import com.rtbishop.look4sat.core.domain.usecase.ISaveImage
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import java.io.File
+import java.io.FileOutputStream
+import java.text.SimpleDateFormat
+import java.util.Date
+import java.util.Locale
+
+//Saves images to the device gallery using MediaStore (API 29+) or direct file write (API < 29)
+class SaveImage(private val context: Context) : ISaveImage {
+
+    override suspend fun invoke(pixels: IntArray, width: Int, height: Int, modeName: String): Boolean {
+        return withContext(Dispatchers.IO) {
+            try {
+                val bitmap = Bitmap.createBitmap(pixels, width, height, Bitmap.Config.ARGB_8888)
+                val timestamp = SimpleDateFormat("yyyyMMdd_HHmmss", Locale.US).format(Date())
+                val filename = "SSTV_${modeName}_$timestamp.png"
+                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
+                    saveWithMediaStore(bitmap, filename)
+                } else {
+                    saveToExternalStorage(bitmap, filename)
+                }
+                bitmap.recycle()
+                true
+            } catch (_: Exception) {
+                false
+            }
+        }
+    }
+
+    private fun saveWithMediaStore(bitmap: Bitmap, filename: String) {
+        val values = ContentValues().apply {
+            put(MediaStore.Images.Media.DISPLAY_NAME, filename)
+            put(MediaStore.Images.Media.MIME_TYPE, "image/png")
+            put(MediaStore.Images.Media.RELATIVE_PATH, "${Environment.DIRECTORY_PICTURES}/Look4Sat")
+            put(MediaStore.Images.Media.IS_PENDING, 1)
+        }
+        val resolver = context.contentResolver
+        val uri = resolver.insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values)
+            ?: throw IllegalStateException("Failed to create MediaStore entry")
+        resolver.openOutputStream(uri)?.use { stream ->
+            bitmap.compress(Bitmap.CompressFormat.PNG, 100, stream)
+        }
+        values.clear()
+        values.put(MediaStore.Images.Media.IS_PENDING, 0)
+        resolver.update(uri, values, null, null)
+    }
+
+    private fun saveToExternalStorage(bitmap: Bitmap, filename: String) {
+        val picturesDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES)
+        val dir = File(picturesDir, "Look4Sat")
+        if (!dir.exists()) dir.mkdirs()
+        val file = File(dir, filename)
+        FileOutputStream(file).use { stream ->
+            bitmap.compress(Bitmap.CompressFormat.PNG, 100, stream)
+        }
+    }
+}

core/data/src/test/java/com/rtbishop/look4sat/core/data/framework/Ft817CatProtocolTest.kt

@@ -1,30 +1,29 @@
-package com.rtbishop.look4sat.core.data
+package com.rtbishop.look4sat.core.data.framework
 
-import com.rtbishop.look4sat.core.data.framework.Ft817CatProtocol
+import org.junit.Assert.assertArrayEquals
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNotNull
+import org.junit.Assert.assertNull
 import org.junit.Test
-import kotlin.test.assertContentEquals
-import kotlin.test.assertEquals
-import kotlin.test.assertNotNull
-import kotlin.test.assertNull
 
 class Ft817CatProtocolTest {
 
     @Test
     fun encodeFrequencyBcd_145500000() {
         val bcd = Ft817CatProtocol.encodeFrequencyBcd(145500000L)
-        assertContentEquals(byteArrayOf(0x14, 0x55, 0x00, 0x00), bcd)
+        assertArrayEquals(byteArrayOf(0x14, 0x55, 0x00, 0x00), bcd)
     }
 
     @Test
     fun encodeFrequencyBcd_435100000() {
         val bcd = Ft817CatProtocol.encodeFrequencyBcd(435100000L)
-        assertContentEquals(byteArrayOf(0x43, 0x51, 0x00, 0x00), bcd)
+        assertArrayEquals(byteArrayOf(0x43, 0x51, 0x00, 0x00), bcd)
     }
 
     @Test
     fun encodeFrequencyBcd_7074000() {
         val bcd = Ft817CatProtocol.encodeFrequencyBcd(7074000L)
-        assertContentEquals(byteArrayOf(0x00, 0x70, 0x74, 0x00), bcd)
+        assertArrayEquals(byteArrayOf(0x00, 0x70, 0x74, 0x00), bcd)
     }
 
     @Test
@@ -42,21 +41,21 @@ class Ft817CatProtocolTest {
         val cmd = Ft817CatProtocol.buildSetFreqCommand(145500000L)
         assertEquals(5, cmd.size)
         assertEquals(0x01.toByte(), cmd[4])
-        assertContentEquals(byteArrayOf(0x14, 0x55, 0x00, 0x00, 0x01), cmd)
+        assertArrayEquals(byteArrayOf(0x14, 0x55, 0x00, 0x00, 0x01), cmd)
     }
 
     @Test
     fun buildSetModeCommand_usb() {
         val cmd = Ft817CatProtocol.buildSetModeCommand("USB")
         assertNotNull(cmd)
-        assertContentEquals(byteArrayOf(0x01, 0x00, 0x00, 0x00, 0x07), cmd)
+        assertArrayEquals(byteArrayOf(0x01, 0x00, 0x00, 0x00, 0x07), cmd)
     }
 
     @Test
     fun buildSetModeCommand_fm() {
         val cmd = Ft817CatProtocol.buildSetModeCommand("FM")
         assertNotNull(cmd)
-        assertContentEquals(byteArrayOf(0x08, 0x00, 0x00, 0x00, 0x07), cmd)
+        assertArrayEquals(byteArrayOf(0x08, 0x00, 0x00, 0x00, 0x07), cmd)
     }
 
     @Test
@@ -67,19 +66,19 @@ class Ft817CatProtocolTest {
     @Test
     fun encodeCtcssTone_67_0() {
         val bcd = Ft817CatProtocol.encodeCtcssToneBcd(67.0)
-        assertContentEquals(byteArrayOf(0x06, 0x70), bcd)
+        assertArrayEquals(byteArrayOf(0x06, 0x70), bcd)
     }
 
     @Test
     fun encodeCtcssTone_74_4() {
         val bcd = Ft817CatProtocol.encodeCtcssToneBcd(74.4)
-        assertContentEquals(byteArrayOf(0x07, 0x44), bcd)
+        assertArrayEquals(byteArrayOf(0x07, 0x44), bcd)
     }
 
     @Test
     fun encodeCtcssTone_141_3() {
         val bcd = Ft817CatProtocol.encodeCtcssToneBcd(141.3)
-        assertContentEquals(byteArrayOf(0x14, 0x13), bcd)
+        assertArrayEquals(byteArrayOf(0x14, 0x13), bcd)
     }
 
     @Test
@@ -87,13 +86,13 @@ class Ft817CatProtocolTest {
         val cmd = Ft817CatProtocol.buildSetCtcssToneCommand(67.0)
         assertEquals(5, cmd.size)
         assertEquals(0x0B.toByte(), cmd[4])
-        assertContentEquals(byteArrayOf(0x06, 0x70, 0x00, 0x00, 0x0B), cmd)
+        assertArrayEquals(byteArrayOf(0x06, 0x70, 0x00, 0x00, 0x0B), cmd)
     }
 
     @Test
     fun buildCtcssModeCommand_enable() {
         val cmd = Ft817CatProtocol.buildCtcssModeCommand(true)
-        assertContentEquals(byteArrayOf(0x2A, 0x00, 0x00, 0x00, 0x0A), cmd)
+        assertArrayEquals(byteArrayOf(0x2A, 0x00, 0x00, 0x00, 0x0A), cmd)
     }
 
     @Test
@@ -108,6 +107,7 @@ class Ft817CatProtocolTest {
         val response = byteArrayOf(0x14, 0x55, 0x00, 0x00, 0x01)
         val result = Ft817CatProtocol.parseReadResponse(response)
         assertNotNull(result)
+        result ?: return
         assertEquals(145500000L, result.first)
         assertEquals("USB", result.second)
     }
@@ -117,6 +117,7 @@ class Ft817CatProtocolTest {
         val response = byteArrayOf(0x14, 0x60, 0x00, 0x00, 0x08)
         val result = Ft817CatProtocol.parseReadResponse(response)
         assertNotNull(result)
+        result ?: return
         assertEquals(146000000L, result.first)
         assertEquals("FM", result.second)
     }
@@ -135,7 +136,7 @@ class Ft817CatProtocolTest {
     @Test
     fun buildPttCommands() {
         val on = Ft817CatProtocol.buildPttOnCommand()
-        assertContentEquals(byteArrayOf(0x00, 0x00, 0x00, 0x00, 0x08), on)
+        assertArrayEquals(byteArrayOf(0x00, 0x00, 0x00, 0x00, 0x08), on)
 
         val off = Ft817CatProtocol.buildPttOffCommand()
         assertEquals(0x88.toByte(), off[4])
@@ -144,6 +145,6 @@ class Ft817CatProtocolTest {
     @Test
     fun buildReadCommand() {
         val cmd = Ft817CatProtocol.buildReadFreqModeCommand()
-        assertContentEquals(byteArrayOf(0x00, 0x00, 0x00, 0x00, 0x03), cmd)
+        assertArrayEquals(byteArrayOf(0x00, 0x00, 0x00, 0x00, 0x03), cmd)
     }
 }

core/data/src/test/java/com/rtbishop/look4sat/core/data/repository/DatabaseRepoTest.kt

@@ -0,0 +1,234 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.data.repository
+
+import com.rtbishop.look4sat.core.domain.model.DataSourcesSettings
+import com.rtbishop.look4sat.core.domain.model.DatabaseState
+import com.rtbishop.look4sat.core.domain.model.OtherSettings
+import com.rtbishop.look4sat.core.domain.model.PassesSettings
+import com.rtbishop.look4sat.core.domain.model.RCSettings
+import com.rtbishop.look4sat.core.domain.model.RadioControlSettings
+import com.rtbishop.look4sat.core.domain.model.SatItem
+import com.rtbishop.look4sat.core.domain.model.SatRadio
+import com.rtbishop.look4sat.core.domain.predict.GeoPos
+import com.rtbishop.look4sat.core.domain.predict.OrbitalData
+import com.rtbishop.look4sat.core.domain.predict.OrbitalObject
+import com.rtbishop.look4sat.core.domain.repository.ISettingsRepo
+import com.rtbishop.look4sat.core.domain.source.ILocalSource
+import com.rtbishop.look4sat.core.domain.source.IRemoteSource
+import com.rtbishop.look4sat.core.domain.utility.DataParser
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.test.StandardTestDispatcher
+import kotlinx.coroutines.test.runTest
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import java.io.InputStream
+
+@OptIn(ExperimentalCoroutinesApi::class)
+class DatabaseRepoTest {
+
+    private val dispatcher = StandardTestDispatcher()
+    private val dataParser = DataParser(dispatcher)
+
+    @Test
+    fun `manual satellite import parses csv stream from content uri`() = runTest(dispatcher) {
+        val uri = "content://look4sat/import/satellites"
+        val localSource = FakeLocalSource()
+        val remoteSource = FakeRemoteSource().apply {
+            fileStreams[uri] = { validCsvStream() }
+        }
+        val settingsRepo = FakeSettingsRepo()
+        val repository = DatabaseRepo(dispatcher, dataParser, localSource, remoteSource, settingsRepo)
+
+        repository.updateTLEFromFile(uri)
+
+        assertEquals(1, localSource.insertedEntries.size)
+        assertEquals(25544, localSource.insertedEntries.first().catnum)
+        assertEquals(listOf(25544), settingsRepo.satelliteTypeIdsByType["Other"])
+        assertTrue(settingsRepo.databaseState.value.numberOfSatellites > 0)
+    }
+
+    @Test
+    fun `manual satellite import keeps tle support`() = runTest(dispatcher) {
+        val uri = "content://look4sat/import/legacy"
+        val localSource = FakeLocalSource()
+        val remoteSource = FakeRemoteSource().apply {
+            fileStreams[uri] = { validTleStream() }
+        }
+        val settingsRepo = FakeSettingsRepo()
+        val repository = DatabaseRepo(dispatcher, dataParser, localSource, remoteSource, settingsRepo)
+
+        repository.updateTLEFromFile(uri)
+
+        assertEquals(1, localSource.insertedEntries.size)
+        assertEquals(25544, localSource.insertedEntries.first().catnum)
+    }
+
+    @Test
+    fun `custom data source imports omm csv from web`() = runTest(dispatcher) {
+        val customCsvUrl = "https://example.com/custom-omm.csv"
+        val localSource = FakeLocalSource()
+        val remoteSource = FakeRemoteSource().apply {
+            networkStreams[customCsvUrl] = { validCsvStream() }
+        }
+        val settingsRepo = FakeSettingsRepo(
+            dataSources = DataSourcesSettings(
+                useCustomTLE = true,
+                useCustomTransceivers = false,
+                tleUrl = customCsvUrl,
+                transceiversUrl = ""
+            )
+        )
+        val repository = DatabaseRepo(dispatcher, dataParser, localSource, remoteSource, settingsRepo)
+
+        repository.updateFromRemote()
+
+        assertTrue(localSource.insertedEntries.any { it.catnum == 25544 })
+        assertEquals(listOf(25544), settingsRepo.satelliteTypeIdsByType["Other"])
+    }
+
+    private fun validCsvStream(): InputStream = """
+        OBJECT_NAME,OBJECT_ID,EPOCH,MEAN_MOTION,ECCENTRICITY,INCLINATION,RA_OF_ASC_NODE,ARG_OF_PERICENTER,MEAN_ANOMALY,EPHEMERIS_TYPE,CLASSIFICATION_TYPE,NORAD_CAT_ID,ELEMENT_SET_NO,REV_AT_EPOCH,BSTAR,MEAN_MOTION_DOT,MEAN_MOTION_DDOT
+        ISS (ZARYA),1998-067A,2021-11-16T12:28:09.322176,15.48582035,.0004694,51.6447,309.4881,203.6966,299.8876,0,U,25544,999,31220,.31985E-4,.1288E-4,0
+    """.trimIndent().byteInputStream()
+
+    private fun validTleStream(): InputStream = """
+        ISS (ZARYA)
+        1 25544U 98067A   21320.51955234  .00001288  00000+0  31985-4 0  9990
+        2 25544  51.6447 309.4881 0004694 203.6966 299.8876 15.48582035312205
+    """.trimIndent().byteInputStream()
+}
+
+private class FakeRemoteSource : IRemoteSource {
+    val fileStreams: MutableMap<String, () -> InputStream> = mutableMapOf()
+    val networkStreams: MutableMap<String, () -> InputStream> = mutableMapOf()
+
+    override suspend fun getFileStream(uri: String): InputStream? = fileStreams[uri]?.invoke()
+
+    override suspend fun getNetworkStream(url: String): InputStream? = networkStreams[url]?.invoke()
+}
+
+private class FakeLocalSource : ILocalSource {
+    val insertedEntries = mutableListOf<OrbitalData>()
+    private val insertedRadios = mutableListOf<SatRadio>()
+
+    override suspend fun getEntriesTotal(): Int = insertedEntries.size
+
+    override suspend fun getEntriesList(): List<SatItem> = emptyList()
+
+    override suspend fun getEntriesWithIds(ids: List<Int>): List<OrbitalObject> = emptyList()
+
+    override suspend fun insertEntries(entries: List<OrbitalData>) {
+        insertedEntries += entries
+    }
+
+    override suspend fun deleteEntries() {
+        insertedEntries.clear()
+    }
+
+    override suspend fun getIdsWithModes(modes: List<String>): List<Int> = emptyList()
+
+    override suspend fun getRadiosTotal(): Int = insertedRadios.size
+
+    override suspend fun getRadiosWithId(id: Int): List<SatRadio> = emptyList()
+
+    override suspend fun insertRadios(radios: List<SatRadio>) {
+        insertedRadios += radios
+    }
+
+    override suspend fun deleteRadios() {
+        insertedRadios.clear()
+    }
+}
+
+private class FakeSettingsRepo(dataSources: DataSourcesSettings = defaultDataSourcesSettings()) : ISettingsRepo {
+
+    override val appVersionName: String = "test"
+
+    override val selectedIds: StateFlow<List<Int>> = MutableStateFlow(emptyList())
+
+    override val selectedTypes: StateFlow<List<String>> = MutableStateFlow(emptyList())
+
+    override val passesSettings: StateFlow<PassesSettings> = MutableStateFlow(
+        PassesSettings(hoursAhead = 24, minElevation = 0.0, selectedModes = emptyList())
+    )
+
+    override val stationPosition: StateFlow<GeoPos> = MutableStateFlow(GeoPos(0.0, 0.0))
+
+    override val databaseState: MutableStateFlow<DatabaseState> = MutableStateFlow(DatabaseState(0, 0, 0L))
+
+    override val rcSettings: StateFlow<RCSettings> = MutableStateFlow(
+        RCSettings(false, "", "", "", false, "", "", "", false, "", "", "", false, "", "")
+    )
+
+    override val otherSettings: StateFlow<OtherSettings> = MutableStateFlow(
+        OtherSettings(false, false, false, false, false, false, false, false)
+    )
+
+    override val dataSourcesSettings: MutableStateFlow<DataSourcesSettings> = MutableStateFlow(dataSources)
+
+    override val radioControlSettings: StateFlow<RadioControlSettings> = MutableStateFlow(
+        RadioControlSettings(false, RadioControlSettings.MODEL_YAESU_FT817, "", "", "", "", 9600)
+    )
+
+    val satelliteTypeIdsByType = mutableMapOf<String, List<Int>>()
+
+    override fun setSelectedIds(ids: List<Int>) = Unit
+
+    override fun setSelectedTypes(types: List<String>) = Unit
+
+    override fun setPassesSettings(settings: PassesSettings) = Unit
+
+    override fun setStationPosition(latitude: Double, longitude: Double, altitude: Double): Boolean = true
+
+    override fun setStationPosition(): Boolean = true
+
+    override fun setStationPosition(locator: String): Boolean = true
+
+    override fun getSatelliteTypesIds(types: List<String>): List<Int> = emptyList()
+
+    override fun setSatelliteTypeIds(type: String, ids: List<Int>) {
+        satelliteTypeIdsByType[type] = ids
+    }
+
+    override fun updateDatabaseState(state: DatabaseState) {
+        databaseState.value = state
+    }
+
+    override fun updateRCSettings(settings: RCSettings) = Unit
+
+    override fun updateOtherSettings(transform: (OtherSettings) -> OtherSettings) = Unit
+
+    override fun updateDataSourcesSettings(settings: DataSourcesSettings) {
+        dataSourcesSettings.value = settings
+    }
+
+    override fun updateRadioControlSettings(settings: RadioControlSettings) = Unit
+}
+
+private fun defaultDataSourcesSettings(): DataSourcesSettings {
+    return DataSourcesSettings(
+        useCustomTLE = false,
+        useCustomTransceivers = false,
+        tleUrl = "",
+        transceiversUrl = ""
+    )
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/cw/CwBayesianDecoder.kt

@@ -0,0 +1,154 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.domain.cw
+
+/**
+ * Bayesian Morse timing decoder.
+ * Replaces hard thresholds with probability-based decision making.
+ *
+ * Inspired by VE3NEA's CW Skimmer approach:
+ * "Instead of making a hard decision at every input sample whether the signal
+ * is present or not, compute the probability that the signal is present."
+ *
+ * Uses Gaussian probability density centered on expected durations:
+ *   P(dit | duration) = exp(-(duration - dotMs)^2 / (2 * variance^2))
+ *   P(dash | duration) = exp(-(duration - 3*dotMs)^2 / (2 * variance^2))
+ */
+internal class CwBayesianDecoder {
+
+    // Morse timing parameters
+    private var dotDurationMs = 60f // initial 20 WPM
+    private var speedWpm = 20f
+
+    // Current symbol being accumulated
+    private var currentSymbol = StringBuilder()
+    private var textBuffer = StringBuilder()
+
+    // Recent dit lengths for speed estimation
+    private val recentDits = mutableListOf<Float>()
+
+    // Output
+    private var _decodedText = ""
+    val decodedText: String get() = _decodedText
+
+    /** Gaussian probability. */
+    private fun gaussianProb(durationMs: Float, expectedMs: Float, varianceMs: Float): Float {
+        if (varianceMs <= 0f) return 0f
+        val diff = durationMs - expectedMs
+        return kotlin.math.exp(-(diff * diff) / (2 * varianceMs * varianceMs))
+    }
+
+    /** Process a tone duration. Returns the symbol type with highest probability. */
+    fun processTone(durationMs: Float): ToneResult {
+        val ditProb = gaussianProb(durationMs, dotDurationMs, dotDurationMs * 0.4f)
+        val dashProb = gaussianProb(durationMs, dotDurationMs * 3f, dotDurationMs * 0.6f)
+
+        return if (ditProb > dashProb && ditProb > 0.05f) {
+            currentSymbol.append('0')
+            recentDits.add(durationMs)
+            updateSpeed()
+            ToneResult('0', ditProb)
+        } else if (dashProb > 0.05f) {
+            currentSymbol.append('1')
+            ToneResult('1', dashProb)
+        } else {
+            ToneResult(null, 0f)
+        }
+    }
+
+    /** Process a gap duration. Returns decoded character or null. */
+    fun processGap(durationMs: Float): Char? {
+        if (currentSymbol.isEmpty()) {
+            val wordProb = gaussianProb(durationMs, dotDurationMs * 7f, dotDurationMs * 1.2f)
+            if (wordProb > 0.2f) {
+                textBuffer.append(' ')
+                _decodedText = textBuffer.toString()
+                return ' '
+            }
+            return null
+        }
+
+        val interCharProb = gaussianProb(durationMs, dotDurationMs * 3f, dotDurationMs * 0.6f)
+        val wordProb = gaussianProb(durationMs, dotDurationMs * 7f, dotDurationMs * 1.2f)
+
+        if (wordProb > interCharProb && wordProb > 0.2f) {
+            val char = flushSymbol()
+            textBuffer.append(' ')
+            _decodedText = textBuffer.toString()
+            return char
+        }
+        if (interCharProb > 0.15f) {
+            val char = flushSymbol()
+            _decodedText = textBuffer.toString()
+            return char
+        }
+        return null
+    }
+
+    private fun flushSymbol(): Char? {
+        if (currentSymbol.isEmpty()) return null
+        val morse = currentSymbol.toString()
+        currentSymbol.clear()
+        val char = morseToChar(morse)
+        if (char != null) textBuffer.append(char)
+        return char
+    }
+
+    private fun updateSpeed() {
+        if (recentDits.size < 3) return
+        val sorted = recentDits.sorted()
+        val median = sorted[sorted.size / 2]
+        if (median > 0f) {
+            dotDurationMs = dotDurationMs * 0.7f + median * 0.3f
+            val wpm = 60.0f / (50.0f * dotDurationMs / 1000.0f)
+            if (wpm in 5f..55f) speedWpm = wpm
+        }
+    }
+
+    fun getSpeed(): Float = speedWpm
+
+    fun reset() {
+        dotDurationMs = 60f
+        speedWpm = 20f
+        recentDits.clear()
+        currentSymbol.clear()
+        textBuffer.clear()
+        _decodedText = ""
+    }
+
+    companion object {
+        private val MORSE_TABLE = mapOf(
+            "01" to 'A', "1000" to 'B', "1010" to 'C', "100" to 'D', "0" to 'E',
+            "0010" to 'F', "110" to 'G', "0000" to 'H', "00" to 'I', "0111" to 'J',
+            "101" to 'K', "0100" to 'L', "11" to 'M', "10" to 'N', "111" to 'O',
+            "0110" to 'P', "1101" to 'Q', "010" to 'R', "000" to 'S', "1" to 'T',
+            "001" to 'U', "0001" to 'V', "011" to 'W', "1001" to 'X', "1011" to 'Y',
+            "1100" to 'Z', "01111" to '1', "00111" to '2', "00011" to '3',
+            "00001" to '4', "00000" to '5', "10000" to '6', "11000" to '7',
+            "11100" to '8', "11110" to '9', "11111" to '0',
+            "010101" to '.', "110011" to ',', "001100" to '?', "011110" to '\'',
+            "101011" to '!', "10010" to '/', "10110" to '(', "101101" to ')',
+            "01000" to '&', "111000" to ':', "101010" to ';', "10001" to '=',
+            "01010" to '+', "100001" to '-', "001101" to '_', "010010" to '"',
+            "0001001" to '$', "011010" to '@'
+        )
+        fun morseToChar(morse: String): Char? = MORSE_TABLE[morse]
+    }
+}
+
+data class ToneResult(val symbol: Char?, val probability: Float)

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/cw/CwChannelTracker.kt

@@ -0,0 +1,114 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.domain.cw
+
+/**
+ * Multi-channel CW signal tracker.
+ * Monitors the spectrogram for active frequency bins and extracts
+ * energy envelopes for each detected signal.
+ *
+ * Inspired by CW Skimmer's multi-channel approach:
+ * tracks all active signals in the passband simultaneously,
+ * selects the best one for decoded output.
+ */
+internal class CwChannelTracker(
+    private val spectrogram: CwSpectrogram,
+    private val maxChannels: Int = 3
+) {
+    data class Channel(
+        val bin: Int,
+        val frequency: Float,
+        var active: Boolean = false,
+        var energy: Float = 0f,
+        val history: MutableList<Float> = mutableListOf(),
+        var confidence: Float = 0f
+    )
+
+    private val channels = Array(maxChannels) { Channel(0, 0f) }
+
+    /** Scan the current spectrogram column and update channel tracking. */
+    fun update(): List<Channel> {
+        val col = spectrogram.getCurrentColumn()
+        val peaks = findPeaks(col, threshold = 0.3f, minDistance = 2)
+
+        // Update existing channels
+        for (ch in channels) {
+            if (ch.active) {
+                if (peaks.contains(ch.bin)) {
+                    ch.energy = col[ch.bin]
+                    ch.history.add(ch.energy)
+                    if (ch.history.size > 40) ch.history.removeAt(0)
+                    ch.confidence = computeConfidence(ch.history)
+                } else {
+                    // Signal lost — decay confidence
+                    ch.history.add(0f)
+                    if (ch.history.size > 40) ch.history.removeAt(0)
+                    ch.confidence *= 0.9f
+                    if (ch.confidence < 0.1f) ch.active = false
+                }
+            }
+        }
+
+        // Assign new peaks to inactive channels
+        var peakIdx = 0
+        for (ch in channels) {
+            if (!ch.active && peakIdx < peaks.size) {
+                val bin = peaks[peakIdx]
+                val freq = spectrogram.binToFreq(bin)
+                // Re-initialize channel
+                channels[peakIdx] = Channel(bin, freq, true, col[bin], mutableListOf(), 0.5f)
+                peakIdx++
+            }
+        }
+
+        return channels.filter { it.active }
+    }
+
+    /** Find peak bins in the spectrum. */
+    private fun findPeaks(spectrum: FloatArray, threshold: Float, minDistance: Int): List<Int> {
+        val peaks = mutableListOf<Int>()
+        for (i in 1 until spectrum.size - 1) {
+            if (spectrum[i] > spectrum[i - 1] && spectrum[i] > spectrum[i + 1] && spectrum[i] > threshold) {
+                if (peaks.isEmpty() || i - peaks.last() >= minDistance) {
+                    peaks.add(i)
+                }
+            }
+        }
+        return peaks.sortedByDescending { spectrum[it] }
+    }
+
+    /** Compute confidence from energy history. Lower variance = higher confidence. */
+    private fun computeConfidence(history: List<Float>): Float {
+        if (history.size < 10) return 0.3f
+        val recent = history.takeLast(10)
+        val mean = recent.average().toFloat()
+        val variance = recent.map { (it - mean) * (it - mean) }.average().toFloat()
+        return if (mean > 0f) (mean / (mean + variance + 0.1f)).coerceIn(0f, 1f) else 0f
+    }
+
+    /** Get the channel with highest confidence. */
+    fun getBestChannel(): Channel? {
+        return channels.filter { it.active }.maxByOrNull { it.confidence }
+    }
+
+    fun reset() {
+        for (i in channels.indices) {
+            channels[i] = Channel(0, 0f)
+        }
+    }
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/cw/CwDecoder.kt

@@ -0,0 +1,165 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.domain.cw
+
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+
+/**
+ * CW (Morse code) decoder v3 — Spectrogram-based multi-channel Bayesian decoder.
+ *
+ * Architecture inspired by Morse Expert / CW Skimmer (VE3NEA):
+ *   1. FFT spectrogram creates a frequency×time matrix
+ *   2. Multi-channel peak detector finds all active signals
+ *   3. Per-channel energy envelope extraction
+ *   4. Bayesian probability for symbol timing (Gaussian likelihood)
+ *   5. Best channel selected for output
+ *
+ * Timing analysis is performed per spectrogram column (hop).
+ * Each column represents hopSize/sampleRate seconds of audio.
+ */
+class CwDecoder(
+    val sampleRate: Int = 8000,
+    cwToneFreq: Float = -1f // ignored in v3 (auto-detect via spectrogram)
+) {
+    companion object {
+        private const val FFT_SIZE = 256
+        private const val HOP_SIZE = 64
+    }
+
+    private val spectrogram = CwSpectrogram(
+        fftSize = FFT_SIZE,
+        hopSize = HOP_SIZE,
+        sampleRate = sampleRate,
+        minBin = 6,
+        maxBin = 38,
+        historyCols = 40
+    )
+    private val channelTracker = CwChannelTracker(spectrogram, maxChannels = 3)
+    private val bayesianDecoder = CwBayesianDecoder()
+
+    // Timing state per channel
+    private data class ChannelTiming(
+        var isSignal: Boolean = false,
+        var toneTicks: Int = 0,
+        var gapTicks: Int = 0
+    )
+    private val timingStates = Array(3) { ChannelTiming() }
+
+    // Time per spectrogram column in milliseconds
+    private val tickMs = 1000f * HOP_SIZE / sampleRate
+
+    // Output flows
+    private val _decodedTextFlow = MutableStateFlow("")
+    val decodedTextFlow: StateFlow<String> = _decodedTextFlow
+
+    private val _signalStrength = MutableStateFlow(0f)
+    val signalStrength: StateFlow<Float> = _signalStrength
+
+    private val _estimatedPitch = MutableStateFlow<Float?>(null)
+    val estimatedPitch: StateFlow<Float?> = _estimatedPitch
+
+    private val _estimatedSpeed = MutableStateFlow<Float?>(null)
+    val estimatedSpeed: StateFlow<Float?> = _estimatedSpeed
+
+    private var frameCount = 0
+
+    init {
+        if (cwToneFreq > 0f) {
+            _estimatedPitch.value = cwToneFreq
+        }
+    }
+
+    fun processBuffer(buffer: FloatArray) {
+        // 1. Feed samples to spectrogram
+        spectrogram.addSamples(buffer)
+
+        // 2. Get number of new columns generated
+        val newCols = spectrogram.getNewColumns()
+        if (newCols == 0) return
+
+        // 3. Update channel tracker (uses latest column for peak detection)
+        val activeChannels = channelTracker.update()
+
+        // 4. Process each new column for timing analysis
+        //    Columns are indexed 0..historyCols-1, where historyCols-1 is the newest
+        val baseIdx = (spectrogram.historyCols - newCols).coerceAtLeast(0)
+        for (colOffset in 0 until newCols) {
+            val col = spectrogram.getColumn(baseIdx + colOffset)
+
+            for ((idx, channel) in activeChannels.withIndex()) {
+                if (idx >= timingStates.size) break
+                val state = timingStates[idx]
+                val energy = if (channel.bin in col.indices) col[channel.bin] else 0f
+
+                // Adaptive threshold
+                val threshold = 0.3f + (energy - 0.3f) * 0.3f
+
+                if (energy > threshold) {
+                    if (!state.isSignal) {
+                        if (state.gapTicks > 0) {
+                            val gapMs = state.gapTicks * tickMs
+                            bayesianDecoder.processGap(gapMs)
+                        }
+                        state.gapTicks = 0
+                        state.isSignal = true
+                    }
+                    state.toneTicks++
+                } else {
+                    if (state.isSignal) {
+                        if (state.toneTicks > 0) {
+                            val toneMs = state.toneTicks * tickMs
+                            bayesianDecoder.processTone(toneMs)
+                        }
+                        state.toneTicks = 0
+                        state.isSignal = false
+                    }
+                    state.gapTicks++
+                }
+            }
+        }
+
+        // 5. Update outputs
+        frameCount++
+        if (frameCount % 5 == 0) {
+            val bestChannel = channelTracker.getBestChannel()
+            if (bestChannel != null) {
+                _estimatedPitch.value = bestChannel.frequency
+                _signalStrength.value = bestChannel.confidence
+                _estimatedSpeed.value = bayesianDecoder.getSpeed()
+            }
+            _decodedTextFlow.value = bayesianDecoder.decodedText
+        }
+    }
+
+    fun resetDecoder() {
+        spectrogram.reset()
+        channelTracker.reset()
+        bayesianDecoder.reset()
+        for (state in timingStates) {
+            state.isSignal = false
+            state.toneTicks = 0
+            state.gapTicks = 0
+        }
+        frameCount = 0
+        _decodedTextFlow.value = ""
+        _signalStrength.value = 0f
+        _estimatedPitch.value = null
+        _estimatedSpeed.value = null
+    }
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/cw/CwDsp.kt

@@ -0,0 +1,102 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.domain.cw
+
+import kotlin.math.PI
+import kotlin.math.cos
+import kotlin.math.sin
+import kotlin.math.sqrt
+
+/**
+ * DSP utilities for CW (Morse code) decoding.
+ * Pure Kotlin, no NDK required.
+ */
+internal object CwDsp {
+
+    /**
+     * Design a simple bandpass FIR filter coefficients using windowed sinc method.
+     * @param lowCutoff  lower cutoff frequency (Hz) as fraction of sampleRate
+     * @param highCutoff upper cutoff frequency (Hz) as fraction of sampleRate
+     * @param taps       filter length (must be odd)
+     */
+    fun bandpassFir(lowCutoff: Double, highCutoff: Double, taps: Int): FloatArray {
+        val n = if (taps % 2 == 0) taps + 1 else taps
+        val half = n / 2
+        val coeffs = FloatArray(n)
+        for (i in 0 until n) {
+            val idx = i - half
+            if (idx == 0) {
+                coeffs[i] = (2.0 * (highCutoff - lowCutoff)).toFloat()
+            } else {
+                val x = PI * idx
+                coeffs[i] = ((sin(2 * highCutoff * x) - sin(2 * lowCutoff * x)) / x).toFloat()
+            }
+            // Hamming window
+            coeffs[i] = (coeffs[i] * (0.54 - 0.46 * cos(2 * PI * i / (n - 1)))).toFloat()
+        }
+        // Normalize
+        val sum = coeffs.sum()
+        if (sum != 0f) for (i in 0 until n) coeffs[i] /= sum
+        return coeffs
+    }
+
+    /** Apply FIR filter to a buffer. */
+    fun applyFir(buffer: FloatArray, coeffs: FloatArray): FloatArray {
+        val out = FloatArray(buffer.size)
+        for (i in buffer.indices) {
+            var sum = 0f
+            for (j in coeffs.indices) {
+                val idx = i - j
+                if (idx >= 0) sum += buffer[idx] * coeffs[j]
+            }
+            out[i] = sum
+        }
+        return out
+    }
+
+    /** Simple envelope detector: abs + low-pass smoothing. */
+    fun envelope(signal: FloatArray, alpha: Float = 0.1f): FloatArray {
+        val env = FloatArray(signal.size)
+        var s = 0f
+        for (i in signal.indices) {
+            s = alpha * kotlin.math.abs(signal[i]) + (1 - alpha) * s
+            env[i] = s
+        }
+        return env
+    }
+
+    /** Estimate noise floor from envelope for adaptive thresholding. */
+    fun noiseFloor(env: FloatArray, fraction: Float = 0.3f): Float {
+        val sorted = env.sortedArray()
+        val median = sorted[sorted.size / 2]
+        return median + (sorted[sorted.size * 9 / 10] - median) * fraction
+    }
+
+    /** Simple Goertzel to detect a specific tone frequency. */
+    fun goertzel(buffer: FloatArray, targetFreq: Float, sampleRate: Int): Float {
+        val omega = 2.0 * PI * targetFreq / sampleRate
+        val coeff = 2.0 * cos(omega)
+        var s0 = 0.0; var s1 = 0.0; var s2 = 0.0
+        for (sample in buffer) {
+            s0 = sample.toDouble() + coeff * s1 - s2
+            s2 = s1; s1 = s0
+        }
+        val power = s2 * s2 + s1 * s1 - coeff * s1 * s2
+        return sqrt(kotlin.math.abs(power)).toFloat()
+    }
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/cw/CwFFT.kt

@@ -0,0 +1,87 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.domain.cw
+
+import kotlin.math.cos
+import kotlin.math.sqrt
+
+/**
+ * Radix-2 FFT for real-valued input.
+ * Produces magnitude spectrum for the first N/2+1 bins.
+ * Used by CwSpectrogram for time-frequency analysis.
+ */
+internal class CwFFT(private val n: Int) {
+    init {
+        require(n > 0 && n and (n - 1) == 0) { "FFT size must be power of 2, got $n" }
+    }
+
+    private val cosTable = FloatArray(n / 2)
+    private val sinTable = FloatArray(n / 2)
+
+    init {
+        for (i in 0 until n / 2) {
+            val angle = -2.0 * kotlin.math.PI * i / n
+            cosTable[i] = cos(angle).toFloat()
+            sinTable[i] = kotlin.math.sin(angle).toFloat()
+        }
+    }
+
+    /** Compute magnitude spectrum for real input. Returns array of size n/2+1. */
+    fun magnitudeSpectrum(input: FloatArray): FloatArray {
+        require(input.size == n) { "Input size must be $n, got ${input.size}" }
+
+        val real = input.copyOf()
+        val imag = FloatArray(n)
+
+        // Bit-reversal permutation
+        var j = 0
+        for (i in 1 until n) {
+            var bit = n shr 1
+            while (j and bit != 0) { j = j xor bit; bit = bit shr 1 }
+            j = j xor bit
+            if (i < j) {
+                var tmp = real[i]; real[i] = real[j]; real[j] = tmp
+            }
+        }
+
+        // Radix-2 Cooley-Tukey FFT
+        var len = 2
+        while (len <= n) {
+            val half = len / 2
+            val step = n / len
+            for (i in 0 until n step len) {
+                for (k in 0 until half) {
+                    val tReal = real[i + k + half] * cosTable[k * step] - imag[i + k + half] * sinTable[k * step]
+                    val tImag = real[i + k + half] * sinTable[k * step] + imag[i + k + half] * cosTable[k * step]
+                    real[i + k + half] = real[i + k] - tReal
+                    imag[i + k + half] = imag[i + k] - tImag
+                    real[i + k] += tReal
+                    imag[i + k] += tImag
+                }
+            }
+            len = len shl 1
+        }
+
+        // Magnitude spectrum (first N/2+1 bins)
+        val mag = FloatArray(n / 2 + 1)
+        for (i in 0..n / 2) {
+            mag[i] = sqrt(real[i] * real[i] + imag[i] * imag[i]) / n
+        }
+        return mag
+    }
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/cw/CwFilter.kt

@@ -0,0 +1,48 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.domain.cw
+
+/**
+ * First-order IIR filters.
+ * Ported from ggmorse/src/filter.h
+ */
+internal class CwFilter {
+    private var z1 = 0f
+
+    companion object {
+        private const val PI_F = 3.141592653589793f
+    }
+
+    fun highPass(sample: Float, cutoffHz: Float, sampleRate: Float): Float {
+        val rc = 1.0f / (2f * PI_F * cutoffHz)
+        val dt = 1.0f / sampleRate
+        val alpha = dt / (rc + dt)
+        z1 = alpha * (z1 + sample - z1)
+        return sample - z1
+    }
+
+    fun lowPass(sample: Float, cutoffHz: Float, sampleRate: Float): Float {
+        val rc = 1.0f / (2f * PI_F * cutoffHz)
+        val dt = 1.0f / sampleRate
+        val alpha = dt / (rc + dt)
+        z1 += alpha * (sample - z1)
+        return z1
+    }
+
+    fun reset() { z1 = 0f }
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/cw/CwGoertzel.kt

@@ -0,0 +1,54 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.domain.cw
+
+import kotlin.math.cos
+import kotlin.math.sqrt
+
+/**
+ * Running Goertzel filter for CW tone detection.
+ * Tracks a specific frequency over time with a sliding window.
+ * Ported from ggmorse/src/goertzel.h
+ */
+internal class CwGoertzel {
+    private var s1 = 0.0
+    private var s2 = 0.0
+    private var coeff = 0.0
+
+    fun init(sampleRate: Float, targetFreq: Float) {
+        val omega = 2.0 * kotlin.math.PI * targetFreq / sampleRate
+        coeff = 2.0 * cos(omega)
+        s1 = 0.0
+        s2 = 0.0
+    }
+
+    fun process(sample: Float) {
+        val s0 = sample.toDouble() + coeff * s1 - s2
+        s2 = s1
+        s1 = s0
+    }
+
+    fun getPower(): Float {
+        return sqrt(s2 * s2 + s1 * s1 - coeff * s1 * s2).toFloat()
+    }
+
+    fun reset() {
+        s1 = 0.0
+        s2 = 0.0
+    }
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/cw/CwResampler.kt

@@ -0,0 +1,53 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.domain.cw
+
+/**
+ * Simple linear resampler.
+ * Downsamples from input sample rate to output sample rate.
+ * Ported from ggmorse/src/resampler.h
+ */
+internal class CwResampler(private val inputRate: Float, private val outputRate: Float) {
+    private val ratio = inputRate / outputRate
+    private var lastSample = 0f
+
+    fun process(input: FloatArray): FloatArray {
+        if (ratio <= 0f || input.isEmpty()) return input
+        val outputLen = (input.size / ratio).toInt() + 1
+        val output = FloatArray(outputLen)
+        var idx = 0f
+        for (i in output.indices) {
+            val intIdx = idx.toInt()
+            val frac = idx - intIdx
+            if (intIdx + 1 < input.size) {
+                output[i] = input[intIdx] * (1 - frac) + input[intIdx + 1] * frac
+            } else if (intIdx < input.size) {
+                output[i] = input[intIdx] * (1 - frac) + lastSample * frac
+            } else {
+                output[i] = lastSample
+            }
+            idx += ratio
+        }
+        lastSample = input.lastOrNull() ?: lastSample
+        return output
+    }
+
+    fun reset() {
+        lastSample = 0f
+    }
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/cw/CwSTFFT.kt

@@ -0,0 +1,61 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.domain.cw
+
+import kotlin.math.cos
+import kotlin.math.sin
+import kotlin.math.sqrt
+
+/**
+ * Lightweight pitch detector using DFT at specific frequency bins.
+ * Only scans [200, 1200] Hz in configurable steps — much faster than full FFT.
+ * Ported from ggmorse/src/stfft.h (simplified for CW use case).
+ */
+internal class CwPitchDetector(
+    private val sampleRate: Float,
+    private val minFreq: Float = 200f,
+    private val maxFreq: Float = 1200f,
+    private val stepHz: Float = 10f
+) {
+    /**
+     * Find the dominant pitch frequency in the buffer.
+     * Returns null if no significant pitch found.
+     */
+    fun findPitch(buffer: FloatArray): Float? {
+        if (buffer.isEmpty()) return null
+        var bestFreq = 0f
+        var bestPower = 0f
+        var freq = minFreq
+        while (freq <= maxFreq) {
+            var real = 0.0
+            var imag = 0.0
+            val omega = 2.0 * kotlin.math.PI * freq / sampleRate
+            for (i in buffer.indices) {
+                real += buffer[i] * cos(omega * i)
+                imag += buffer[i] * -sin(omega * i)
+            }
+            val power = (real * real + imag * imag).toFloat()
+            if (power > bestPower) {
+                bestPower = power
+                bestFreq = freq
+            }
+            freq += stepHz
+        }
+        return if (bestPower > 0.001f) bestFreq else null
+    }
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/cw/CwSpectrogram.kt

@@ -0,0 +1,170 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.domain.cw
+
+/**
+ * Sliding-window spectrogram for CW decoding.
+ * Maintains a time-frequency matrix updated with each audio frame.
+ *
+ * FFT size: 256, hop size: 64, sample rate: 4000 (or native)
+ * Frequency bins: 6..38 (187-1187 Hz, covers typical CW range)
+ * History: 40 columns (320 ms window)
+ * Time resolution: 64/4000 = 16 ms, Frequency resolution: 4000/256 = 15.625 Hz
+ */
+internal class CwSpectrogram(
+    private val fftSize: Int = 256,
+    private val hopSize: Int = 64,
+    private val sampleRate: Int = 4000,
+    private val minBin: Int = 6,
+    private val maxBin: Int = 38,
+    val historyCols: Int = 40
+) {
+    private val fft = CwFFT(fftSize)
+    val numBins: Int get() = maxBin - minBin + 1
+
+    // Hanning window
+    private val hanning = FloatArray(fftSize) {
+        (0.5 - 0.5 * kotlin.math.cos(2.0 * kotlin.math.PI * it / (fftSize - 1))).toFloat()
+    }
+
+    // Spectrogram data: [timeCol][freqBin]
+    private val spectrogram = Array(historyCols) { FloatArray(numBins) }
+    private var currentCol = 0
+    private var samplesBuffered = 0
+    private val buffer = FloatArray(fftSize)
+
+    // Per-bin running energy for normalization
+    private val binEnergy = FloatArray(numBins) { 1f }
+    private val alpha = 0.95f
+
+    // Counter for new columns generated since last check
+    private var newColumnCount = 0
+
+    /** Add audio samples, compute FFTs for each complete hop. */
+    fun addSamples(samples: FloatArray) {
+        var offset = 0
+        while (offset < samples.size) {
+            val needed = fftSize - samplesBuffered
+            val copyLen = minOf(needed, samples.size - offset)
+            System.arraycopy(samples, offset, buffer, samplesBuffered, copyLen)
+            samplesBuffered += copyLen
+            offset += copyLen
+
+            if (samplesBuffered >= fftSize) {
+                processFrame()
+                newColumnCount++
+                // Shift buffer: keep last (fftSize - hopSize) samples
+                System.arraycopy(buffer, hopSize, buffer, 0, fftSize - hopSize)
+                samplesBuffered = fftSize - hopSize
+            }
+        }
+    }
+
+    /** Get number of new columns generated since the last call to this method. */
+    fun getNewColumns(): Int {
+        val count = newColumnCount
+        newColumnCount = 0
+        return count
+    }
+
+    private fun processFrame() {
+        // Apply Hanning window
+        val windowed = FloatArray(fftSize) { buffer[it] * hanning[it] }
+
+        // Compute FFT magnitude spectrum
+        val mag = fft.magnitudeSpectrum(windowed)
+
+        // Update spectrogram column
+        val col = spectrogram[currentCol]
+        for (b in 0 until numBins) {
+            val binIdx = minBin + b
+            val rawMag = mag[binIdx]
+            // Running energy normalization
+            binEnergy[b] = alpha * binEnergy[b] + (1 - alpha) * rawMag
+            col[b] = if (binEnergy[b] > 1e-6f) rawMag / binEnergy[b] else 0f
+        }
+
+        currentCol = (currentCol + 1) % historyCols
+    }
+
+    /** Get the current spectrogram as a 2D array in chronological order. */
+    fun getSpectrogram(): Array<FloatArray> {
+        val result = Array(historyCols) { i ->
+            val srcIdx = (currentCol + i) % historyCols
+            spectrogram[srcIdx].copyOf()
+        }
+        return result
+    }
+
+    /** Get the most recent column (current energy across all frequencies). */
+    fun getCurrentColumn(): FloatArray {
+        val prevCol = (currentCol - 1 + historyCols) % historyCols
+        return spectrogram[prevCol].copyOf()
+    }
+
+    /** Get a column by index from the history (0 = oldest, historyCols-1 = newest). */
+    fun getColumn(index: Int): FloatArray {
+        val clamped = index.coerceIn(0, historyCols - 1)
+        val srcIdx = (currentCol - historyCols + clamped + historyCols) % historyCols
+        return spectrogram[srcIdx].copyOf()
+    }
+
+    /** Find the frequency bin with peak energy. Returns -1 if no significant signal. */
+    fun findPeakBin(): Int {
+        val col = getCurrentColumn()
+        var maxBin = -1
+        var maxVal = 0f
+        for (i in col.indices) {
+            if (col[i] > maxVal) {
+                maxVal = col[i]
+                maxBin = i
+            }
+        }
+        return if (maxVal > 0.3f) maxBin else -1
+    }
+
+    /** Get energy at a specific bin over the last N columns in chronological order. */
+    fun getBinEnergy(bin: Int, numCols: Int): FloatArray {
+        val clamped = minOf(numCols, historyCols)
+        val result = FloatArray(clamped)
+        for (i in 0 until clamped) {
+            val colIdx = (currentCol - clamped + i + historyCols) % historyCols
+            result[i] = spectrogram[colIdx][bin]
+        }
+        return result
+    }
+
+    /** Get the bin index for a frequency in Hz. */
+    fun freqToBin(freqHz: Float): Int {
+        val bin = (freqHz * fftSize / sampleRate).toInt()
+        return (bin - minBin).coerceIn(0, numBins - 1)
+    }
+
+    /** Get the center frequency for a bin. */
+    fun binToFreq(bin: Int): Float {
+        return (minBin + bin).toFloat() * sampleRate / fftSize
+    }
+
+    fun reset() {
+        for (col in spectrogram) col.fill(0f)
+        currentCol = 0
+        samplesBuffered = 0
+        buffer.fill(0f)
+        binEnergy.fill(1f)
+    }
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/model/Settings.kt

@@ -27,6 +27,9 @@ data class PassesSettings(
     val showDeepSpace: Boolean = true,
     val hoursAhead: Int,
     val minElevation: Double,
+    val aosStartMinute: Int = 0,
+    val aosEndMinute: Int = 23 * 60 + 59,
+    val invertAosTimeWindow: Boolean = false,
     val selectedModes: List<String>
 )
 
@@ -54,8 +57,12 @@ data class OtherSettings(
     val stateOfSweep: Boolean,
     val stateOfUtc: Boolean,
     val stateOfLightTheme: Boolean,
+    val stateOfNightMode: Boolean = false,
     val shouldSeeWarning: Boolean,
-    val shouldSeeWhatsNew: Boolean
+    val shouldSeeWhatsNew: Boolean,
+    val sstvMode: String = "Auto",
+    val lowElevation: Double = 15.0,
+    val highElevation: Double = 45.0
 )
 
 data class DataSourcesSettings(
@@ -72,12 +79,20 @@ data class RadioControlSettings(
     val rxRadioAddress: String,
     val txRadioName: String,
     val rxRadioName: String,
-    val baudRate: Int
+    val baudRate: Int,
+    /** IC-705 only: use single-radio split-VFO mode instead of two radios. */
+    val splitMode: Boolean = false
 ) {
     companion object {
-        val SUPPORTED_RADIOS = listOf(
-            "Yaesu FT-817/818",
-            "Yaesu FT-857/897"
-        )
+        const val MODEL_YAESU_FT817   = "Yaesu FT-817/818"
+        const val MODEL_YAESU_FT857   = "Yaesu FT-857/897"
+        const val MODEL_ICOM_IC705    = "Icom IC-705"
+
+        val SUPPORTED_RADIOS = listOf(MODEL_YAESU_FT817, MODEL_YAESU_FT857, MODEL_ICOM_IC705)
+
+        /** Baud rates available for Yaesu radios. */
+        val BAUD_RATES_YAESU = listOf(4800, 9600, 38400)
+        /** Baud rates available for Icom IC-705 (higher speeds supported via CI-V USB/BT). */
+        val BAUD_RATES_ICOM  = listOf(4800, 9600, 19200, 38400, 57600, 115200)
     }
 }

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/predict/CelestialComputer.kt

@@ -0,0 +1,667 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.domain.predict
+
+import com.rtbishop.look4sat.core.domain.utility.toDegrees
+import com.rtbishop.look4sat.core.domain.utility.toRadians
+import kotlin.math.PI
+import kotlin.math.abs
+import kotlin.math.acos
+import kotlin.math.asin
+import kotlin.math.atan
+import kotlin.math.atan2
+import kotlin.math.cos
+import kotlin.math.floor
+import kotlin.math.log10
+import kotlin.math.pow
+import kotlin.math.sin
+import kotlin.math.sqrt
+import kotlin.math.tan
+
+/**
+ * Standalone celestial computations extracted from PREDICT v2.2.5.
+ * Provides Sun position, Moon position, satellite visibility classification,
+ * orbital metadata, RA/Dec conversion, and rise/set finding for Sun and Moon.
+ *
+ * All angles are in degrees unless noted. Time is Unix epoch milliseconds.
+ *
+ * Shared math utilities (thetaGJD, modulus, mod2PI, deltaET, millisToDaynum,
+ * solarPositionECI, eciToGeodetic) live in OrbitalMath.kt in the same package.
+ */
+object CelestialComputer {
+
+    // ── Result types ──
+
+    /** Sun position as seen from a ground observer. */
+    data class SunPosition(
+        val azimuth: Double,         // degrees, 0=N, 90=E
+        val elevation: Double,       // degrees, >0 above horizon
+        val distance: Double,        // normalized: 1.0 + ((range - AU) / AU)
+        val rangeRate: Double,       // km/s
+        val latitude: Double,        // sub-solar point latitude, degrees
+        val longitude: Double,       // sub-solar point longitude, degrees
+        val rightAscension: Double,  // degrees
+        val declination: Double      // degrees
+    )
+
+    /** Moon position as seen from a ground observer. */
+    data class MoonPosition(
+        val azimuth: Double,         // degrees, 0=N, 90=E
+        val elevation: Double,       // degrees
+        val rightAscension: Double,  // degrees
+        val declination: Double,     // degrees
+        val gha: Double,             // Greenwich Hour Angle, degrees
+        val angularDiameter: Double, // apparent diameter relative to Earth's diameter
+        val radialVelocity: Double   // m/s, Doppler radial velocity for EME
+    )
+
+    /**
+     * 3-state satellite visibility classification.
+     * - [VISIBLE]: satellite is sunlit, observer is in darkness (sun below -12°) — optically visible
+     * - [DAYLIGHT]: satellite is sunlit, observer is in daylight
+     * - [ECLIPSED]: satellite is in Earth's shadow
+     */
+    enum class SatVisibility { VISIBLE, DAYLIGHT, ECLIPSED }
+
+    /** Orbital metadata not typically included in pass data. */
+    data class OrbitalMetadata(
+        val footprintDiameter: Double, // km, ground coverage circle diameter
+        val orbitNumber: Long,         // current orbit/revolution number
+        val betaAngle: Double,         // degrees, angle between orbital plane and Sun
+        val orbitalPhase: Double       // 0-256 phase within current orbit
+    )
+
+    // ── Sun position ──
+
+    /**
+     * Compute the Sun's full position as seen from [observer] at [timeMillis].
+     * Includes az/el, RA/Dec, sub-solar lat/lon, range, and range rate.
+     * Based on FindSun() from PREDICT v2.2.5.
+     */
+    fun getSunPosition(observer: GeoPos, timeMillis: Long): SunPosition {
+        val daynum = millisToDaynum(timeMillis)
+        val julUtc = daynum + 2444238.5
+        val sunVec = solarPositionECI(julUtc)
+        val zeroVel = doubleArrayOf(0.0, 0.0, 0.0)
+        val obsGeo = observerGeodetic(observer)
+
+        // Az, El, Range, RangeRate
+        val obsSet = computeObsAngles(julUtc, sunVec, zeroVel, obsGeo)
+
+        // Lat/Lon of sub-solar point
+        val latLon = eciToGeodetic(julUtc, sunVec)
+
+        // RA/Dec
+        val raDec = calculateRADec(julUtc, sunVec, zeroVel, obsGeo)
+
+        return SunPosition(
+            azimuth = obsSet[0].toDegrees(),
+            elevation = obsSet[1].toDegrees(),
+            distance = 1.0 + ((obsSet[2] - ASTRONOMICAL_UNIT) / ASTRONOMICAL_UNIT),
+            rangeRate = 1000.0 * obsSet[3],
+            latitude = latLon[0].toDegrees(),
+            longitude = latLon[1].toDegrees().let { if (it > 180.0) it - 360.0 else it },
+            rightAscension = raDec[0].toDegrees(),
+            declination = raDec[1].toDegrees()
+        )
+    }
+
+    // ── Moon position ──
+
+    /**
+     * Compute the Moon's position as seen from [observer] at [timeMillis].
+     * Full Meeus lunar ephemeris from PREDICT v2.2.5 with expanded terms
+     * and radial velocity approximation for EME Doppler.
+     */
+    fun getMoonPosition(observer: GeoPos, timeMillis: Long): MoonPosition {
+        val daynum = millisToDaynum(timeMillis)
+        val jd = daynum + 2444238.5
+        var t = (jd - 2415020.0) / 36525.0
+        val t2 = t * t
+        val t3 = t2 * t
+
+        var l1 = 270.434164 + 481267.8831 * t - 0.001133 * t2 + 0.0000019 * t3
+        var mSun = 358.475833 + 35999.0498 * t - 0.00015 * t2 - 0.0000033 * t3
+        var m1 = 296.104608 + 477198.8491 * t + 0.009192 * t2 + 0.0000144 * t3
+        var d = 350.737486 + 445267.1142 * t - 0.001436 * t2 + 0.0000019 * t3
+        var ff = 11.250889 + 483202.0251 * t - 0.003211 * t2 - 0.0000003 * t3
+        val om = (259.183275 - 1934.142 * t + 0.002078 * t2 + 0.0000022 * t3) * DEG2RAD
+
+        val correction512 = sin((51.2 + 20.2 * t) * DEG2RAD)
+        val ss = 0.003964 * sin((346.56 + 132.87 * t - 0.0091731 * t2) * DEG2RAD)
+        l1 += 0.000233 * correction512 + ss + 0.001964 * sin(om)
+        mSun -= 0.001778 * correction512
+        m1 += 0.000817 * correction512 + ss + 0.002541 * sin(om)
+        d += 0.002011 * correction512 + ss + 0.001964 * sin(om)
+        ff += ss - 0.024691 * sin(om) - 0.004328 * sin(om + (275.05 - 2.3 * t) * DEG2RAD)
+
+        val ex = 1.0 - 0.002495 * t - 0.00000752 * t2
+        l1 = primeAngle(l1); mSun = primeAngle(mSun); m1 = primeAngle(m1)
+        d = primeAngle(d); ff = primeAngle(ff)
+
+        val mR = mSun * DEG2RAD
+        val m1R = m1 * DEG2RAD
+        val dR = d * DEG2RAD
+        val ffR = ff * DEG2RAD
+
+        // Ecliptic longitude — expanded v225 terms
+        var l = l1 + 6.28875 * sin(m1R) + 1.274018 * sin(2 * dR - m1R) + 0.658309 * sin(2 * dR)
+        l += 0.213616 * sin(2 * m1R) - ex * 0.185596 * sin(mR) - 0.114336 * sin(2 * ffR)
+        l += 0.058793 * sin(2 * dR - 2 * m1R) + ex * 0.057212 * sin(2 * dR - mR - m1R) + 0.05332 * sin(2 * dR + m1R)
+        l += ex * 0.045874 * sin(2 * dR - mR) + ex * 0.041024 * sin(m1R - mR) - 0.034718 * sin(dR)
+        l -= ex * 0.030465 * sin(mR + m1R) + 0.015326 * sin(2 * dR - 2 * ffR) - 0.012528 * sin(2 * ffR + m1R)
+        l -= 0.01098 * sin(2 * ffR - m1R) + 0.010674 * sin(4 * dR - m1R) + 0.010034 * sin(3 * m1R)
+        l += 0.008548 * sin(4 * dR - 2 * m1R) - ex * 0.00791 * sin(mR - m1R + 2 * dR)
+        l -= ex * 0.006783 * sin(2 * dR + mR)
+        l += 0.005162 * sin(m1R - dR) + ex * 0.005 * sin(mR + dR) + ex * 0.004049 * sin(m1R - mR + 2 * dR)
+        l += 0.003996 * sin(2 * m1R + 2 * dR) + 0.003862 * sin(4 * dR) + 0.003665 * sin(2 * dR - 3 * m1R)
+        l += ex * 0.002695 * sin(2 * m1R - mR) + 0.002602 * sin(m1R - 2 * ffR - 2 * dR)
+        l += ex * 0.002396 * sin(2 * dR - mR - 2 * m1R)
+        l -= 0.002349 * sin(m1R + dR) + ex * ex * 0.002249 * sin(2 * dR - 2 * mR)
+        l -= ex * 0.002125 * sin(2 * m1R + mR)
+        l -= ex * ex * 0.002079 * sin(2 * mR) + ex * ex * 0.002059 * sin(2 * dR - m1R - 2 * mR)
+        l -= 0.001773 * sin(m1R + 2 * dR - 2 * ffR)
+        l += ex * 0.00122 * sin(4 * dR - mR - m1R) - 0.00111 * sin(2 * m1R + 2 * ffR) + 0.000892 * sin(m1R - 3 * dR)
+        l -= ex * 0.000811 * sin(mR + m1R + 2 * dR) + ex * 0.000761 * sin(4 * dR - mR - 2 * m1R)
+        l += ex * ex * 0.000717 * sin(m1R - 2 * mR)
+        l += ex * ex * 0.000704 * sin(m1R - 2 * mR - 2 * dR) + ex * 0.000693 * sin(mR - 2 * m1R + 2 * dR)
+        l += ex * 0.000598 * sin(2 * dR - mR - 2 * ffR) + 0.00055 * sin(m1R + 4 * dR)
+        l += 0.000538 * sin(4 * m1R) + ex * 0.000521 * sin(4 * dR - mR) + 0.000486 * sin(2 * m1R - dR)
+        l -= 0.001595 * sin(2 * ffR + 2 * dR)
+
+        // Ecliptic latitude — expanded v225 terms
+        var b =
+            5.128189 * sin(ffR) + 0.280606 * sin(m1R + ffR) + 0.277693 * sin(m1R - ffR) + 0.173238 * sin(2 * dR - ffR)
+        b += 0.055413 * sin(2 * dR + ffR - m1R) + 0.046272 * sin(2 * dR - ffR - m1R) + 0.032573 * sin(2 * dR + ffR)
+        b += 0.017198 * sin(2 * m1R + ffR) + 9.266999e-03 * sin(2 * dR + m1R - ffR) + 0.008823 * sin(2 * m1R - ffR)
+        b += ex * 0.008247 * sin(2 * dR - mR - ffR) + 0.004323 * sin(2 * dR - ffR - 2 * m1R)
+        b += 0.0042 * sin(2 * dR + ffR + m1R)
+        b += ex * 0.003372 * sin(ffR - mR - 2 * dR) + ex * 0.002472 * sin(2 * dR + ffR - mR - m1R)
+        b += ex * 0.002222 * sin(2 * dR + ffR - mR)
+        b += 0.002072 * sin(2 * dR - ffR - mR - m1R) + ex * 0.001877 * sin(ffR - mR + m1R)
+        b += 0.001828 * sin(4 * dR - ffR - m1R)
+        b -= ex * 0.001803 * sin(ffR + mR) - 0.00175 * sin(3 * ffR)
+        b += ex * 0.00157 * sin(m1R - mR - ffR) - 0.001487 * sin(ffR + dR)
+        b -= ex * 0.001481 * sin(ffR + mR + m1R) + ex * 0.001417 * sin(ffR - mR - m1R)
+        b += ex * 0.00135 * sin(ffR - mR) + 0.00133 * sin(ffR - dR)
+        b += 0.001106 * sin(ffR + 3 * m1R) + 0.00102 * sin(4 * dR - ffR) + 0.000833 * sin(ffR + 4 * dR - m1R)
+        b += 0.000781 * sin(m1R - 3 * ffR) + 0.00067 * sin(ffR + 4 * dR - 2 * m1R)
+        b += 0.000606 * sin(2 * dR - 3 * ffR)
+        b += 0.000597 * sin(2 * dR + 2 * m1R - ffR) + ex * 0.000492 * sin(2 * dR + m1R - mR - ffR)
+        b += 0.00045 * sin(2 * m1R - ffR - 2 * dR)
+        b += 0.000439 * sin(3 * m1R - ffR) + 0.000423 * sin(ffR + 2 * dR + 2 * m1R)
+        b += 0.000422 * sin(2 * dR - ffR - 3 * m1R)
+        b -= ex * 0.000367 * sin(mR + ffR + 2 * dR - m1R) - ex * 0.000353 * sin(mR + ffR + 2 * dR)
+        b += 0.000331 * sin(ffR + 4 * dR)
+        b += ex * 0.000317 * sin(2 * dR + ffR - mR + m1R) + ex * ex * 0.000306 * sin(2 * dR - 2 * mR - ffR)
+        b -= 0.000283 * sin(m1R + 3 * ffR)
+
+        val w1 = 0.0004664 * cos(om)
+        val w2 = 0.0000754 * cos(om + (275.05 - 2.3 * t) * DEG2RAD)
+        val bt = b * (1.0 - w1 - w2)
+
+        // Parallax — expanded v225 terms
+        var p =
+            0.950724 + 0.051818 * cos(m1R) + 0.009531 * cos(2 * dR - m1R) + 0.007843 * cos(2 * dR) + 0.002824 * cos(2 * m1R)
+        p += 0.000857 * cos(2 * dR + m1R) + ex * 0.000533 * cos(2 * dR - mR) + ex * 0.000401 * cos(2 * dR - mR - m1R)
+        p += 0.000173 * cos(3 * m1R) + 0.000167 * cos(4 * dR - m1R) - ex * 0.000111 * cos(mR)
+        p += 0.000103 * cos(4 * dR - 2 * m1R) - 0.000084 * cos(2 * m1R - 2 * dR) - ex * 0.000083 * cos(2 * dR + mR)
+        p += 0.000079 * cos(2 * dR + 2 * m1R)
+        p += 0.000072 * cos(4 * dR) + ex * 0.000064 * cos(2 * dR - mR + m1R) - ex * 0.000063 * cos(2 * dR + mR - m1R)
+        p += ex * 0.000041 * cos(mR + dR) + ex * 0.000035 * cos(2 * m1R - mR) - 0.000033 * cos(3 * m1R - 2 * dR)
+        p -= 0.00003 * cos(m1R + dR) - 0.000029 * cos(2 * ffR - 2 * dR) - ex * 0.000029 * cos(2 * m1R + mR)
+        p += ex * ex * 0.000026 * cos(2 * dR - 2 * mR) - 0.000023 * cos(2 * ffR - 2 * dR + m1R)
+        p += ex * 0.000019 * cos(4 * dR - mR - m1R)
+
+        val bRad = bt * DEG2RAD
+        val lm = l * DEG2RAD
+        val moonDx = 3.0 / (PI * p)
+
+        // Ecliptic → equatorial
+        val z = (jd - 2415020.5) / 365.2422
+        val ob = (23.452294 - (0.46845 * z + 5.9e-07 * z * z) / 3600.0).toRadians()
+        val dec = asin(sin(bRad) * cos(ob) + cos(bRad) * sin(ob) * sin(lm))
+        var ra = acos(cos(bRad) * cos(lm) / cos(dec)); if (lm > PI) ra = TWO_PI - ra
+
+        val n = observer.latitude * DEG2RAD
+        t = (jd - 2451545.0) / 36525.0
+        var teg = 280.46061837 + 360.98564736629 * (jd - 2451545.0) + (0.000387933 * t - t * t / 38710000.0) * t
+        while (teg > 360.0) teg -= 360.0
+        // LST = GMST + east longitude (positive east convention)
+        val th = mod2PI((teg + observer.longitude) * DEG2RAD)
+        val h = th - ra
+        val azVal = atan2(sin(h), cos(h) * sin(n) - tan(dec) * cos(n)) + PI
+        val el = asin(sin(n) * sin(dec) + cos(n) * cos(dec) * cos(h))
+
+        // Moon radial velocity approximation (from "Amateur Radio Software", GM4ANB, RSGB 1985)
+        val mm = fixAngle(1.319238 + daynum * 0.228027135)
+        val radT2 = 0.10976
+        val radT1 = mm + radT2 * sin(mm)
+        var dv = 0.01255 * moonDx * moonDx * sin(radT1) * (1.0 + radT2 * cos(mm))
+        dv *= 4449.0
+        val earthR = 6378.0
+        val moonDist = 384401.0
+        val radT3 = earthR * moonDist * (cos(dec) * cos(n) * sin(h)) /
+            sqrt(moonDist * moonDist - moonDist * earthR * sin(el))
+        val moonDv = dv + radT3 * 0.0753125
+
+        val moonRa = ra / DEG2RAD
+        var moonGha = teg - moonRa
+        if (moonGha < 0.0) moonGha += 360.0
+
+        return MoonPosition(
+            azimuth = azVal / DEG2RAD,
+            elevation = el / DEG2RAD,
+            rightAscension = moonRa,
+            declination = dec / DEG2RAD,
+            gha = moonGha,
+            angularDiameter = moonDx,
+            radialVelocity = moonDv
+        )
+    }
+
+    // ── Satellite visibility ──
+
+    /**
+     * Classify satellite visibility given its eclipse state and the Sun's elevation
+     * at the observer's location.
+     *
+     * @param isEclipsed whether the satellite is in Earth's shadow
+     * @param sunElevationDeg Sun elevation at observer in degrees
+     * @param satElevationDeg satellite elevation at observer in degrees (must be >= 0)
+     */
+    fun classifyVisibility(
+        isEclipsed: Boolean,
+        sunElevationDeg: Double,
+        satElevationDeg: Double
+    ): SatVisibility {
+        if (isEclipsed) return SatVisibility.ECLIPSED
+        return if (sunElevationDeg <= -12.0 && satElevationDeg >= 0.0) SatVisibility.VISIBLE
+        else SatVisibility.DAYLIGHT
+    }
+
+    // ── Orbital metadata ──
+
+    /**
+     * Compute orbital metadata for a satellite at its current position.
+     *
+     * @param altitudeKm satellite altitude in km
+     * @param meanMotion revolutions per day from TLE
+     * @param bstar drag term from TLE
+     * @param meanAnomaly mean anomaly at epoch (radians)
+     * @param revNumAtEpoch revolution number at TLE epoch
+     * @param ageDays days since TLE epoch (julUTC - julEpoch)
+     * @param phase orbital phase in radians (from SGP4/SDP4 output)
+     * @param satPosECI satellite ECI position [x, y, z]
+     * @param satVelECI satellite ECI velocity [vx, vy, vz]
+     * @param sunPosECI sun ECI position [x, y, z]
+     */
+    fun computeOrbitalMetadata(
+        altitudeKm: Double,
+        meanMotion: Double,
+        bstar: Double,
+        meanAnomaly: Double,
+        revNumAtEpoch: Int,
+        ageDays: Double,
+        phase: Double,
+        satPosECI: DoubleArray,
+        satVelECI: DoubleArray,
+        sunPosECI: DoubleArray
+    ): OrbitalMetadata {
+        // Footprint diameter (km)
+        val footprint = 12756.33 * acos(EARTH_RADIUS / (EARTH_RADIUS + altitudeKm))
+
+        // Orbit number
+        val xmnpda = 1.44E3
+        val orbitNum = floor(
+            (meanMotion * xmnpda / TWO_PI + ageDays * bstar) * ageDays + meanAnomaly / TWO_PI
+        ).toLong() + revNumAtEpoch
+
+        // Beta angle: angle between orbital plane and Sun direction
+        // Orbital plane normal = cross(pos, vel)
+        val nx = satPosECI[1] * satVelECI[2] - satPosECI[2] * satVelECI[1]
+        val ny = satPosECI[2] * satVelECI[0] - satPosECI[0] * satVelECI[2]
+        val nz = satPosECI[0] * satVelECI[1] - satPosECI[1] * satVelECI[0]
+        val nMag = sqrt(nx * nx + ny * ny + nz * nz)
+        val sMag = sqrt(sunPosECI[0] * sunPosECI[0] + sunPosECI[1] * sunPosECI[1] + sunPosECI[2] * sunPosECI[2])
+        val dotNS = nx * sunPosECI[0] + ny * sunPosECI[1] + nz * sunPosECI[2]
+        val betaAngle = if (nMag > 0 && sMag > 0) {
+            (PI / 2.0 - acos(dotNS / (nMag * sMag))).toDegrees()
+        } else 0.0
+
+        // Phase (0-256 scale, matching PREDICT convention)
+        val orbitalPhase = 256.0 * (phase / TWO_PI)
+
+        return OrbitalMetadata(footprint, orbitNum, betaAngle, orbitalPhase)
+    }
+
+    // ── Satellite status checks ──
+
+    /** Check if a satellite is geostationary (mean motion ≈ 1.0027 rev/day). */
+    fun isGeostationary(meanMotion: Double): Boolean = abs(meanMotion - 1.0027) < 0.0002
+
+    /**
+     * Check if a satellite has likely decayed based on drag and time since epoch.
+     *
+     * @param meanMotion revolutions per day
+     * @param drag first derivative of mean motion / 2 (from TLE line 1)
+     * @param epochDaynum TLE epoch as daynum (days since 31Dec79)
+     * @param currentDaynum current time as daynum
+     */
+    fun hasDecayed(meanMotion: Double, drag: Double, epochDaynum: Double, currentDaynum: Double): Boolean {
+        return epochDaynum + ((16.666666 - meanMotion) / (10.0 * abs(drag))) < currentDaynum
+    }
+
+    // ── Rise/Set finding ──
+
+    /** Rise and set times for a celestial body. */
+    data class RiseSetTimes(
+        val riseTimeMillis: Long,  // 0 if not found
+        val setTimeMillis: Long    // 0 if not found
+    )
+
+    /**
+     * Find the next sunrise and sunset times from [startMillis] for [observer].
+     * Uses elevation threshold of -0.8333° to match the standard civil definition:
+     * upper limb on geometric horizon with standard atmospheric refraction (~0.57°)
+     * and solar semidiameter (~0.27°) corrections applied, matching USNO/timeanddate.com.
+     */
+    fun findSunRiseSet(observer: GeoPos, startMillis: Long): RiseSetTimes {
+        // Standard civil threshold: center elevation when upper limb meets geometric horizon
+        // -0.8333° = standard refraction (~0.5667°) + solar semidiameter (~0.2667°)
+        val threshold = 0.8333
+        var daynum = millisToDaynum(startMillis)
+        var sunPos = getSunPosition(observer, daynumToMillis(daynum))
+
+        // Phase 1: if sun is above threshold, fast-forward to well past sunset into night
+        if (sunPos.elevation > -threshold) {
+            var guard = 0
+            while (sunPos.elevation > -threshold && guard++ < 500) {
+                daynum += 0.008  // fixed ~11.5 min steps past the setting sun
+                sunPos = getSunPosition(observer, daynumToMillis(daynum))
+            }
+            // Now advance until sun is clearly below minimum (deep night)
+            guard = 0
+            while (sunPos.elevation > -12.0 && guard++ < 500) {
+                daynum += 0.02
+                sunPos = getSunPosition(observer, daynumToMillis(daynum))
+            }
+        }
+
+        // Phase 2: advance until sun starts rising toward threshold (elevation increasing)
+        var guard = 0
+        while (sunPos.elevation < -threshold && guard++ < 500) {
+            daynum += 0.008
+            sunPos = getSunPosition(observer, daynumToMillis(daynum))
+        }
+
+        // Phase 3: converge symmetrically on elevation = -threshold (sunrise)
+        var sunrise = 0.0
+        guard = 0
+        while (sunrise == 0.0 && guard++ < 200) {
+            val delta = sunPos.elevation + threshold
+            if (abs(delta) < 0.01) {
+                sunrise = daynum
+            } else {
+                daynum -= 0.004 * delta
+                sunPos = getSunPosition(observer, daynumToMillis(daynum))
+            }
+        }
+        if (sunrise == 0.0) sunrise = daynum
+
+        // Phase 4: fast-forward through the day until sun drops back below threshold
+        daynum = sunrise
+        sunPos = getSunPosition(observer, daynumToMillis(daynum))
+        guard = 0
+        while (sunPos.elevation > -threshold && guard++ < 500) {
+            daynum += 0.008
+            sunPos = getSunPosition(observer, daynumToMillis(daynum))
+        }
+
+        // Phase 5: converge symmetrically on elevation = -threshold (sunset)
+        var sunset = 0.0
+        guard = 0
+        while (sunset == 0.0 && guard++ < 200) {
+            val delta = sunPos.elevation + threshold
+            if (abs(delta) < 0.01) {
+                sunset = daynum
+            } else {
+                daynum += 0.004 * delta
+                sunPos = getSunPosition(observer, daynumToMillis(daynum))
+            }
+        }
+        if (sunset == 0.0) sunset = daynum
+
+        return RiseSetTimes(daynumToMillis(sunrise), daynumToMillis(sunset))
+    }
+
+    /**
+     * Find the next moonrise and moonset times from [startMillis] for [observer].
+     * Uses the adaptive iteration from PREDICT v2.2.5's PredictMoon().
+     */
+    fun findMoonRiseSet(observer: GeoPos, startMillis: Long): RiseSetTimes {
+        var daynum = millisToDaynum(startMillis)
+        var moonPos = getMoonPosition(observer, daynumToMillis(daynum))
+
+        // If moon is already up, move forward until it sets
+        var guard = 0
+        if (moonPos.elevation > 0) {
+            while (moonPos.elevation > 0 && guard++ < 1000) {
+                daynum += 0.004 * sin(DEG2RAD * (moonPos.elevation + 0.5))
+                moonPos = getMoonPosition(observer, daynumToMillis(daynum))
+            }
+            daynum += 0.4
+            moonPos = getMoonPosition(observer, daynumToMillis(daynum))
+        }
+        // Find moonrise
+        var moonrise = 0.0
+        guard = 0
+        while (moonrise == 0.0 && guard++ < 1000) {
+            if (abs(moonPos.elevation) < 0.03) {
+                moonrise = daynum
+            } else {
+                daynum -= 0.004 * moonPos.elevation
+                moonPos = getMoonPosition(observer, daynumToMillis(daynum))
+            }
+        }
+        if (moonrise == 0.0) moonrise = daynum
+
+        // Find moonset from moonrise
+        daynum = moonrise
+        moonPos = getMoonPosition(observer, daynumToMillis(daynum))
+        guard = 0
+        while (moonPos.elevation > -1 && guard++ < 1000) {
+            daynum += 0.04 * cos(DEG2RAD * (moonPos.elevation + 0.5))
+            moonPos = getMoonPosition(observer, daynumToMillis(daynum))
+        }
+        var moonset = 0.0
+        guard = 0
+        while (moonset == 0.0 && guard++ < 1000) {
+            if (abs(moonPos.elevation) < 0.03) {
+                moonset = daynum
+            } else {
+                daynum += 0.004 * moonPos.elevation
+                moonPos = getMoonPosition(observer, daynumToMillis(daynum))
+            }
+        }
+        if (moonset == 0.0) moonset = daynum
+
+        return RiseSetTimes(daynumToMillis(moonrise), daynumToMillis(moonset))
+    }
+
+    // ── Visual magnitude estimation ──
+
+    /**
+     * Estimate the apparent visual magnitude of a satellite.
+     *
+     * Uses the standard formula from McCants/Heavens-Above:
+     *   apparentMag = stdMag + 5 * log10(range / 1000) - 15 * log10(cos(phaseAngle / 2))
+     *
+     * @param rangeKm slant range from observer to satellite in km
+     * @param phaseAngleDeg Sun-satellite-observer angle in degrees
+     * @param stdMag intrinsic/standard magnitude (default 4.0)
+     * @return estimated apparent visual magnitude
+     */
+    fun estimateVisualMagnitude(rangeKm: Double, phaseAngleDeg: Double, stdMag: Double = 4.0): Double {
+        if (rangeKm <= 0) return stdMag
+        val halfPhaseRad = phaseAngleDeg.toRadians() / 2.0
+        val cosHalfPhase = cos(halfPhaseRad)
+        val phaseTerm = if (cosHalfPhase > 1e-6) -15.0 * log10(cosHalfPhase) else 99.0
+        return stdMag + 5.0 * log10(rangeKm / 1000.0) + phaseTerm
+    }
+
+    /**
+     * Compute the phase angle (Sun-satellite-observer) in degrees.
+     *
+     * @param satPosECI satellite ECI position [x, y, z] in km
+     * @param sunPosECI sun ECI position [x, y, z] in km
+     * @param obsPosECI observer ECI position [x, y, z] in km
+     * @return phase angle in degrees (0 = fully illuminated face toward observer)
+     */
+    fun computePhaseAngle(satPosECI: DoubleArray, sunPosECI: DoubleArray, obsPosECI: DoubleArray): Double {
+        val toSunX = sunPosECI[0] - satPosECI[0]
+        val toSunY = sunPosECI[1] - satPosECI[1]
+        val toSunZ = sunPosECI[2] - satPosECI[2]
+        val toObsX = obsPosECI[0] - satPosECI[0]
+        val toObsY = obsPosECI[1] - satPosECI[1]
+        val toObsZ = obsPosECI[2] - satPosECI[2]
+        val dot = toSunX * toObsX + toSunY * toObsY + toSunZ * toObsZ
+        val magSun = sqrt(toSunX * toSunX + toSunY * toSunY + toSunZ * toSunZ)
+        val magObs = sqrt(toObsX * toObsX + toObsY * toObsY + toObsZ * toObsZ)
+        if (magSun == 0.0 || magObs == 0.0) return 90.0
+        val cosAngle = (dot / (magSun * magObs)).coerceIn(-1.0, 1.0)
+        return acos(cosAngle).toDegrees()
+    }
+
+    // ── Doppler ──
+
+    /**
+     * Compute Doppler shift for a given base frequency and range rate.
+     *
+     * @param frequencyHz base frequency in Hz
+     * @param rangeRateKmS range rate in km/s (negative = approaching)
+     * @return shifted frequency in Hz
+     */
+    fun dopplerShift(frequencyHz: Double, rangeRateKmS: Double): Double {
+        return frequencyHz * (299792.458 - rangeRateKmS) / 299792.458
+    }
+
+    // ── Internal helpers ──
+
+    private fun observerGeodetic(pos: GeoPos): DoubleArray {
+        // [lat_rad, lon_rad, alt_km] — longitude positive east, matching OrbitalObject convention.
+        // LST = thetaGJD(julUtc) + obsGeo[1] = GMST + lon_rad (correct).
+        return doubleArrayOf(pos.latitude * DEG2RAD, pos.longitude * DEG2RAD, pos.altitude / 1000.0)
+    }
+
+    /**
+     * Convert az/el observation to Right Ascension / Declination.
+     * Returns [ra_rad, dec_rad].
+     * Based on Calculate_RADec() from PREDICT v2.2.5 (Escobal method).
+     */
+    private fun calculateRADec(
+        julUtc: Double,
+        targetPos: DoubleArray,
+        targetVel: DoubleArray,
+        obsGeo: DoubleArray
+    ): DoubleArray {
+        val obsSet = computeObsAngles(julUtc, targetPos, targetVel, obsGeo)
+        val az = obsSet[0]
+        val el = obsSet[1]
+        val phi = obsGeo[0]
+        val theta = mod2PI(thetaGJD(julUtc) + obsGeo[1])
+        val sinTheta = sin(theta)
+        val cosTheta = cos(theta)
+        val sinPhi = sin(phi)
+        val cosPhi = cos(phi)
+        val lxh = -cos(az) * cos(el)
+        val lyh = sin(az) * cos(el)
+        val lzh = sin(el)
+        val sx = sinPhi * cosTheta
+        val ex2 = -sinTheta
+        val zx = cosTheta * cosPhi
+        val sy = sinPhi * sinTheta
+        val zy = sinTheta * cosPhi
+        val sz = -cosPhi
+        val lx = sx * lxh + ex2 * lyh + zx * lzh
+        val ly = sy * lxh + cosTheta * lyh + zy * lzh
+        val lz = sz * lxh + 0.0 * lyh + sinPhi * lzh
+        val dec = asin(lz)
+        val cosDelta = sqrt(1.0 - lz * lz)
+        val sinAlpha = ly / cosDelta
+        val cosAlpha = lx / cosDelta
+        val ra = mod2PI(atan2(sinAlpha, cosAlpha))
+        return doubleArrayOf(ra, dec)
+    }
+
+    /**
+     * Compute observer look-angles (az, el, range, rangeRate) to a target at ECI position.
+     * Returns [azimuth_rad, elevation_rad, range_km, rangeRate_km/s].
+     * Azimuth is north-referenced (0=N, π/2=E), matching OrbitalObject's convention.
+     */
+    private fun computeObsAngles(
+        julUtc: Double,
+        targetPos: DoubleArray,
+        targetVel: DoubleArray,
+        obsGeo: DoubleArray // [lat_rad, lon_rad, alt_km]
+    ): DoubleArray {
+        val theta = mod2PI(thetaGJD(julUtc) + obsGeo[1])
+        val c = 1.0 / sqrt(1 + FLAT_FACT * (FLAT_FACT - 2) * sin(obsGeo[0]).pow(2))
+        val sq = (1 - FLAT_FACT).pow(2) * c
+        val achcp = (EARTH_RADIUS * c + obsGeo[2]) * cos(obsGeo[0])
+        val ox = achcp * cos(theta)
+        val oy = achcp * sin(theta)
+        val oz = (EARTH_RADIUS * sq + obsGeo[2]) * sin(obsGeo[0])
+        val ovx = -MFACTOR * oy
+        val ovy = MFACTOR * ox
+
+        val rx = targetPos[0] - ox
+        val ry = targetPos[1] - oy
+        val rz = targetPos[2] - oz
+        val rMag = sqrt(rx * rx + ry * ry + rz * rz)
+        val rvx = targetVel[0] - ovx
+        val rvy = targetVel[1] - ovy
+        val rvz = targetVel[2]
+
+        val sinLat = sin(obsGeo[0])
+        val cosLat = cos(obsGeo[0])
+        val sinTheta = sin(theta)
+        val cosTheta = cos(theta)
+        val topS = sinLat * cosTheta * rx + sinLat * sinTheta * ry - cosLat * rz
+        val topE = -sinTheta * rx + cosTheta * ry
+        val topZ = cosLat * cosTheta * rx + cosLat * sinTheta * ry + sinLat * rz
+
+        // Match north-based convention (0=N, 90=E) used by OrbitalObject.calculateObs
+        // Must use atan(-topE / topS) not atan2(-topE, topS) — they differ in quadrant handling
+        var azim = atan(-topE / topS)
+        if (topS > 0.0) azim += PI
+        if (azim < 0.0) azim += TWO_PI
+        val el = asin(topZ / rMag)
+        val rangeRate = (rx * rvx + ry * rvy + rz * rvz) / rMag
+
+        return doubleArrayOf(azim, el, rMag, rangeRate)
+    }
+
+    private const val MFACTOR = 7.292115E-5
+
+    private fun primeAngle(x: Double) = x - 360.0 * floor(x / 360.0)
+
+    private fun fixAngle(x: Double): Double {
+        var a = x; while (a > TWO_PI) a -= TWO_PI; return a
+    }
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/predict/Constants.kt

@@ -21,6 +21,7 @@ const val ASTRONOMICAL_UNIT = 1.49597870691E8
 const val DEG2RAD = 0.017453292519943295
 const val RAD2DEG = 57.29577951308232
 const val EARTH_RADIUS = 6378.137
+const val EARTH_ROT_PER_SID_DAY = 1.00273790934
 const val EPSILON = 1.0E-12
 const val FLAT_FACT = 3.35281066474748E-3
 const val J3_HARMONIC = -2.53881E-6

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/predict/OrbitalData.kt

@@ -27,7 +27,8 @@ data class OrbitalData(
     val argper: Double,
     val meanan: Double,
     val catnum: Int,
-    val bstar: Double
+    val bstar: Double,
+    val ndot: Double = 0.0
 ) {
     val xincl: Double = incl * DEG2RAD
     val xnodeo: Double = raan * DEG2RAD
@@ -37,4 +38,29 @@ data class OrbitalData(
     val orbitalPeriod: Double = MIN_PER_DAY / meanmo
     val isDeepSpace: Boolean = orbitalPeriod >= 225.0 // NearEarth (period < 225 min) or DeepSpace (period >= 225 min)
     fun getObject(): OrbitalObject = if (isDeepSpace) DeepSpaceObject(this) else NearEarthObject(this)
+
+    /** Check if satellite has likely decayed by the given time. */
+    fun hasDecayed(currentTimeMillis: Long): Boolean {
+        if (ndot == 0.0) return false
+        val currentDaynum = (currentTimeMillis - 315446400000L) / 86400000.0
+        val epochDaynum = epochToDaynum(epoch)
+        return CelestialComputer.hasDecayed(meanmo, ndot, epochDaynum, currentDaynum)
+    }
+
+    private fun epochToDaynum(epoch: Double): Double {
+        var year = kotlin.math.floor(epoch * 1E-3)
+        val day = (epoch * 1E-3 - year) * 1000.0
+        year = if (year < 57) year + 2000 else year + 1900
+        // daynum = days since 31 Dec 1979, Julian date of 31Dec79 = 2444238.5
+        val jan1Jd = julianDateOfYear(year)
+        return jan1Jd + day - 2444238.5
+    }
+
+    private fun julianDateOfYear(theYear: Double): Double {
+        val aYear = theYear - 1
+        val a = kotlin.math.floor(aYear / 100).toLong()
+        val b = 2 - a + a / 4
+        val i = kotlin.math.floor(365.25 * aYear).toLong()
+        return i + (30.6001 * 14).toLong() + 1720994.5 + b
+    }
 }

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/predict/OrbitalMath.kt

@@ -0,0 +1,141 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.domain.predict
+
+import kotlin.math.abs
+import kotlin.math.atan2
+import kotlin.math.cos
+import kotlin.math.floor
+import kotlin.math.sin
+import kotlin.math.sqrt
+
+// ── Shared orbital math utilities ──
+// Used by both CelestialComputer (sun/moon/celestial) and OrbitalObject (SGP4/SDP4).
+// Package-internal — not part of the public API.
+
+/**
+ * Greenwich Mean Sidereal Time from Julian Date, in radians [0, 2π).
+ * Identical algorithm used in PREDICT v2.2.5 for both solar and satellite calculations.
+ */
+internal fun thetaGJD(jd: Double): Double {
+    val ut = fraction(jd + 0.5)
+    val aJD = jd - ut
+    val tu = (aJD - 2451545.0) / 36525.0
+    var gmst = 24110.54841 + tu * (8640184.812866 + tu * (0.093104 - tu * 6.2E-6))
+    gmst = modulus(gmst + SEC_PER_DAY * EARTH_ROT_PER_SID_DAY * ut, SEC_PER_DAY)
+    return TWO_PI * gmst / SEC_PER_DAY
+}
+
+/** Fractional part of [arg]. */
+internal fun fraction(arg: Double): Double = arg - floor(arg)
+
+/** Modulo: returns [arg1] mod [arg2], result always in [0, arg2). */
+internal fun modulus(arg1: Double, arg2: Double): Double {
+    var r = arg1
+    val i = floor(r / arg2).toInt()
+    r -= i * arg2
+    if (r < 0.0) r += arg2
+    return r
+}
+
+/** Reduce [value] to [0, 2π). */
+internal fun mod2PI(value: Double): Double {
+    var r = value
+    val i = (r / TWO_PI).toInt()
+    r -= i * TWO_PI
+    if (r < 0.0) r += TWO_PI
+    return r
+}
+
+/**
+ * Delta-ET: difference between Universal Time and Ephemeris Time (seconds).
+ * Based on least-squares fit from 1950 to 1991 (PREDICT v2.2.5).
+ */
+internal fun deltaET(year: Double): Double =
+    26.465 + 0.747622 * (year - 1950) + 1.886913 * sin(TWO_PI * (year - 1975) / 33)
+
+/**
+ * Convert Unix epoch milliseconds to daynum (days since 31 Dec 1979 00:00:00 UTC).
+ */
+internal fun millisToDaynum(timeMillis: Long): Double =
+    (timeMillis - 315446400000L) / 86400000.0
+
+/** Convert daynum back to Unix epoch milliseconds. */
+internal fun daynumToMillis(daynum: Double): Long =
+    ((daynum + 3651.0) * 86400000.0).toLong()
+
+/**
+ * Compute the Sun's ECI position vector at [julUtc] (Julian UTC).
+ * Returns [x, y, z, magnitude] in km.
+ * Based on Calculate_Solar_Position() / FindSun() from PREDICT v2.2.5.
+ */
+internal fun solarPositionECI(julUtc: Double): DoubleArray {
+    val mjd = julUtc - 2415020.0
+    val year = 1900 + mjd / 365.25
+    val t = (mjd + deltaET(year) / SEC_PER_DAY) / 36525.0
+    val mDeg = mod360(358.47583 + mod360(35999.04975 * t) - (0.000150 + 0.0000033 * t) * t * t)
+    val m = mDeg * DEG2RAD
+    val lDeg = mod360(279.69668 + mod360(36000.76892 * t) + 0.0003025 * t * t)
+    val l = lDeg * DEG2RAD
+    val e = 0.01675104 - (0.0000418 + 0.000000126 * t) * t
+    val cDeg = (1.919460 - (0.004789 + 0.000014 * t) * t) * sin(m) +
+        (0.020094 - 0.000100 * t) * sin(2 * m) + 0.000293 * sin(3 * m)
+    val c = cDeg * DEG2RAD
+    val oDeg = mod360(259.18 - 1934.142 * t)
+    val o = oDeg * DEG2RAD
+    val lsa = mod2PI(l + c - (0.00569 - 0.00479 * sin(o)) * DEG2RAD)
+    val nu = mod2PI(m + c)
+    var r = 1.0000002 * (1.0 - e * e) / (1.0 + e * cos(nu))
+    val epsDeg = 23.452294 - (0.0130125 + (0.00000164 - 0.000000503 * t) * t) * t + 0.00256 * cos(o)
+    val eps = epsDeg * DEG2RAD
+    r *= ASTRONOMICAL_UNIT
+    return doubleArrayOf(r * cos(lsa), r * sin(lsa) * cos(eps), r * sin(lsa) * sin(eps), r)
+}
+
+/**
+ * Convert ECI position [eciPos] = [x, y, z] (km) to geodetic [lat_rad, lon_rad, alt_km].
+ * Based on Calculate_LatLonAlt() from PREDICT v2.2.5.
+ */
+internal fun eciToGeodetic(julUtc: Double, eciPos: DoubleArray): DoubleArray {
+    val thetaPos = atan2(eciPos[1], eciPos[0])
+    val lon = mod2PI(thetaPos - thetaGJD(julUtc))
+    val r = sqrt(eciPos[0] * eciPos[0] + eciPos[1] * eciPos[1])
+    val e2 = FLAT_FACT * (2.0 - FLAT_FACT)
+    var lat = atan2(eciPos[2], r)
+    var phi: Double
+    var c: Double
+    var i = 0
+    do {
+        phi = lat
+        c = 1.0 / sqrt(1.0 - e2 * sin(phi) * sin(phi))
+        lat = atan2(eciPos[2] + EARTH_RADIUS * c * e2 * sin(phi), r)
+    } while (i++ < 10 && abs(lat - phi) >= 1E-10)
+    val alt = r / cos(lat) - EARTH_RADIUS * c
+    if (lat > PI_2) lat -= TWO_PI
+    return doubleArrayOf(lat, lon, alt)
+}
+
+// Private helpers
+
+private fun mod360(x: Double): Double {
+    var r = x
+    val i = (r / 360.0).toInt()
+    r -= i * 360.0
+    if (r < 0.0) r += 360.0
+    return r
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/predict/OrbitalObject.kt

@@ -314,14 +314,8 @@ abstract class OrbitalObject(val data: OrbitalData) {
         return 1.0 / value
     }
 
-    // Calculates the modulus of 2 * PI
-    internal fun mod2PI(value: Double): Double {
-        var retVal = value
-        val i = (retVal / TWO_PI).toInt()
-        retVal -= i * TWO_PI
-        if (retVal < 0.0) retVal += TWO_PI
-        return retVal
-    }
+    // Delegates to package-level mod2PI in OrbitalMath.kt
+    internal fun mod2PI(value: Double): Double = com.rtbishop.look4sat.core.domain.predict.mod2PI(value)
 
     // Solves Keplers' Equation
     internal fun converge(temp: DoubleArray, axn: Double, ayn: Double, capu: Double) {
@@ -423,19 +417,8 @@ abstract class OrbitalObject(val data: OrbitalData) {
         return acos(dot(v1, v2) / (v1.w * v2.w))
     }
 
-    /**
-     * The function Delta_ET has been added to allow calculations on the
-     * position of the sun. It provides the difference between UT (approximately
-     * the same as UTC) and ET (now referred to as TDT) This function is based
-     * on the least squares fit of data from 1950 to 1991 and will need to be
-     * updated periodically.
-     *
-     * Values determined using data from 1950-1991 in the 1990 Astronomical
-     * Almanac. See DELTA_ET.WQ1 for details.
-     */
-    private fun deltaEt(year: Double): Double {
-        return 26.465 + 0.747622 * (year - 1950) + (1.886913 * sin(TWO_PI * (year - 1975) / 33))
-    }
+    // Delegates to package-level deltaET in OrbitalMath.kt
+    private fun deltaEt(year: Double): Double = deltaET(year)
 
     private fun radians(degrees: Double): Double {
         return degrees * DEG2RAD
@@ -446,23 +429,13 @@ abstract class OrbitalObject(val data: OrbitalData) {
         return v1.x * v2.x + v1.y * v2.y + v1.z * v2.z
     }
 
-    // Returns fractional part of double argument
-    private fun fraction(arg: Double): Double {
-        return arg - floor(arg)
-    }
-
     // Calculates scalar magnitude of a vector4 argument
     private fun magnitude(v: Vector4) {
         v.w = sqrt(sqr(v.x) + sqr(v.y) + sqr(v.z))
     }
 
-    private fun modulus(arg1: Double, arg2: Double = SEC_PER_DAY): Double {
-        var returnValue = arg1
-        val i = floor(returnValue / arg2).toInt()
-        returnValue -= i * arg2
-        if (returnValue < 0.0) returnValue += arg2
-        return returnValue
-    }
+    private fun modulus(arg1: Double, arg2: Double = SEC_PER_DAY): Double =
+        com.rtbishop.look4sat.core.domain.predict.modulus(arg1, arg2)
 
     // Multiplies the vector v1 by the scalar k
     private fun scaleVector(k: Double, v: Vector4) {
@@ -470,13 +443,6 @@ abstract class OrbitalObject(val data: OrbitalData) {
         magnitude(v)
     }
 
-    private fun thetaGJD(theJD: Double): Double {
-        val earthRotPerSidDay = 1.00273790934
-        val ut = fraction(theJD + 0.5)
-        val aJD = theJD - ut
-        val tu = (aJD - 2451545.0) / 36525.0
-        var gmst = 24110.54841 + tu * (8640184.812866 + tu * (0.093104 - tu * 6.2E-6))
-        gmst = modulus(gmst + SEC_PER_DAY * earthRotPerSidDay * ut)
-        return TWO_PI * gmst / SEC_PER_DAY
-    }
+    // Delegates to package-level thetaGJD in OrbitalMath.kt
+    private fun thetaGJD(theJD: Double): Double = com.rtbishop.look4sat.core.domain.predict.thetaGJD(theJD)
 }

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/predict/OrbitalPass.kt

@@ -25,9 +25,10 @@ data class OrbitalPass(
     val altitude: Int = 1000,
     val maxElevation: Double = 75.0,
     val orbitalObject: OrbitalObject,
-    val progress: Float = 0.0f
+    val progress: Float = 0.0f,
+    val hasDecayed: Boolean = false
 ) {
     val catNum: Int = orbitalObject.data.catnum
-    val name: String = orbitalObject.data.name
+    val name: String = if (hasDecayed) "${orbitalObject.data.name} (decayed?)" else orbitalObject.data.name
     val isDeepSpace: Boolean = orbitalObject.data.isDeepSpace
 }

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/predict/OrbitalPos.kt

@@ -63,10 +63,8 @@ data class OrbitalPos(
         val sinBeta = sin(beta)
         for (azimuth in 0..720) {
             val rads = azimuth * DEG2RAD
-            val sinRads = sin(rads)
-            val cosRads = cos(rads)
-            val lat = asin(sinLat * cosBeta + cosLat * sinBeta * cosRads)
-            val lon = longitude + atan2(sinRads * sinBeta * cosLat, cosBeta - sinLat * sin(lat))
+            val lat = asin(sinLat * cosBeta + cosLat * sinBeta * cos(rads))
+            val lon = longitude + atan2(sin(rads) * sinBeta * cosLat, cosBeta - sinLat * sin(lat))
             rangeCirclePoints.add(GeoPos(lat * RAD2DEG, lon * RAD2DEG))
         }
         return rangeCirclePoints

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/repository/IDatabaseRepo.kt

@@ -18,8 +18,8 @@
 package com.rtbishop.look4sat.core.domain.repository
 
 interface IDatabaseRepo {
-    suspend fun updateTLEFromFile(uri: String)
-    suspend fun updateTransceiversFromFile(uri: String)
+    suspend fun updateTLEFromFile(uri: String): Int
+    suspend fun updateTransceiversFromFile(uri: String): Int
     suspend fun updateFromRemote()
     suspend fun clearAllData()
 }

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/repository/IMainContainer.kt

@@ -1,8 +1,28 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
 package com.rtbishop.look4sat.core.domain.repository
-
+import com.rtbishop.look4sat.core.domain.model.SatRadio
 import com.rtbishop.look4sat.core.domain.usecase.IAddToCalendar
+import com.rtbishop.look4sat.core.domain.usecase.IAudioCapture
+import com.rtbishop.look4sat.core.domain.usecase.ISaveImage
 import com.rtbishop.look4sat.core.domain.usecase.IShowToast
 import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.flow.StateFlow
 
 interface IMainContainer {
     val appScope: CoroutineScope
@@ -10,6 +30,9 @@ interface IMainContainer {
     val selectionRepo: ISelectionRepo
     val satelliteRepo: ISatelliteRepo
     val databaseRepo: IDatabaseRepo
+    val radioTrackingService: IRadioTrackingService
+    val mutualPassData: StateFlow<MutualPassData>
+    fun setMutualPassData(data: MutualPassData)
     fun provideAddToCalendar(): IAddToCalendar
     fun provideShowToast(): IShowToast
     fun provideBluetoothReporter(): IReporter
@@ -17,9 +40,29 @@ interface IMainContainer {
     fun provideSensorsRepo(): ISensorsRepo
     fun provideTxRadioController(): IRadioController
     fun provideRxRadioController(): IRadioController
-    val radioTrackingService: IRadioTrackingService
+    fun provideAudioCapture(): IAudioCapture
+    fun provideSaveImage(): ISaveImage
 }
 
+data class MutualPassData(
+    val samples: List<Pair<Long, Pair<Double, Double>>> = emptyList(),
+    val trackSamples: List<TrackSampleData> = emptyList(),
+    val startTime: Long = 0L,
+    val endTime: Long = 0L,
+    val maxElev: Double = 10.0,
+    val labelA: String = "你",
+    val labelB: String = "友台"
+)
+
+/** Minimal track sample for cross-module sharing (angles in degrees). */
+data class TrackSampleData(
+    val time: Long = 0L,
+    val azimuthA: Double,
+    val elevationA: Double,
+    val azimuthB: Double,
+    val elevationB: Double
+)
+
 interface IContainerProvider {
     fun getMainContainer(): IMainContainer
 }

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/repository/IRadioController.kt

@@ -38,4 +38,51 @@ interface IRadioController {
     suspend fun pttOn(): Boolean
 
     suspend fun pttOff(): Boolean
+
+    // ── Extended operations (IC-705 / CI-V) ──────────────────────────────
+
+    /**
+     * Select the band matching [frequencyHz] via the band stacking register.
+     * Must be called before [setFrequency] and [setMode] when first tracking.
+     * Default: no-op (Yaesu radios auto-switch band via frequency).
+     */
+    suspend fun setBand(frequencyHz: Long): Boolean = false
+
+    /**
+     * Select the active VFO.
+     * @param vfoA true → VFO-A (main/RX), false → VFO-B (sub/TX in split).
+     */
+    suspend fun setVfo(vfoA: Boolean): Boolean = false
+
+    /**
+     * Enable or disable SPLIT mode (TX on sub-VFO, RX on main VFO).
+     * Default: not supported.
+     */
+    suspend fun setSplitMode(enabled: Boolean): Boolean = false
+
+    /**
+     * Set the frequency of the currently active VFO (IC-705: CMD 0x25 sub 0x00).
+     * Default: delegates to [setFrequency].
+     */
+    suspend fun setWorkingFrequency(frequencyHz: Long): Boolean = setFrequency(frequencyHz)
+
+    /**
+     * Set the frequency of the inactive/TX VFO (IC-705: CMD 0x25 sub 0x01).
+     * Sent every tracking cycle alongside [setWorkingFrequency] in split mode.
+     * Default: delegates to [setWorkingFrequency].
+     */
+    suspend fun setTxVfoFrequency(frequencyHz: Long): Boolean = setWorkingFrequency(frequencyHz)
+
+    /**
+     * Read the frequency of the currently active VFO (IC-705: CMD 0x25 sub 0x00).
+     * Default: delegates to [readFrequencyAndMode].
+     */
+    suspend fun readWorkingFrequency(): Long? = readFrequencyAndMode()?.first
+
+    /**
+     * Read the frequency of the inactive/TX VFO (IC-705: CMD 0x25 sub 0x01).
+     * Used for tuning detection in split mode.
+     * Default: delegates to [readWorkingFrequency].
+     */
+    suspend fun readTxVfoFrequency(): Long? = readWorkingFrequency()
 }

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/repository/ISatelliteRepo.kt

@@ -34,11 +34,25 @@ interface ISatelliteRepo {
     /** Whether the repo is currently calculating passes. */
     val isCalculating: StateFlow<Boolean>
 
+    /** Currently selected pass (catNum + aosTime), persisted across screen navigations. */
+    val selectedPass: StateFlow<Pair<Int, Long>>
+
+    /** Set the currently selected pass. */
+    fun selectPass(catNum: Int, aosTime: Long)
+
     /** Load satellite objects from DB based on the current selection. */
     suspend fun initRepository()
 
     /** Recalculate passes with the given filter parameters. */
-    suspend fun calculatePasses(time: Long, hoursAhead: Int, minElevation: Double, modes: List<String>)
+    suspend fun calculatePasses(
+        time: Long,
+        hoursAhead: Int,
+        minElevation: Double,
+        aosStartMinute: Int,
+        aosEndMinute: Int,
+        invertAosTimeWindow: Boolean,
+        modes: List<String>
+    )
 
     /** Get the current position of a single satellite. */
     suspend fun getPosition(sat: OrbitalObject, pos: GeoPos, time: Long): OrbitalPos

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/repository/ISensorsRepo.kt

@@ -21,7 +21,7 @@ import com.rtbishop.look4sat.core.domain.predict.GeoPos
 import kotlinx.coroutines.flow.StateFlow
 
 interface ISensorsRepo {
-    val orientation: StateFlow<Pair<Float, Float>>
+    val sensorData: StateFlow<Pair<Float, Float>>
     fun getMagDeclination(geoPos: GeoPos, time: Long = System.currentTimeMillis()): Float
     fun enableSensor()
     fun disableSensor()

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/source/Sources.kt

@@ -18,7 +18,6 @@
 package com.rtbishop.look4sat.core.domain.source
 
 object Sources {
-    const val RADIO_DATA_URL = "https://db.satnogs.org/api/transmitters/?format=json&status=active"
     val satelliteDataUrls = mapOf(
         "All" to "https://celestrak.org/NORAD/elements/gp.php?GROUP=active&FORMAT=csv",
         "Amateur" to "https://celestrak.org/NORAD/elements/gp.php?GROUP=amateur&FORMAT=csv",
@@ -49,4 +48,7 @@ object Sources {
         "R4UAB" to "https://r4uab.ru/satonline.txt",
         "Other" to "" // key for sats filter
     )
+    val transceiversDataUrls = mapOf(
+        "SatNOGS" to "https://db.satnogs.org/api/transmitters/?format=json&status=active"
+    )
 }

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/sstv/SstvDecoder.kt

@@ -0,0 +1,816 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.domain.sstv
+
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.channels.BufferOverflow
+import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.SharedFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.withContext
+import kotlin.math.PI
+import kotlin.math.abs
+import kotlin.math.round
+import kotlin.math.sqrt
+
+class SstvFrame(
+    val scopePixels: IntArray?,
+    val scopeWidth: Int,
+    val scopeHeight: Int,
+    val imagePixels: IntArray?,
+    val imageWidth: Int,
+    val imageHeight: Int,
+    val modeName: String,
+    val imageComplete: Boolean,
+    val inputRms: Float,
+    val appliedGain: Float,
+    val syncHitRate: Float,
+    val predictedLineBursts: Int,
+    val maxPredictedStreak: Int,
+    val timingErrorSamples: Int
+)
+
+/**
+ * Decoder quality metrics for diagnostics and logging. Useful for profiling decode
+ * performance on noisy recordings.
+ */
+data class SstvQualityMetrics(
+    val syncHitRate: Float,
+    val predictedLineBursts: Int,
+    val maxPredictedStreak: Int,
+    val timingErrorSamples: Int
+)
+
+enum class LineRecoveryStrategy {
+    Look4SatLimited,
+    Robot36Compatible
+}
+
+class SstvDiagnosticsHandle internal constructor(
+    val enabled: Boolean,
+    val metrics: StateFlow<SstvQualityMetrics?>
+)
+
+class SstvDecoder(
+    sampleRate: Int = 44100,
+    scopeWidth: Int = 320,
+    scopeHeight: Int = 256,
+    private val channelSelect: Int = 0,
+    targetRmsLevel: Float = 0.25f,
+    private val includeScopeData: Boolean = false,
+    private val enableRmsNormalization: Boolean = true,
+    preFilterCutoffHz: Double = 500.0,
+    enablePreFilter: Boolean = true,
+    private val enableDiagnosticsHandle: Boolean = false,
+    lineRecoveryStrategy: LineRecoveryStrategy = LineRecoveryStrategy.Look4SatLimited
+) {
+    private val scopeBuffer = PixelBuffer(scopeWidth, scopeHeight * 2)
+    private val imageBuffer = PixelBuffer(scopeWidth, scopeHeight)
+    private val decoder = DecoderEngine(scopeBuffer, imageBuffer, "Raw", sampleRate, lineRecoveryStrategy)
+    private val _frames = MutableSharedFlow<SstvFrame>(
+        replay = 1,
+        onBufferOverflow = BufferOverflow.DROP_OLDEST
+    )
+    private var lastInputRms = 0f
+    private var lastAppliedGain = 1f
+    private val _qualityMetrics = MutableStateFlow<SstvQualityMetrics?>(null)
+    private val preFilter = if (enablePreFilter) HighPassFilter(preFilterCutoffHz, sampleRate.toDouble()) else null
+    private val diagnosticsHandle = SstvDiagnosticsHandle(enableDiagnosticsHandle, _qualityMetrics)
+    val frames: SharedFlow<SstvFrame> = _frames
+    val supportedModes: List<String> = decoder.allModes.map { it.name }
+
+    suspend fun feedSamples(samples: FloatArray) = withContext(Dispatchers.Default) {
+        // Optional pre-filtering: remove DC offset and subsonic noise that can mask
+        // weak signals and corrupt the RMS normalization baseline.
+        preFilter?.apply(samples)
+
+        // Optional RMS normalization: bring input to a consistent level so the
+        // FM demodulator operates in a predictable region. However, this amplifies
+        // noise proportionally. Aggressive RMS targets (e.g., 0.25) can hurt weak
+        // signals by boosting noise floor. Safer defaults: 0.35-0.50 for noisy inputs.
+        // Disable entirely for direct line-level inputs (e.g., receiver discriminator).
+        val gain = if (enableRmsNormalization) normalise(samples) else GainInfo(0f, 1f)
+        lastInputRms = gain.inputRms
+        lastAppliedGain = gain.appliedGain
+        val hasNewLines = decoder.process(samples, channelSelect)
+        if (hasNewLines) emitFrame()
+    }
+
+    fun lockMode(modeName: String) = decoder.setMode(modeName)
+
+    fun clearPixels() {
+        imageBuffer.line = -1
+        imageBuffer.pixels.fill(0)
+        decoder.resetQuality()
+        if (enableDiagnosticsHandle) _qualityMetrics.value = null
+    }
+
+    fun getDiagnosticsHandle(): SstvDiagnosticsHandle? = diagnosticsHandle.takeIf { it.enabled }
+
+    /**
+     * Export quality metrics for logging/diagnostics. Useful for profiling decode
+     * performance on noisy recordings. Returns null before first frame is emitted.
+     */
+    @Suppress("unused")
+    fun getQualityMetrics(): SstvQualityMetrics? {
+        if (enableDiagnosticsHandle) return _qualityMetrics.value
+        val q = decoder.quality()
+        return SstvQualityMetrics(
+            syncHitRate = q.syncHitRate,
+            predictedLineBursts = q.predictedLineBursts,
+            maxPredictedStreak = q.maxPredictedStreak,
+            timingErrorSamples = q.timingErrorSamples
+        )
+    }
+
+    private fun emitFrame() {
+        val imageWidth = imageBuffer.width
+        val imageHeight = imageBuffer.height
+        val quality = decoder.quality()
+        if (enableDiagnosticsHandle) {
+            _qualityMetrics.value = SstvQualityMetrics(
+                syncHitRate = quality.syncHitRate,
+                predictedLineBursts = quality.predictedLineBursts,
+                maxPredictedStreak = quality.maxPredictedStreak,
+                timingErrorSamples = quality.timingErrorSamples
+            )
+        }
+        val imageComplete = imageBuffer.line >= imageHeight && imageBuffer.line > 0
+        // Copy only the active image region — imageBuffer.pixels is pre-allocated
+        // at the maximum possible size (PD-290: 800×616), so we must not copyOf()
+        // the entire array and send padding pixels to the observer.
+        val imagePixels = if (imageBuffer.line > 0) imageBuffer.pixels.copyOf(imageWidth * imageHeight) else null
+        val modeName = decoder.currentMode.name
+        val scopePixels = if (includeScopeData) scopeBuffer.pixels.copyOf() else null
+        val scopeWidth = if (includeScopeData) scopeBuffer.width else 0
+        val scopeHeight = if (includeScopeData) scopeBuffer.height else 0
+        _frames.tryEmit(
+            SstvFrame(
+                scopePixels = scopePixels,
+                scopeWidth = scopeWidth,
+                scopeHeight = scopeHeight,
+                imagePixels = imagePixels,
+                imageWidth = imageWidth,
+                imageHeight = imageHeight,
+                modeName = modeName,
+                imageComplete = imageComplete,
+                inputRms = lastInputRms,
+                appliedGain = lastAppliedGain,
+                syncHitRate = quality.syncHitRate,
+                predictedLineBursts = quality.predictedLineBursts,
+                maxPredictedStreak = quality.maxPredictedStreak,
+                timingErrorSamples = quality.timingErrorSamples
+            )
+        )
+    }
+
+    // Target RMS level for the normalizer. 0.25 leaves headroom while keeping the
+    // FM demodulator well above its noise floor regardless of input gain.
+    // TUNING GUIDE:
+    //   - 0.20-0.25: Aggressive, best for clean direct-coupled inputs, worst for mic noise
+    //   - 0.35-0.40: Moderate, good balance for typical phone/mic inputs (RECOMMENDED)
+    //   - 0.50-0.60: Conservative, best for noisy environments, reduces amplitude resolution
+    // Disable RMS normalization entirely if using a professional receiver discriminator output.
+    private val targetRms = targetRmsLevel.coerceIn(0.05f, 0.8f)
+
+    private class GainInfo(
+        val inputRms: Float,
+        val appliedGain: Float
+    )
+
+    // Bring the buffer to a fixed RMS so that microphone and direct-coupled inputs
+    // both decode reliably. The guard prevents amplifying pure silence into noise.
+    private fun normalise(buffer: FloatArray): GainInfo {
+        var sumSq = 0f
+        for (s in buffer) sumSq += s * s
+        val rms = sqrt(sumSq / buffer.size)
+        if (rms > 1e-6f) {
+            val gain = targetRms / rms
+            for (i in buffer.indices) buffer[i] *= gain
+            return GainInfo(rms, gain)
+        }
+        return GainInfo(rms, 1f)
+    }
+}
+
+/**
+ * Simple high-pass filter to remove DC offset and subsonic interference before RMS
+ * normalization. Improves noise floor estimation and prevents low-freq noise from
+ * corrupting the gain calculation.
+ *
+ * Design: First-order butterworth (pole at cutoff frequency). Fast, minimal latency,
+ * suitable for real-time preprocessing.
+ */
+internal class HighPassFilter(cutoffHz: Double, sampleRateHz: Double) {
+    private val alpha: Float
+    private var prevInput = 0f
+    private var prevOutput = 0f
+
+    init {
+        // First-order pole placement: alpha = wc / (wc + ws) where wc = 2*pi*fc, ws = 2*pi*fs
+        val omega = 2f * PI.toFloat() * (cutoffHz / sampleRateHz).toFloat()
+        alpha = omega / (omega + 1f)
+    }
+
+    fun apply(buffer: FloatArray) {
+        for (i in buffer.indices) {
+            val input = buffer[i]
+            prevOutput = alpha * (prevOutput + input - prevInput)
+            buffer[i] = prevOutput
+            prevInput = input
+        }
+    }
+}
+
+internal class DecoderQuality(
+    val syncHitRate: Float,
+    val predictedLineBursts: Int,
+    val maxPredictedStreak: Int,
+    val timingErrorSamples: Int
+)
+
+internal enum class SyncPulseWidth { FiveMs, NineMs, TwentyMs }
+
+internal class SyncPulseDetector(sampleRate: Int) {
+
+    companion object {
+        const val SYNC_FREQ = 1200.0
+        const val BLACK_FREQ = 1500.0
+        const val WHITE_FREQ = 2300.0
+    }
+
+    var detectedWidth: SyncPulseWidth = SyncPulseWidth.NineMs; private set
+    var pulseOffset: Int = 0; private set
+    var freqOffset: Float = 0f; private set
+
+    private val bandwidth = WHITE_FREQ - BLACK_FREQ
+    private val fm = FmDemodulator(bandwidth, sampleRate.toDouble())
+    private val min5ms: Int = round(0.0025 * sampleRate).toInt()
+    private val max5ms: Int = round(0.007 * sampleRate).toInt()
+    private val max9ms: Int = round(0.0145 * sampleRate).toInt()
+    private val max20ms: Int = round(0.025 * sampleRate).toInt()
+    private val filterDelay: Int
+    private val avgFilter: MovingAverage
+    private val delayLine: Delay
+    private val lowPass: ComplexFirFilter
+    private val oscillator: Phasor
+    private val syncFreqValue: Float
+    private val syncFreqTolerance: Float
+    private val trigger: SchmittTrigger
+    private var counter = 0
+    private var baseBand = Complex()
+
+    init {
+        val filterLen = round(0.0025 * sampleRate).toInt() or 1
+        filterDelay = (filterLen - 1) / 2
+        avgFilter = MovingAverage(filterLen)
+        delayLine = Delay(filterLen)
+        val loFreq = 1000.0
+        val hiFreq = 2800.0
+        val cutoff = (hiFreq - loFreq) / 2
+        val lpLen = round(0.002 * sampleRate).toInt() or 1
+        lowPass = ComplexFirFilter(lpLen)
+        for (i in 0 until lpLen)
+            lowPass.taps[i] = (WindowFunctions.kaiser(2.0, i, lpLen) * WindowFunctions.sinc(
+                cutoff,
+                sampleRate.toDouble(),
+                i,
+                lpLen
+            )).toFloat()
+        val center = (loFreq + hiFreq) / 2
+        oscillator = Phasor(-center, sampleRate.toDouble())
+        syncFreqValue = ((SYNC_FREQ - center) * 2 / bandwidth).toFloat()
+        syncFreqTolerance = (50 * 2 / bandwidth).toFloat()
+        val porchFreq = 1500.0
+        val hiThresh = (SYNC_FREQ + porchFreq) / 2
+        val loThresh = (SYNC_FREQ + hiThresh) / 2
+        trigger = SchmittTrigger(
+            ((loThresh - center) * 2 / bandwidth).toFloat(),
+            ((hiThresh - center) * 2 / bandwidth).toFloat()
+        )
+    }
+
+    fun process(buffer: FloatArray, channelSelect: Int): Boolean {
+        var detected = false
+        val channels = if (channelSelect > 0) 2 else 1
+        // NOTE: buffer[i] is overwritten in-place with the FM-demodulated frequency
+        // value for every mono sample (channelSelect == 0). DecoderEngine.process()
+        // reads back these values to populate scanLineBuffer. Callers must not reuse
+        // the buffer after this call.
+        for (i in 0 until buffer.size / channels) {
+            when (channelSelect) {
+                1 -> baseBand.set(buffer[2 * i])
+                2 -> baseBand.set(buffer[2 * i + 1])
+                3 -> baseBand.set(buffer[2 * i] + buffer[2 * i + 1])
+                4 -> baseBand.set(buffer[2 * i], buffer[2 * i + 1])
+                else -> baseBand.set(buffer[i])
+            }
+            baseBand = lowPass.filter(baseBand.mul(oscillator.rotate()))
+            val freq = fm.demodulate(baseBand)
+            val avg = avgFilter.avg(freq)
+            val delayed = delayLine.push(avg)
+            buffer[i] = freq
+            if (!trigger.process(avg)) {
+                ++counter
+            } else if (counter !in min5ms..max20ms || abs(delayed - syncFreqValue) > syncFreqTolerance) {
+                counter = 0
+            } else {
+                detectedWidth = when {
+                    counter < max5ms -> SyncPulseWidth.FiveMs
+                    counter < max9ms -> SyncPulseWidth.NineMs
+                    else -> SyncPulseWidth.TwentyMs
+                }
+                pulseOffset = i - filterDelay
+                freqOffset = delayed - syncFreqValue
+                detected = true
+                counter = 0
+            }
+        }
+        return detected
+    }
+}
+
+internal class DecoderEngine(
+    private val scopeBuffer: PixelBuffer,
+    private val imageBuffer: PixelBuffer,
+    rawName: String,
+    sampleRate: Int,
+    lineRecoveryStrategy: LineRecoveryStrategy
+) {
+    private val pixelBuffer = PixelBuffer(800, 2)
+    private val detector = SyncPulseDetector(sampleRate)
+    private val pulseFilter: MovingAverage
+    private val pulseFilterDelay: Int
+    private val scanLineBuffer: FloatArray
+    private val scratch: FloatArray
+    private val sync5ms = IntArray(5)
+    private val sync9ms = IntArray(5)
+    private val sync20ms = IntArray(5)
+    private val lines5ms = IntArray(4)
+    private val lines9ms = IntArray(4)
+    private val lines20ms = IntArray(4)
+    private val offsets5ms = FloatArray(5)
+    private val offsets9ms = FloatArray(5)
+    private val offsets20ms = FloatArray(5)
+    private val visFreqs = FloatArray(10)
+    private val scanLineMin: Int
+    private val syncTolerance: Int
+    private val lineTolerance: Int
+    private val leaderLen: Int
+    private val leaderTol: Int
+    private val transition: Int
+    private val visBitLen: Int
+    private val visLen: Int
+    private val rawMode: SstvMode
+    private val modes5ms: ArrayList<SstvMode>
+    private val modes9ms: ArrayList<SstvMode>
+    private val modes20ms: ArrayList<SstvMode>
+
+    var currentMode: SstvMode; private set
+    val allModes: List<SstvMode> get() = modes5ms + modes9ms + modes20ms
+
+    private var lockMode = false
+    private var sample = 0
+    private var leaderBreak = 0
+    private var lastSync = 0
+    private var curLineSamples: Int
+    private var lastOffset = 0f
+    private var syncChecks = 0
+    private var syncHits = 0
+    private var predictedLineBursts = 0
+    private var predictedStreak = 0
+    private var maxPredictedStreak = 0
+    private var timingErrorSamples = 0
+
+    // Look4Sat strategy limits synthetic lines to avoid visible vertical collapse.
+    // Robot36 strategy preserves legacy behavior by allowing unlimited synthesis.
+    private val maxConsecutivePredictedLines = when (lineRecoveryStrategy) {
+        LineRecoveryStrategy.Look4SatLimited -> 2
+        LineRecoveryStrategy.Robot36Compatible -> Int.MAX_VALUE
+    }
+
+    init {
+        imageBuffer.line = -1
+        // Pre-allocate for the largest possible mode (PD-290: 800×616 = 492 800 ints)
+        // so that handleHeader/processPulse can reuse the array with a fill(0) instead
+        // of allocating a fresh IntArray on every new image, reducing GC pressure.
+        imageBuffer.pixels = IntArray(800 * 616)
+        val pfLen = round(0.0025 * sampleRate).toInt() or 1
+        pulseFilterDelay = (pfLen - 1) / 2
+        pulseFilter = MovingAverage(pfLen)
+        scanLineBuffer = FloatArray(round(7.0 * sampleRate).toInt())
+        scratch = FloatArray(round(1.1 * sampleRate).toInt())
+        leaderLen = round(0.3 * sampleRate).toInt()
+        leaderTol = round(0.06 * sampleRate).toInt()
+        transition = round(0.0005 * sampleRate).toInt()
+        visBitLen = round(0.03 * sampleRate).toInt()
+        visLen = round(0.3 * sampleRate).toInt()
+        scanLineMin = round(0.05 * sampleRate).toInt()
+        syncTolerance = round(0.03 * sampleRate).toInt()
+        lineTolerance = round(0.001 * sampleRate).toInt()
+        rawMode = RawMode(rawName, sampleRate)
+        val robot36 = Robot36Mode(sampleRate)
+        currentMode = robot36
+        curLineSamples = robot36.scanLineSamples
+        modes5ms = arrayListOf(
+            RgbMode.wraaseSc2180(sampleRate),
+            RgbMode.martin("1", 44, 0.146432, sampleRate),
+            RgbMode.martin("2", 40, 0.073216, sampleRate)
+        )
+        modes9ms = arrayListOf(
+            robot36, Robot72Mode(sampleRate),
+            RgbMode.scottie("1", 60, 0.138240, sampleRate),
+            RgbMode.scottie("2", 56, 0.088064, sampleRate),
+            RgbMode.scottie("DX", 76, 0.3456, sampleRate)
+        )
+        modes20ms = arrayListOf(
+            PdMode("50", 93, 320, 256, 0.09152, sampleRate),
+            PdMode("90", 99, 320, 256, 0.17024, sampleRate),
+            PdMode("120", 95, 640, 496, 0.1216, sampleRate),
+            PdMode("160", 98, 512, 400, 0.195584, sampleRate),
+            PdMode("180", 96, 640, 496, 0.18304, sampleRate),
+            PdMode("240", 97, 640, 496, 0.24448, sampleRate),
+            PdMode("290", 94, 800, 616, 0.2288, sampleRate)
+        )
+    }
+
+    fun process(recordBuffer: FloatArray, channelSelect: Int): Boolean {
+        var newLines = false
+        val detected = detector.process(recordBuffer, channelSelect)
+        syncChecks++
+        if (detected) {
+            syncHits++
+            predictedStreak = 0
+        }
+        var syncIdx = sample + detector.pulseOffset
+        val channels = if (channelSelect > 0) 2 else 1
+        for (j in 0 until recordBuffer.size / channels) {
+            if (sample >= scanLineBuffer.size) {
+                shift(curLineSamples)
+                syncIdx -= curLineSamples
+                if (sample >= scanLineBuffer.size) sample = scanLineBuffer.size - 1
+            }
+            scanLineBuffer[sample++] = recordBuffer[j]
+        }
+        if (detected) {
+            when (detector.detectedWidth) {
+                SyncPulseWidth.FiveMs -> newLines = processPulse(modes5ms, offsets5ms, sync5ms, lines5ms, syncIdx)
+                SyncPulseWidth.NineMs -> {
+                    leaderBreak = syncIdx; newLines = processPulse(modes9ms, offsets9ms, sync9ms, lines9ms, syncIdx)
+                }
+
+                SyncPulseWidth.TwentyMs -> {
+                    leaderBreak = syncIdx; newLines = processPulse(modes20ms, offsets20ms, sync20ms, lines20ms, syncIdx)
+                }
+            }
+        } else if (handleHeader()) {
+            predictedStreak = 0
+            newLines = true
+        } else if (sample > lastSync + (curLineSamples * 5) / 4) {
+            newLines = decodePredictedLine()
+        }
+        return newLines
+    }
+
+    fun setMode(name: String) {
+        val mode = allModes.firstOrNull { it.name == name }
+        if (mode == currentMode) {
+            lockMode = true; return
+        }
+        if (mode != null) {
+            lockMode = true; imageBuffer.line = -1; currentMode = mode; curLineSamples = mode.scanLineSamples; return
+        }
+        lockMode = false
+    }
+
+    fun quality(): DecoderQuality {
+        val hitRate = if (syncChecks > 0) syncHits.toFloat() / syncChecks else 0f
+        return DecoderQuality(
+            syncHitRate = hitRate,
+            predictedLineBursts = predictedLineBursts,
+            maxPredictedStreak = maxPredictedStreak,
+            timingErrorSamples = timingErrorSamples
+        )
+    }
+
+    fun resetQuality() {
+        syncChecks = 0
+        syncHits = 0
+        predictedLineBursts = 0
+        predictedStreak = 0
+        maxPredictedStreak = 0
+        timingErrorSamples = 0
+    }
+
+    private fun mean(a: IntArray): Double = a.sumOf { it.toDouble() } / a.size
+    private fun stdDev(a: IntArray, m: Double): Double {
+        var s = 0.0; for (v in a) s += (v - m) * (v - m); return sqrt(s / a.size)
+    }
+
+    private fun meanF(a: FloatArray): Float {
+        var s = 0f; for (v in a) s += v; return s / a.size
+    }
+
+    private fun detectMode(modes: ArrayList<SstvMode>, samples: Int): SstvMode {
+        var best: SstvMode = rawMode
+        var bestD = Int.MAX_VALUE
+        for (m in modes) {
+            val d = abs(samples - m.scanLineSamples); if (d <= lineTolerance && d < bestD) {
+                bestD = d; best = m
+            }
+        }
+        return best
+    }
+
+    // scopeBuffer is twice the display height. Each decoded scan line is written
+    // to both the current rolling position (top half, wraps at height/2) and the
+    // same row offset in the bottom half. The UI displays a window that always
+    // spans the half-height boundary, giving a seamless non-wrapping scroll effect.
+    private fun copyUnscaled() {
+        val w = minOf(scopeBuffer.width, pixelBuffer.width)
+        for (row in 0 until pixelBuffer.height) {
+            val line = scopeBuffer.width * scopeBuffer.line
+            pixelBuffer.pixels.copyInto(scopeBuffer.pixels, line, row * pixelBuffer.width, row * pixelBuffer.width + w)
+            scopeBuffer.pixels.fill(0, line + w, line + scopeBuffer.width)
+
+            scopeBuffer.pixels.copyInto(
+                scopeBuffer.pixels,
+                scopeBuffer.width * (scopeBuffer.line + scopeBuffer.height / 2),
+                line,
+                line + scopeBuffer.width
+            )
+            scopeBuffer.line = (scopeBuffer.line + 1) % (scopeBuffer.height / 2)
+        }
+    }
+
+    private fun copyScaled(scale: Int) {
+        for (row in 0 until pixelBuffer.height) {
+            val line = scopeBuffer.width * scopeBuffer.line
+            for (col in 0 until pixelBuffer.width) for (i in 0 until scale) scopeBuffer.pixels[line + col * scale + i] =
+                pixelBuffer.pixels[pixelBuffer.width * row + col]
+            scopeBuffer.pixels.fill(0, line + pixelBuffer.width * scale, line + scopeBuffer.width)
+
+            scopeBuffer.pixels.copyInto(
+                scopeBuffer.pixels,
+                scopeBuffer.width * (scopeBuffer.line + scopeBuffer.height / 2),
+                line,
+                line + scopeBuffer.width
+            )
+            scopeBuffer.line = (scopeBuffer.line + 1) % (scopeBuffer.height / 2)
+            repeat(scale - 1) {
+
+                scopeBuffer.pixels.copyInto(
+                    scopeBuffer.pixels, scopeBuffer.width * scopeBuffer.line, line, line + scopeBuffer.width
+                )
+
+                scopeBuffer.pixels.copyInto(
+                    scopeBuffer.pixels,
+                    scopeBuffer.width * (scopeBuffer.line + scopeBuffer.height / 2),
+                    line,
+                    line + scopeBuffer.width
+                )
+                scopeBuffer.line = (scopeBuffer.line + 1) % (scopeBuffer.height / 2)
+            }
+        }
+    }
+
+    private fun copyLines(ok: Boolean) {
+        if (!ok) return
+        var finish = false
+        if (imageBuffer.line in 0 until imageBuffer.height && imageBuffer.width == pixelBuffer.width) {
+            val w = imageBuffer.width
+            for (row in 0 until pixelBuffer.height) {
+                if (imageBuffer.line >= imageBuffer.height) break
+                pixelBuffer.pixels.copyInto(imageBuffer.pixels, imageBuffer.line * w, row * w, row * w + w)
+                imageBuffer.line++
+            }
+            finish = imageBuffer.line == imageBuffer.height
+        }
+        val scale = scopeBuffer.width / pixelBuffer.width
+        if (scale <= 1) copyUnscaled() else copyScaled(scale)
+        if (finish) drawLines(0xff000000.toInt(), 10)
+    }
+
+    private fun decodePredictedLine(): Boolean {
+        // Avoid long streaks of synthetic lines; once we exceed the cap we wait for
+        // real sync to reduce visible vertical compression on weak/noisy signals.
+        if (predictedStreak >= maxConsecutivePredictedLines) return false
+        val expectedSync = lastSync + curLineSamples
+        timingErrorSamples = sample - expectedSync
+        val decoded = currentMode.decodeScanLine(
+            pixelBuffer,
+            scratch,
+            scanLineBuffer,
+            scopeBuffer.width,
+            lastSync,
+            curLineSamples,
+            lastOffset
+        )
+        copyLines(decoded)
+        lastSync = expectedSync
+        predictedLineBursts++
+        predictedStreak++
+        if (predictedStreak > maxPredictedStreak) maxPredictedStreak = predictedStreak
+        return decoded
+    }
+
+    private fun drawLines(color: Int, count: Int) {
+        repeat(count) {
+            scopeBuffer.pixels.fill(
+                color,
+                scopeBuffer.line * scopeBuffer.width,
+                (scopeBuffer.line + 1) * scopeBuffer.width
+            )
+            scopeBuffer.pixels.fill(
+                color,
+                (scopeBuffer.line + scopeBuffer.height / 2) * scopeBuffer.width,
+                (scopeBuffer.line + 1 + scopeBuffer.height / 2) * scopeBuffer.width
+            )
+            scopeBuffer.line = (scopeBuffer.line + 1) % (scopeBuffer.height / 2)
+        }
+    }
+
+    private fun adjust(pulses: IntArray, shift: Int) {
+        for (i in pulses.indices) pulses[i] -= shift
+    }
+
+    private fun shift(amount: Int) {
+        if ((amount <= 0) || (amount > sample)) return
+        sample -= amount; leaderBreak -= amount; lastSync -= amount
+        adjust(sync5ms, amount); adjust(sync9ms, amount); adjust(sync20ms, amount)
+        // Discard already-decoded samples by sliding the live region back to index 0.
+        // System.arraycopy handles the overlapping regions correctly and is a native
+        // memcpy on JVM, so this is fast despite moving the full remaining window.
+        scanLineBuffer.copyInto(scanLineBuffer, 0, amount, amount + sample)
+    }
+
+    private fun handleHeader(): Boolean {
+        if (leaderBreak < visBitLen + leaderTol || sample < leaderBreak + leaderLen + leaderTol + visLen + visBitLen) return false
+        val bp = leaderBreak; leaderBreak = 0
+        var preFreq = 0f
+        for (i in 0 until leaderTol) preFreq += scanLineBuffer[bp - visBitLen - leaderTol + i]
+        val toneFreq = 1900f
+        val center = 1900f
+        val tol = 50f
+        val halfBw = 400f
+        preFreq = preFreq * halfBw / leaderTol + center
+        if (abs(preFreq - toneFreq) > tol) return false
+        var ldrFreq = 0f
+        for (i in transition until leaderLen - leaderTol) ldrFreq += scanLineBuffer[bp + i]
+        val ldrOffset = ldrFreq / (leaderLen - transition - leaderTol)
+        ldrFreq = ldrOffset * halfBw + center
+        if (abs(ldrFreq - toneFreq) > tol) return false
+        val stopFreq = 1200f
+        val pulseThr = ((stopFreq + toneFreq) / 2 - center) / halfBw
+        var vBegin = bp + leaderLen - leaderTol
+        val vEnd = bp + leaderLen + leaderTol + visBitLen
+        repeat(pulseFilter.length) { pulseFilter.avg(scanLineBuffer[vBegin++] - ldrOffset) }
+        while (++vBegin < vEnd) if (pulseFilter.avg(scanLineBuffer[vBegin] - ldrOffset) < pulseThr) break
+        if (vBegin >= vEnd) return false
+        vBegin -= pulseFilterDelay
+        val visEnd = vBegin + visLen
+        visFreqs.fill(0f)
+        for (j in 0 until 10) for (i in transition until visBitLen - transition) visFreqs[j] += scanLineBuffer[vBegin + visBitLen * j + i] - ldrOffset
+        for (i in 0 until 10) visFreqs[i] = visFreqs[i] * halfBw / (visBitLen - 2 * transition) + center
+        if (abs(visFreqs[0] - stopFreq) > tol || abs(visFreqs[9] - stopFreq) > tol) return false
+        for (i in 1 until 9) if (abs(visFreqs[i] - 1100f) > tol && abs(visFreqs[i] - 1300f) > tol) return false
+        var vis = 0
+        for (i in 0 until 8) vis = vis or ((if (visFreqs[i + 1] < stopFreq) 1 else 0) shl i)
+        var chk = true; for (i in 0 until 8) chk = chk xor ((vis and (1 shl i)) != 0)
+        vis = vis and 127; if (!chk) return false
+        val syncThr = ((1200f + 1500f) / 2 - center) / halfBw
+        var sIdx = visEnd - visBitLen
+        val sMax = visEnd + visBitLen
+        repeat(pulseFilter.length) { pulseFilter.avg(scanLineBuffer[sIdx++] - ldrOffset) }
+        while (++sIdx < sMax) if (pulseFilter.avg(scanLineBuffer[sIdx] - ldrOffset) > syncThr) break
+        if (sIdx >= sMax) return false
+        sIdx -= pulseFilterDelay
+        val mode: SstvMode
+        val pulses: IntArray
+        val lines: IntArray
+        val f5 = modes5ms.firstOrNull { it.visCode == vis }
+        val f9 = modes9ms.firstOrNull { it.visCode == vis }
+        val f20 = modes20ms.firstOrNull { it.visCode == vis }
+        when {
+            f5 != null -> {
+                mode = f5; pulses = sync5ms; lines = lines5ms
+            }
+
+            f9 != null -> {
+                mode = f9; pulses = sync9ms; lines = lines9ms
+            }
+
+            f20 != null -> {
+                mode = f20; pulses = sync20ms; lines = lines20ms
+            }
+
+            else -> {
+                if (!lockMode) drawLines(0xffff0000.toInt(), 8); return false
+            }
+        }
+        if (lockMode && mode != currentMode) return false
+        mode.resetState()
+        imageBuffer.width = mode.width; imageBuffer.height = mode.height
+        imageBuffer.pixels.fill(0, 0, mode.width * mode.height); imageBuffer.line = 0
+        currentMode = mode
+        lastSync = sIdx + mode.firstSyncPulseIndex; curLineSamples = mode.scanLineSamples; lastOffset = ldrOffset
+        var oldest = lastSync - (pulses.size - 1) * curLineSamples
+        if (mode.firstSyncPulseIndex > 0) oldest -= curLineSamples
+        for (i in pulses.indices) pulses[i] = oldest + i * curLineSamples
+        lines.fill(curLineSamples)
+        shift(lastSync + mode.firstPixelSampleIndex)
+        drawLines(0xff00ff00.toInt(), 8); drawLines(0xff000000.toInt(), 10)
+        return true
+    }
+
+    private fun processPulse(
+        modes: ArrayList<SstvMode>,
+        freqOffs: FloatArray,
+        syncPulses: IntArray,
+        lineLen: IntArray,
+        latest: Int
+    ): Boolean {
+        predictedStreak = 0
+        for (i in 1 until syncPulses.size) syncPulses[i - 1] = syncPulses[i]
+        syncPulses[syncPulses.size - 1] = latest
+        for (i in 1 until lineLen.size) lineLen[i - 1] = lineLen[i]
+        lineLen[lineLen.size - 1] = syncPulses.last() - syncPulses[syncPulses.size - 2]
+        for (i in 1 until freqOffs.size) freqOffs[i - 1] = freqOffs[i]
+        freqOffs[freqOffs.size - 1] = detector.freqOffset
+        if (lineLen[0] == 0) return false
+        val m = mean(lineLen)
+        val lineSamples = round(m).toInt()
+        if (lineSamples < scanLineMin || lineSamples > scratch.size) return false
+        if (stdDev(lineLen, m) > lineTolerance) return false
+        var changed = false
+        if (lockMode || imageBuffer.line in 0 until imageBuffer.height) {
+            if (currentMode != rawMode && abs(lineSamples - currentMode.scanLineSamples) > lineTolerance) return false
+            // Try continuous decoding
+            if (lockMode && imageBuffer.line == -1 && currentMode != rawMode) {
+                currentMode.resetState()
+                imageBuffer.width = currentMode.width
+                imageBuffer.height = currentMode.height
+                imageBuffer.pixels.fill(0, 0, currentMode.width * currentMode.height)
+                imageBuffer.line = 0
+                drawLines(0xff000000.toInt(), 10); drawLines(0xffffff00.toInt(), 8); drawLines(0xff000000.toInt(), 10)
+            }
+        } else {
+            val prev = currentMode; currentMode = detectMode(modes, lineSamples)
+            changed =
+                currentMode != prev || abs(curLineSamples - lineSamples) > lineTolerance || abs(lastSync + lineSamples - syncPulses.last()) > syncTolerance
+        }
+        if (changed) {
+            drawLines(0xff000000.toInt(), 10); drawLines(0xff00ffff.toInt(), 8); drawLines(0xff000000.toInt(), 10)
+        }
+        val offset = meanF(freqOffs)
+        if (syncPulses[0] >= lineSamples && changed) {
+            val end = syncPulses[0]
+            val extra = end / lineSamples
+            val first = end - extra * lineSamples
+            var p = first; while (p < end) {
+                copyLines(
+                    currentMode.decodeScanLine(
+                        pixelBuffer,
+                        scratch,
+                        scanLineBuffer,
+                        scopeBuffer.width,
+                        p,
+                        lineSamples,
+                        offset
+                    )
+                ); p += lineSamples
+            }
+        }
+        val start = if (changed) 0 else lineLen.size - 1
+        for (i in start until lineLen.size) copyLines(
+            currentMode.decodeScanLine(
+                pixelBuffer,
+                scratch,
+                scanLineBuffer,
+                scopeBuffer.width,
+                syncPulses[i],
+                lineLen[i],
+                offset
+            )
+        )
+        lastSync = syncPulses.last(); curLineSamples = lineSamples; lastOffset = offset
+        shift(lastSync + currentMode.firstPixelSampleIndex)
+        return true
+    }
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/sstv/SstvDsp.kt

@@ -0,0 +1,240 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.domain.sstv
+
+import kotlin.math.PI
+import kotlin.math.cos
+import kotlin.math.pow
+import kotlin.math.round
+import kotlin.math.sin
+import kotlin.math.sqrt
+
+internal class Complex(var real: Float = 0f, var imag: Float = 0f) {
+
+    fun set(real: Float, imag: Float): Complex {
+        this.real = real; this.imag = imag; return this
+    }
+
+    fun set(real: Float): Complex = set(real, 0f)
+
+    fun abs(): Float = sqrt(real * real + imag * imag)
+
+    fun mul(other: Complex): Complex {
+        val tmp = real * other.real - imag * other.imag
+        imag = real * other.imag + imag * other.real
+        real = tmp
+        return this
+    }
+
+    fun div(value: Float): Complex {
+        real /= value; imag /= value; return this
+    }
+}
+
+internal object WindowFunctions {
+
+    fun sinc(cutoff: Double, rate: Double, n: Int, nN: Int): Double {
+        val f = 2 * cutoff / rate
+        val x = n - (nN - 1) / 2.0
+        val fx = f * x
+        return if (fx == 0.0) f else f * sin(PI * fx) / (PI * fx)
+    }
+
+    fun kaiser(a: Double, n: Int, nN: Int): Double {
+        fun square(v: Double) = v * v
+        fun i0(x: Double): Double {
+            val terms = DoubleArray(35)
+            terms[0] = 1.0
+            var v = 1.0
+            for (m in 1 until 35) {
+                v *= x / (2 * m); terms[m] = square(v)
+            }
+            terms.sort()
+            var sum = 0.0; for (m in 34 downTo 0) sum += terms[m]
+            return sum
+        }
+        return i0(PI * a * sqrt(1 - square((2.0 * n) / (nN - 1) - 1))) / i0(PI * a)
+    }
+}
+
+// O(1) ring buffer — simpler and faster than a segment tree for the short window
+// lengths used here (≤512 samples). Float32 accumulated drift over such windows
+// is ~6e-5, negligible for audio-frequency processing.
+internal open class MovingSum(val length: Int) {
+    private val buf = FloatArray(length)
+    private var pos = 0
+    private var runningSum = 0f
+
+    fun add(input: Float) {
+        runningSum += input - buf[pos]
+        buf[pos] = input
+        if (++pos >= length) pos = 0
+    }
+
+    fun sum(): Float = runningSum
+    fun sum(input: Float): Float {
+        add(input); return sum()
+    }
+}
+
+internal class MovingAverage(length: Int) : MovingSum(length) {
+    fun avg(input: Float): Float = sum(input) / length
+}
+
+internal class Ema {
+    private var alpha: Float = 1f
+    private var prev: Float = 0f
+
+    fun process(input: Float): Float {
+        prev = prev * (1 - alpha) + alpha * input; return prev
+    }
+
+    fun setCutoff(freq: Double, rate: Double, order: Int = 1) {
+        alpha = computeAlpha(freq, rate, order)
+    }
+
+    fun reset() {
+        prev = 0f
+    }
+
+    companion object {
+
+        fun computeAlpha(freq: Double, rate: Double, order: Int = 1): Float {
+            val x = cos(2 * PI * (freq.coerceAtMost(rate * 0.499)) / rate)
+            val discriminant = (x * (x - 4) + 3).coerceAtLeast(0.0)
+            return (x - 1 + sqrt(discriminant)).coerceIn(0.0, 1.0).pow(1.0 / order).toFloat()
+        }
+
+        fun withCutoff(freq: Double, rate: Double, order: Int = 1): Ema {
+            return Ema().also { it.setCutoff(freq, rate, order) }
+        }
+    }
+}
+
+internal class Phasor(freq: Double, rate: Double) {
+    private val value = Complex(1f, 0f)
+    private val delta: Complex = run {
+        val omega = 2 * PI * freq / rate
+        Complex(cos(omega).toFloat(), sin(omega).toFloat())
+    }
+    private var count = 0
+
+    // Renormalize every 512 rotations to prevent magnitude drift accumulation,
+    // eliminating the per-sample sqrt without sacrificing demodulation accuracy.
+    fun rotate(): Complex {
+        value.mul(delta)
+        if (++count == 512) { value.div(value.abs()); count = 0 }
+        return value
+    }
+}
+
+internal class FmDemodulator(bandwidth: Double, sampleRate: Double) {
+    private val scale = (sampleRate / (bandwidth * PI)).toFloat()
+    private val pi = PI.toFloat()
+    private val twoPi = (2 * PI).toFloat()
+    private var prev = 0f
+
+    fun demodulate(input: Complex): Float {
+        // Use fast polynomial atan2 instead of the exact trigonometric call.
+        // Max error ~0.005 rad translates to <1 Hz frequency error at 44100 Hz,
+        // well within the 50 Hz sync tolerance.
+        val phase = fastAtan2(input.imag, input.real)
+        var delta = phase - prev; prev = phase
+        if (delta < -pi) delta += twoPi else if (delta > pi) delta -= twoPi
+        return scale * delta
+    }
+
+    // Rajan's polynomial approximation of atan2 — avoids a transcendental call
+    // in the per-sample hot path (~44 k calls/s at 44100 Hz sample rate).
+    private fun fastAtan2(y: Float, x: Float): Float {
+        val absY = kotlin.math.abs(y) + 1e-10f
+        val r: Float
+        val angle: Float
+        if (x >= 0f) {
+            r = (x - absY) / (x + absY)
+            angle = 0.1963f * r * r * r - 0.9817f * r + pi / 4f
+        } else {
+            r = (x + absY) / (absY - x)
+            angle = 0.1963f * r * r * r - 0.9817f * r + 3f * pi / 4f
+        }
+        return if (y < 0f) -angle else angle
+    }
+}
+
+internal class ComplexFirFilter(val length: Int) {
+    private val real = FloatArray(length)
+    private val imag = FloatArray(length)
+    private val sum = Complex()
+    private var pos = 0
+
+    val taps = FloatArray(length)
+
+    fun filter(input: Complex): Complex {
+        real[pos] = input.real; imag[pos] = input.imag
+        if (++pos >= length) pos = 0
+        sum.real = 0f; sum.imag = 0f
+        for (tap in taps) {
+            sum.real += tap * real[pos]; sum.imag += tap * imag[pos]; if (++pos >= length) pos = 0
+        }
+        return sum
+    }
+}
+
+internal class Delay(val length: Int) {
+    private val buf = FloatArray(length)
+    private var pos = 0
+
+    fun push(input: Float): Float {
+        val tmp = buf[pos]; buf[pos] = input; if (++pos >= length) pos = 0; return tmp
+    }
+}
+
+internal class SchmittTrigger(private val low: Float, private val high: Float) {
+    private var state = false
+
+    fun process(input: Float): Boolean {
+        if (state) {
+            if (input < low) state = false
+        } else {
+            if (input > high) state = true
+        }
+        return state
+    }
+}
+
+internal object ColorConverter {
+
+    private fun clamp(v: Int) = v.coerceIn(0, 255)
+    private fun toInt(level: Float) = clamp(round(255 * level).toInt())
+    private fun compress(level: Float) = toInt(sqrt(level.coerceIn(0f, 1f)))
+
+    private fun yuv2rgb(yY: Int, uU: Int, vV: Int): Int {
+        val y = yY - 16
+        val u = uU - 128
+        val v = vV - 128
+        val r = clamp((298 * y + 409 * v + 128) shr 8)
+        val g = clamp((298 * y - 100 * u - 208 * v + 128) shr 8)
+        val b = clamp((298 * y + 516 * u + 128) shr 8)
+        return 0xff000000.toInt() or (r shl 16) or (g shl 8) or b
+    }
+
+    fun gray(level: Float): Int = 0xff000000.toInt() or (0x00010101 * compress(level))
+    fun rgb(r: Float, g: Float, b: Float): Int = 0xff000000.toInt() or (toInt(r) shl 16) or (toInt(g) shl 8) or toInt(b)
+    fun yuv2rgb(yY: Float, uU: Float, vV: Float): Int = yuv2rgb(toInt(yY), toInt(uU), toInt(vV))
+    fun yuv2rgb(packed: Int): Int = yuv2rgb((packed shr 16) and 0xff, (packed shr 8) and 0xff, packed and 0xff)
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/sstv/SstvModes.kt

@@ -0,0 +1,434 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.domain.sstv
+
+import kotlin.math.round
+
+internal class PixelBuffer(var width: Int, var height: Int) {
+    var pixels = IntArray(width * height)
+    var line = 0
+}
+
+internal sealed interface SstvMode {
+    val name: String
+    val visCode: Int
+    val width: Int
+    val height: Int
+    val firstPixelSampleIndex: Int
+    val firstSyncPulseIndex: Int
+    val scanLineSamples: Int
+
+    fun resetState() {}
+
+    fun decodeScanLine(
+        pixelBuffer: PixelBuffer,
+        scratch: FloatArray,
+        scanLine: FloatArray,
+        scopeWidth: Int,
+        syncPulseIndex: Int,
+        lineSamples: Int,
+        freqOffset: Float
+    ): Boolean
+}
+
+internal class RgbMode(
+    override val name: String,
+    override val visCode: Int,
+    private val hPixels: Int,
+    private val vPixels: Int,
+    override val firstSyncPulseIndex: Int,
+    override val scanLineSamples: Int,
+    override val firstPixelSampleIndex: Int,
+    private val redBegin: Int,
+    private val redLen: Int,
+    private val greenBegin: Int,
+    private val greenLen: Int,
+    private val blueBegin: Int,
+    private val blueLen: Int,
+    private val endSamples: Int,
+) : SstvMode {
+    override val width get() = hPixels
+    override val height get() = vPixels
+    private val ema = Ema.withCutoff(hPixels.toDouble(), (2 * greenLen).toDouble(), 2)
+
+    override fun decodeScanLine(
+        pixelBuffer: PixelBuffer,
+        scratch: FloatArray,
+        scanLine: FloatArray,
+        scopeWidth: Int,
+        syncPulseIndex: Int,
+        lineSamples: Int,
+        freqOffset: Float
+    ): Boolean {
+        val begin = firstPixelSampleIndex
+        if (syncPulseIndex + begin < 0 || syncPulseIndex + endSamples > scanLine.size) return false
+        ema.reset()
+        for (i in 0 until endSamples - begin) scratch[i] = ema.process(scanLine[syncPulseIndex + begin + i])
+        ema.reset()
+        for (i in endSamples - begin - 1 downTo 0) scratch[i] = freqToLevel(ema.process(scratch[i]), freqOffset)
+        for (i in 0 until hPixels) {
+            val r = redBegin + (i * redLen) / hPixels
+            val g = greenBegin + (i * greenLen) / hPixels
+            val b = blueBegin + (i * blueLen) / hPixels
+            pixelBuffer.pixels[i] = ColorConverter.rgb(scratch[r], scratch[g], scratch[b])
+        }
+        pixelBuffer.width = hPixels; pixelBuffer.height = 1
+        return true
+    }
+
+    companion object {
+        fun martin(variant: String, code: Int, channelSec: Double, sampleRate: Int): RgbMode {
+            val sync = 0.004862
+            val sep = 0.000572
+            val scanLine = sync + sep + 3 * (channelSec + sep)
+            val gEnd = sep + channelSec
+            val bBegin = gEnd + sep
+            val bEnd = bBegin + channelSec
+            val rBegin = bEnd + sep
+            val rEnd = rBegin + channelSec
+            return fromSeconds(
+                name = "Martin $variant",
+                code = code,
+                firstSyncSec = 0.0,
+                scanLineSec = scanLine,
+                beginSec = sep,
+                rBeginSec = rBegin,
+                rEndSec = rEnd,
+                gBeginSec = sep,
+                gEndSec = gEnd,
+                bBeginSec = bBegin,
+                bEndSec = bEnd,
+                endSec = rEnd,
+                sr = sampleRate
+            )
+        }
+
+        fun scottie(variant: String, code: Int, channelSec: Double, sampleRate: Int): RgbMode {
+            val sync = 0.009
+            val sep = 0.0015
+            val firstSync = sync + 2 * (sep + channelSec)
+            val scanLine = sync + 3 * (channelSec + sep)
+            val bEnd = -sync
+            val bBegin = bEnd - channelSec
+            val gEnd = bBegin - sep
+            val gBegin = gEnd - channelSec
+            val rEnd = sep + channelSec
+            return fromSeconds(
+                name = "Scottie $variant",
+                code = code,
+                firstSyncSec = firstSync,
+                scanLineSec = scanLine,
+                beginSec = gBegin,
+                rBeginSec = sep,
+                rEndSec = rEnd,
+                gBeginSec = gBegin,
+                gEndSec = gEnd,
+                bBeginSec = bBegin,
+                bEndSec = bEnd,
+                endSec = rEnd,
+                sr = sampleRate
+            )
+        }
+
+        fun wraaseSc2180(sampleRate: Int): RgbMode {
+            val sync = 0.0055225
+            val porch = 0.0005
+            val ch = 0.235
+            val scanLine = sync + porch + 3 * ch
+            val rEnd = porch + ch
+            val gEnd = rEnd + ch
+            val bEnd = gEnd + ch
+            return fromSeconds(
+                name = "Wraase SC2-180",
+                code = 55,
+                firstSyncSec = 0.0,
+                scanLineSec = scanLine,
+                beginSec = porch,
+                rBeginSec = porch,
+                rEndSec = rEnd,
+                gBeginSec = rEnd,
+                gEndSec = gEnd,
+                bBeginSec = gEnd,
+                bEndSec = bEnd,
+                endSec = bEnd,
+                sr = sampleRate
+            )
+        }
+
+        private fun fromSeconds(
+            name: String, code: Int, w: Int = 320, h: Int = 256,
+            firstSyncSec: Double, scanLineSec: Double, beginSec: Double,
+            rBeginSec: Double, rEndSec: Double, gBeginSec: Double, gEndSec: Double,
+            bBeginSec: Double, bEndSec: Double, endSec: Double, sr: Int
+        ): RgbMode {
+            val begin = round(beginSec * sr).toInt()
+            return RgbMode(
+                name = name, visCode = code, hPixels = w, vPixels = h,
+                firstSyncPulseIndex = round(firstSyncSec * sr).toInt(),
+                scanLineSamples = round(scanLineSec * sr).toInt(),
+                firstPixelSampleIndex = begin,
+                redBegin = round(rBeginSec * sr).toInt() - begin,
+                redLen = round((rEndSec - rBeginSec) * sr).toInt(),
+                greenBegin = round(gBeginSec * sr).toInt() - begin,
+                greenLen = round((gEndSec - gBeginSec) * sr).toInt(),
+                blueBegin = round(bBeginSec * sr).toInt() - begin,
+                blueLen = round((bEndSec - bBeginSec) * sr).toInt(),
+                endSamples = round(endSec * sr).toInt()
+            )
+        }
+    }
+}
+
+internal class Robot36Mode(sampleRate: Int) : SstvMode {
+    override val name = "Robot 36 Color"
+    override val visCode = 8
+    override val width = 320
+    override val height = 240
+    override val firstSyncPulseIndex = 0
+    override val scanLineSamples: Int
+    override val firstPixelSampleIndex: Int
+
+    private val lumSamples: Int
+    private val sepSamples: Int
+    private val chromSamples: Int
+    private val lumBegin: Int
+    private val sepBegin: Int
+    private val chromBegin: Int
+    private val end: Int
+    private val ema: Ema
+    private var lastEven = false
+
+    init {
+        val syncPorch = 0.003
+        val lum = 0.088
+        val sep = 0.0045
+        val porch = 0.0015
+        val chrom = 0.044
+        scanLineSamples = round((0.009 + syncPorch + lum + sep + porch + chrom) * sampleRate).toInt()
+        lumSamples = round(lum * sampleRate).toInt(); sepSamples = round(sep * sampleRate).toInt()
+        chromSamples = round(chrom * sampleRate).toInt()
+        lumBegin = round(syncPorch * sampleRate).toInt(); firstPixelSampleIndex = lumBegin
+        sepBegin = round((syncPorch + lum) * sampleRate).toInt()
+        chromBegin = round((syncPorch + lum + sep + porch) * sampleRate).toInt()
+        end = round((syncPorch + lum + sep + porch + chrom) * sampleRate).toInt()
+        ema = Ema.withCutoff(width.toDouble(), (2 * lumSamples).toDouble(), 2)
+    }
+
+    override fun resetState() {
+        lastEven = false
+    }
+
+    override fun decodeScanLine(
+        pixelBuffer: PixelBuffer,
+        scratch: FloatArray,
+        scanLine: FloatArray,
+        scopeWidth: Int,
+        syncPulseIndex: Int,
+        lineSamples: Int,
+        freqOffset: Float
+    ): Boolean {
+        if (syncPulseIndex + firstPixelSampleIndex < 0 || syncPulseIndex + end > scanLine.size) return false
+        var sep = 0f
+        for (i in 0 until sepSamples) sep += scanLine[syncPulseIndex + sepBegin + i]
+        sep = sep / sepSamples - freqOffset
+        var even = sep < 0
+        if (sep < -1.1f || (sep > -0.9f && sep < 0.9f) || sep > 1.1f) even = !lastEven
+        lastEven = even
+        ema.reset()
+        for (i in firstPixelSampleIndex until end) scratch[i] = ema.process(scanLine[syncPulseIndex + i])
+        ema.reset()
+        for (i in end - 1 downTo firstPixelSampleIndex) scratch[i] = freqToLevel(ema.process(scratch[i]), freqOffset)
+        for (i in 0 until width) {
+            val lPos = lumBegin + (i * lumSamples) / width
+            val cPos = chromBegin + (i * chromSamples) / width
+            if (even) {
+                // Even line: store Y in the red channel slot and Cr in the blue slot,
+                // using ColorConverter.rgb() as a convenient 3×byte packer (not RGB).
+                // The odd line will read these back and combine with its own Cb to
+                // produce the final YUV→RGB conversion for both rows.
+                pixelBuffer.pixels[i] = ColorConverter.rgb(scratch[lPos], 0f, scratch[cPos])
+            } else {
+                val evenYuv = pixelBuffer.pixels[i]
+                // Even pixel packing: 0xAARRGGBB → Y=RR, Cb=GG(unused), Cr=BB
+                // Odd pixel:  Y=lPos, Cb=cPos, Cr=(borrowed from even's BB slot)
+                // Merge: take Y+Cr from even row (bits 0x00ff00ff) and Cb from odd (0x0000ff00).
+                val oddYuv = ColorConverter.rgb(scratch[lPos], scratch[cPos], 0f)
+                pixelBuffer.pixels[i] = ColorConverter.yuv2rgb((evenYuv and 0x00ff00ff) or (oddYuv and 0x0000ff00))
+                pixelBuffer.pixels[i + width] =
+                    ColorConverter.yuv2rgb((oddYuv and 0x00ffff00) or (evenYuv and 0x000000ff))
+            }
+        }
+        pixelBuffer.width = width; pixelBuffer.height = 2
+        return !even
+    }
+}
+
+internal class Robot72Mode(sampleRate: Int) : SstvMode {
+    override val name = "Robot 72 Color"
+    override val visCode = 12
+    override val width = 320
+    override val height = 240
+    override val firstSyncPulseIndex = 0
+    override val scanLineSamples: Int
+    override val firstPixelSampleIndex: Int
+
+    private val lumSamples: Int
+    private val chromSamples: Int
+    private val yBegin: Int
+    private val vBegin: Int
+    private val uBegin: Int
+    private val end: Int
+    private val ema: Ema
+
+    init {
+        val syncPorch = 0.003
+        val lum = 0.138
+        val sep = 0.0045
+        val porch = 0.0015
+        val chrom = 0.069
+        scanLineSamples = round((0.009 + syncPorch + lum + 2 * (sep + porch + chrom)) * sampleRate).toInt()
+        lumSamples = round(lum * sampleRate).toInt(); chromSamples = round(chrom * sampleRate).toInt()
+        yBegin = round(syncPorch * sampleRate).toInt(); firstPixelSampleIndex = yBegin
+        vBegin = round((syncPorch + lum + sep + porch) * sampleRate).toInt()
+        uBegin = round((syncPorch + lum + sep + porch + chrom + sep + porch) * sampleRate).toInt()
+        end = round((syncPorch + lum + 2 * (sep + porch + chrom)) * sampleRate).toInt()
+        ema = Ema.withCutoff(width.toDouble(), (2 * lumSamples).toDouble(), 2)
+    }
+
+    override fun decodeScanLine(
+        pixelBuffer: PixelBuffer,
+        scratch: FloatArray,
+        scanLine: FloatArray,
+        scopeWidth: Int,
+        syncPulseIndex: Int,
+        lineSamples: Int,
+        freqOffset: Float
+    ): Boolean {
+        if (syncPulseIndex + firstPixelSampleIndex < 0 || syncPulseIndex + end > scanLine.size) return false
+        ema.reset()
+        for (i in firstPixelSampleIndex until end) scratch[i] = ema.process(scanLine[syncPulseIndex + i])
+        ema.reset()
+        for (i in end - 1 downTo firstPixelSampleIndex) scratch[i] = freqToLevel(ema.process(scratch[i]), freqOffset)
+        for (i in 0 until width) {
+            val yP = yBegin + (i * lumSamples) / width
+            val uP = uBegin + (i * chromSamples) / width
+            val vP = vBegin + (i * chromSamples) / width
+            pixelBuffer.pixels[i] = ColorConverter.yuv2rgb(scratch[yP], scratch[uP], scratch[vP])
+        }
+        pixelBuffer.width = width; pixelBuffer.height = 1
+        return true
+    }
+}
+
+internal class PdMode(
+    variant: String,
+    override val visCode: Int,
+    private val hPixels: Int,
+    private val vPixels: Int,
+    channelSec: Double,
+    sampleRate: Int
+) : SstvMode {
+    override val name = "PD $variant"
+    override val width get() = hPixels
+    override val height get() = vPixels
+    override val firstSyncPulseIndex = 0
+    override val scanLineSamples: Int
+    override val firstPixelSampleIndex: Int
+
+    private val chSamples: Int
+    private val yEvenBegin: Int
+    private val vAvgBegin: Int
+    private val uAvgBegin: Int
+    private val yOddBegin: Int
+    private val end: Int
+    private val ema: Ema
+
+    init {
+        val syncPorch = 0.00208
+        scanLineSamples = round((0.02 + syncPorch + 4 * channelSec) * sampleRate).toInt()
+        chSamples = round(channelSec * sampleRate).toInt()
+        yEvenBegin = round(syncPorch * sampleRate).toInt(); firstPixelSampleIndex = yEvenBegin
+        vAvgBegin = round((syncPorch + channelSec) * sampleRate).toInt()
+        uAvgBegin = round((syncPorch + 2 * channelSec) * sampleRate).toInt()
+        yOddBegin = round((syncPorch + 3 * channelSec) * sampleRate).toInt()
+        end = round((syncPorch + 4 * channelSec) * sampleRate).toInt()
+        ema = Ema.withCutoff(hPixels.toDouble(), (2 * chSamples).toDouble(), 2)
+    }
+
+    override fun decodeScanLine(
+        pixelBuffer: PixelBuffer,
+        scratch: FloatArray,
+        scanLine: FloatArray,
+        scopeWidth: Int,
+        syncPulseIndex: Int,
+        lineSamples: Int,
+        freqOffset: Float
+    ): Boolean {
+        if (syncPulseIndex + firstPixelSampleIndex < 0 || syncPulseIndex + end > scanLine.size) return false
+        ema.reset()
+        for (i in firstPixelSampleIndex until end) scratch[i] = ema.process(scanLine[syncPulseIndex + i])
+        ema.reset()
+        for (i in end - 1 downTo firstPixelSampleIndex) scratch[i] = freqToLevel(ema.process(scratch[i]), freqOffset)
+        for (i in 0 until hPixels) {
+            val pos = (i * chSamples) / hPixels
+            pixelBuffer.pixels[i] =
+                ColorConverter.yuv2rgb(scratch[pos + yEvenBegin], scratch[pos + uAvgBegin], scratch[pos + vAvgBegin])
+            pixelBuffer.pixels[i + hPixels] =
+                ColorConverter.yuv2rgb(scratch[pos + yOddBegin], scratch[pos + uAvgBegin], scratch[pos + vAvgBegin])
+        }
+        pixelBuffer.width = hPixels; pixelBuffer.height = 2
+        return true
+    }
+}
+
+internal class RawMode(override val name: String, sampleRate: Int) : SstvMode {
+    override val visCode = -1
+    override val width = -1
+    override val height = -1
+    override val firstPixelSampleIndex = 0
+    override val firstSyncPulseIndex = -1
+    override val scanLineSamples = -1
+
+    private val smallMax = round(0.125 * sampleRate).toInt()
+    private val medMax = round(0.175 * sampleRate).toInt()
+    private val ema = Ema()
+
+    override fun decodeScanLine(
+        pixelBuffer: PixelBuffer,
+        scratch: FloatArray,
+        scanLine: FloatArray,
+        scopeWidth: Int,
+        syncPulseIndex: Int,
+        lineSamples: Int,
+        freqOffset: Float
+    ): Boolean {
+        if (syncPulseIndex < 0 || syncPulseIndex + lineSamples > scanLine.size) return false
+        var px = scopeWidth
+        if (lineSamples < smallMax) px /= 2
+        if (lineSamples < medMax) px /= 2
+        ema.setCutoff(px.toDouble(), (2 * lineSamples).toDouble(), 2); ema.reset()
+        for (i in 0 until lineSamples) scratch[i] = ema.process(scanLine[syncPulseIndex + i])
+        ema.reset()
+        for (i in lineSamples - 1 downTo 0) scratch[i] = freqToLevel(ema.process(scratch[i]), freqOffset)
+        for (i in 0 until px) pixelBuffer.pixels[i] = ColorConverter.gray(scratch[(i * lineSamples) / px])
+        pixelBuffer.width = px; pixelBuffer.height = 1
+        return true
+    }
+}
+
+private fun freqToLevel(frequency: Float, offset: Float): Float = 0.5f * (frequency - offset + 1f)

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/usecase/IAudioCapture.kt

@@ -0,0 +1,34 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.domain.usecase
+
+import kotlinx.coroutines.flow.Flow
+
+/**
+ * Platform abstraction for microphone audio capture.
+ * Produces a flow of mono Float PCM buffers at the configured sample rate.
+ */
+interface IAudioCapture {
+    val sampleRate: Int
+
+    /**
+     * Start capturing audio. Emits FloatArray buffers continuously until the flow is canceled.
+     * Caller is responsible for holding RECORD_AUDIO permission before calling this.
+     */
+    fun audioFlow(): Flow<FloatArray>
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/usecase/ISaveImage.kt

@@ -0,0 +1,26 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.domain.usecase
+
+/**
+ * Saves a decoded SSTV image to the device gallery.
+ * @return true if the image was saved successfully
+ */
+interface ISaveImage {
+    suspend operator fun invoke(pixels: IntArray, width: Int, height: Int, modeName: String): Boolean
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/utility/DataParser.kt

@@ -58,8 +58,6 @@ class DataParser(private val dispatcher: CoroutineDispatcher) {
         }.getOrDefault(emptyList())
     }
 
-    fun isLeapYear(year: Int): Boolean = (year % 4 == 0 && year % 100 != 0) || year % 400 == 0
-
     private fun parseCSV(values: List<String>): OrbitalData? = runCatching {
         val name = values[0]
         val timestamp = values[2]
@@ -84,7 +82,8 @@ class DataParser(private val dispatcher: CoroutineDispatcher) {
             argper = values[7].toDouble(),
             meanan = values[8].toDouble(),
             catnum = values[11].toInt(),
-            bstar = values[14].toDouble()
+            bstar = values[14].toDouble(),
+            ndot = values[15].toDouble()
         )
     }.onFailure { println("CSV parsing exception: $it") }.getOrNull()
 
@@ -101,11 +100,14 @@ class DataParser(private val dispatcher: CoroutineDispatcher) {
             argper = line2.substring(34, 42).toDouble(),
             meanan = line2.substring(43, 51).toDouble(),
             catnum = line1.substring(2, 7).trim().toInt(),
-            bstar = 1e-5 * line1.substring(53, 59).toDouble() / 10.0.pow(line1.substring(60, 61).toDouble())
+            bstar = 1e-5 * line1.substring(53, 59).toDouble() / 10.0.pow(line1.substring(60, 61).toDouble()),
+            ndot = line1.substring(33, 43).trim().toDouble()
         )
     }.onFailure { println("TLE parsing exception: $it") }.getOrNull()
 
-    private fun getDayOfYear(year: Int, month: Int, dayOfMonth: Int): Int {
+    fun isLeapYear(year: Int): Boolean = (year % 4 == 0 && year % 100 != 0) || year % 400 == 0
+
+    fun getDayOfYear(year: Int, month: Int, dayOfMonth: Int): Int {
         val daysInMonth = intArrayOf(31, if (isLeapYear(year)) 29 else 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31)
         return daysInMonth.take(month - 1).sum() + dayOfMonth
     }

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/utility/DopplerFrequencyCalculator.kt

@@ -0,0 +1,173 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ */
+package com.rtbishop.look4sat.core.domain.utility
+
+import com.rtbishop.look4sat.core.domain.model.SatRadio
+import com.rtbishop.look4sat.core.domain.predict.OrbitalPos
+import java.util.Locale
+
+/**
+ * Computes Doppler-corrected reciprocal frequencies for linear transponders.
+ *
+ * The full physical path:
+ *
+ * TX→RX (uplink → downlink):
+ *   ① 地面发射 f_tx
+ *   ② 卫星收到 f_tx × (c - v) / c  （上行多普勒）
+ *   ③ 卫星转发 = passband映射(②)    （在卫星上做映射）
+ *   ④ 地面听到 ③ × (c - v) / c     （下行多普勒）
+ *
+ * RX→TX (downlink → uplink):
+ *   ④ 地面听到 f_rx
+ *   ③ 卫星转发 = f_rx × (c + v) / c  （逆下行多普勒）
+ *   ② 卫星收到 = 逆passband映射(③)
+ *   ① 地面应发射 = ② × (c + v) / c   （逆上行多普勒）
+ *
+ * Addresses GitHub issue #91 (Custom frequency Doppler correction).
+ */
+object DopplerFrequencyCalculator {
+
+    /**
+     * Given a downlink frequency (what the user hears), compute the
+     * uplink frequency the user should transmit.
+     * Full path: ④→③→②→①
+     */
+    fun computeUplinkFromDownlink(
+        downlinkHz: Long,
+        transponder: SatRadio,
+        orbitalPos: OrbitalPos
+    ): Long? {
+        if (!isLinearTransponder(transponder)) return null
+        // ④→③ 逆下行多普勒：卫星转发的频率
+        val satTx = orbitalPos.getUplinkFreq(downlinkHz)
+        // ③→② 逆 passband 映射
+        val satRx = TransponderMapper.mapDownlinkToUplink(satTx, transponder) ?: return null
+        // ②→① 逆上行多普勒：地面应发射的频率
+        return orbitalPos.getUplinkFreq(satRx)
+    }
+
+    /**
+     * Given a downlink frequency (what the user hears), compute the
+     * uplink frequency the user should transmit, with an offset applied
+     * to the downlink (in Hz).
+     * Full path: ④→③→②→①
+     *
+     * The user-entered downlink frequency already includes the offset, so subtract
+     * it before the inverse downlink Doppler.
+     */
+    fun computeUplinkFromDownlinkWithOffset(
+        downlinkHz: Long,
+        transponder: SatRadio,
+        orbitalPos: OrbitalPos,
+        offsetHz: Long
+    ): Long? {
+        if (!isLinearTransponder(transponder)) return null
+        // ④→③ 逆下行多普勒：卫星转发的频率（含 offset）
+        val satTxWithOffset = orbitalPos.getUplinkFreq(downlinkHz)
+        // ③ 去掉 offset（offset 在卫星本地频率域）
+        val satTx = satTxWithOffset - offsetHz
+        // ③→② 逆 passband 映射
+        val satRx = TransponderMapper.mapDownlinkToUplink(satTx, transponder) ?: return null
+        // ②→① 逆上行多普勒：地面应发射的频率
+        return orbitalPos.getUplinkFreq(satRx)
+    }
+
+    /**
+     * Given an uplink frequency (what the user transmits), compute the
+     * downlink frequency the user will hear.
+     * Full path: ①→②→③→④
+     */
+    fun computeDownlinkFromUplink(
+        uplinkHz: Long,
+        transponder: SatRadio,
+        orbitalPos: OrbitalPos
+    ): Long? {
+        if (!isLinearTransponder(transponder)) return null
+        // ①→② 上行多普勒：卫星收到的频率
+        val satRx = orbitalPos.getDownlinkFreq(uplinkHz)
+        // ②→③ passband 映射
+        val satTx = TransponderMapper.mapUplinkToDownlink(satRx, transponder) ?: return null
+        // ③→④ 下行多普勒：地面听到的
+        return orbitalPos.getDownlinkFreq(satTx)
+    }
+
+    /**
+     * Given an uplink frequency (what the user transmits), compute the
+     * downlink frequency the user will hear, with an offset applied
+     * to the downlink (in Hz).
+     * Full path: ①→②→③→④
+     */
+    fun computeDownlinkFromUplinkWithOffset(
+        uplinkHz: Long,
+        transponder: SatRadio,
+        orbitalPos: OrbitalPos,
+        offsetHz: Long
+    ): Long? {
+        if (!isLinearTransponder(transponder)) return null
+        // ①→② 上行多普勒：卫星收到的频率
+        val satRx = orbitalPos.getDownlinkFreq(uplinkHz)
+        // ②→③ passband 映射
+        val satTx = TransponderMapper.mapUplinkToDownlink(satRx, transponder) ?: return null
+        // ③ 加上 offset（offset 在卫星本地频率域）
+        // ③→④ 下行多普勒：地面听到的
+        return orbitalPos.getDownlinkFreq(satTx + offsetHz)
+    }
+
+    /** True if this transponder supports linear passband mapping. */
+    fun isLinearTransponder(transponder: SatRadio): Boolean {
+        val upLow = transponder.uplinkLow
+        val upHigh = transponder.uplinkHigh
+        val downLow = transponder.downlinkLow
+        val downHigh = transponder.downlinkHigh
+        return upLow != null && upHigh != null && downLow != null && downHigh != null
+                && upLow != upHigh && downLow != downHigh
+    }
+
+    /**
+     * True for the radio entry that should drive the standalone Calculator page.
+     *
+     * A frequency range alone is not enough: some non-user-facing or drifting data entries
+     * can also have low/high frequencies. The calculator is meant for the named linear
+     * transponder entry, e.g. "Linear Transponder", "Linear Transp.", "SSB Transponder".
+     */
+    fun isNamedLinearTransponder(transponder: SatRadio): Boolean {
+        if (!isLinearTransponder(transponder)) return false
+
+        val info = transponder.info.lowercase(Locale.ENGLISH)
+        val modes = listOfNotNull(transponder.downlinkMode, transponder.uplinkMode)
+            .joinToString(separator = " ")
+            .lowercase(Locale.ENGLISH)
+        val hasLinearName = info.contains("linear") || info.contains(" lin") || info.startsWith("lin")
+        val hasTransponderName = info.contains("transponder") || info.contains("transp") ||
+                info.contains("xponder") || info.contains("xpdr")
+        val hasLinearMode = listOf("ssb", "usb", "lsb", "cw").any { modes.contains(it) }
+
+        return (hasLinearName && hasTransponderName) || (hasTransponderName && hasLinearMode) ||
+                (hasLinearName && hasLinearMode)
+    }
+
+    /**
+     * Removes duplicate transponder entries that describe the same physical
+     * transponder with different mode labels (e.g. SatNOGS lists AO-7's Mode A
+     * as both "Lin SSB" and "Lin CW", and JO-97's U/V transponder as both
+     * "CW Transponder" and "SSB Transponder").
+     *
+     * Entries sharing the same uplink/downlink frequency range are considered
+     * the same transponder. The non-CW entry is preferred because its invert
+     * flag is more reliable (e.g. JO-97's CW entry wrongly has invert=false).
+     */
+    fun deduplicateTransponders(radios: List<SatRadio>): List<SatRadio> {
+        return radios.groupBy { radio ->
+            listOf(radio.uplinkLow, radio.uplinkHigh, radio.downlinkLow, radio.downlinkHigh)
+        }.values.map { group ->
+            group.firstOrNull { it.downlinkMode?.equals("CW", ignoreCase = true) != true } ?: group.first()
+        }
+    }
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/utility/GeoConverter.kt

@@ -17,11 +17,18 @@
  */
 package com.rtbishop.look4sat.core.domain.utility
 
+import com.rtbishop.look4sat.core.domain.predict.GeoPos
 import com.rtbishop.look4sat.core.domain.predict.DEG2RAD
+import com.rtbishop.look4sat.core.domain.predict.OrbitalPos
 import com.rtbishop.look4sat.core.domain.predict.RAD2DEG
+import kotlin.math.acos
+import kotlin.math.atan2
+import kotlin.math.cos
 import kotlin.math.max
 import kotlin.math.min
+import kotlin.math.sin
 
+private const val AVG_EARTH_RADIUS_KM = 6371.009
 private const val MIN_LATITUDE = -85.05112877980658
 private const val MAX_LATITUDE = 85.05112877980658
 private const val MIN_LONGITUDE = -180.0
@@ -48,6 +55,27 @@ fun Double.toRadians(): Double = this * DEG2RAD
 //    return MIN_LONGITUDE + (MAX_LONGITUDE - MIN_LONGITUDE) * this
 //}
 
+// Great-circle distance between two positions in kilometers using the spherical law of cosines.
+fun greatCircleDistanceKm(lat1: Double, lon1: Double, lat2: Double, lon2: Double): Double {
+    val lat1R = lat1.toRadians()
+    val lat2R = lat2.toRadians()
+    val lon1R = lon1.toRadians()
+    val lon2R = lon2.toRadians()
+    return acos(
+        sin(lat1R) * sin(lat2R) + cos(lat1R) * cos(lat2R) * cos(lon2R - lon1R)
+    ) * AVG_EARTH_RADIUS_KM
+}
+
+// Initial bearing (azimuth) from position 1 to position 2, in degrees (0-360).
+fun bearingDeg(lat1: Double, lon1: Double, lat2: Double, lon2: Double): Double {
+    val lat1R = lat1.toRadians()
+    val lat2R = lat2.toRadians()
+    val dLon = (lon2 - lon1).toRadians()
+    val y = sin(dLon) * cos(lat2R)
+    val x = cos(lat1R) * sin(lat2R) - sin(lat1R) * cos(lat2R) * cos(dLon)
+    return (atan2(y, x).toDegrees() + 360) % 360
+}
+
 fun clipLat(latitude: Double): Double {
     return clip(latitude, MIN_LATITUDE, MAX_LATITUDE)
 }
@@ -59,6 +87,13 @@ fun clipLon(longitude: Double): Double {
     return clip(result, MIN_LONGITUDE, MAX_LONGITUDE)
 }
 
+fun OrbitalPos.toMapGeoPos(): GeoPos {
+    return GeoPos(
+        latitude = clipLat(latitude.toDegrees()),
+        longitude = clipLon(longitude.toDegrees())
+    )
+}
+
 private fun clip(currentValue: Double, minValue: Double, maxValue: Double): Double {
     return min(max(currentValue, minValue), maxValue)
 }

core/domain/src/test/java/com/rtbishop/look4sat/core/domain/DataParserTest.kt

@@ -59,10 +59,53 @@ class DataParserTest {
     @Test
     fun `Given valid CSV stream returns valid data`() = runTest(testDispatcher) {
         val parsedList = dataParser.parseCSVStream(validCSVStream)
+        assert(parsedList.size == 2)
         assert(parsedList[0].epoch == 21320.51955234)
         assert(parsedList[1].epoch == 24069.23963816)
     }
 
+    @Test
+    fun `Given valid CSV stream all orbital fields are parsed correctly`() = runTest(testDispatcher) {
+        val csvStream = """
+            OBJECT_NAME,OBJECT_ID,EPOCH,MEAN_MOTION,ECCENTRICITY,INCLINATION,RA_OF_ASC_NODE,ARG_OF_PERICENTER,MEAN_ANOMALY,EPHEMERIS_TYPE,CLASSIFICATION_TYPE,NORAD_CAT_ID,ELEMENT_SET_NO,REV_AT_EPOCH,BSTAR,MEAN_MOTION_DOT,MEAN_MOTION_DDOT
+            ISS (ZARYA),1998-067A,2021-11-16T12:28:09.322176,15.48582035,.0004694,51.6447,309.4881,203.6966,299.8876,0,U,25544,999,31220,.31985E-4,.1288E-4,0
+        """.trimIndent().byteInputStream()
+        val sat = dataParser.parseCSVStream(csvStream)[0]
+        assert(sat.name == "ISS (ZARYA)")
+        assert(sat.catnum == 25544)
+        assert(sat.meanmo == 15.48582035)
+        assert(sat.eccn == 0.0004694)
+        assert(sat.incl == 51.6447)
+        assert(sat.raan == 309.4881)
+        assert(sat.argper == 203.6966)
+        assert(sat.meanan == 299.8876)
+        assert(sat.bstar == 0.31985E-4)
+        assert(sat.ndot == 0.1288E-4)
+    }
+
+    @Test
+    fun `Given valid CSV stream ndot is parsed for decay detection`() = runTest(testDispatcher) {
+        val csvStream = """
+            OBJECT_NAME,OBJECT_ID,EPOCH,MEAN_MOTION,ECCENTRICITY,INCLINATION,RA_OF_ASC_NODE,ARG_OF_PERICENTER,MEAN_ANOMALY,EPHEMERIS_TYPE,CLASSIFICATION_TYPE,NORAD_CAT_ID,ELEMENT_SET_NO,REV_AT_EPOCH,BSTAR,MEAN_MOTION_DOT,MEAN_MOTION_DDOT
+            ISS (ZARYA),1998-067A,2021-11-16T12:28:09.322176,15.48582035,.0004694,51.6447,309.4881,203.6966,299.8876,0,U,25544,999,31220,.31985E-4,.1288E-4,0
+        """.trimIndent().byteInputStream()
+        val sat = dataParser.parseCSVStream(csvStream)[0]
+        // ISS is healthy, should not be decayed even years later
+        assert(!sat.hasDecayed(System.currentTimeMillis()))
+    }
+
+    @Test
+    fun `Given CSV with high drag satellite detects decay`() = runTest(testDispatcher) {
+        // Simulate a satellite with high drag and old epoch that should have decayed
+        val csvStream = """
+            OBJECT_NAME,OBJECT_ID,EPOCH,MEAN_MOTION,ECCENTRICITY,INCLINATION,RA_OF_ASC_NODE,ARG_OF_PERICENTER,MEAN_ANOMALY,EPHEMERIS_TYPE,CLASSIFICATION_TYPE,NORAD_CAT_ID,ELEMENT_SET_NO,REV_AT_EPOCH,BSTAR,MEAN_MOTION_DOT,MEAN_MOTION_DDOT
+            DEBRIS,2020-001A,2020-01-15T00:00:00.000000,15.9,.001,51.0,100.0,200.0,300.0,0,U,99999,1,100,.5E-3,.05,0
+        """.trimIndent().byteInputStream()
+        val sat = dataParser.parseCSVStream(csvStream)[0]
+        // High mean motion (15.9) + high drag (.05) + old epoch → should be decayed by now
+        assert(sat.hasDecayed(System.currentTimeMillis()))
+    }
+
     @Test
     fun `Given invalid CSV stream returns empty list`() = runTest(testDispatcher) {
         assert(dataParser.parseCSVStream(invalidCSVStream).isEmpty())
@@ -71,10 +114,41 @@ class DataParserTest {
     @Test
     fun `Given valid TLE stream returns valid data`() = runTest(testDispatcher) {
         val parsedList = dataParser.parseTLEStream(validTLEStream)
+        assert(parsedList.size == 2)
         assert(parsedList[0].epoch == 21320.51955234)
         assert(parsedList[1].epoch == 24069.23963816)
     }
 
+    @Test
+    fun `Given valid TLE stream all orbital fields are parsed correctly`() = runTest(testDispatcher) {
+        val tleStream = """
+            ISS (ZARYA)
+            1 25544U 98067A   21320.51955234  .00001288  00000+0  31985-4 0  9990
+            2 25544  51.6447 309.4881 0004694 203.6966 299.8876 15.48582035312205
+        """.trimIndent().byteInputStream()
+        val sat = dataParser.parseTLEStream(tleStream)[0]
+        assert(sat.name == "ISS (ZARYA)")
+        assert(sat.catnum == 25544)
+        assert(sat.meanmo == 15.48582035)
+        assert(sat.eccn == 0.0004694)
+        assert(sat.incl == 51.6447)
+        assert(sat.raan == 309.4881)
+        assert(sat.argper == 203.6966)
+        assert(sat.meanan == 299.8876)
+        assert(sat.ndot == 0.00001288)
+    }
+
+    @Test
+    fun `Given valid TLE stream ndot is parsed for decay detection`() = runTest(testDispatcher) {
+        val tleStream = """
+            ISS (ZARYA)
+            1 25544U 98067A   21320.51955234  .00001288  00000+0  31985-4 0  9990
+            2 25544  51.6447 309.4881 0004694 203.6966 299.8876 15.48582035312205
+        """.trimIndent().byteInputStream()
+        val sat = dataParser.parseTLEStream(tleStream)[0]
+        assert(!sat.hasDecayed(System.currentTimeMillis()))
+    }
+
     @Test
     fun `Given invalid TLE stream returns empty list`() = runTest(testDispatcher) {
         assert(dataParser.parseTLEStream(invalidTLEStream).isEmpty())
@@ -85,6 +159,43 @@ class DataParserTest {
         assert(dataParser.parseJSONStream(validJSONStream)[0].downlinkLow == 136658500L)
     }
 
+    @Test
+    fun `Given valid JSON stream all radio fields are parsed correctly`() = runTest(testDispatcher) {
+        val jsonStream = """
+            [{"uuid":"UzPz4gcsNBPKPKAFPmer7g","description":"Upper side band (drifting)","alive":true,"type":"Transmitter","uplink_low":145900000,"uplink_high":146000000,"uplink_drift":null,"downlink_low":136658500,"downlink_high":136700000,"downlink_drift":null,"mode":"USB","mode_id":9,"uplink_mode":"FM","invert":true,"baud":null,"sat_id":"SCHX-0895-2361-9925-0309","norad_cat_id":965,"status":"active","updated":"2019-04-18T05:39:53.343316Z","citation":"CITATION NEEDED","service":"Unknown","coordination":"","coordination_url":""}]
+        """.trimIndent().byteInputStream()
+        val radio = dataParser.parseJSONStream(jsonStream)[0]
+        assert(radio.uuid == "UzPz4gcsNBPKPKAFPmer7g")
+        assert(radio.info == "Upper side band (drifting)")
+        assert(radio.isAlive)
+        assert(radio.downlinkLow == 136658500L)
+        assert(radio.downlinkHigh == 136700000L)
+        assert(radio.downlinkMode == "USB")
+        assert(radio.uplinkLow == 145900000L)
+        assert(radio.uplinkHigh == 146000000L)
+        assert(radio.uplinkMode == "FM")
+        assert(radio.isInverted)
+        assert(radio.catnum == 965)
+    }
+
+    @Test
+    fun `Given JSON with null optional fields parses without error`() = runTest(testDispatcher) {
+        val jsonStream = """
+            [{"uuid":"abc123","description":"Beacon","alive":false,"type":"Transmitter","uplink_low":null,"uplink_high":null,"uplink_drift":null,"downlink_low":145800000,"downlink_high":null,"downlink_drift":null,"mode":null,"mode_id":null,"uplink_mode":null,"invert":false,"baud":null,"sat_id":"TEST","norad_cat_id":12345,"status":"active","updated":"2024-01-01T00:00:00Z","citation":"","service":"Unknown","coordination":"","coordination_url":""}]
+        """.trimIndent().byteInputStream()
+        val radio = dataParser.parseJSONStream(jsonStream)[0]
+        assert(radio.uuid == "abc123")
+        assert(!radio.isAlive)
+        assert(radio.downlinkLow == 145800000L)
+        assert(radio.downlinkHigh == null)
+        assert(radio.downlinkMode == null)
+        assert(radio.uplinkLow == null)
+        assert(radio.uplinkHigh == null)
+        assert(radio.uplinkMode == null)
+        assert(!radio.isInverted)
+        assert(radio.catnum == 12345)
+    }
+
     @Test
     fun `Given invalid JSON stream returns empty list`() = runTest(testDispatcher) {
         assert(dataParser.parseJSONStream(invalidJSONStream).isEmpty())
@@ -96,10 +207,36 @@ class DataParserTest {
     }
 
     @Test
-    fun `Function isLeapYear returns correct data`() = runTest(testDispatcher) {
-        val years = listOf(1900, 1984, 1994, 2016, 2022, 2024, 2042, 2048)
-        val answers = listOf(false, true, false, true, false, true, false, true)
+    fun `isLeapYear returns correct results`() {
+        val years = listOf(1900, 1984, 1994, 2000, 2016, 2022, 2024, 2042, 2048, 2100)
+        val expected = listOf(false, true, false, true, true, false, true, false, true, false)
         val results = years.map { dataParser.isLeapYear(it) }
-        assert(results == answers)
+        assert(results == expected)
+    }
+
+    @Test
+    fun `getDayOfYear returns correct day for January 1st`() {
+        assert(dataParser.getDayOfYear(2024, 1, 1) == 1)
+        assert(dataParser.getDayOfYear(2023, 1, 1) == 1)
+    }
+
+    @Test
+    fun `getDayOfYear returns correct day for March 1st in leap and non-leap years`() {
+        // 2024 is leap: Jan(31) + Feb(29) + 1 = 61
+        assert(dataParser.getDayOfYear(2024, 3, 1) == 61)
+        // 2023 is not leap: Jan(31) + Feb(28) + 1 = 60
+        assert(dataParser.getDayOfYear(2023, 3, 1) == 60)
+    }
+
+    @Test
+    fun `getDayOfYear returns correct day for December 31st`() {
+        assert(dataParser.getDayOfYear(2024, 12, 31) == 366) // leap year
+        assert(dataParser.getDayOfYear(2023, 12, 31) == 365) // non-leap year
+    }
+
+    @Test
+    fun `getDayOfYear returns correct day for November 16th`() {
+        // Matches the CSV test data epoch: 2021-11-16 → day 320
+        assert(dataParser.getDayOfYear(2021, 11, 16) == 320)
     }
 }

core/domain/src/test/java/com/rtbishop/look4sat/core/domain/DopplerFrequencyCalculatorTest.kt

@@ -0,0 +1,275 @@
+package com.rtbishop.look4sat.core.domain
+
+import com.rtbishop.look4sat.core.domain.model.SatRadio
+import com.rtbishop.look4sat.core.domain.predict.OrbitalPos
+import com.rtbishop.look4sat.core.domain.utility.DopplerFrequencyCalculator
+import org.junit.Assert.*
+import org.junit.Test
+
+class DopplerFrequencyCalculatorTest {
+
+    private fun linearTransponder(
+        uuid: String = "linear",
+        upLow: Long = 145_000_000L,
+        upHigh: Long = 145_500_000L,
+        downLow: Long = 435_000_000L,
+        downHigh: Long? = 435_500_000L,
+        inverted: Boolean = false,
+        info: String = "Linear Transponder",
+        downlinkMode: String? = "USB",
+        uplinkMode: String? = "LSB"
+    ) = SatRadio(
+        uuid = uuid, info = info, isAlive = true,
+        downlinkLow = downLow, downlinkHigh = downHigh,
+        downlinkMode = downlinkMode, uplinkLow = upLow, uplinkHigh = upHigh,
+        uplinkMode = uplinkMode, isInverted = inverted, catnum = 12345
+    )
+
+    private fun fmTransponder() = SatRadio(
+        uuid = "fm", info = "FM Repeater", isAlive = true,
+        downlinkLow = 435_600_000L, downlinkHigh = null,
+        downlinkMode = "FM", uplinkLow = 145_900_000L, uplinkHigh = null,
+        uplinkMode = "FM", isInverted = false, catnum = 99999
+    )
+
+    private fun pos(distanceRateKmS: Double = 0.0) = OrbitalPos().apply {
+        this.distanceRate = distanceRateKmS
+    }
+
+    @Test
+    fun isLinearTransponder_returnsTrueForLinear() {
+        assertTrue(DopplerFrequencyCalculator.isLinearTransponder(linearTransponder()))
+    }
+
+    @Test
+    fun isLinearTransponder_returnsFalseForFM() {
+        assertFalse(DopplerFrequencyCalculator.isLinearTransponder(fmTransponder()))
+    }
+
+    @Test
+    fun isLinearTransponder_returnsFalseForNullDownlinkHigh() {
+        val xpdr = linearTransponder(downHigh = null)
+        assertFalse(DopplerFrequencyCalculator.isLinearTransponder(xpdr))
+    }
+
+    @Test
+    fun isNamedLinearTransponder_returnsTrueForLinearTransponderName() {
+        assertTrue(DopplerFrequencyCalculator.isNamedLinearTransponder(linearTransponder()))
+    }
+
+    @Test
+    fun isNamedLinearTransponder_returnsTrueForSsbTransponderName() {
+        val xpdr = linearTransponder(info = "Mode V/U SSB Transponder", downlinkMode = "USB", uplinkMode = "LSB")
+        assertTrue(DopplerFrequencyCalculator.isNamedLinearTransponder(xpdr))
+    }
+
+    @Test
+    fun isNamedLinearTransponder_returnsFalseForRangeEntryWithoutTransponderName() {
+        val driftingRangeEntry = linearTransponder(info = "Upper side band (drifting)")
+        assertFalse(DopplerFrequencyCalculator.isNamedLinearTransponder(driftingRangeEntry))
+    }
+
+    @Test
+    fun isNamedLinearTransponder_returnsTrueForAbbreviatedLinName() {
+        // AO-7 style: "Mode V/A (A) Lin SSB" — "Lin" abbreviation, no "transponder" word
+        val ao7Entry = linearTransponder(info = "Mode V/A (A) Lin SSB", downlinkMode = "USB", uplinkMode = "USB")
+        assertTrue(DopplerFrequencyCalculator.isNamedLinearTransponder(ao7Entry))
+        val ao7CwEntry = linearTransponder(info = "Mode V/A (A) Lin CW", downlinkMode = "CW", uplinkMode = "CW")
+        assertTrue(DopplerFrequencyCalculator.isNamedLinearTransponder(ao7CwEntry))
+        val ao7ModeBEntry = linearTransponder(info = "Mode U/V (B) Lin", downlinkMode = "USB", uplinkMode = "LSB")
+        assertTrue(DopplerFrequencyCalculator.isNamedLinearTransponder(ao7ModeBEntry))
+    }
+
+    @Test
+    fun isNamedLinearTransponder_returnsTrueForLinearWithoutTransponderWord() {
+        // AO-73 style: "Mode U/V Linear" — has "Linear" but no "transponder"
+        val ao73Entry = linearTransponder(info = "Mode U/V Linear", downlinkMode = "USB", uplinkMode = "LSB")
+        assertTrue(DopplerFrequencyCalculator.isNamedLinearTransponder(ao73Entry))
+    }
+
+    @Test
+    fun isNamedLinearTransponder_returnsFalseForDownlinkContainingLinInsideWord() {
+        // "Downlink" contains "lin" but is not a linear-transponder name
+        val downlinkEntry = linearTransponder(info = "Mode U Downlink", downlinkMode = "FM", uplinkMode = "FM")
+        assertFalse(DopplerFrequencyCalculator.isNamedLinearTransponder(downlinkEntry))
+    }
+
+    @Test
+    fun isNamedLinearTransponder_returnsFalseForFmRepeater() {
+        assertFalse(DopplerFrequencyCalculator.isNamedLinearTransponder(fmTransponder()))
+    }
+
+    @Test
+    fun deduplicateTransponders_mergesSameFrequencyRange() {
+        // AO-7's Mode A: same range, SSB and CW entries
+        val ssb = linearTransponder(
+            uuid = "ssb-uuid", info = "Mode V/A (A) Lin SSB",
+            downlinkMode = "USB", uplinkMode = "USB"
+        )
+        val cw = linearTransponder(
+            uuid = "cw-uuid", info = "Mode V/A (A) Lin CW",
+            downlinkMode = "CW", uplinkMode = "CW"
+        )
+        val modeB = linearTransponder(
+            uuid = "modeb-uuid", info = "Mode U/V (B) Lin",
+            upLow = 432_125_000L, upHigh = 432_175_000L,
+            downLow = 145_925_000L, downHigh = 145_975_000L,
+            downlinkMode = "USB", uplinkMode = "LSB"
+        )
+        val result = DopplerFrequencyCalculator.deduplicateTransponders(listOf(ssb, cw, modeB))
+        assertEquals(2, result.size)
+        // SSB entry should be preferred over CW (same range)
+        assertEquals("ssb-uuid", result[0].uuid)
+        assertEquals("modeb-uuid", result[1].uuid)
+    }
+
+    @Test
+    fun deduplicateTransponders_prefersNonCwEntry() {
+        // JO-97: CW entry has invert=false (wrong), SSB has invert=true (correct)
+        val cw = linearTransponder(
+            uuid = "cw-uuid", info = "U/V CW Transponder",
+            downlinkMode = "CW", uplinkMode = "CW",
+            upLow = 435_100_000L, upHigh = 435_120_000L,
+            downLow = 145_855_000L, downHigh = 145_875_000L
+        )
+        val ssb = linearTransponder(
+            uuid = "ssb-uuid", info = "U/V SSB Transponder",
+            downlinkMode = "USB", uplinkMode = "LSB",
+            upLow = 435_100_000L, upHigh = 435_120_000L,
+            downLow = 145_855_000L, downHigh = 145_875_000L,
+            inverted = true
+        )
+        val result = DopplerFrequencyCalculator.deduplicateTransponders(listOf(cw, ssb))
+        assertEquals(1, result.size)
+        assertEquals("ssb-uuid", result[0].uuid)
+        // Verify the correct invert flag is preserved
+        assertTrue(result[0].isInverted)
+    }
+
+    @Test
+    fun deduplicateTransponders_preservesUniqueEntries() {
+        val t1 = linearTransponder(uuid = "t1", upLow = 145_000_000L, upHigh = 145_500_000L,
+            downLow = 435_000_000L, downHigh = 435_500_000L)
+        val t2 = linearTransponder(uuid = "t2", upLow = 435_000_000L, upHigh = 435_500_000L,
+            downLow = 145_000_000L, downHigh = 145_500_000L)
+        val result = DopplerFrequencyCalculator.deduplicateTransponders(listOf(t1, t2))
+        assertEquals(2, result.size)
+    }
+
+    @Test
+    fun computeUplinkFromDownlink_linear_noDoppler() {
+        val xpdr = linearTransponder()
+        val orbitalPos = pos(0.0)
+        val uplink = DopplerFrequencyCalculator.computeUplinkFromDownlink(435_200_000L, xpdr, orbitalPos)
+        assertNotNull(uplink)
+        assertTrue(uplink!! > 0)
+        // With zero Doppler, result equals mapDownlinkToUplink output
+        assertEquals(145_200_000L, uplink)
+    }
+
+    @Test
+    fun computeDownlinkFromUplink_linear_noDoppler() {
+        val xpdr = linearTransponder()
+        val orbitalPos = pos(0.0)
+        val downlink = DopplerFrequencyCalculator.computeDownlinkFromUplink(145_200_000L, xpdr, orbitalPos)
+        assertNotNull(downlink)
+        assertEquals(435_200_000L, downlink)
+    }
+
+    @Test
+    fun computeUplinkFromDownlink_withDoppler_positiveRangeRate() {
+        // Satellite receding (positive range rate) → ground must transmit higher freq to compensate
+        val xpdr = linearTransponder()
+        val orbitalPos = pos(7.0)  // ~7 km/s receding
+        val uplink = DopplerFrequencyCalculator.computeUplinkFromDownlink(435_200_000L, xpdr, orbitalPos)
+        assertNotNull(uplink)
+        // Uplink freq should be Doppler shifted UP (compensating for receding)
+        assertTrue(uplink!! > 145_200_000L)
+    }
+
+    @Test
+    fun computeUplinkFromDownlink_fm_transponder_returnsNull() {
+        val orbitalPos = pos()
+        val result = DopplerFrequencyCalculator.computeUplinkFromDownlink(435_600_000L, fmTransponder(), orbitalPos)
+        assertNull(result)
+    }
+
+    @Test
+    fun computeDownlinkFromUplink_fm_transponder_returnsNull() {
+        val orbitalPos = pos()
+        val result = DopplerFrequencyCalculator.computeDownlinkFromUplink(145_900_000L, fmTransponder(), orbitalPos)
+        assertNull(result)
+    }
+
+    @Test
+    fun computeDownlinkFromUplink_withPositiveOffset_addsOffsetToDownlink() {
+        val xpdr = linearTransponder()
+        val orbitalPos = pos(0.0)
+        val downlink = DopplerFrequencyCalculator.computeDownlinkFromUplinkWithOffset(
+            uplinkHz = 145_200_000L,
+            transponder = xpdr,
+            orbitalPos = orbitalPos,
+            offsetHz = 2_500L
+        )
+        assertEquals(435_202_500L, downlink)
+    }
+
+    @Test
+    fun computeUplinkFromDownlink_withPositiveOffset_subtractsOffsetBeforeMapping() {
+        val xpdr = linearTransponder()
+        val orbitalPos = pos(0.0)
+        val uplink = DopplerFrequencyCalculator.computeUplinkFromDownlinkWithOffset(
+            downlinkHz = 435_202_500L,
+            transponder = xpdr,
+            orbitalPos = orbitalPos,
+            offsetHz = 2_500L
+        )
+        assertEquals(145_200_000L, uplink)
+    }
+
+    @Test
+    fun computeOffsetRoundTrip_handlesNegativeOffset() {
+        val xpdr = linearTransponder()
+        val orbitalPos = pos(0.0)
+        val downlink = DopplerFrequencyCalculator.computeDownlinkFromUplinkWithOffset(
+            uplinkHz = 145_200_000L,
+            transponder = xpdr,
+            orbitalPos = orbitalPos,
+            offsetHz = -2_500L
+        )
+        assertEquals(435_197_500L, downlink)
+
+        val uplink = DopplerFrequencyCalculator.computeUplinkFromDownlinkWithOffset(
+            downlinkHz = downlink!!,
+            transponder = xpdr,
+            orbitalPos = orbitalPos,
+            offsetHz = -2_500L
+        )
+        assertEquals(145_200_000L, uplink)
+    }
+
+    @Test
+    fun computeUplinkFromDownlink_invertedTransponder() {
+        val xpdr = linearTransponder(inverted = true, downHigh = 435_500_000L)
+        val orbitalPos = pos(0.0)
+        val uplink = DopplerFrequencyCalculator.computeUplinkFromDownlink(435_200_000L, xpdr, orbitalPos)
+        assertNotNull(uplink)
+        // Inverted: offset from high end → maps to high end of uplink
+        assertEquals(145_300_000L, uplink)
+    }
+
+    @Test
+    fun computeUplinkFromDownlink_roundTrip() {
+        // downlink → uplink → downlink should round-trip
+        val xpdr = linearTransponder()
+        val orbitalPos = pos(3.5)
+        val originalDownlink = 435_250_000L
+        val uplink = DopplerFrequencyCalculator.computeUplinkFromDownlink(originalDownlink, xpdr, orbitalPos)
+        assertNotNull(uplink)
+        val roundTripDownlink = DopplerFrequencyCalculator.computeDownlinkFromUplink(uplink!!, xpdr, orbitalPos)
+        assertNotNull(roundTripDownlink)
+        // Doppler round-trip: small residual due to freq-dependent Doppler
+        val error = kotlin.math.abs(roundTripDownlink!! - originalDownlink)
+        assertTrue("Round-trip error too large: $error", error < 10000)
+    }
+}

core/domain/src/test/java/com/rtbishop/look4sat/core/domain/cw/CwDecoderTest.kt

@@ -0,0 +1,301 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.domain.cw
+
+import org.junit.Assert.*
+import org.junit.Test
+import kotlin.math.PI
+import kotlin.math.sin
+
+class CwDecoderTest {
+
+    // --- Morse table ---
+
+    @Test
+    fun morseToChar_basicLetters() {
+        assertEquals('A', CwBayesianDecoder.morseToChar("01"))
+        assertEquals('S', CwBayesianDecoder.morseToChar("000"))
+        assertEquals('O', CwBayesianDecoder.morseToChar("111"))
+    }
+
+    @Test
+    fun morseToChar_numbers() {
+        assertEquals('1', CwBayesianDecoder.morseToChar("01111"))
+        assertEquals('0', CwBayesianDecoder.morseToChar("11111"))
+    }
+
+    @Test
+    fun morseToChar_unknown_returnsNull() {
+        assertNull(CwBayesianDecoder.morseToChar("......."))
+        assertNull(CwBayesianDecoder.morseToChar(""))
+    }
+
+    // --- FFT ---
+
+    @Test
+    fun fft_magnitudeSpectrum_detectsTone() {
+        val fft = CwFFT(256)
+        val sampleRate = 8000f
+        val freq = 700f
+        val buffer = FloatArray(256) { (sin(2.0 * PI * freq * it / sampleRate)).toFloat() }
+        val mag = fft.magnitudeSpectrum(buffer)
+        // Peak should be at bin around 700 * 256 / 8000 ≈ 22.4
+        var maxBin = 0
+        var maxVal = 0f
+        for (i in mag.indices) {
+            if (mag[i] > maxVal) { maxVal = mag[i]; maxBin = i }
+        }
+        assertTrue("Peak bin $maxBin should be near 22", maxBin in 18..26)
+        assertTrue("Peak value $maxVal should be positive", maxVal > 0.01f)
+    }
+
+    @Test
+    fun fft_magnitudeSpectrum_silence_isFlat() {
+        val fft = CwFFT(256)
+        val buffer = FloatArray(256) { 0f }
+        val mag = fft.magnitudeSpectrum(buffer)
+        for (v in mag) assertEquals("Silence spectrum should be 0, got $v", 0f, v, 1e-6f)
+    }
+
+    @Test
+    fun fft_rejectsWrongSize() {
+        assertThrows(IllegalArgumentException::class.java) { CwFFT(100) }
+    }
+
+    // --- Spectrogram ---
+
+    @Test
+    fun spectrogram_addSamples_updatesEnergy() {
+        val spec = CwSpectrogram(sampleRate = 8000)
+        val freq = 700f
+        // Feed multiple frames to stabilize energy normalization
+        for (i in 0..5) {
+            val buffer = FloatArray(256) { (sin(2.0 * PI * freq * it / 8000.0)).toFloat() }
+            spec.addSamples(buffer)
+        }
+        val col = spec.getCurrentColumn()
+        val peakBin = spec.findPeakBin()
+        assertTrue("Peak bin $peakBin should be >= 0", peakBin >= 0)
+    }
+
+    @Test
+    fun spectrogram_findPeakBin_returnsValidBin() {
+        val spec = CwSpectrogram(sampleRate = 8000)
+        // Add multiple frames of 700 Hz tone
+        for (i in 0..5) {
+            val buffer = FloatArray(256) { (sin(2.0 * PI * 700.0 * it / 8000.0)).toFloat() }
+            spec.addSamples(buffer)
+        }
+        val peakBin = spec.findPeakBin()
+        assertTrue("Peak bin should be >= 0, got $peakBin", peakBin >= 0)
+    }
+
+    @Test
+    fun spectrogram_freqToBin_roundtrip() {
+        val spec = CwSpectrogram(sampleRate = 8000)
+        val freq = 700f
+        val bin = spec.freqToBin(freq)
+        val backFreq = spec.binToFreq(bin)
+        assertTrue("Freq $freq → bin $bin → freq $backFreq", backFreq > 600f && backFreq < 800f)
+    }
+
+    @Test
+    fun spectrogram_getBinEnergy_returnsCorrectLength() {
+        val spec = CwSpectrogram(sampleRate = 8000)
+        val energy = spec.getBinEnergy(0, 10)
+        assertEquals(10, energy.size)
+    }
+
+    @Test
+    fun spectrogram_reset() {
+        val spec = CwSpectrogram(sampleRate = 8000)
+        spec.addSamples(FloatArray(256) { 1f })
+        spec.reset()
+        assertEquals(-1, spec.findPeakBin())
+    }
+
+    // --- Bayesian decoder ---
+
+    @Test
+    fun bayesian_processTone_dit() {
+        val decoder = CwBayesianDecoder()
+        // At 20 WPM, dot = 60 ms
+        val result = decoder.processTone(60f)
+        assertEquals('0', result.symbol)
+        assertTrue("Dit probability should be positive", result.probability > 0.1f)
+    }
+
+    @Test
+    fun bayesian_processTone_dash() {
+        val decoder = CwBayesianDecoder()
+        // Dash = 3 * dot = 180 ms
+        val result = decoder.processTone(180f)
+        assertEquals('1', result.symbol)
+        assertTrue("Dash probability should be positive", result.probability > 0.1f)
+    }
+
+    @Test
+    fun bayesian_processTone_unknown_returnsNull() {
+        val decoder = CwBayesianDecoder()
+        // Very long tone — low probability for both dit and dash
+        val result = decoder.processTone(5000f)
+        assertNull(result.symbol)
+    }
+
+    @Test
+    fun bayesian_processGap_interChar_returnsChar() {
+        val decoder = CwBayesianDecoder()
+        decoder.processTone(60f) // dit
+        decoder.processTone(60f) // dit
+        decoder.processTone(60f) // dit
+        // 3 dots = "000" = 'S'
+        val char = decoder.processGap(180f) // 3 * dot = inter-char gap
+        assertEquals('S', char)
+    }
+
+    @Test
+    fun bayesian_processGap_wordGap_addsSpace() {
+        val decoder = CwBayesianDecoder()
+        decoder.processTone(60f) // dit = 'E'
+        decoder.processGap(180f) // inter-char gap
+        // Now word gap
+        val space = decoder.processGap(420f) // 7 * dot
+        assertEquals(' ', space)
+    }
+
+    @Test
+    fun bayesian_decodedText_accumulates() {
+        val decoder = CwBayesianDecoder()
+        decoder.processTone(60f) // dit = 'E'
+        decoder.processGap(180f) // inter-char
+        assertTrue(decoder.decodedText.isNotEmpty())
+    }
+
+    @Test
+    fun bayesian_reset() {
+        val decoder = CwBayesianDecoder()
+        decoder.processTone(60f)
+        decoder.reset()
+        assertEquals("", decoder.decodedText)
+    }
+
+    @Test
+    fun bayesian_getSpeed() {
+        val decoder = CwBayesianDecoder()
+        // Send 3 dits at 20 WPM (60 ms each)
+        decoder.processTone(60f)
+        decoder.processTone(60f)
+        decoder.processTone(60f)
+        val speed = decoder.getSpeed()
+        assertTrue("Speed should be ~20 WPM, got $speed", speed > 15f && speed < 30f)
+    }
+
+    // --- Channel tracker ---
+
+    @Test
+    fun channelTracker_initialState() {
+        val spec = CwSpectrogram(sampleRate = 8000)
+        val tracker = CwChannelTracker(spec)
+        val channels = tracker.update()
+        assertTrue("No channels should be active initially", channels.isEmpty())
+    }
+
+    @Test
+    fun channelTracker_detectsTone() {
+        val spec = CwSpectrogram(sampleRate = 8000)
+        // Feed a tone
+        for (i in 0..5) {
+            spec.addSamples(FloatArray(256) { (sin(2.0 * PI * 700.0 * it / 8000.0)).toFloat() })
+        }
+        val tracker = CwChannelTracker(spec)
+        val channels = tracker.update()
+        assertTrue("Should detect at least 1 channel", channels.isNotEmpty())
+    }
+
+    @Test
+    fun channelTracker_bestChannel() {
+        val spec = CwSpectrogram(sampleRate = 8000)
+        for (i in 0..5) {
+            spec.addSamples(FloatArray(256) { (sin(2.0 * PI * 700.0 * it / 8000.0)).toFloat() })
+        }
+        val tracker = CwChannelTracker(spec)
+        tracker.update()
+        val best = tracker.getBestChannel()
+        assertNotNull("Best channel should exist", best)
+        if (best != null) assertTrue(best.frequency in 600f..800f)
+    }
+
+    @Test
+    fun channelTracker_reset() {
+        val spec = CwSpectrogram(sampleRate = 8000)
+        for (i in 0..5) {
+            spec.addSamples(FloatArray(256) { (sin(2.0 * PI * 700.0 * it / 8000.0)).toFloat() })
+        }
+        val tracker = CwChannelTracker(spec)
+        tracker.update()
+        tracker.reset()
+        assertNull(tracker.getBestChannel())
+    }
+
+    // --- Full decoder ---
+
+    @Test
+    fun decoder_initialState() {
+        val decoder = CwDecoder()
+        assertEquals("", decoder.decodedTextFlow.value)
+        assertEquals(0f, decoder.signalStrength.value, 0.001f)
+    }
+
+    @Test
+    fun decoder_processSilence_doesNotCrash() {
+        val decoder = CwDecoder()
+        decoder.processBuffer(FloatArray(256) { 0f })
+        assertEquals("", decoder.decodedTextFlow.value)
+    }
+
+    @Test
+    fun decoder_processNoise_doesNotCrash() {
+        val decoder = CwDecoder()
+        decoder.processBuffer(FloatArray(256) { (Math.random() * 2 - 1).toFloat() * 0.1f })
+        assertNotNull(decoder.decodedTextFlow.value)
+    }
+
+    @Test
+    fun decoder_processTone_doesNotCrash() {
+        val decoder = CwDecoder()
+        for (i in 0..20) {
+            decoder.processBuffer(FloatArray(256) { (sin(2.0 * PI * 700.0 * it / 8000.0)).toFloat() })
+        }
+        assertNotNull(decoder.decodedTextFlow.value)
+    }
+
+    @Test
+    fun decoder_reset() {
+        val decoder = CwDecoder()
+        decoder.processBuffer(FloatArray(256) { 1f })
+        decoder.resetDecoder()
+        assertEquals("", decoder.decodedTextFlow.value)
+        assertEquals(0f, decoder.signalStrength.value, 0.001f)
+    }
+
+    @Test
+    fun decoder_withFixedPitch() {
+        val decoder = CwDecoder(sampleRate = 8000, cwToneFreq = 700f)
+        assertEquals(700f, decoder.estimatedPitch.value)
+    }
+}

core/presentation/src/main/java/com/rtbishop/look4sat/core/presentation/BubblesEffect.kt

@@ -0,0 +1,424 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.presentation
+
+import android.graphics.Paint
+import android.graphics.LinearGradient
+import android.graphics.RadialGradient
+import android.graphics.Shader
+import androidx.compose.foundation.Canvas
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.Immutable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableIntStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.runtime.withFrameNanos
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.geometry.Size
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.drawscope.DrawScope
+import androidx.compose.ui.graphics.nativeCanvas
+import androidx.core.graphics.withRotation
+import kotlinx.coroutines.isActive
+import kotlin.math.atan2
+import kotlin.math.cos
+import kotlin.math.min
+import kotlin.math.sin
+import kotlin.math.sqrt
+import kotlin.random.Random
+
+@Immutable
+data class BubblesStyle(
+    val bgColor: Color = Color.Black,
+    val bubbleCount: Int = 16,
+    val minBubbleCount: Int = 8,
+    val maxBubbleCount: Int = 16,
+    val adaptiveBubbleCount: Boolean = true,
+    val spawnIntervalMs: Long = 800L,
+    val bubbleRadiusFraction: Float = 0.24f,
+    val adaptiveSizing: Boolean = true,
+    val referenceMinSizePx: Float = 360f,
+    val referenceAreaPx: Float = 360f * 800f,
+    val minBubbleRadiusPx: Float = 16f,
+    val maxBubbleRadiusPx: Float = 256f,
+    val speedScale: Float = 0.99f,
+    val minVelocity: Float = 0.8f,
+    val maxVelocity: Float = 3.2f,
+    val hueRotationSpeedDps: Float = 60f, // degrees per second
+)
+
+@Composable
+fun BubblesEffect(
+    modifier: Modifier = Modifier,
+    isRunning: Boolean = true,
+    style: BubblesStyle = BubblesStyle(),
+) {
+    val renderer = remember { BubblesRenderer() }
+    var frameSignal by remember { mutableIntStateOf(0) }
+
+    // Animation loop
+    LaunchedEffect(isRunning, style) {
+        if (!isRunning) return@LaunchedEffect
+        var previousNanos = 0L
+        while (isActive) {
+            withFrameNanos { now ->
+                if (previousNanos == 0L) previousNanos = now
+                val deltaSec = ((now - previousNanos).coerceAtMost(MAX_STEP_NANOS)).toFloat() / NANOS_TO_SECONDS
+                previousNanos = now
+                renderer.update(deltaSec, style)
+                frameSignal++
+            }
+        }
+    }
+    Canvas(modifier = modifier) {
+        frameSignal
+        renderer.ensureLayout(size)
+        renderer.draw(this, style)
+    }
+}
+
+private const val MAX_STEP_NANOS = 16_666_667L // ~60 FPS
+private const val NANOS_TO_SECONDS = 1_000_000_000f
+private val SHELL_GRADIENT_STOPS = floatArrayOf(0f, 0.52f, 0.66f, 0.79f, 0.90f, 0.968f, 0.993f, 1f)
+private val INNER_GRADIENT_STOPS = floatArrayOf(0f, 0.34f, 0.68f, 1f)
+
+private data class Velocity(var x: Float, var y: Float)
+
+private data class Bubble(
+    var x: Float,
+    var y: Float,
+    val radius: Float,
+    val velocity: Velocity,
+    val baseHue: Float, // 0-360, unique for each bubble
+)
+
+private class BubblesRenderer {
+    private var width = 0f
+    private var height = 0f
+    private val bubbles = mutableListOf<Bubble>()
+    private val random = Random(System.currentTimeMillis())
+    private var globalHueRotation = 0f // degrees, rotates all bubbles hues
+    private var spawnAccumulatorSec = 0f
+    private val paint = Paint(Paint.ANTI_ALIAS_FLAG)
+    private val shellColors = IntArray(8)
+    private val innerColors = IntArray(4)
+
+    fun ensureLayout(size: Size) {
+        val targetWidth = size.width
+        val targetHeight = size.height
+        if (targetWidth <= 0f || targetHeight <= 0f) return
+        val shouldRebuild = width != targetWidth || height != targetHeight
+        if (shouldRebuild) {
+            width = targetWidth
+            height = targetHeight
+            bubbles.clear()
+            spawnAccumulatorSec = 0f
+        }
+    }
+
+    fun spawnBubble(style: BubblesStyle): Boolean {
+        if (width <= 0f || height <= 0f) return false
+        val radius = resolveBubbleRadius(style)
+        val (velocityMin, velocityMax) = resolveVelocityRange(style)
+        val bubble = Bubble(
+            x = radius,
+            y = height - radius,
+            radius = radius,
+            velocity = Velocity(
+                x = randomInRange(velocityMin, velocityMax),
+                y = -randomInRange(velocityMin, velocityMax),
+            ),
+            baseHue = random.nextFloat() * 360f, // Random starting hue for this bubble
+        )
+        bubbles.add(bubble)
+        return true
+    }
+
+    fun update(deltaSeconds: Float, style: BubblesStyle) {
+        if (width <= 0f || height <= 0f) return
+
+        spawnMissingBubbles(deltaSeconds, style)
+
+        // Rotate hue for all bubbles
+        globalHueRotation += style.hueRotationSpeedDps * deltaSeconds
+        if (globalHueRotation >= 360f) globalHueRotation -= 360f
+        val frameScale = deltaSeconds * 60f
+        for (i in bubbles.indices) {
+            val bubble = bubbles[i]
+            // Update position
+            bubble.x += bubble.velocity.x * frameScale
+            bubble.y += bubble.velocity.y * frameScale
+            // Bounce off walls
+            if (bubble.x > width - bubble.radius) {
+                bubble.x = width - bubble.radius
+                bubble.velocity.x *= -1
+            }
+            if (bubble.x < bubble.radius) {
+                bubble.x = bubble.radius
+                bubble.velocity.x *= -1
+            }
+            if (bubble.y > height - bubble.radius) {
+                bubble.y = height - bubble.radius
+                bubble.velocity.y *= -1
+            }
+            if (bubble.y < bubble.radius) {
+                bubble.y = bubble.radius
+                bubble.velocity.y *= -1
+            }
+        }
+        // Collision detection and resolution
+        for (i in bubbles.indices) {
+            for (j in (i + 1) until bubbles.size) {
+                val b1 = bubbles[i]
+                val b2 = bubbles[j]
+                if (isCollided(b1, b2)) resolveCollision(b1, b2)
+            }
+        }
+    }
+
+    private fun spawnMissingBubbles(deltaSeconds: Float, style: BubblesStyle) {
+        val targetCount = resolveTargetBubbleCount(style)
+        if (bubbles.size >= targetCount) return
+
+        val spawnIntervalSec = style.spawnIntervalMs.coerceAtLeast(1L) / 1_000f
+        spawnAccumulatorSec += deltaSeconds
+
+        while (bubbles.size < targetCount && spawnAccumulatorSec >= spawnIntervalSec) {
+            if (!spawnBubble(style)) break
+            spawnAccumulatorSec -= spawnIntervalSec
+        }
+    }
+
+    fun draw(scope: DrawScope, style: BubblesStyle) {
+        if (width <= 0f || height <= 0f) return
+        scope.drawRect(style.bgColor)
+        val canvas = scope.drawContext.canvas.nativeCanvas
+        for (i in bubbles.indices) {
+            drawBubbleWithGradient(canvas, bubbles[i])
+        }
+    }
+
+    private fun drawBubbleWithGradient(canvas: android.graphics.Canvas, bubble: Bubble) {
+        val hue = (bubble.baseHue + globalHueRotation) % 360f
+        val lit = 53.33f + maxOf(0f, (70f - kotlin.math.abs(244f - hue)) / 4f)
+        val rgb = hueToRgb(hue, lit)
+        val shellColor = mixWithWhite(rgb, 0.04f)
+        val innerColor = mixWithWhite(rgb, 0.10f)
+        val shimmerColor = mixWithWhite(rgb, 0.35f)
+        // Outer shell
+        val shellGradient = RadialGradient(
+            bubble.x, bubble.y, bubble.radius,
+            buildShellColors(shellColor),
+            SHELL_GRADIENT_STOPS,
+            Shader.TileMode.CLAMP
+        )
+        paint.style = Paint.Style.FILL
+        paint.shader = shellGradient
+        canvas.drawCircle(bubble.x, bubble.y, bubble.radius, paint)
+        // Subtle thin rim
+        paint.shader = null
+        paint.style = Paint.Style.STROKE
+        paint.strokeWidth = maxOf(1f, bubble.radius * 0.024f)
+        paint.color = colorWithAlpha(mixWithWhite(shellColor, 0.08f), 0.30f)
+        canvas.drawCircle(bubble.x, bubble.y, bubble.radius - paint.strokeWidth * 0.5f, paint)
+        // Top internal bubble
+        val innerTop = bubble.y - bubble.radius * 0.96f
+        val innerBottom = bubble.y + bubble.radius * 0.48f
+        val innerLeft = bubble.x - bubble.radius * 0.84f
+        val innerRight = bubble.x + bubble.radius * 0.84f
+        val innerGradient = LinearGradient(
+            bubble.x,
+            innerTop,
+            bubble.x,
+            innerBottom,
+            buildInnerColors(innerColor),
+            INNER_GRADIENT_STOPS,
+            Shader.TileMode.CLAMP
+        )
+        paint.style = Paint.Style.FILL
+        paint.shader = innerGradient
+        canvas.drawOval(
+            innerLeft,
+            innerTop,
+            innerRight,
+            innerBottom,
+            paint
+        )
+        // Top-left shimmer
+        paint.shader = null
+        paint.style = Paint.Style.FILL
+        paint.color = colorWithAlpha(shimmerColor, 0.95f)
+        val shimmerCx = bubble.x - bubble.radius * 0.40f
+        val shimmerCy = bubble.y - bubble.radius * 0.72f
+        val shimmerHalfWidth = bubble.radius * 0.06f
+        val shimmerHalfHeight = bubble.radius * 0.21f
+        canvas.withRotation(60f, shimmerCx, shimmerCy) {
+            drawOval(
+                shimmerCx - shimmerHalfWidth,
+                shimmerCy - shimmerHalfHeight,
+                shimmerCx + shimmerHalfWidth,
+                shimmerCy + shimmerHalfHeight,
+                paint
+            )
+        }
+    }
+
+    private fun isCollided(bubble1: Bubble, bubble2: Bubble): Boolean {
+        val dx = bubble1.x - bubble2.x
+        val dy = bubble1.y - bubble2.y
+        val radius = (bubble1.radius + bubble2.radius) * 0.9f
+        return dx * dx + dy * dy < radius * radius
+    }
+
+    private fun resolveCollision(particle: Bubble, otherParticle: Bubble) {
+        val xVelocityDiff = particle.velocity.x - otherParticle.velocity.x
+        val yVelocityDiff = particle.velocity.y - otherParticle.velocity.y
+        val xDist = otherParticle.x - particle.x
+        val yDist = otherParticle.y - particle.y
+        // Prevent accidental overlap
+        if (xVelocityDiff * xDist + yVelocityDiff * yDist >= 0) {
+            val angle = -atan2(otherParticle.y - particle.y, otherParticle.x - particle.x)
+            val m1 = 1f
+            val m2 = 1f
+            val u1 = rotate(particle.velocity, angle)
+            val u2 = rotate(otherParticle.velocity, angle)
+            val v1 = Velocity(
+                x = (u1.x * (m1 - m2)) / (m1 + m2) + (u2.x * 2 * m2) / (m1 + m2),
+                y = u1.y,
+            )
+            val v2 = Velocity(
+                x = (u2.x * (m1 - m2)) / (m1 + m2) + (u1.x * 2 * m2) / (m1 + m2),
+                y = u2.y,
+            )
+            val vFinal1 = rotate(v1, -angle)
+            val vFinal2 = rotate(v2, -angle)
+            particle.velocity.x = vFinal1.x
+            particle.velocity.y = vFinal1.y
+            otherParticle.velocity.x = vFinal2.x
+            otherParticle.velocity.y = vFinal2.y
+        }
+    }
+
+    private fun rotate(velocity: Velocity, angle: Float): Velocity {
+        return Velocity(
+            x = velocity.x * cos(angle) - velocity.y * sin(angle),
+            y = velocity.x * sin(angle) + velocity.y * cos(angle),
+        )
+    }
+
+    private fun buildShellColors(shellColor: Int): IntArray {
+        shellColors[0] = colorWithAlpha(shellColor, 0f)
+        shellColors[1] = colorWithAlpha(shellColor, 0f)
+        shellColors[2] = colorWithAlpha(shellColor, 0.04f)
+        shellColors[3] = colorWithAlpha(shellColor, 0.12f)
+        shellColors[4] = colorWithAlpha(shellColor, 0.28f)
+        shellColors[5] = colorWithAlpha(shellColor, 0.44f)
+        shellColors[6] = colorWithAlpha(shellColor, 0.58f)
+        shellColors[7] = colorWithAlpha(shellColor, 0.64f)
+        return shellColors
+    }
+
+    private fun buildInnerColors(innerColor: Int): IntArray {
+        innerColors[0] = colorWithAlpha(innerColor, 0.48f)
+        innerColors[1] = colorWithAlpha(innerColor, 0.36f)
+        innerColors[2] = colorWithAlpha(innerColor, 0.08f)
+        innerColors[3] = colorWithAlpha(innerColor, 0f)
+        return innerColors
+    }
+
+    private fun resolveBubbleRadius(style: BubblesStyle): Float {
+        val minDimension = min(width, height)
+        val baseRadius = minDimension * style.bubbleRadiusFraction
+        val minRadius = style.minBubbleRadiusPx.coerceAtLeast(1f)
+        val maxRadius = maxOf(minRadius, style.maxBubbleRadiusPx)
+        if (!style.adaptiveSizing || minDimension <= 0f) {
+            return baseRadius.coerceIn(minRadius, maxRadius)
+        }
+
+        val reference = style.referenceMinSizePx.coerceAtLeast(1f)
+        val dampening = sqrt((reference / minDimension).coerceAtMost(1f))
+        return (baseRadius * dampening).coerceIn(minRadius, maxRadius)
+    }
+
+    private fun resolveTargetBubbleCount(style: BubblesStyle): Int {
+        val baseCount = style.bubbleCount.coerceAtLeast(1)
+        if (!style.adaptiveBubbleCount) return baseCount
+
+        val area = width * height
+        val referenceArea = style.referenceAreaPx.coerceAtLeast(1f)
+        val areaScale = sqrt((area / referenceArea).coerceAtLeast(0.25f))
+        val scaledCount = (baseCount * areaScale).toInt()
+        val minCount = style.minBubbleCount.coerceAtLeast(1)
+        val maxCount = maxOf(minCount, style.maxBubbleCount.coerceAtLeast(1))
+        return scaledCount.coerceIn(minCount, maxCount)
+    }
+
+    private fun resolveVelocityRange(style: BubblesStyle): Pair<Float, Float> {
+        val referenceMaxVelocity = maxOf(height / 300f, 1f)
+        val velocityMin = (style.minVelocity * style.speedScale).coerceAtLeast(0.05f)
+        val velocityMax = maxOf(velocityMin, min(style.maxVelocity, referenceMaxVelocity) * style.speedScale)
+        return velocityMin to velocityMax
+    }
+
+    private fun randomInRange(min: Float, max: Float): Float {
+        return random.nextFloat() * (max - min) + min
+    }
+}
+
+private fun hueToRgb(h: Float, l: Float): Int {
+    val hNorm = h / 360f
+    val lNorm = l / 100f
+    val sNorm = 1f
+    val c = (1f - kotlin.math.abs(2f * lNorm - 1f)) * sNorm
+    val hp = hNorm * 6f
+    val x = c * (1f - kotlin.math.abs((hp % 2f) - 1f))
+    val m = lNorm - c / 2f
+    val (r, g, b) = when {
+        hp < 1f -> Triple(c, x, 0f)
+        hp < 2f -> Triple(x, c, 0f)
+        hp < 3f -> Triple(0f, c, x)
+        hp < 4f -> Triple(0f, x, c)
+        hp < 5f -> Triple(x, 0f, c)
+        else -> Triple(c, 0f, x)
+    }
+    val r8 = ((r + m) * 255).toInt().coerceIn(0, 255)
+    val g8 = ((g + m) * 255).toInt().coerceIn(0, 255)
+    val b8 = ((b + m) * 255).toInt().coerceIn(0, 255)
+    return (0xFF shl 24) or (r8 shl 16) or (g8 shl 8) or b8
+}
+
+private fun colorWithAlpha(color: Int, alpha: Float): Int {
+    val a = (alpha * 255).toInt().coerceIn(0, 255)
+    val r = (color shr 16) and 0xFF
+    val g = (color shr 8) and 0xFF
+    val b = color and 0xFF
+    return (a shl 24) or (r shl 16) or (g shl 8) or b
+}
+
+private fun mixWithWhite(color: Int, amount: Float): Int {
+    val t = amount.coerceIn(0f, 1f)
+    val r = (color shr 16) and 0xFF
+    val g = (color shr 8) and 0xFF
+    val b = color and 0xFF
+    val mixedR = (r + (255 - r) * t).toInt().coerceIn(0, 255)
+    val mixedG = (g + (255 - g) * t).toInt().coerceIn(0, 255)
+    val mixedB = (b + (255 - b) * t).toInt().coerceIn(0, 255)
+    return (0xFF shl 24) or (mixedR shl 16) or (mixedG shl 8) or mixedB
+}

core/presentation/src/main/java/com/rtbishop/look4sat/core/presentation/Components.kt

@@ -39,24 +39,44 @@ import androidx.compose.material3.CardDefaults
 import androidx.compose.material3.CircularProgressIndicator
 import androidx.compose.material3.ElevatedButton
 import androidx.compose.material3.ElevatedCard
+import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.Icon
+import androidx.compose.material3.LocalTextStyle
 import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.ModalBottomSheet
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
+import androidx.compose.material3.rememberModalBottomSheetState
 import androidx.compose.material3.adaptive.currentWindowAdaptiveInfo
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.compositionLocalOf
 import androidx.compose.runtime.remember
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.geometry.Offset
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.drawscope.Stroke
+import androidx.compose.ui.input.nestedscroll.NestedScrollConnection
+import androidx.compose.ui.input.nestedscroll.NestedScrollSource
+import androidx.compose.ui.input.nestedscroll.nestedScroll
 import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.semantics.hideFromAccessibility
+import androidx.compose.ui.semantics.semantics
+import androidx.compose.ui.text.TextLayoutResult
+import androidx.compose.ui.text.TextStyle
+import androidx.compose.ui.text.font.FontFamily
+import androidx.compose.ui.text.font.FontStyle
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.text.style.TextDecoration
 import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.TextUnit
+import androidx.compose.ui.unit.Velocity
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
-import androidx.compose.ui.window.Dialog
 import com.rtbishop.look4sat.core.domain.predict.NearEarthObject
 import com.rtbishop.look4sat.core.domain.predict.OrbitalData
 import com.rtbishop.look4sat.core.domain.predict.OrbitalPass
@@ -137,30 +157,28 @@ fun RowScope.NextPassRow(pass: OrbitalPass, modifier: Modifier = Modifier, isUtc
                 .padding(start = 6.dp, top = 1.dp, end = 6.dp, bottom = 0.dp)
         ) {
             Row(verticalAlignment = Alignment.CenterVertically) {
-                Text(
-                    text = "${stringResource(R.string.pass_satId, pass.catNum)} - ",
-                    color = MaterialTheme.colorScheme.primary
-                )
                 Text(
                     text = pass.name,
                     modifier = Modifier
                         .weight(1f)
                         .padding(end = 6.dp)
                         .infiniteMarquee(),
+                    color = MaterialTheme.colorScheme.primary,
                     fontWeight = FontWeight.Medium,
                     maxLines = 1,
                     overflow = TextOverflow.Ellipsis
                 )
+                val elevColor = elevationColor(pass.maxElevation)
                 Icon(
                     painter = painterResource(R.drawable.ic_elevation),
                     contentDescription = null,
-                    tint = MaterialTheme.colorScheme.primary,
+                    tint = elevColor,
                     modifier = Modifier.size(16.dp)
                 )
                 Spacer(modifier = Modifier.width(4.dp))
                 Text(
                     text = "${pass.maxElevation}°",
-                    color = MaterialTheme.colorScheme.primary
+                    color = elevColor
                 )
             }
             Row(
@@ -178,12 +196,6 @@ fun RowScope.NextPassRow(pass: OrbitalPass, modifier: Modifier = Modifier, isUtc
                     horizontalArrangement = Arrangement.Center,
                     verticalAlignment = Alignment.CenterVertically
                 ) {
-                    Icon(
-                        painter = painterResource(R.drawable.ic_altitude),
-                        contentDescription = null,
-                        modifier = Modifier.size(16.dp)
-                    )
-                    Spacer(modifier = Modifier.width(4.dp))
                     Text(text = "${pass.altitude} km", fontSize = 15.sp)
                 }
                 Text(
@@ -212,14 +224,11 @@ fun CardButton(onClick: () -> Unit, text: String, modifier: Modifier = Modifier)
 }
 
 @Composable
-fun IconCard(action: () -> Unit, resId: Int, modifier: Modifier = Modifier) {
-    ElevatedCard(modifier = Modifier.size(48.dp)) {
-        Box(
-            modifier = Modifier
-                .clickable(onClick = action)
-                .fillMaxSize(),
-            contentAlignment = Alignment.Center
-        ) { Icon(painter = painterResource(resId), contentDescription = null, modifier = modifier) }
+fun IconCard(action: () -> Unit, resId: Int, modifier: Modifier = Modifier, enabled: Boolean = true) {
+    ElevatedCard(modifier = Modifier.size(48.dp), enabled = enabled, onClick = action) {
+        Box(modifier = Modifier.fillMaxSize(), contentAlignment = Alignment.Center) {
+            Icon(painter = painterResource(resId), contentDescription = null, modifier = modifier)
+        }
     }
 }
 
@@ -275,55 +284,87 @@ fun getDefaultPass(): OrbitalPass = OrbitalPass(
 fun SharedDialog(
     title: String, onCancel: () -> Unit, onAccept: () -> Unit, content: @Composable () -> Unit
 ) {
-    DialogShell(title = title, titleFontSize = 16, onDismissRequest = onCancel) {
+    SharedDialog(title = title, onDismissRequest = onCancel, onCancel = onCancel, onAccept = onAccept) { _ ->
         content()
-        Row(modifier = Modifier.padding(start = it, bottom = it, end = it)) {
-            CardButton(onClick = onCancel, text = stringResource(R.string.btn_cancel))
-            Spacer(modifier = Modifier.weight(1f))
-            CardButton(onClick = onAccept, text = stringResource(R.string.btn_accept))
-        }
     }
 }
 
 @Composable
-fun InfoDialog(title: String, text: String, onDismiss: () -> Unit) {
-    DialogShell(title = title, titleFontSize = 18, onDismissRequest = {}) {
-        Text(
-            text = text,
-            fontSize = 16.sp,
-            color = MaterialTheme.colorScheme.onSurface,
-            modifier = Modifier.padding(horizontal = it)
-        )
-        Row(modifier = Modifier.padding(start = it, bottom = it, end = it)) {
-            Spacer(modifier = Modifier.weight(1f))
-            CardButton(onClick = onDismiss, text = stringResource(R.string.btn_accept))
+fun SharedDialog(
+    title: String,
+    onDismissRequest: () -> Unit,
+    onCancel: (() -> Unit)? = null,
+    onAccept: (() -> Unit)? = null,
+    titleFontSize: Int = 16,
+    titleTextAlign: TextAlign = if (onCancel != null && onAccept != null) TextAlign.Center else TextAlign.Start,
+    content: @Composable (padding: Dp) -> Unit
+) {
+    DialogShell(onDismissRequest = onDismissRequest) { padding ->
+        Row(
+            verticalAlignment = Alignment.CenterVertically,
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(start = padding, top = padding, end = padding)
+        ) {
+            if (onCancel != null) {
+                CardButton(onClick = onCancel, text = stringResource(R.string.btn_cancel))
+            }
+            Text(
+                text = title,
+                fontSize = titleFontSize.sp,
+                fontWeight = FontWeight.Medium,
+                color = MaterialTheme.colorScheme.primary,
+                textAlign = titleTextAlign,
+                maxLines = 1,
+                overflow = TextOverflow.Ellipsis,
+                modifier = Modifier
+                    .weight(1f)
+                    .padding(horizontal = if (onCancel != null && onAccept != null) padding else 0.dp)
+            )
+            if (onAccept != null) {
+                CardButton(onClick = onAccept, text = stringResource(R.string.btn_accept))
+            }
         }
+        content(padding)
     }
 }
 
+@OptIn(ExperimentalMaterial3Api::class)
 @Composable
 private fun DialogShell(
-    title: String,
-    titleFontSize: Int,
     onDismissRequest: () -> Unit,
-    content: @Composable (padding: androidx.compose.ui.unit.Dp) -> Unit
+    content: @Composable (padding: Dp) -> Unit
 ) {
     val padding = LocalSpacing.current.large
-    Dialog(onDismissRequest = onDismissRequest) {
-        ElevatedCard {
-            Column(
-                horizontalAlignment = Alignment.CenterHorizontally,
-                verticalArrangement = Arrangement.spacedBy(padding)
-            ) {
-                Text(
-                    text = title,
-                    fontSize = titleFontSize.sp,
-                    fontWeight = FontWeight.Medium,
-                    color = MaterialTheme.colorScheme.primary,
-                    modifier = Modifier.padding(start = padding, top = padding, end = padding)
-                )
-                content(padding)
+    val sheetState = rememberModalBottomSheetState(skipPartiallyExpanded = true)
+    val stopSheetFling = remember {
+        object : NestedScrollConnection {
+            override suspend fun onPostFling(consumed: Velocity, available: Velocity): Velocity {
+                return available
             }
+
+            override fun onPostScroll(
+                consumed: Offset,
+                available: Offset,
+                source: NestedScrollSource
+            ): Offset = Offset.Zero
+        }
+    }
+    ModalBottomSheet(
+        onDismissRequest = onDismissRequest,
+        sheetState = sheetState,
+        dragHandle = null,
+        shape = MaterialTheme.shapes.medium,
+        scrimColor = Color.Black.copy(alpha = 0.64f)
+    ) {
+        Column(
+            horizontalAlignment = Alignment.CenterHorizontally,
+            verticalArrangement = Arrangement.spacedBy(padding),
+            modifier = Modifier
+                .fillMaxWidth()
+                .nestedScroll(stopSheetFling)
+        ) {
+            content(padding)
         }
     }
 }
@@ -385,3 +426,98 @@ fun TopBar(
         TopBar { startAction(); topInfo(); bottomInfo(); endAction() }
     }
 }
+
+@Composable
+fun elevationColor(elevation: Double): Color {
+    val thresholds = LocalElevationThresholds.current
+    return when {
+        elevation < thresholds.low -> ElevationLowColor // soft red for low elevation
+        elevation < thresholds.high -> MaterialTheme.colorScheme.primary // accent yellow for normal
+        else -> ElevationHighColor // soft green for high elevation
+    }
+}
+
+/** User-configurable elevation highlight thresholds (in degrees). */
+data class ElevationThresholds(val low: Double = 15.0, val high: Double = 45.0)
+
+/** Provided at the app root from settings; defaults keep the original 15°/45° behavior. */
+val LocalElevationThresholds = compositionLocalOf { ElevationThresholds() }
+
+/** Soft red used for elevations below the low threshold. */
+val ElevationLowColor = Color(0xFFEF5350)
+
+/** Soft green used for elevations above the high threshold. */
+val ElevationHighColor = Color(0xFF66BB6A)
+
+@Composable
+fun OutlinedText(
+    text: String,
+    modifier: Modifier = Modifier,
+    fillColor: Color = Color.Unspecified,
+    outlineColor: Color,
+    fontSize: TextUnit = TextUnit.Unspecified,
+    fontStyle: FontStyle? = null,
+    fontWeight: FontWeight? = null,
+    fontFamily: FontFamily? = null,
+    letterSpacing: TextUnit = TextUnit.Unspecified,
+    textDecoration: TextDecoration? = null,
+    textAlign: TextAlign? = null,
+    lineHeight: TextUnit = TextUnit.Unspecified,
+    overflow: TextOverflow = TextOverflow.Clip,
+    softWrap: Boolean = true,
+    maxLines: Int = Int.MAX_VALUE,
+    minLines: Int = 1,
+    onTextLayout: (TextLayoutResult) -> Unit = {},
+    style: TextStyle = LocalTextStyle.current,
+    outlineDrawStyle: Stroke = Stroke(width = 8f),
+) {
+    Box(modifier = modifier) {
+        Text(
+            text = text,
+            modifier = Modifier.semantics { hideFromAccessibility() },
+            color = outlineColor,
+            fontSize = fontSize,
+            fontStyle = fontStyle,
+            fontWeight = fontWeight,
+            fontFamily = fontFamily,
+            letterSpacing = letterSpacing,
+            textDecoration = null,
+            textAlign = textAlign,
+            lineHeight = lineHeight,
+            overflow = overflow,
+            softWrap = softWrap,
+            maxLines = maxLines,
+            minLines = minLines,
+            onTextLayout = onTextLayout,
+            style = style.copy(shadow = null, drawStyle = outlineDrawStyle),
+        )
+
+        Text(
+            text = text,
+            color = fillColor,
+            fontSize = fontSize,
+            fontStyle = fontStyle,
+            fontWeight = fontWeight,
+            fontFamily = fontFamily,
+            letterSpacing = letterSpacing,
+            textDecoration = textDecoration,
+            textAlign = textAlign,
+            lineHeight = lineHeight,
+            overflow = overflow,
+            softWrap = softWrap,
+            maxLines = maxLines,
+            minLines = minLines,
+            onTextLayout = onTextLayout,
+            style = style,
+        )
+    }
+}
+
+// Formats a frequency in Hz as "MMM.KKK.HHH" (e.g. 145.825.000) or "---"
+fun formatFrequency(frequencyHz: Long): String {
+    if (frequencyHz <= 0) return "---"
+    val mhz = frequencyHz / 1_000_000
+    val khz = (frequencyHz % 1_000_000) / 1_000
+    val hz = frequencyHz % 1_000
+    return String.format(Locale.ENGLISH, "%d.%03d.%03d", mhz, khz, hz)
+}

core/presentation/src/main/java/com/rtbishop/look4sat/core/presentation/MatrixEffect.kt

@@ -0,0 +1,260 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.presentation
+
+import android.graphics.Paint
+import android.graphics.Typeface
+import androidx.compose.foundation.Canvas
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.Immutable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableIntStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.runtime.withFrameNanos
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.geometry.Size
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.nativeCanvas
+import androidx.compose.ui.platform.LocalDensity
+import androidx.compose.ui.unit.TextUnit
+import androidx.compose.ui.unit.sp
+import kotlinx.coroutines.isActive
+import kotlin.math.floor
+import kotlin.math.max
+import kotlin.math.min
+import kotlin.random.Random
+
+@Immutable
+data class MatrixStyle(
+    val bgColor: Color = Color.Black,
+    val bodyColor: Color = Color(0xFF29C94A),
+    val headColor: Color = Color(0xFFC2FFC6),
+    val tailAlphaFloor: Float = 0.14f, // 0.14f - 0.18f,
+    val fontSize: TextUnit = 14.sp, // 11.sp - 14.sp
+    val minStreamLength: Int = 8, // 6 - 8
+    val maxStreamLength: Int = 28,  // 20 - 28
+    val minSpeedRps: Float = 10f, // 10f - 15f
+    val maxSpeedRps: Float = 38f, // 38f - 45f
+    val resetPauseSec: ClosedFloatingPointRange<Float> = 0.1f..1.0f,
+)
+
+@Composable
+fun MatrixEffect(
+    modifier: Modifier = Modifier,
+    isRunning: Boolean = true,
+    style: MatrixStyle = MatrixStyle(),
+    symbols: String = DEFAULT_SYMBOLS,
+) {
+    val density = LocalDensity.current
+    val renderer = remember { MatrixRenderer() }
+    var frameSignal by remember { mutableIntStateOf(0) }
+
+    LaunchedEffect(isRunning, style, symbols) {
+        if (!isRunning) return@LaunchedEffect
+
+        var previousNanos = 0L
+        while (isActive) {
+            withFrameNanos { now ->
+                if (previousNanos == 0L) previousNanos = now
+                val deltaSec = ((now - previousNanos).coerceAtMost(MAX_STEP_NANOS)).toFloat() / NANOS_TO_SECONDS
+                previousNanos = now
+                renderer.update(deltaSec, style)
+                frameSignal++
+            }
+        }
+    }
+
+    Canvas(modifier = modifier) {
+        frameSignal
+        renderer.ensureLayout(size, density.density, style, symbols)
+        renderer.draw(this, style)
+    }
+}
+
+private const val MAX_STEP_NANOS = 33_333_333L
+private const val NANOS_TO_SECONDS = 1_000_000_000f
+private const val DEFAULT_SYMBOLS = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789<>=*+-~:;/[]{}()"
+
+private fun Color.toArgb(): Int {
+    val a = (alpha.coerceIn(0f, 1f) * 255f + 0.5f).toInt()
+    val r = (red.coerceIn(0f, 1f) * 255f + 0.5f).toInt()
+    val g = (green.coerceIn(0f, 1f) * 255f + 0.5f).toInt()
+    val b = (blue.coerceIn(0f, 1f) * 255f + 0.5f).toInt()
+    return (a shl 24) or (r shl 16) or (g shl 8) or b
+}
+
+private class MatrixRenderer {
+    private var columns = 0
+    private var rows = 0
+    private var width = 0f
+    private var height = 0f
+    private var fontSizePx = 0f
+    private var charWidth = 0f
+    private var charHeight = 0f
+    private var baselineOffset = 0f
+    private var symbolSet = ""
+    private var symbols = charArrayOf()
+
+    private var glyphs = charArrayOf()
+    private var streams = emptyArray<StreamState>()
+
+    private val bodyPaint = Paint(Paint.ANTI_ALIAS_FLAG).apply { typeface = Typeface.MONOSPACE }
+    private val headPaint = Paint(Paint.ANTI_ALIAS_FLAG).apply { typeface = Typeface.MONOSPACE }
+    private val charBuffer = CharArray(1)
+    private val random = Random(System.currentTimeMillis())
+
+    fun ensureLayout(size: Size, density: Float, style: MatrixStyle, symbols: String) {
+        val targetFontPx = style.fontSize.value * density
+        val targetWidth = size.width
+        val targetHeight = size.height
+        val targetSymbols = symbols.ifBlank { DEFAULT_SYMBOLS }
+
+        if (targetWidth <= 0f || targetHeight <= 0f) return
+
+        val shouldRebuild = width != targetWidth ||
+            height != targetHeight ||
+            fontSizePx != targetFontPx ||
+            symbolSet != targetSymbols
+
+        if (!shouldRebuild) return
+
+        width = targetWidth
+        height = targetHeight
+        fontSizePx = targetFontPx
+        symbolSet = targetSymbols
+        this.symbols = targetSymbols.toCharArray()
+
+        bodyPaint.textSize = targetFontPx
+        headPaint.textSize = targetFontPx
+        charWidth = max(bodyPaint.measureText("W"), 1f)
+        val metrics = bodyPaint.fontMetrics
+        charHeight = max(metrics.descent - metrics.ascent, 1f)
+        baselineOffset = -metrics.ascent
+
+        columns = max((width / charWidth).toInt(), 1)
+        rows = max((height / charHeight).toInt() + 2, 1)
+
+        glyphs = CharArray(columns * rows) { randomGlyph() }
+        streams = Array(columns) { StreamState.random(rows, style, random) }
+    }
+
+    fun update(deltaSeconds: Float, style: MatrixStyle) {
+        if (columns == 0 || rows == 0 || deltaSeconds <= 0f) return
+
+        for (column in streams.indices) {
+            val stream = streams[column]
+            stream.pauseSec -= deltaSeconds
+            if (stream.pauseSec > 0f) continue
+
+            val previousHead = floor(stream.headRow).toInt()
+            stream.headRow += stream.speedRps * deltaSeconds
+            val newHead = floor(stream.headRow).toInt()
+
+            if (newHead > previousHead) {
+                for (row in (previousHead + 1)..newHead) {
+                    if (row in 0 until rows) {
+                        glyphs[row * columns + column] = randomGlyph()
+                    }
+                }
+            }
+
+            if (newHead - stream.length > rows) {
+                stream.reset(rows, style, random)
+            }
+        }
+    }
+
+    fun draw(scope: androidx.compose.ui.graphics.drawscope.DrawScope, style: MatrixStyle) {
+        if (columns == 0 || rows == 0) return
+
+        scope.drawRect(style.bgColor)
+
+        bodyPaint.color = style.bodyColor.toArgb()
+        headPaint.color = style.headColor.toArgb()
+        val tailAlphaFloor = style.tailAlphaFloor.coerceIn(0f, 1f)
+
+        val canvas = scope.drawContext.canvas.nativeCanvas
+        for (column in streams.indices) {
+            val stream = streams[column]
+            if (stream.pauseSec > 0f) continue
+
+            val head = floor(stream.headRow).toInt()
+            val startRow = max(0, head - stream.length + 1)
+            val endRow = min(rows - 1, head)
+            if (startRow > endRow) continue
+
+            for (row in endRow downTo startRow) {
+                val tailIndex = head - row
+
+                val paint = if (tailIndex == 0) headPaint else bodyPaint
+                if (tailIndex != 0) {
+                    val normalized = ((stream.length - tailIndex).toFloat() / stream.length).coerceIn(0f, 1f)
+                    val alpha = tailAlphaFloor + (1f - tailAlphaFloor) * normalized
+                    paint.alpha = (alpha * 255).toInt()
+                } else {
+                    paint.alpha = 255
+                }
+
+                val glyph = glyphs[row * columns + column]
+                charBuffer[0] = glyph
+                val x = column * charWidth
+                val y = row * charHeight + baselineOffset
+                canvas.drawText(charBuffer, 0, 1, x, y, paint)
+            }
+        }
+    }
+
+    private fun randomGlyph(): Char = symbols[random.nextInt(symbols.size)]
+}
+
+private data class StreamState(
+    var headRow: Float,
+    var length: Int,
+    var speedRps: Float,
+    var pauseSec: Float,
+) {
+    fun reset(rows: Int, style: MatrixStyle, random: Random) {
+        val randomOffset = random.nextFloat() * rows
+        headRow = -randomOffset
+        length = random.nextInt(
+            from = style.minStreamLength.coerceAtLeast(2),
+            until = (style.maxStreamLength.coerceAtLeast(style.minStreamLength + 1) + 1),
+        )
+        speedRps = random.nextFloat() * (style.maxSpeedRps - style.minSpeedRps) + style.minSpeedRps
+        pauseSec = random.nextFloat() * (style.resetPauseSec.endInclusive - style.resetPauseSec.start) +
+            style.resetPauseSec.start
+    }
+
+    companion object {
+        fun random(rows: Int, style: MatrixStyle, random: Random): StreamState {
+            val length = random.nextInt(
+                from = style.minStreamLength.coerceAtLeast(2),
+                until = (style.maxStreamLength.coerceAtLeast(style.minStreamLength + 1) + 1),
+            )
+            return StreamState(
+                headRow = -random.nextFloat() * rows,
+                length = length,
+                speedRps = random.nextFloat() * (style.maxSpeedRps - style.minSpeedRps) + style.minSpeedRps,
+                pauseSec = random.nextFloat() * (style.resetPauseSec.endInclusive - style.resetPauseSec.start) +
+                    style.resetPauseSec.start,
+            )
+        }
+    }
+}

core/presentation/src/main/java/com/rtbishop/look4sat/core/presentation/Navigation.kt

@@ -30,14 +30,44 @@ sealed class Screen(val iconResId: Int, val titleResId: Int) : NavKey {
     data object Passes : Screen(R.drawable.ic_passes, R.string.nav_pass)
 
     @Serializable
-    data class Radar(val catNum: Int = 0, val aosTime: Long = 0L) : Screen(R.drawable.ic_radar, R.string.nav_radar)
-
-    @Serializable
-    data class RadioControl(val catNum: Int = 0, val aosTime: Long = 0L) : Screen(0, 0)
+    data object Radar : Screen(R.drawable.ic_radar, R.string.nav_radar)
 
     @Serializable
     data object Map : Screen(R.drawable.ic_map, R.string.nav_map)
 
+    @Serializable
+    data object Mutual : Screen(R.drawable.ic_match, R.string.nav_mutual)
+
     @Serializable
     data object Settings : Screen(R.drawable.ic_settings, R.string.nav_prefs)
 }
+
+@Serializable
+data object RadarDestination : NavKey
+
+interface IDeeplinkMatcher {
+    fun match(deeplink: String): NavKey?
+}
+
+object PassDetailsMatcher : IDeeplinkMatcher {
+    val passDetailsRegex = """https://github.com/rt-bishop/Look4Sat/passes/(.*)""".toRegex()
+
+    override fun match(deeplink: String): NavKey? {
+        val passMatch = passDetailsRegex.find(deeplink)
+        passMatch?.let { match ->
+            val passId = match.groupValues[1]
+            if (passId.isNotEmpty()) return RadarDestination
+        }
+        return null
+    }
+}
+
+class DeeplinkResolver(private val fallbackDestination: NavKey = Screen.Passes) {
+
+    private val matchers: List<IDeeplinkMatcher> = listOf(PassDetailsMatcher)
+
+    fun resolve(deeplink: String): NavKey {
+        matchers.forEach { it.match(deeplink)?.let { match -> return match } }
+        return fallbackDestination
+    }
+}

core/presentation/src/main/java/com/rtbishop/look4sat/core/presentation/SwipeableItem.kt

@@ -0,0 +1,105 @@
+package com.rtbishop.look4sat.core.presentation
+
+import androidx.compose.animation.core.animateDpAsState
+import androidx.compose.animation.core.animateFloatAsState
+import androidx.compose.foundation.border
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.fillMaxHeight
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.size
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.SwipeToDismissBox
+import androidx.compose.material3.SwipeToDismissBoxValue
+import androidx.compose.material3.rememberSwipeToDismissBoxState
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.derivedStateOf
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.dropShadow
+import androidx.compose.ui.draw.innerShadow
+import androidx.compose.ui.draw.rotate
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.RectangleShape
+import androidx.compose.ui.graphics.graphicsLayer
+import androidx.compose.ui.hapticfeedback.HapticFeedbackType
+import androidx.compose.ui.platform.LocalDensity
+import androidx.compose.ui.platform.LocalHapticFeedback
+import androidx.compose.ui.res.painterResource
+import androidx.compose.ui.unit.dp
+import kotlinx.coroutines.launch
+
+@Composable
+fun SwipeableItem(onSwipeRight: () -> Unit, onSwipeLeft: () -> Unit, content: @Composable () -> Unit) {
+    val coroutineScope = rememberCoroutineScope()
+    val dismissThresholdPx = with(LocalDensity.current) { 120.dp.toPx() }
+    val dismissState = rememberSwipeToDismissBoxState { dismissThresholdPx }
+    val willTrigger by remember { derivedStateOf { dismissState.targetValue != SwipeToDismissBoxValue.Settled } }
+    val hapticFeedback = LocalHapticFeedback.current
+    LaunchedEffect(willTrigger) {
+        val feedbackType = if (willTrigger) HapticFeedbackType.LongPress else HapticFeedbackType.SegmentTick
+        if (willTrigger) hapticFeedback.performHapticFeedback(feedbackType)
+    }
+    SwipeToDismissBox(
+        state = dismissState,
+        enableDismissFromStartToEnd = true,
+        enableDismissFromEndToStart = true,
+        backgroundContent = {
+            val isSwipeRight = dismissState.dismissDirection == SwipeToDismissBoxValue.StartToEnd
+            SwipeBackground(isSwipeRight, willTrigger, MaterialTheme.colorScheme.primary)
+        },
+        content = { content() },
+        onDismiss = {
+            val targetValue = dismissState.targetValue
+            when (targetValue) {
+                SwipeToDismissBoxValue.StartToEnd -> onSwipeRight()
+                SwipeToDismissBoxValue.EndToStart -> onSwipeLeft()
+                SwipeToDismissBoxValue.Settled -> {}
+            }
+            if (targetValue != SwipeToDismissBoxValue.Settled) {
+                coroutineScope.launch { dismissState.snapTo(SwipeToDismissBoxValue.Settled) }
+            }
+        }
+    )
+}
+
+@Composable
+fun SwipeBackground(isSwipeRight: Boolean, willTrigger: Boolean, bgColor: Color = Color(0x00000000)) {
+    val shape = RectangleShape
+    Box(
+        contentAlignment = if (isSwipeRight) Alignment.CenterStart else Alignment.CenterEnd,
+        modifier = Modifier
+            .fillMaxSize()
+            .border(width = 1.dp, shape = shape, color = bgColor)
+            .dropShadow(shape = shape) {
+                color = bgColor
+                radius = 40f
+                alpha = if (willTrigger) .2f else 0f
+            }
+            .innerShadow(shape = shape) {
+                color = bgColor
+                radius = 40f
+                alpha = if (willTrigger) 1f else .2f
+            }
+    ) {
+        val iconScale by animateFloatAsState(targetValue = if (willTrigger) 1f else .8f)
+        val slide by animateDpAsState(targetValue = if (willTrigger) 32.dp else (12).dp)
+        Icon(
+            painter = painterResource(R.drawable.ic_filter),
+            contentDescription = null,
+            modifier = Modifier
+                .size(32.dp)
+                .fillMaxHeight()
+                .rotate(if (isSwipeRight) 0f else 180f)
+                .graphicsLayer {
+                    scaleX = iconScale
+                    scaleY = iconScale
+                    translationX = slide.toPx()
+                }
+        )
+    }
+}

core/presentation/src/main/res/drawable/ic_delete.xml

@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="@android:color/white"
+        android:pathData="M6,19c0,1.1 0.9,2 2,2h8c1.1,0 2,-0.9 2,-2V7H6v12zM19,4h-3.5l-1,-1h-5l-1,1H5v2h14V4z" />
+</vector>

core/presentation/src/main/res/drawable/ic_match.xml

@@ -0,0 +1,22 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="96"
+    android:viewportHeight="96">
+
+    <path
+        android:fillColor="@android:color/transparent"
+        android:strokeColor="@android:color/white"
+        android:strokeWidth="6"
+        android:strokeLineCap="round"
+        android:strokeLineJoin="round"
+        android:pathData="M 8 76 C 8 44, 21 24, 39 24 C 57 24, 70 44, 70 76" />
+
+    <path
+        android:fillColor="@android:color/transparent"
+        android:strokeColor="@android:color/white"
+        android:strokeWidth="6"
+        android:strokeLineCap="round"
+        android:strokeLineJoin="round"
+        android:pathData="M 30 76 C 30 54, 44 42, 62 42 C 80 42, 94 54, 94 76" />
+</vector>

core/presentation/src/main/res/drawable/ic_moon.xml

@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="@android:color/white"
+        android:pathData="M12.34,2.02C6.59,1.82 2,6.42 2,12c0,5.52 4.48,10 10,10c3.71,0 6.93,-2.02 8.66,-5.02C13.15,16.73 8.57,8.55 12.34,2.02z" />
+</vector>

core/presentation/src/main/res/drawable/ic_pause.xml

@@ -5,5 +5,5 @@
     android:viewportHeight="24">
     <path
         android:fillColor="@android:color/white"
-        android:pathData="M4,20h16v2L4,22zM4,2h16v2L4,4zM13,9h3l-4,-4 -4,4h3v6L8,15l4,4 4,-4h-3z" />
+        android:pathData="M6,19h4L10,5L6,5v14zM14,5v14h4L18,5h-4z" />
 </vector>

core/presentation/src/main/res/drawable/ic_play.xml

@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="@android:color/white"
+        android:pathData="M8,5v14l11,-7z" />
+</vector>

core/presentation/src/main/res/drawable/ic_save.xml

@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="@android:color/white"
+        android:pathData="M17,3L5,3c-1.11,0 -2,0.9 -2,2v14c0,1.1 0.89,2 2,2h14c1.1,0 2,-0.9 2,-2L21,7l-4,-4zM12,19c-1.66,0 -3,-1.34 -3,-3s1.34,-3 3,-3 3,1.34 3,3 -1.34,3 -3,3zM15,9L5,9L5,5h10v4z" />
+</vector>

core/presentation/src/main/res/drawable/ic_sun.xml

@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="@android:color/white"
+        android:pathData="M11,4V2c0,-0.55 0.45,-1 1,-1s1,0.45 1,1v2c0,0.55 -0.45,1 -1,1S11,4.55 11,4zM18.36,7.05l1.41,-1.42c0.39,-0.39 0.39,-1.02 0,-1.41c-0.39,-0.39 -1.02,-0.39 -1.41,0l-1.41,1.42c-0.39,0.39 -0.39,1.02 0,1.41C17.34,7.44 17.97,7.44 18.36,7.05zM22,11h-2c-0.55,0 -1,0.45 -1,1s0.45,1 1,1h2c0.55,0 1,-0.45 1,-1S22.55,11 22,11zM12,19c-0.55,0 -1,0.45 -1,1v2c0,0.55 0.45,1 1,1s1,-0.45 1,-1v-2C13,19.45 12.55,19 12,19zM5.64,7.05L4.22,5.64c-0.39,-0.39 -0.39,-1.03 0,-1.41s1.03,-0.39 1.41,0l1.41,1.41c0.39,0.39 0.39,1.03 0,1.41S6.02,7.44 5.64,7.05zM16.95,16.95c-0.39,0.39 -0.39,1.03 0,1.41l1.41,1.41c0.39,0.39 1.03,0.39 1.41,0c0.39,-0.39 0.39,-1.03 0,-1.41l-1.41,-1.41C17.98,16.56 17.34,16.56 16.95,16.95zM2,13h2c0.55,0 1,-0.45 1,-1s-0.45,-1 -1,-1H2c-0.55,0 -1,0.45 -1,1S1.45,13 2,13zM5.64,19.78l1.41,-1.41c0.39,-0.39 0.39,-1.03 0,-1.41s-1.03,-0.39 -1.41,0l-1.41,1.41c-0.39,0.39 -0.39,1.03 0,1.41C4.61,20.17 5.25,20.17 5.64,19.78zM12,6c-3.31,0 -6,2.69 -6,6s2.69,6 6,6s6,-2.69 6,-6S15.31,6 12,6z" />
+</vector>

core/presentation/src/main/res/values-es/strings.xml

@@ -31,7 +31,10 @@
     <!-- Passes screen -->
     <string name="pass_filter_title">Filtrar pases</string>
     <string name="pass_filter_elev">Elevación mínima</string>
-    <string name="pass_filter_hours">Horas por delante</string>
+    <string name="pass_filter_hours">Tiempo por delante</string>
+    <string name="pass_filter_aos_time">Ventana AOS</string>
+    <string name="pass_filter_invert_time">Invertir ventana AOS</string>
+    <string name="pass_filter_deep_space">DeepSpace (período &gt;225min)</string>
     <string name="pass_modes_title">Tipo de modulación</string>
     <string name="pass_elevation">Elevación: %.1f°</string>
     <string name="pass_altitude">Altitud: %.0f km</string>
@@ -132,12 +135,19 @@
     <string name="prefs_bt_frequency_device_hint">Id dispositivo</string>
     <string name="prefs_bt_frequency_output_hint">Formato de datos</string>
     <string name="prefs_bt_perm_error">Revisa los permisos de Bluetooth</string>
+    <string name="prefs_net_perm_error">Revisa los permisos de red</string>
 
     <string name="prefs_other_title">Otros ajustes</string>
     <string name="prefs_other_switch_utc">Mostrar tiempos de pase en UTC</string>
     <string name="prefs_other_switch_update">Habilitar auto actualización de datos</string>
     <string name="prefs_other_switch_sweep">Habilitar animaciones radar</string>
     <string name="prefs_other_switch_sensors">Usar sensores para rotar vista de radar</string>
+    <string name="prefs_other_switch_night_mode">Activar filtro nocturno rojo</string>
+
+    <string name="prefs_highlight_title">Resaltado de elevación</string>
+    <string name="prefs_highlight_low">Baja &lt; %1$d°</string>
+    <string name="prefs_highlight_mid">Media %1$d-%2$d°</string>
+    <string name="prefs_highlight_high">Alta &gt; %1$d°</string>
 
     <string name="prefs_outro_title">Me gustaría dar las gracias a:</string>
     <string name="prefs_outro_license">La app viene sin garantías de ningún tipo.</string>

core/presentation/src/main/res/values-ru/strings.xml

@@ -30,7 +30,10 @@
     <!-- Passes screen -->
     <string name="pass_filter_title">Фильтровать пролеты</string>
     <string name="pass_filter_elev">Минимальная элевация</string>
-    <string name="pass_filter_hours">Количество часов</string>
+    <string name="pass_filter_hours">Период расчёта</string>
+    <string name="pass_filter_aos_time">Окно AOS</string>
+    <string name="pass_filter_invert_time">Инвертировать окно AOS</string>
+    <string name="pass_filter_deep_space">DeepSpace (период &gt;225мин)</string>
     <string name="pass_modes_title">Выберите тип модуляции</string>
     <string name="pass_elevation">Элевация: %.1f°</string>
     <string name="pass_altitude">Высота: %d км</string>
@@ -131,12 +134,19 @@
     <string name="prefs_bt_frequency_device_hint">Id устройства</string>
     <string name="prefs_bt_frequency_output_hint">Формат</string>
     <string name="prefs_bt_perm_error">Нет разрешения использовать bluetooth</string>
+    <string name="prefs_net_perm_error">Нет разрешения использовать сеть</string>
 
     <string name="prefs_other_title">Другие настройки</string>
     <string name="prefs_other_switch_utc">Показывать время по UTC</string>
     <string name="prefs_other_switch_update">Обновлять данные автоматически</string>
     <string name="prefs_other_switch_sweep">Показывать анимацию радара</string>
     <string name="prefs_other_switch_sensors">Использовать сенсоры устройства</string>
+    <string name="prefs_other_switch_night_mode">Включить красный ночной фильтр</string>
+
+    <string name="prefs_highlight_title">Подсветка высоты</string>
+    <string name="prefs_highlight_low">Низко &lt; %1$d°</string>
+    <string name="prefs_highlight_mid">Средне %1$d-%2$d°</string>
+    <string name="prefs_highlight_high">Высоко &gt; %1$d°</string>
 
     <string name="prefs_outro_title">Я хотел бы сказать спасибо:</string>
     <string name="prefs_outro_license">Это ПО поставляется без гарантий.</string>

core/presentation/src/main/res/values-si/strings.xml

@@ -31,7 +31,10 @@
     <!-- Passes screen -->
     <string name="pass_filter_title">පසුකිරිම් පිරිපහදුව</string>
     <string name="pass_filter_elev">අවම උත්තෝලනය</string>
-    <string name="pass_filter_hours">ඉදිරි පැය</string>
+    <string name="pass_filter_hours">ඉදිරි කාලය</string>
+    <string name="pass_filter_aos_time">AOS කවුළුව</string>
+    <string name="pass_filter_invert_time">AOS කවුළුව ප්‍රතිවිරුද්ධ කරන්න</string>
+    <string name="pass_filter_deep_space">DeepSpace (කාලය &gt;225min)</string>
     <string name="pass_modes_title">මූර්ජන ආකාරය තෝරන්න</string>
     <string name="pass_elevation">උත්තෝලනය: %.1f°</string>
     <string name="pass_altitude">උන්නතාශය: %d km</string>
@@ -132,12 +135,19 @@
     <string name="prefs_bt_frequency_device_hint">උපාංග id</string>
     <string name="prefs_bt_frequency_output_hint">දත්ත අකාරය</string>
     <string name="prefs_bt_perm_error">Bluetooth අවසර පරික්‍ෂා ක°</string>
+    <string name="prefs_net_perm_error">Network අවසර පරික්‍ෂා කරන්න</string>
 
     <string name="prefs_other_title">වෙනත් සැකසුම්</string>
     <string name="prefs_other_switch_utc">පසුකර වේලාවන් UTC මගින්</string>
     <string name="prefs_other_switch_update">ස්වයං දත්ත යාවත්කාලීනය</string>
     <string name="prefs_other_switch_sweep">radar sweep සජීවිකරණය සබල කරන්න</string>
     <string name="prefs_other_switch_sensors">Radar දර්ශනය කරකැවීමට සංවේදක භාවිතා කරන්න </string>
+    <string name="prefs_other_switch_night_mode">රතු රාත්‍රී පෙරහන සබල කරන්න</string>
+
+    <string name="prefs_highlight_title">උස් උද්දීපනය</string>
+    <string name="prefs_highlight_low">අඩු &lt; %1$d°</string>
+    <string name="prefs_highlight_mid">මධ්‍ය %1$d-%2$d°</string>
+    <string name="prefs_highlight_high">ඉහළ &gt; %1$d°</string>
 
     <string name="prefs_outro_title">මම ස්තුති කිරීමට කැමති:</string>
     <string name="prefs_outro_license">මෘදුකාංගය වගකීමක් සමග නොලැබේ</string>

core/presentation/src/main/res/values-tr/strings.xml

@@ -31,7 +31,10 @@
     <!-- Passes screen -->
     <string name="pass_filter_title">Geçişleri filtrele</string>
     <string name="pass_filter_elev">Minimum yükseklik açısı</string>
-    <string name="pass_filter_hours">İlerideki saatler</string>
+    <string name="pass_filter_hours">Gösterilecek zaman</string>
+    <string name="pass_filter_aos_time">AOS aralığı</string>
+    <string name="pass_filter_invert_time">AOS aralığını tersine çevir</string>
+    <string name="pass_filter_deep_space">DeepSpace (periyot &gt;225dk)</string>
     <string name="pass_time_placeholder" translatable="false"> -- : -- : -- </string>
     <string name="pass_modes_title">Modulasyon türü seçin</string>
     <string name="pass_satId" translatable="false">%05d</string>
@@ -66,7 +69,7 @@
     <string name="radar_alt_value" translatable="false">%.0f km</string>
     <string name="radar_dist_text">Mesafe</string>
     <string name="radar_dist_value" translatable="false">%.0f km</string>
-    <string name="radar_eclipsed">Tutulumda</string>
+    <string name="radar_eclipsed">Gölgede</string>
     <string name="radar_downlink">Downlink</string>
     <string name="radar_uplink">Uplink</string>
     <string name="radar_link_low" translatable="false">%.4f</string>
@@ -93,7 +96,7 @@
     <string name="map_longitude">Boylam: %.1f°</string>
     <string name="map_qth" translatable="false">QTH: %s</string>
     <string name="map_phase">Faz: %.1f°</string>
-    <string name="map_eclipsed">Tutulumda</string>
+    <string name="map_eclipsed">Gölgede</string>
     <string name="map_period">Periyot: %.0f dk</string>
     <string name="map_velocity">Hız: %.2f km/s</string>
     <string name="map_visibility">Görünürlük: %s</string>
@@ -175,21 +178,29 @@
     <string name="prefs_bt_frequency_device_hint">Cihaz kimliği</string>
     <string name="prefs_bt_frequency_output_hint">Veri biçimi</string>
     <string name="prefs_bt_perm_error">Bluetooth izninizi kontrol edin</string>
+    <string name="prefs_net_perm_error">Ağ izninizi kontrol edin</string>
 
     <string name="prefs_other_title">Diğer ayarlar</string>
     <string name="prefs_other_switch_utc">Geçiş saatini UTC olarak göster</string>
     <string name="prefs_other_switch_update">Otomatik veri güncellemeyi etkinleştir</string>
     <string name="prefs_other_switch_sweep">Radar taramasını etkinleştir</string>
     <string name="prefs_other_switch_sensors">Radar görünümünü döndürmek için sensörleri kullan</string>
+    <string name="prefs_other_switch_night_mode">Kırmızı gece filtresini etkinleştir</string>
 
-    <string name="prefs_outro_title">Teşekkür etmek istiyorum</string>
+    <string name="prefs_highlight_title">Elevasyon vurgusu</string>
+    <string name="prefs_highlight_low">Düşük &lt; %1$d°</string>
+    <string name="prefs_highlight_mid">Orta %1$d-%2$d°</string>
+    <string name="prefs_highlight_high">Yüksek &gt; %1$d°</string>
+
+    <string name="prefs_outro_title">Teşekkürler</string>
     <string name="prefs_outro_thanks" translatable="false">
         • Look4Sat users and contributors!
         \n• David A. B. Johnson (predict4java)
         \n• Dave Moten (predict4java)
         \n• Alexandru Csete (Gpredict)
         \n• Dr T.S. Kelso (Celestrak)
-        \n• Libre Space Foundation (SatNOGS)</string>
+        \n• Libre Space Foundation (SatNOGS)
+        \n• BG7NTA (CW decoding feature)</string>
     <string name="prefs_outro_license">Bu uygulama herhangi bir garanti sunmaz</string>
 
 </resources>

core/presentation/src/main/res/values-uk/strings.xml

@@ -30,8 +30,11 @@
 
     <!-- Passes screen -->
     <string name="pass_filter_title">Фільтр прольотів</string>
-    <string name="pass_filter_elev">Мінімальне піднесення</string>
-    <string name="pass_filter_hours">Кількість годин</string>
+    <string name="pass_filter_elev">Мінімальне піднесень</string>
+    <string name="pass_filter_hours">Час вперед</string>
+    <string name="pass_filter_aos_time">Вікно AOS</string>
+    <string name="pass_filter_invert_time">Інвертувати вікно AOS</string>
+    <string name="pass_filter_deep_space">DeepSpace (період &gt;225хв)</string>
     <string name="pass_modes_title">Виберіть тип модуляції</string>
     <string name="pass_elevation">Піднес.: %.1f°</string>
     <string name="pass_altitude">Висота: %.0f км</string>
@@ -66,7 +69,7 @@
     <string name="map_prev">Попередній</string>
     <string name="map_next">Наступний</string>
     <string name="map_azimuth">Азимут: %.1f°</string>
-    <string name="map_elevation">Піднесення: %.1f°</string>
+    <string name="map_elevation">Піднесень: %.1f°</string>
     <string name="map_altitude">Висота: %.0f км</string>
     <string name="map_distance">Дистанція: %.0f км</string>
     <string name="map_latitude">Широта: %.1f°</string>
@@ -132,12 +135,19 @@
     <string name="prefs_bt_frequency_device_hint">Id пристрою</string>
     <string name="prefs_bt_frequency_output_hint">Формат даних</string>
     <string name="prefs_bt_perm_error">Перевірте дозвіл Bluetooth</string>
+    <string name="prefs_net_perm_error">Перевірте дозвіл мережі</string>
 
     <string name="prefs_other_title">Інші налаштування</string>
     <string name="prefs_other_switch_utc">Показувати час в UTC</string>
     <string name="prefs_other_switch_update">Автоматичне оновлення даних</string>
     <string name="prefs_other_switch_sweep">Показувати анімацію радара</string>
     <string name="prefs_other_switch_sensors">Використовувати сенсори пристрою</string>
+    <string name="prefs_other_switch_night_mode">Увімкнути червоний нічний фільтр</string>
+
+    <string name="prefs_highlight_title">Підсвічування висоти</string>
+    <string name="prefs_highlight_low">Низько &lt; %1$d°</string>
+    <string name="prefs_highlight_mid">Середньо %1$d-%2$d°</string>
+    <string name="prefs_highlight_high">Високо &gt; %1$d°</string>
 
     <string name="prefs_outro_title">Я хотів би подякувати:</string>
     <string name="prefs_outro_license">Ця програма поставляється без жодних гарантій</string>

core/presentation/src/main/res/values-zh/strings.xml

@@ -9,6 +9,7 @@
     <string name="nav_sat">卫星</string>
     <string name="nav_pass">过境</string>
     <string name="nav_radar">雷达</string>
+    <string name="nav_mutual">匹配</string>
     <string name="nav_map">地图</string>
     <string name="nav_prefs">设置</string>
 
@@ -26,7 +27,10 @@
     <!-- Passes screen -->
     <string name="pass_filter_title">筛选过境</string>
     <string name="pass_filter_elev">仰角值</string>
-    <string name="pass_filter_hours">小时数</string>
+    <string name="pass_filter_hours">提前时间</string>
+    <string name="pass_filter_aos_time">AOS 时间段</string>
+    <string name="pass_filter_invert_time">反选 AOS 时间段</string>
+    <string name="pass_filter_deep_space">DeepSpace（周期 &gt;225分钟）</string>
     <string name="pass_modes_title">选择调制类型</string>
     <string name="pass_elevation">仰角：%.1f°</string>
     <string name="pass_altitude">高度：%d km</string>
@@ -54,6 +58,17 @@
     <string name="radar_string_yes">是</string>
     <string name="radar_visible">日照中</string>
 
+    <string name="radar_doppler_calc">多普勒频率计算器</string>
+    <string name="radar_doppler_tx_hint">输入上行频率 (MHz)</string>
+    <string name="radar_doppler_rx_hint">输入下行频率 (MHz)</string>
+    <string name="radar_doppler_offset_hint">偏移 (kHz)</string>
+    <string name="radar_doppler_info">线性转发器：输入一个频率即可算出另一个</string>
+
+    <string name="radar_cw_decoder">CW 解码器</string>
+    <string name="radar_cw_start">开始</string>
+    <string name="radar_cw_stop">停止</string>
+    <string name="radar_cw_reset">清空</string>
+
     <!-- Map screen -->
     <string name="map_prev">上一个</string>
     <string name="map_next">下一个</string>
@@ -77,7 +92,7 @@
     <string name="prefs_updated_title">更新：%s</string>
     <string name="prefs_updated_time">yyyy MMM d - HH:mm:ss</string>
 
-    <string name="prefs_loc_title">站位</string>
+    <string name="prefs_loc_title">站点位置</string>
     <string name="prefs_loc_gps_title">GPS 定位</string>
     <string name="prefs_loc_gps_error">检查您的位置权限</string>
     <string name="prefs_loc_input_title">输入位置</string>
@@ -85,11 +100,11 @@
     <string name="prefs_loc_qth_title">QTH 网格</string>
     <string name="prefs_loc_qth_error">无效的 QTH 网格</string>
     <string name="prefs_loc_success">位置更新成功</string>
-    <string name="prefs_station_title">站位设置</string>
-    <string name="prefs_station_lat_text">输入站位的纬度</string>
-    <string name="prefs_station_lon_text">输入站位的经度</string>
+    <string name="prefs_station_title">站点位置设置</string>
+    <string name="prefs_station_lat_text">输入站点的纬度</string>
+    <string name="prefs_station_lon_text">输入站点的经度</string>
     <string name="prefs_locator_title">QTH 网格</string>
-    <string name="prefs_locator_text">使用梅登黑德网格设置站位</string>
+    <string name="prefs_locator_text">使用梅登黑德网格设置站点位置</string>
 
     <string name="prefs_data_title">卫星数据更新</string>
     <string name="prefs_data_entries">卫星：%s</string>
@@ -100,6 +115,9 @@
     <string name="prefs_data_clear_success">数据清空成功</string>
     <string name="prefs_data_update_success">更新成功</string>
 
+    <string name="prefs_data_import_satellites_error">未导入卫星。请选择有效的 TLE/3LE (.txt) 或 OMM (.csv) 文件。</string>
+    <string name="prefs_data_import_transceivers_error">未导入收发器。请选择有效的 SatNOGS (.json) 文件。</string>
+
     <string name="prefs_data_sources_title">自定义数据源</string>
     <string name="prefs_data_sources_tle_switch">自定义TLE URL</string>
     <string name="prefs_data_sources_transceivers_switch">自定义收发器URL</string>
@@ -107,6 +125,7 @@
     <string name="prefs_data_output_title">数据输出</string>
     <string name="prefs_net_output">网络</string>
     <string name="prefs_bt_output">蓝牙</string>
+    <string name="prefs_cat_output">CAT</string>
 
     <string name="prefs_net_title">网络数据输出</string>
     <string name="prefs_net_rotator_switch">启用方位俯仰角输出</string>
@@ -124,14 +143,72 @@
     <string name="prefs_bt_frequency_device_hint">蓝牙设备 ID</string>
     <string name="prefs_bt_frequency_output_hint">数据格式</string>
     <string name="prefs_bt_perm_error">请检查蓝牙权限</string>
+    <string name="prefs_net_perm_error">请检查网络权限</string>
+
+    <!-- Radio Control -->
+    <string name="nav_radiocontrol">电台控制</string>
+    <string name="rc_settings_title">CAT 电台控制</string>
+    <string name="rc_radio_model">电台型号</string>
+    <string name="rc_tx_device_hint">发射电台蓝牙地址</string>
+    <string name="rc_rx_device_hint">接收电台蓝牙地址</string>
+    <string name="rc_tx_name_hint">发射电台名称</string>
+    <string name="rc_rx_name_hint">接收电台名称</string>
+    <string name="rc_enable_switch">启用 CAT 控制</string>
 
     <string name="prefs_other_title">其他设置</string>
     <string name="prefs_other_switch_utc">以 UTC 时间显示</string>
     <string name="prefs_other_switch_update">启用卫星数据自动更新</string>
     <string name="prefs_other_switch_sweep">启用雷达扫描动画</string>
     <string name="prefs_other_switch_sensors">使用传感器旋转雷达视图</string>
+    <string name="prefs_other_switch_night_mode">启用红色夜间模式</string>
+
+    <string name="prefs_highlight_title">仰角高亮</string>
+    <string name="prefs_highlight_low">低 &lt; %1$d°</string>
+    <string name="prefs_highlight_mid">中 %1$d-%2$d°</string>
+    <string name="prefs_highlight_high">高 &gt; %1$d°</string>
 
     <string name="prefs_outro_title">我要感谢：</string>
+    <string name="prefs_outro_thanks" translatable="false">
+        • Look4Sat 所有用户及贡献者!
+        \n• David A. B. Johnson (predict4java)
+        \n• Dave Moten (predict4java)
+        \n• Alexandru Csete (Gpredict)
+        \n• Dr T.S. Kelso (Celestrak)
+        \n• Libre Space Foundation (SatNOGS)
+        \n• xdsopl 和 Robot36 贡献者!
+        \n• BG7NTA（CW解码功能）</string>
     <string name="prefs_outro_license">该应用程序不提供任何保修.</string>
 
+    <!-- 匹配页 Mutual match page -->
+    <string name="mutual_title">过境匹配</string>
+    <string name="mutual_station_you">你的位置</string>
+    <string name="mutual_station_opposite">友台位置</string>
+    <string name="mutual_label_you">你</string>
+    <string name="mutual_label_opposite">友台</string>
+    <string name="mutual_status_calculating">正在计算双方共同可见窗口…</string>
+    <string name="mutual_status_error">请修正提示后重新查询</string>
+    <string name="mutual_status_matches">找到 %d 个匹配 · 点击卡片展开曲线</string>
+    <string name="mutual_status_none">未找到共同可见窗口，调整时间或仰角后重试</string>
+    <string name="mutual_status_idle">输入双方位置后点击查询</string>
+    <string name="mutual_chip_calculating">计算中</string>
+    <string name="mutual_chip_error">有错误</string>
+    <string name="mutual_chip_matches">%d 个匹配</string>
+    <string name="mutual_chip_none">无匹配</string>
+    <string name="mutual_chip_idle">待查询</string>
+    <string name="mutual_use_current">填入当前位置</string>
+    <string name="mutual_lat">纬度</string>
+    <string name="mutual_lon">经度</string>
+    <string name="mutual_grid">网格</string>
+    <string name="mutual_grid_hint">支持 4/6/8 位 Maidenhead 网格；也可直接输入经纬度</string>
+    <string name="mutual_min_elevation">最小仰角：%d°</string>
+    <string name="mutual_time_range">时间范围</string>
+    <string name="mutual_calculating">计算中…</string>
+    <string name="mutual_query">查询匹配</string>
+    <string name="mutual_elevation_you">你：%d°</string>
+    <string name="mutual_elevation_opposite">友台：%d°</string>
+    <string name="mutual_both_tracks">双方轨迹</string>
+    <string name="mutual_open_radar">查看雷达</string>
+    <string name="mutual_station_a">站点A</string>
+    <string name="mutual_station_b">站点B</string>
+
 </resources>

core/presentation/src/main/res/values/strings.xml

@@ -10,6 +10,7 @@
     <string name="nav_sat">Satellites</string>
     <string name="nav_pass">Passes</string>
     <string name="nav_radar">Radar</string>
+    <string name="nav_mutual">Match</string>
     <string name="nav_map">Map</string>
     <string name="nav_prefs">Settings</string>
 
@@ -31,7 +32,9 @@
     <!-- Passes screen -->
     <string name="pass_filter_title">Filter passes</string>
     <string name="pass_filter_elev">Minimal elevation</string>
-    <string name="pass_filter_hours">Hours ahead</string>
+    <string name="pass_filter_hours">Time ahead</string>
+    <string name="pass_filter_aos_time">AOS window</string>
+    <string name="pass_filter_invert_time">Invert AOS window</string>
     <string name="pass_filter_deep_space">DeepSpace (period >225min)</string>
     <string name="pass_time_placeholder" translatable="false"> -- : -- : -- </string>
     <string name="pass_modes_title">Select modulation type</string>
@@ -49,10 +52,8 @@
         \n\nPlease update the database at least weekly to get accurate predictions.</string>
     <string name="pass_whatsnew_title" translatable="false">What\'s new in Look4Sat</string>
     <string name="pass_whatsnew_message" translatable="false">
-        * Added Turkish translation, by Emre Can Akdaş (TA3ECR)
-        \n* Added DeepSpace passes filter option to the dialog
-        \n* Fixed the radar blip disappearing while eclipsed
-        \n* Fixed (hopefully) the refresh indicator being stuck
+        * Added required tweaks to support Android 17 (API 37)
+        \n\n* Added ACCESS_LOCAL_NETWORK permission check to support network data output
     </string>
 
     <!-- Radar screen -->
@@ -80,6 +81,16 @@
     <string name="radar_string_no">No</string>
     <string name="radar_string_yes">Yes</string>
     <string name="radar_visible">Visible</string>
+    <string name="radar_doppler_calc">Doppler Frequency Calculator</string>
+    <string name="radar_doppler_tx_hint">Enter TX freq (MHz)</string>
+    <string name="radar_doppler_rx_hint">Enter RX freq (MHz)</string>
+    <string name="radar_doppler_offset_hint">Offset (kHz)</string>
+    <string name="radar_doppler_info">For linear transponders, type one frequency to see the other</string>
+
+    <string name="radar_cw_decoder">CW Decoder</string>
+    <string name="radar_cw_start">Start</string>
+    <string name="radar_cw_stop">Stop</string>
+    <string name="radar_cw_reset">Clear</string>
 
     <!-- Map screen -->
     <string name="map_prev">Prev</string>
@@ -138,6 +149,8 @@
     <string name="prefs_data_clear">Clear</string>
     <string name="prefs_data_clear_success">Data was cleared successfully</string>
     <string name="prefs_data_update_success">Update completed successfully</string>
+    <string name="prefs_data_import_satellites_error">No satellites imported. Select a valid TLE/3LE (.txt) or OMM (.csv) file.</string>
+    <string name="prefs_data_import_transceivers_error">No transceivers imported. Select a valid SatNOGS (.json) file.</string>
 
     <string name="prefs_data_sources_title">Custom data sources</string>
     <string name="prefs_data_sources_tle_switch">Custom TLE URL</string>
@@ -175,21 +188,63 @@
     <string name="prefs_bt_frequency_device_hint">Device id</string>
     <string name="prefs_bt_frequency_output_hint">Data format</string>
     <string name="prefs_bt_perm_error">Check your bluetooth permission</string>
+    <string name="prefs_net_perm_error">Check your network permission</string>
 
     <string name="prefs_other_title">Other settings</string>
     <string name="prefs_other_switch_utc">Show pass time in UTC</string>
     <string name="prefs_other_switch_update">Enable automatic data update</string>
     <string name="prefs_other_switch_sweep">Enable radar sweep animation</string>
     <string name="prefs_other_switch_sensors">Use sensors to rotate radar view</string>
+    <string name="prefs_other_switch_night_mode">Enable red night mode filter</string>
+
+    <string name="prefs_highlight_title">Elevation highlight</string>
+    <string name="prefs_highlight_low">Low &lt; %1$d°</string>
+    <string name="prefs_highlight_mid">Mid %1$d–%2$d°</string>
+    <string name="prefs_highlight_high">High &gt; %1$d°</string>
 
     <string name="prefs_outro_title">I would like to say thanks to</string>
     <string name="prefs_outro_thanks" translatable="false">
-        • Look4Sat users and contributors!
-        \n• David A. B. Johnson (predict4java)
-        \n• Dave Moten (predict4java)
-        \n• Alexandru Csete (Gpredict)
-        \n• Dr T.S. Kelso (Celestrak)
-        \n• Libre Space Foundation (SatNOGS)</string>
+        * Look4Sat users and contributors!
+        \n* David A. B. Johnson (predict4java)
+        \n* Dave Moten (predict4java)
+        \n* Alexandru Csete (Gpredict)
+        \n* Dr T.S. Kelso (Celestrak)
+        \n* Libre Space Foundation (SatNOGS)
+        \n* xdsopl and Robot36 contributors!
+        \n* BG7NTA (CW decoding feature)
+    </string>
     <string name="prefs_outro_license">The app comes with no warranty</string>
 
+    <!-- Mutual match page -->
+    <string name="mutual_title">Pass Match</string>
+    <string name="mutual_station_you">Your Station</string>
+    <string name="mutual_station_opposite">Opposite Station</string>
+    <string name="mutual_label_you">You</string>
+    <string name="mutual_label_opposite">Opposite</string>
+    <string name="mutual_status_calculating">Calculating mutual visibility windows…</string>
+    <string name="mutual_status_error">Fix the reported issues and retry</string>
+    <string name="mutual_status_matches">%d matches found · tap a card to expand</string>
+    <string name="mutual_status_none">No mutual windows found. Adjust time or min elevation and retry</string>
+    <string name="mutual_status_idle">Enter both stations, then tap Query</string>
+    <string name="mutual_chip_calculating">Calculating</string>
+    <string name="mutual_chip_error">Error</string>
+    <string name="mutual_chip_matches">%d matches</string>
+    <string name="mutual_chip_none">No matches</string>
+    <string name="mutual_chip_idle">Idle</string>
+    <string name="mutual_use_current">Use current</string>
+    <string name="mutual_lat">Lat</string>
+    <string name="mutual_lon">Lon</string>
+    <string name="mutual_grid">Grid</string>
+    <string name="mutual_grid_hint">Supports 4/6/8-char Maidenhead grid; or enter lat/lon directly</string>
+    <string name="mutual_min_elevation">Min elevation: %d°</string>
+    <string name="mutual_time_range">Time range</string>
+    <string name="mutual_calculating">Calculating…</string>
+    <string name="mutual_query">Query Match</string>
+    <string name="mutual_elevation_you">You: %d°</string>
+    <string name="mutual_elevation_opposite">Opposite: %d°</string>
+    <string name="mutual_both_tracks">Both tracks</string>
+    <string name="mutual_open_radar">Open Radar</string>
+    <string name="mutual_station_a">Station A</string>
+    <string name="mutual_station_b">Station B</string>
+
 </resources>

core/presentation/src/test/java/com/rtbishop/look4sat/core/presentation/DeeplinkResolverTest.kt

@@ -0,0 +1,39 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.presentation
+
+import org.junit.Test
+
+class DeeplinkResolverTest {
+
+    @Test
+    fun returnsDefaultDestination() {
+        val deeplinkResolver = DeeplinkResolver()
+        val result = deeplinkResolver.resolve("/deeplink")
+        assert(result == Screen.Passes)
+    }
+
+    @Test
+    fun returnsRadarDestination() {
+        val passId = "some-pass-id"
+        val passDeeplink = "https://github.com/rt-bishop/Look4Sat/passes/$passId"
+        val deeplinkResolver = DeeplinkResolver()
+        val result = deeplinkResolver.resolve(passDeeplink)
+        assert(result == RadarDestination)
+    }
+}

fastlane/metadata/android/en-US/changelogs/default.txt

@@ -1,4 +1,2 @@
-* Added Turkish translation, by Emre Can Akdaş (TA3ECR)
-* Added DeepSpace passes filter option to the dialog
-* Fixed the radar blip disappearing while eclipsed
-* Fixed (hopefully) the refresh indicator being stuck
+* Added required tweaks to support Android 17 (API 37)
+* Added ACCESS_LOCAL_NETWORK permission check to support network data output

fastlane/metadata/android/en-US/whatsnew/whatsnew-en-US

@@ -1,4 +0,0 @@
-* Added Turkish translation, by Emre Can Akdaş (TA3ECR)
-* Added DeepSpace passes filter option to the dialog
-* Fixed the radar blip disappearing while eclipsed
-* Fixed (hopefully) the refresh indicator being stuck

feature/cw/build.gradle.kts

@@ -0,0 +1,38 @@
+import com.android.build.api.dsl.LibraryExtension
+import com.android.build.api.variant.CanProduceConsumerProguardFiles
+
+plugins {
+    alias(libs.plugins.convention.featurePlugin)
+}
+
+android {
+    namespace = "com.rtbishop.look4sat.feature.cw"
+    compileOptions {
+        encoding = "UTF-8"
+    }
+    // 照搬 Morse Expert 1.15: native 解码器仅 armeabi-v7a
+    defaultConfig {
+        ndk {
+            abiFilters += listOf("armeabi-v7a")
+        }
+    }
+}
+
+// CW 类保持规则(JNI 按类名注册 + 照搬混淆类保逻辑), 由 app 的 R8 消费
+// AGP 9: consumer 规则走 variant 级 CanProduceConsumerProguardFiles
+androidComponents {
+    onVariants(selector().all()) { variant ->
+        (variant as? CanProduceConsumerProguardFiles)?.consumerProguardFiles?.add(
+            project.layout.projectDirectory.file("proguard-rules.pro")
+        )
+    }
+}
+
+dependencies {
+    implementation("androidx.constraintlayout:constraintlayout:2.2.1")
+}
+
+// 照搬的 Java 源码含中文注释, 强制 UTF-8 编译(compileOptions 在部分 AGP 版本不生效)
+tasks.withType<JavaCompile>().configureEach {
+    options.encoding = "UTF-8"
+}

feature/cw/proguard-rules.pro

@@ -0,0 +1,31 @@
+# Look4Sat Pro — CW 解码模块(照搬 Morse Expert 1.15)混淆规则
+# 所有 CW 类保持原名: pas.* 通过 RegisterNatives 按类名注册 JNI(混淆即崩);
+# 其余为照搬的混淆名类(命名已无混淆意义, 保持以保逻辑完整)。
+
+# JNI 引擎(RegisterNatives 按类名/方法名查表)
+-keep class pas.** { *; }
+
+# 照搬的解码/UI 类(全部保持)
+-keep class com.ve3nea.morse_expert.** { *; }
+-keep class H2.** { *; }
+-keep class I2.b { *; }
+-keep class J2.** { *; }
+-keep class k3.** { *; }
+-keep class i3.** { *; }
+-keep class g3.** { *; }
+-keep class j3.** { *; }
+-keep class s.** { *; }
+-keep class d1.AbstractC1518b { *; }
+-keep class B0.b { *; }
+-keep class B.RunnableC0001b { *; }
+-keep class D.n { *; }
+-keep class E2.g { *; }
+-keep class F2.a { *; }
+-keep class I0.d { *; }
+-keep class K1.a { *; }
+-keep class j1.C1646n { *; }
+
+# sun.misc stub(Android 无此类, 仅编译期; 防止 R8 异常处理)
+-dontwarn sun.misc.**
+-keep class sun.misc.Unsafe { *; }
+-keep class sun.misc.Cleaner { *; }

feature/cw/src/main/java/B/RunnableC0001b.java

@@ -0,0 +1,63 @@
+package B;
+
+import android.text.SpannableStringBuilder;
+import com.ve3nea.morse_expert.DecodedTextView;
+import com.ve3nea.morse_expert.MainActivity;
+import H2.b;
+
+/**
+ * 照搬自 Morse Expert 1.15 B.RunnableC0001b, 类名保持混淆原名。
+ * R8 合并 Runnable 手术: 构造按 smali 真实签名 5 参 (Object,Object,int,int,boolean),
+ * 字段 = i(Object)/h(Object)/g(int)/f(int); run() 仅保留 case 4(f==2 对应 pswitch_4:
+ * 解码文本 UI 更新, H2.b 调用), 其余 case(权限/Intent/通知等库代码)已裁剪。
+ * 注: jadx 4 参构造为错误还原, 已按 smali 修正。
+ */
+public final class RunnableC0001b implements Runnable {
+    public final /* synthetic */ int f;
+
+    /* renamed from: g, reason: collision with root package name */
+    public final int g;
+
+    /* renamed from: h, reason: collision with root package name */
+    public final Object h;
+
+    /* renamed from: i, reason: collision with root package name */
+    public final Object i;
+
+    public /* synthetic */ RunnableC0001b(Object obj, Object obj2, int i4, int i5, boolean z) {
+        this.i = obj;
+        this.h = obj2;
+        this.g = i4;
+        this.f = i5;
+    }
+
+    @Override // java.lang.Runnable
+    public final void run() {
+        if (this.f == 2) {
+            MainActivity mainActivity = ((b) this.i).f620p;
+            if (mainActivity != null) {
+                SpannableStringBuilder spannableStringBuilder = (SpannableStringBuilder) this.h;
+                int i5 = this.g;
+                DecodedTextView decodedTextView = (DecodedTextView) mainActivity.f11035D.f11888g;
+                if (!decodedTextView.f11032n && !decodedTextView.f11033o.get()) {
+                    decodedTextView.beginBatchEdit();
+                    try {
+                        int length2 = decodedTextView.length();
+                        int min = Math.min(length2, i5);
+                        if (min > 0) {
+                            decodedTextView.getEditableText().delete(length2 - min, length2);
+                        }
+                        decodedTextView.q(spannableStringBuilder);
+                        decodedTextView.endBatchEdit();
+                        return;
+                    } catch (Throwable th) {
+                        decodedTextView.endBatchEdit();
+                        throw th;
+                    }
+                }
+                return;
+            }
+            return;
+        }
+    }
+}

feature/cw/src/main/java/B0/b.java

@@ -0,0 +1,61 @@
+package B0;
+
+import android.widget.TextView;
+import com.ve3nea.morse_expert.MainActivity;
+import com.ve3nea.morse_expert.ScaleView;
+import java.util.Locale;
+import d1.AbstractC1518b;
+
+/**
+ * 照搬自 Morse Expert 1.15 B0.b, 类名保持混淆原名。
+ * R8 合并 Runnable 手术: 构造按 smali 真实签名 (H2/b, String, [I) -> f=4;
+ * 只保留 case 4(状态栏更新: dBFS/Hz/dB/WPM + ScaleView 频率标记, H2.b 调用),
+ * 其余 case(WorkManager/动画等库代码)已裁剪。
+ * r3 = scaleView.getHeight()(smali 证实, jadx 寄存器未展开)。
+ */
+public final class b implements Runnable {
+    public final /* synthetic */ int f;
+
+    /* renamed from: g, reason: collision with root package name */
+    public final Object g;
+
+    /* renamed from: h, reason: collision with root package name */
+    public final Object h;
+
+    /* renamed from: i, reason: collision with root package name */
+    public final Object i;
+
+    public b(H2.b bVar, String str, int[] iArr) {
+        this.f = 4;
+        this.g = bVar;
+        this.h = iArr;
+        this.i = str;
+    }
+
+    @Override // java.lang.Runnable
+    public final void run() {
+        if (this.f == 4) {
+            MainActivity mainActivity = ((H2.b) this.g).f621q;
+            if (mainActivity != null) {
+                String str2 = (String) this.i;
+                int[] iArr = (int[]) this.h;
+                String concat;
+                String format = String.format(Locale.US, " %3d dBFS", Integer.valueOf(iArr[0]));
+                if (iArr[5] == 0) {
+                    concat = format.concat("  Idle    ");
+                } else {
+                    concat = format.concat(String.format(Locale.US, "    %4d Hz    %2d dB    %2d WPM    ", Integer.valueOf(iArr[1]), Integer.valueOf(iArr[2]), Integer.valueOf(iArr[3])));
+                }
+                ((TextView) mainActivity.f11035D.f11890i).setText(AbstractC1518b.e(concat, str2));
+                ScaleView scaleView = (ScaleView) mainActivity.f11035D.f11889h;
+                int i4 = iArr[1];
+                scaleView.f11041g = iArr[5];
+                // r3 = scaleView.getHeight()(smali 证实)
+                scaleView.f = (scaleView.getHeight() - 1) - Math.round(((Math.round(i4 * 0.128f) - H2.b.f606z) * scaleView.getHeight()) / H2.b.f603B);
+                scaleView.invalidate();
+                return;
+            }
+            return;
+        }
+    }
+}

feature/cw/src/main/java/D/n.java

@@ -0,0 +1,69 @@
+package D;
+
+import android.graphics.Bitmap;
+import android.opengl.GLES20;
+import android.opengl.GLUtils;
+import com.ve3nea.morse_expert.WaterfallSurfaceView;
+
+/**
+ * 照搬自 Morse Expert 1.15, 类名保持混淆原名。
+ * R8 合并 Runnable 手术: 只保留 case 1(瀑布图频谱->OpenGL 纹理, H2.b 调用),
+ * 其余 case(库/广告)已裁剪。
+ */
+public final /* synthetic */ class n implements Runnable {
+    public final /* synthetic */ int f;
+
+    /* renamed from: g, reason: collision with root package name */
+    public final /* synthetic */ Object f224g;
+
+    /* renamed from: h, reason: collision with root package name */
+    public final /* synthetic */ Object f225h;
+
+    public /* synthetic */ n(Object obj, int i4, Object obj2) {
+        this.f = i4;
+        this.f224g = obj;
+        this.f225h = obj2;
+    }
+
+    @Override // java.lang.Runnable
+    public final void run() {
+        int i4 = this.f;
+        Object obj = this.f225h;
+        Object obj2 = this.f224g;
+        if (i4 == 1) {
+            float[] fArr = (float[]) obj;
+            J2.b bVar = ((WaterfallSurfaceView) obj2).f;
+            Bitmap bitmap = bVar.f733h;
+            int width = bVar.f730d.getWidth();
+            double d4 = width;
+            double b4 = (bVar.b() + 4.0d) % d4;
+            double d5 = bVar.f737l - b4;
+            if (d5 > d4 / 2.0d) {
+                d5 -= d4;
+            } else if (d5 < (-width) / 2.0d) {
+                d5 += d4;
+            }
+            if (Math.abs(d5) > 8.0d) {
+                bVar.f737l = (int) Math.floor(b4);
+            } else {
+                bVar.f732g = (d5 * 1.0E-5d) + bVar.f732g;
+            }
+            int height = bitmap.getHeight() - 1;
+            for (int i5 = 0; i5 <= height; i5++) {
+                J2.a aVar = bVar.f734i;
+                int round = Math.round((fArr[i5] * 4.0f) + 30.0f);
+                aVar.getClass();
+                bitmap.setPixel(0, height - i5, aVar.f727a[Math.max(0, Math.min(255, round))]);
+            }
+            int i6 = bVar.f737l;
+            GLES20.glBindTexture(3553, bVar.f728a[0]);
+            J2.b.a();
+            GLUtils.texSubImage2D(3553, 0, i6, 0, bitmap);
+            J2.b.a();
+            int i7 = bVar.f737l + 1;
+            bVar.f737l = i7;
+            bVar.f737l = i7 % width;
+            return;
+        }
+    }
+}

feature/cw/src/main/java/E2/g.java

@@ -0,0 +1,44 @@
+package E2;
+
+import android.util.Log;
+import android.view.MotionEvent;
+import android.view.View;
+import com.ve3nea.morse_expert.MainActivity;
+import com.ve3nea.morse_expert.ScaleView;
+
+/**
+ * 照搬自 Morse Expert 1.15 (com.ve3nea.morse_expert), 类名保持混淆原名。
+ * R8 合并类手术: 只保留 case 1(瀑布图触摸选频率=应用逻辑),
+ * 其余 case(广告 P4 / appcompat 焦点 / 弹窗)为库代码, 已裁剪。
+ */
+public final class g implements View.OnTouchListener {
+    public final /* synthetic */ int f;
+
+    /* renamed from: g, reason: collision with root package name */
+    public final /* synthetic */ Object f411g;
+
+    public /* synthetic */ g(Object obj, int i4) {
+        this.f = i4;
+        this.f411g = obj;
+    }
+
+    @Override // android.view.View.OnTouchListener
+    public final boolean onTouch(View view, MotionEvent motionEvent) {
+        int i4 = this.f;
+        Object obj = this.f411g;
+        if (i4 == 1) {
+            MainActivity mainActivity = (MainActivity) obj;
+            if (motionEvent.getActionMasked() == 0 && mainActivity.f11037F != null) {
+                // smali 证实: p1 先被重赋值为 f11035D.h(ScaleView)再 getHeight;
+                // 公式 = round((f606z + ((scaleH-1-y)*f603B/scaleH)) / 0.128f)
+                ScaleView scaleView = (ScaleView) mainActivity.f11035D.f11889h;
+                float y3 = motionEvent.getY();
+                int round = Math.round((H2.b.f606z + ((((scaleView.getHeight() - 1) - y3) * H2.b.f603B) / scaleView.getHeight())) / 0.128f);
+                mainActivity.f11037F.f622r.set(round);
+                Log.i("Waterfall", String.format("Touch at %d Hz`", Integer.valueOf(round)));
+            }
+            return false;
+        }
+        return false;
+    }
+}

feature/cw/src/main/java/F2/a.java

@@ -0,0 +1,53 @@
+package F2;
+
+import com.rtbishop.look4sat.feature.cw.R;
+import android.view.ActionMode;
+import android.view.Menu;
+import android.view.MenuItem;
+import com.ve3nea.morse_expert.DecodedTextView;
+
+/* loaded from: classes.dex */
+public final class a implements ActionMode.Callback {
+
+    /* renamed from: a, reason: collision with root package name */
+    public final /* synthetic */ DecodedTextView f564a;
+
+    public a(DecodedTextView decodedTextView) {
+        this.f564a = decodedTextView;
+    }
+
+    @Override // android.view.ActionMode.Callback
+    public final boolean onActionItemClicked(ActionMode actionMode, MenuItem menuItem) {
+        int itemId = menuItem.getItemId();
+        DecodedTextView decodedTextView = this.f564a;
+        if (itemId != 73) {
+            if (itemId != 74) {
+                return false;
+            }
+            decodedTextView.s();
+            return true;
+        }
+        decodedTextView.r();
+        actionMode.finish();
+        return true;
+    }
+
+    @Override // android.view.ActionMode.Callback
+    public final boolean onCreateActionMode(ActionMode actionMode, Menu menu) {
+        this.f564a.f11032n = true;
+        // 原: if (menu.findItem(R.id.shareText) == null) 检查(shareText 为原 APK 资源, 简化后始终添加)
+        menu.add(0, 74, 0, "Share").setIcon(R.drawable.ic_baseline_share_24);
+        menu.add(0, 73, 0, "Save").setIcon(R.drawable.ic_baseline_save_24);
+        return true;
+    }
+
+    @Override // android.view.ActionMode.Callback
+    public final void onDestroyActionMode(ActionMode actionMode) {
+        this.f564a.f11032n = false;
+    }
+
+    @Override // android.view.ActionMode.Callback
+    public final boolean onPrepareActionMode(ActionMode actionMode, Menu menu) {
+        return false;
+    }
+}

feature/cw/src/main/java/H2/a.java

@@ -0,0 +1,82 @@
+package H2;
+
+import android.media.AudioRecord;
+import android.util.Log;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+/* loaded from: classes.dex */
+public final class a implements Runnable {
+    public final int f;
+
+    /* renamed from: g, reason: collision with root package name */
+    public final AudioRecord f596g;
+
+    /* renamed from: h, reason: collision with root package name */
+    public final ExecutorService f597h;
+
+    /* renamed from: i, reason: collision with root package name */
+    public final AtomicBoolean f598i;
+
+    /* renamed from: j, reason: collision with root package name */
+    public final short[] f599j;
+
+    /* renamed from: k, reason: collision with root package name */
+    public final float[] f600k;
+
+    /* renamed from: l, reason: collision with root package name */
+    public b f601l;
+
+    public a() {
+        int minBufferSize = AudioRecord.getMinBufferSize(8000, 16, 2);
+        int i4 = b.f604C;
+        this.f = i4;
+        ExecutorService newSingleThreadExecutor = Executors.newSingleThreadExecutor();
+        this.f597h = newSingleThreadExecutor;
+        AtomicBoolean atomicBoolean = new AtomicBoolean(false);
+        this.f598i = atomicBoolean;
+        this.f599j = new short[i4];
+        this.f600k = new float[i4];
+        AudioRecord audioRecord = new AudioRecord(1, 8000, 16, 2, minBufferSize * 4);
+        this.f596g = audioRecord;
+        if (audioRecord.getState() == 1) {
+            audioRecord.startRecording();
+            if (audioRecord.getState() != 1) {
+                Log.e("AudioRecord", "cannot start");
+            }
+            atomicBoolean.set(true);
+            newSingleThreadExecutor.execute(this);
+            return;
+        }
+        Log.e("AudioInput", "Failed to initialize");
+    }
+
+    @Override // java.lang.Runnable
+    public final void run() {
+        while (true) {
+            try {
+                if (this.f598i.get()) {
+                    float[] fArr = this.f600k;
+                    AudioRecord audioRecord = this.f596g;
+                    short[] sArr = this.f599j;
+                    int i4 = this.f;
+                    if (audioRecord.read(sArr, 0, i4) == i4) {
+                        for (int i5 = 0; i5 < i4; i5++) {
+                            fArr[i5] = sArr[i5] / 32768.0f;
+                        }
+                        b bVar = this.f601l;
+                        if (bVar != null) {
+                            bVar.a(fArr);
+                        }
+                    }
+                } else {
+                    TimeUnit.MILLISECONDS.sleep(100L);
+                }
+            } catch (Exception e4) {
+                Log.e("Audio thread", "Exception: ", e4);
+            }
+        }
+    }
+}

feature/cw/src/main/java/H2/b.java

@@ -0,0 +1,582 @@
+package H2;
+
+import B.RunnableC0001b;
+import D.n;
+import android.content.Context;
+import android.media.MediaScannerConnection;
+import android.os.Handler;
+import android.os.Looper;
+import android.text.SpannableStringBuilder;
+import android.text.format.DateFormat;
+import android.text.style.ForegroundColorSpan;
+import android.util.Log;
+import com.ve3nea.morse_expert.MainActivity;
+import com.ve3nea.morse_expert.WaterfallSurfaceView;
+import i3.d;
+import java.io.BufferedOutputStream;
+import java.io.DataOutputStream;
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.Date;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
+import k3.s;
+import pas.decoder;
+import pas.nativedecoder;
+
+/* loaded from: classes.dex */
+public final class b {
+
+    /* renamed from: A, reason: collision with root package name */
+    public static final int f602A;
+
+    /* renamed from: B, reason: collision with root package name */
+    public static final int f603B;
+
+    /* renamed from: C, reason: collision with root package name */
+    public static final int f604C;
+
+    /* renamed from: D, reason: collision with root package name */
+    public static final d f605D;
+
+    /* renamed from: z, reason: collision with root package name */
+    public static final int f606z;
+
+    /* renamed from: a, reason: collision with root package name */
+    public final float[] f607a;
+
+    /* renamed from: b, reason: collision with root package name */
+    public final float[] f608b;
+    public final float[] c;
+
+    /* renamed from: d, reason: collision with root package name */
+    public final float[] f609d;
+
+    /* renamed from: e, reason: collision with root package name */
+    public final nativedecoder.TNativeDecoder f610e;
+    public int f;
+
+    /* renamed from: g, reason: collision with root package name */
+    public int f611g;
+
+    /* renamed from: h, reason: collision with root package name */
+    public int f612h;
+
+    /* renamed from: i, reason: collision with root package name */
+    public decoder.TDecoderState f613i;
+
+    /* renamed from: j, reason: collision with root package name */
+    public String f614j;
+
+    /* renamed from: k, reason: collision with root package name */
+    public final c f615k;
+
+    /* renamed from: l, reason: collision with root package name */
+    public int f616l;
+
+    /* renamed from: m, reason: collision with root package name */
+    public final I2.b f617m;
+
+    /* renamed from: n, reason: collision with root package name */
+    public final Handler f618n;
+
+    /* renamed from: o, reason: collision with root package name */
+    public WaterfallSurfaceView f619o;
+
+    /* renamed from: p, reason: collision with root package name */
+    public MainActivity f620p;
+
+    /* renamed from: q, reason: collision with root package name */
+    public MainActivity f621q;
+
+    /* renamed from: r, reason: collision with root package name */
+    public final AtomicInteger f622r;
+
+    /* renamed from: s, reason: collision with root package name */
+    public final AtomicBoolean f623s;
+
+    /* renamed from: t, reason: collision with root package name */
+    public final Context f624t;
+
+    /* renamed from: u, reason: collision with root package name */
+    public int f625u;
+
+    /* renamed from: v, reason: collision with root package name */
+    public final AtomicBoolean f626v;
+
+    /* renamed from: w, reason: collision with root package name */
+    public DataOutputStream f627w;
+
+    /* renamed from: x, reason: collision with root package name */
+    public int f628x;
+
+    /* renamed from: y, reason: collision with root package name */
+    public String f629y;
+
+    /* JADX WARN: Removed duplicated region for block: B:14:0x012d  */
+    /* JADX WARN: Type inference failed for: r0v4, types: [i3.d, java.lang.Object] */
+    static {
+        boolean z3;
+        float f;
+        float f4;
+        float f5;
+        int round = Math.round(25.6f);
+        f606z = round;
+        int round2 = Math.round(153.6f);
+        f602A = round2;
+        f603B = round2 - round;
+        f604C = Math.round(85.333336f);
+        i3.d obj = new i3.d();
+        if (2048 > 1073741824) {
+            z3 = true;
+        } else {
+            z3 = false;
+        }
+        obj.f11709l = z3;
+        int i4 = (int) 1024;
+        obj.f11700a = i4;
+        obj.f11701b = 1024L;
+        if (!z3) {
+            obj.f11708k = 1;
+            int[] iArr = new int[((int) g3.c.a((1 << (((int) (g3.c.d(((float) 1024) + 0.5f) / g3.c.d(2.0d))) / 2)) + 2)) + 2];
+            obj.c = iArr;
+            float[] fArr = new float[i4];
+            obj.f11703e = fArr;
+            int i5 = (i4 * 2) >> 2;
+            obj.f11704g = i5;
+            iArr[0] = i5;
+            iArr[1] = 1;
+            if (i5 > 2) {
+                int i6 = i5 >> 1;
+                float f6 = 0.7853982f / i6;
+                float f7 = 2.0f * f6;
+                float b4 = (float) g3.c.b(i6 * f6);  // r9 = i6 (smali)
+                fArr[0] = 1.0f;
+                fArr[1] = b4;
+                if (i6 == 4) {
+                    double d4 = f7;
+                    f4 = 0.5f;
+                    fArr[2] = (float) g3.c.b(d4);
+                    fArr[3] = (float) g3.c.f(d4);
+                } else {
+                    f4 = 0.5f;
+                    if (i6 > 4) {
+                        iArr[2] = 0;
+                        iArr[3] = 16;
+                        int i7 = i5;
+                        int i8 = 2;
+                        f5 = 1.0f;
+                        while (i7 > 32) {
+                            int i9 = i8 << 1;
+                            int i10 = i8 << 4;
+                            for (int i11 = i8; i11 < i9; i11++) {
+                                int i12 = iArr[i11] << 2;
+                                iArr[i8 + i11] = i12;
+                                iArr[i9 + i11] = i12 + i10;
+                            }
+                            i7 >>= 2;
+                            i8 = i9;
+                        }
+                        fArr[2] = 0.5f / ((float) g3.c.b(f7));
+                        fArr[3] = 0.5f / ((float) g3.c.b(6.0f * f6));
+                        for (int i13 = 4; i13 < i6; i13 += 4) {
+                            float f8 = i13 * f6;
+                            double d5 = f8;
+                            fArr[i13] = (float) g3.c.b(d5);
+                            fArr[i13 + 1] = (float) g3.c.f(d5);
+                            double d6 = 3.0f * f8;
+                            fArr[i13 + 2] = (float) g3.c.b(d6);
+                            fArr[i13 + 3] = -((float) g3.c.f(d6));
+                        }
+                        int i14 = 0;
+                        while (i6 > 2) {
+                            int i15 = i14 + i6;
+                            i6 >>= 1;
+                            fArr[i15] = f5;
+                            fArr[i15 + 1] = b4;
+                            if (i6 == 4) {
+                                float f9 = fArr[i14 + 4];
+                                float f10 = fArr[i14 + 5];
+                                fArr[i15 + 2] = f9;
+                                fArr[i15 + 3] = f10;
+                            } else if (i6 > 4) {
+                                float f11 = fArr[i14 + 4];
+                                float f12 = fArr[i14 + 6];
+                                fArr[i15 + 2] = f4 / f11;
+                                fArr[i15 + 3] = f4 / f12;
+                                for (int i16 = 4; i16 < i6; i16 += 4) {
+                                    int i17 = (i16 * 2) + i14;
+                                    int i18 = i15 + i16;
+                                    float f13 = fArr[i17];
+                                    float f14 = fArr[i17 + 1];
+                                    float f15 = fArr[i17 + 2];
+                                    float f16 = fArr[i17 + 3];
+                                    fArr[i18] = f13;
+                                    fArr[i18 + 1] = f14;
+                                    fArr[i18 + 2] = f15;
+                                    fArr[i18 + 3] = f16;
+                                }
+                            }
+                            i14 = i15;
+                        }
+                    }
+                }
+                f5 = 1.0f;
+                int i142 = 0;
+                while (i6 > 2) {
+                }
+            }
+            int i19 = i4 >> 2;
+            obj.f11706i = i19;
+            iArr[1] = i19;
+            if (i19 > 1) {
+                int i20 = i19 >> 1;
+                float f17 = 0.7853982f / i20;
+                float b5 = (float) g3.c.b(i20 * f17);  // r6 = i20 (smali)
+                fArr[i5] = b5;
+                fArr[i5 + i20] = b5 * 0.5f;
+                for (int i21 = 1; i21 < i20; i21++) {
+                    double d7 = i21 * f17;
+                    fArr[i5 + i21] = ((float) g3.c.b(d7)) * 0.5f;
+                    fArr[(i5 + i19) - i21] = ((float) g3.c.f(d7)) * 0.5f;
+                }
+            }
+        } else {
+            obj.f11708k = 1;
+            s sVar = new s(((long) g3.c.a((1 << ((int) (((long) (g3.c.d(((float) 1024) + 0.5f) / g3.c.d(2.0d))) / 2))) + 2)) + 2, true);
+            obj.f11702d = sVar;
+            k3.d dVar = new k3.d(1024L, true);
+            obj.f = dVar;
+            obj.f11705h = 512L;
+            sVar.c(0L, 512L);
+            sVar.c(1L, 1L);
+            if (512 > 2) {
+                long j4 = 512 >> 1;
+                float f18 = 0.7853982f / ((float) j4);
+                float f19 = f18 * 2.0f;
+                float b6 = (float) g3.c.b(j4 * f18);  // r14 = j4 (smali 同模式)
+                dVar.c(0L, 1.0f);
+                dVar.c(1L, b6);
+                if (j4 == 4) {
+                    f = 0.5f;
+                    double d8 = f19;
+                    dVar.c(2L, (float) g3.c.b(d8));
+                    dVar.c(3L, (float) g3.c.f(d8));
+                } else {
+                    f = 0.5f;
+                    if (j4 > 4) {
+                        sVar.c(2L, 0L);
+                        sVar.c(3L, 16L);
+                        long j5 = 2;
+                        long j6 = 512;
+                        while (j6 > 32) {
+                            long j7 = j5 << 1;
+                            long j8 = j5 << 4;
+                            long j9 = j5;
+                            while (j9 < j7) {
+                                long b7 = sVar.b(j9) << 2;
+                                sVar.c(j5 + j9, b7);
+                                sVar.c(j7 + j9, b7 + j8);
+                                j9++;
+                                f19 = f19;
+                            }
+                            j6 >>= 2;
+                            j5 = j7;
+                        }
+                        dVar.c(2L, 0.5f / ((float) g3.c.b(f19)));
+                        dVar.c(3L, 0.5f / ((float) g3.c.b(6.0f * f18)));
+                        long j10 = 4;
+                        while (j10 < j4) {
+                            float f20 = ((float) j10) * f18;
+                            double d9 = f20;
+                            dVar.c(j10, (float) g3.c.b(d9));
+                            dVar.c(j10 + 1, (float) g3.c.f(d9));
+                            double d10 = 3.0f * f20;
+                            long j11 = j10;
+                            dVar.c(j10 + 2, (float) g3.c.b(d10));
+                            dVar.c(j11 + 3, -((float) g3.c.f(d10)));
+                            j10 = j11 + 4;
+                        }
+                    }
+                }
+                long j12 = 0;
+                long j13 = 2;
+                while (j4 > j13) {
+                    long j14 = j12 + j4;
+                    j4 >>= 1;
+                    dVar.c(j14, 1.0f);
+                    dVar.c(j14 + 1, b6);
+                    if (j4 == 4) {
+                        float b8 = dVar.b(j12 + 4);
+                        float b9 = dVar.b(j12 + 5);
+                        j13 = 2;
+                        dVar.c(j14 + 2, b8);
+                        dVar.c(j14 + 3, b9);
+                    } else {
+                        j13 = 2;
+                        if (j4 > 4) {
+                            float b10 = dVar.b(j12 + 4);
+                            float b11 = dVar.b(6 + j12);
+                            dVar.c(j14 + 2, f / b10);
+                            dVar.c(j14 + 3, f / b11);
+                            long j15 = 4;
+                            while (j15 < j4) {
+                                long j16 = (j15 * 2) + j12;
+                                float f21 = b6;
+                                long j17 = j14 + j15;
+                                long j18 = j12;
+                                float b12 = dVar.b(j16);
+                                long j19 = j14;
+                                float b13 = dVar.b(j16 + 1);
+                                float b14 = dVar.b(j16 + 2);
+                                float b15 = dVar.b(j16 + 3);
+                                dVar.c(j17, b12);
+                                dVar.c(j17 + 1, b13);
+                                dVar.c(j17 + 2, b14);
+                                dVar.c(j17 + 3, b15);
+                                j15 += 4;
+                                b6 = f21;
+                                j12 = j18;
+                                j14 = j19;
+                            }
+                        }
+                    }
+                    b6 = b6;
+                    j12 = j14;
+                }
+            }
+            long j20 = 256;
+            obj.f11707j = 256L;
+            long j21 = 1;
+            sVar.c(1L, 256L);
+            if (256 > 1) {
+                long j22 = 256 >> 1;
+                float f22 = 0.7853982f / ((float) j22);
+                long j23 = 512;
+                dVar.c(512L, (float) g3.c.b(j22 * f22));  // r1 = j22 (smali)
+                dVar.c(512 + j22, dVar.b(512L) * 0.5f);
+                long j24 = 1;
+                while (j24 < j22) {
+                    long j25 = j20;
+                    long j26 = j21;
+                    double d11 = ((float) j24) * f22;
+                    long j27 = j23;
+                    dVar.c(j23 + j24, ((float) g3.c.b(d11)) * 0.5f);
+                    dVar.c((j27 + j25) - j24, ((float) g3.c.f(d11)) * 0.5f);
+                    j24 += j26;
+                    j20 = j25;
+                    j21 = j26;
+                    j23 = j27;
+                }
+            }
+        }
+        f605D = obj;
+    }
+
+    public b(Context context) {
+        float[] fArr = new float[1024];
+        fArr[512] = 1.0f;
+        for (int i4 = 1; i4 < 512; i4++) {
+            double d4 = (i4 * 6.283185307179586d) / 1024;
+            float cos = (float) ((Math.cos(d4 * 2.0d) * 0.08d) + (0.42d - (Math.cos(d4) * 0.5d)));
+            fArr[i4] = cos;
+            double d5 = 0.003125f * 6.283185307179586d * (i4 - 512);
+            float sin = (float) ((Math.sin(d5) / d5) * cos);
+            fArr[i4] = sin;
+            fArr[1024 - i4] = sin;
+        }
+        this.f607a = fArr;
+        this.f608b = new float[1024];
+        this.c = new float[1024];
+        this.f609d = new float[f603B];
+        this.f610e = nativedecoder.TNativeDecoder.Create();
+        this.f614j = "";
+        this.f615k = new c(4000, 0);
+        I2.b bVar = new I2.b();
+        this.f617m = bVar;
+        this.f618n = new Handler(Looper.getMainLooper());
+        this.f622r = new AtomicInteger();
+        this.f623s = new AtomicBoolean(false);
+        this.f625u = 0;
+        this.f626v = new AtomicBoolean(false);
+        this.f628x = 0;
+        this.f624t = context;
+        bVar.b(context);
+    }
+
+    /* JADX WARN: Removed duplicated region for block: B:57:0x01e2  */
+    /* JADX WARN: Removed duplicated region for block: B:63:0x020a A[LOOP:6: B:62:0x0208->B:63:0x020a, LOOP_END] */
+    /* JADX WARN: Removed duplicated region for block: B:66:0x0216 A[LOOP:7: B:65:0x0214->B:66:0x0216, LOOP_END] */
+    /* JADX WARN: Removed duplicated region for block: B:70:0x0232  */
+    /* JADX WARN: Removed duplicated region for block: B:73:? A[RETURN, SYNTHETIC] */
+    /*
+        Code decompiled incorrectly, please refer to instructions dump.
+    */
+    public final void a(float[] fArr) {
+        c cVar;
+        float[] fArr2;
+        float[] fArr3;
+        b bVar;
+        Exception exc;
+        int i4;
+        float f;
+        int i5;
+        WaterfallSurfaceView waterfallSurfaceView;
+        int length = fArr.length;
+        int i6 = 0;
+        while (true) {
+            cVar = this.f615k;
+            if (i6 >= length) {
+                break;
+            }
+            cVar.c(Math.abs(fArr[i6]));
+            i6++;
+        }
+        this.f616l = Math.round(((float) Math.log10(Math.max(-0.5d, cVar.f633e))) * 20.0f);
+        int i7 = f604C;
+        int i8 = 1024 - i7;
+        float[] fArr4 = this.f608b;
+        System.arraycopy(fArr4, i7, fArr4, 0, i8);
+        System.arraycopy(fArr, 0, fArr4, i8, i7);
+        int i9 = 0;
+        while (true) {
+            fArr2 = this.c;
+            if (i9 >= 1024) {
+                break;
+            }
+            fArr2[i9] = fArr4[i9] * this.f607a[i9];
+            i9++;
+        }
+        f605D.k(fArr2, 0);
+        int i10 = f606z;
+        int i11 = i10;
+        while (true) {
+            int i12 = f602A;
+            float f4 = 0.0f;
+            fArr3 = this.f609d;
+            if (i11 < i12) {
+                int i13 = i11 * 2;
+                float f5 = fArr2[i13];
+                float f6 = fArr2[i13 + 1];
+                float f7 = ((f6 * f6) + (f5 * f5)) * 0.001f;
+                if (!Float.isNaN(f7)) {
+                    f4 = f7;
+                }
+                fArr3[i11 - i10] = f4;
+                i11++;
+            } else {
+                // smali: 循环内无 try; 录音写入 try 在循环后(见下)
+                break;
+            }
+        }
+        DataOutputStream dataOutputStream = this.f627w;
+        Context context = this.f624t;
+        AtomicBoolean atomicBoolean = this.f626v;
+        try { // smali try_start_0: 录音写入整块(原 jadx 误把 try 放 break 处)
+            if (dataOutputStream == null && atomicBoolean.get()) {
+                File file = new File(context.getExternalFilesDir(null), ((String) DateFormat.format("yyyy-MM-dd_HH_mm_ss", new Date())) + "_spectra.bin");
+                this.f629y = file.getAbsoluteFile().toString();
+                this.f627w = new DataOutputStream(new BufferedOutputStream(new FileOutputStream(file, false)));
+                this.f628x = 0;
+                this.f614j = " Recording...";
+            }
+            if (this.f627w != null) {
+                for (float f8 : fArr3) {
+                    this.f627w.writeFloat(f8);
+                }
+            }
+            if (atomicBoolean.get()) {
+                int i14 = this.f628x + 1;
+                this.f628x = i14;
+                if (i14 >= 2048) {
+                    atomicBoolean.set(false);
+                    this.f627w.close();
+                    this.f627w = null;
+                    this.f614j = "";
+                    MediaScannerConnection.scanFile(context, new String[]{this.f629y}, new String[]{"application/x-binary"}, null);
+                }
+            }
+        } catch (IOException e4) {
+            Log.e("File write", "Exception: ", e4);
+        }
+        nativedecoder.TNativeDecoder tNativeDecoder = this.f610e;
+        try {
+            this.f613i = tNativeDecoder.ProcessSpectrum(fArr3);
+            int i15 = this.f625u + 1;
+            this.f625u = i15;
+            Handler handler = this.f618n;
+            if (i15 == 15) {
+                try {
+                    this.f625u = 0;
+                    this.f = tNativeDecoder.getPitch();
+                    this.f611g = tNativeDecoder.getSnr();
+                    this.f612h = tNativeDecoder.getWpm();
+                    handler.post(new B0.b(this, this.f614j, new int[]{this.f616l, this.f, this.f611g, this.f612h, tNativeDecoder.getSignalCount(), this.f613i.Value}));
+                    AtomicInteger atomicInteger = this.f622r;
+                    int i16 = atomicInteger.get();
+                    if (i16 != 0) {
+                        tNativeDecoder.LockToPitch(i16);
+                        atomicInteger.set(0);
+                    }
+                    tNativeDecoder.setHamMode(this.f623s.get());
+                } catch (Exception e5) {
+                    // jadx 幻觉区(空循环/空 if 为 catch 错位还原)已裁剪; 原 smali: 记录异常后跳回正常流程尾部
+                    exc = e5;
+                    bVar = this;
+                    Log.e("Audio Processor", "Exception", exc);
+                }
+            }
+            int charCount = tNativeDecoder.getCharCount();
+            if (charCount > 0) {
+                SpannableStringBuilder spannableStringBuilder = new SpannableStringBuilder();
+                int i18 = 0;
+                while (i18 < charCount) {
+                    decoder.TCharInfo GetChar = tNativeDecoder.GetChar(i18);
+                    spannableStringBuilder.append(GetChar.getChar());
+                    ForegroundColorSpan foregroundColorSpan = new ForegroundColorSpan(this.f617m.a(GetChar));
+                    int i19 = i18 + 1;
+                    spannableStringBuilder.setSpan(foregroundColorSpan, i18, i19, 33);
+                    i18 = i19;
+                }
+                bVar = this;
+                try {
+                    handler.post(new RunnableC0001b(bVar, spannableStringBuilder, tNativeDecoder.getDeleteCount(), 2, false));
+                } catch (Exception e6) {
+                    // jadx 幻觉区已裁剪(同 catch e5); 原 smali: 记录异常后跳回正常流程尾部
+                    exc = e6;
+                    Log.e("Audio Processor", "Exception", exc);
+                }
+            } else {
+                bVar = this;
+            }
+        } catch (Exception e7) {
+            // jadx 幻觉(e 变量)已裁剪
+            bVar = this;
+        }
+        i4 = f603B;
+        int i1722 = i4 / 2;
+        float[] copyOfRange22 = Arrays.copyOfRange(fArr3, i1722 - 20, i1722 + 20);
+        Arrays.sort(copyOfRange22);
+        f = copyOfRange22[20];
+        if (f > 0.0f) {
+            for (int i20 = 0; i20 < i4; i20++) {
+                fArr3[i20] = fArr3[i20] / f;
+            }
+        }
+        float[] fArr522 = (float[]) fArr3.clone();
+        new c(12, 1).a(fArr522);
+        new c(12, 0).a(fArr522);
+        for (i5 = 0; i5 < i4; i5++) {
+            fArr3[i5] = fArr3[i5] - fArr522[i5];
+        }
+        for (int i21 = 0; i21 < i4; i21++) {
+            fArr3[i21] = ((float) Math.log10(Math.max(-0.5d, fArr3[i21]) + 1.0d)) * 10.0f;
+        }
+        waterfallSurfaceView = bVar.f619o;
+        if (waterfallSurfaceView != null) {
+            waterfallSurfaceView.queueEvent(new n(waterfallSurfaceView, 1, (float[]) fArr3.clone()));
+        }
+    }
+}

feature/cw/src/main/java/H2/c.java

@@ -0,0 +1,89 @@
+package H2;
+
+/* loaded from: classes.dex */
+public final class c {
+
+    /* renamed from: a, reason: collision with root package name */
+    public final int f630a;
+
+    /* renamed from: b, reason: collision with root package name */
+    public float[] f631b;
+    public int c;
+
+    /* renamed from: d, reason: collision with root package name */
+    public float f632d;
+
+    /* renamed from: e, reason: collision with root package name */
+    public float f633e;
+    public final /* synthetic */ int f;
+
+    public c(int i4, int i5) {
+        this.f = i5;
+        this.f630a = i4 - 1;
+    }
+
+    public final void a(float[] fArr) {
+        int i4 = this.f630a / 2;
+        int length = fArr.length;
+        if (length > i4) {
+            this.f631b = null;
+            for (int i5 = 0; i5 < i4; i5++) {
+                c(fArr[i5]);
+            }
+            for (int i6 = i4; i6 < length; i6++) {
+                fArr[i6 - i4] = c(fArr[i6]);
+            }
+            for (int i7 = length; i7 < length + i4; i7++) {
+                fArr[i7 - i4] = c(fArr[length - 1]);
+            }
+            return;
+        }
+        throw new IllegalArgumentException("Sliding Filter error: input too short");
+    }
+
+    public final float b(float f, float f4) {
+        switch (this.f) {
+            case 0:
+                return Math.max(f, f4);
+            default:
+                return Math.min(f, f4);
+        }
+    }
+
+    public final float c(float f) {
+        float[] fArr = this.f631b;
+        int i4 = this.f630a;
+        if (fArr == null) {
+            this.f631b = new float[i4];
+            for (int i5 = 0; i5 < i4; i5++) {
+                this.f631b[i5] = f;
+            }
+            this.f632d = f;
+            return f;
+        }
+        float b4 = b(this.f632d, f);
+        this.f632d = b4;
+        this.f633e = b(this.f631b[this.c], b4);
+        float[] fArr2 = this.f631b;
+        int i6 = this.c;
+        int i7 = i6 + 1;
+        this.c = i7;
+        fArr2[i6] = f;
+        if (i7 == i4) {
+            int length = fArr2.length;
+            while (true) {
+                this.c = length - 1;
+                int i8 = this.c;
+                if (i8 <= 0) {
+                    break;
+                }
+                float[] fArr3 = this.f631b;
+                fArr3[i8 - 1] = b(fArr3[i8 - 1], fArr3[i8]);
+                length = this.c;
+            }
+            this.c = 0;
+            this.f632d = f;
+        }
+        return this.f633e;
+    }
+}

feature/cw/src/main/java/I0/d.java

@@ -0,0 +1,42 @@
+package I0;
+
+/**
+ * 照搬自 Morse Expert 1.15 I0.d, 类名保持混淆原名。
+ * R8 合并类手术: 只保留 (i3.d, int, int, float[]) FFT 任务构造;
+ * run() 按 smali 原样还原: R8 已将任务体优化为死代码(aget 后 throw null,
+ * 永不执行), 保留原语义(行为与原 APK 完全一致)。
+ * SystemForegroundService(work 库)case 已裁剪。
+ */
+public final class d implements Runnable {
+    public final /* synthetic */ int f = 0;
+
+    /* renamed from: g, reason: collision with root package name */
+    public final /* synthetic */ int f653g;
+
+    /* renamed from: h, reason: collision with root package name */
+    public final /* synthetic */ int f654h;
+
+    /* renamed from: i, reason: collision with root package name */
+    public final /* synthetic */ Object f655i;
+
+    /* renamed from: j, reason: collision with root package name */
+    public final /* synthetic */ Object f656j;
+
+    public d(i3.d dVar, int i4, int i5, float[] fArr) {
+        this.f656j = dVar;
+        this.f653g = i4;
+        this.f654h = i5;
+        this.f655i = fArr;
+    }
+
+    @Override // java.lang.Runnable
+    public final void run() {
+        int i6 = this.f654h;
+        int i7 = this.f653g;
+        if (i7 >= i6) {
+            return;
+        }
+        float f = ((float[]) this.f655i)[i7 * 2];
+        // R8 原代码: aget 后 throw null(死代码, 永不执行) —— 照搬语义, 不执行任何计算
+    }
+}

feature/cw/src/main/java/I2/b.java

@@ -0,0 +1,73 @@
+package I2;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import pas.decoder;
+
+/* loaded from: classes.dex */
+public final class b {
+
+    /* renamed from: b, reason: collision with root package name */
+    public static final String[] f663b = {"bg_color", "text_color", "text_color_weak", "call_color", "call_color_weak", "cq_color", "cq_color_weak", "rst_color", "rst_color_weak"};
+    public static final String[] c = {"Background color", "Text color", "Text color, weak", "Callsign color", "Callsign color, weak", "CQ color", "CQ color, weak", "RST color", "RST color, weak"};
+
+    /* renamed from: d, reason: collision with root package name */
+    public static final int[] f664d = {-3084048, -16777216, -5592406, -65536, -30584, -16776961, -7829249, -65281, -30465};
+
+    /* renamed from: a, reason: collision with root package name */
+    public final int[] f665a = (int[]) f664d.clone();
+
+    public final int a(decoder.TCharInfo tCharInfo) {
+        boolean lowSnr = tCharInfo.getLowSnr();
+        int[] iArr = this.f665a;
+        if (lowSnr) {
+            int i4 = tCharInfo.getWordType().Value;
+            if (i4 != 0) {
+                if (i4 != 1) {
+                    if (i4 != 2) {
+                        if (i4 != 3) {
+                            if (i4 != 4) {
+                                if (i4 == 5) {
+                                    return iArr[4];
+                                }
+                                return -16777216;
+                            }
+                            return iArr[2];
+                        }
+                        return iArr[6];
+                    }
+                    return iArr[8];
+                }
+                return iArr[2];
+            }
+            return iArr[2];
+        }
+        int i5 = tCharInfo.getWordType().Value;
+        if (i5 != 0) {
+            if (i5 != 1) {
+                if (i5 != 2) {
+                    if (i5 != 3) {
+                        if (i5 != 4) {
+                            if (i5 != 5) {
+                                return -16777216;
+                            }
+                            return iArr[3];
+                        }
+                        return iArr[1];
+                    }
+                    return iArr[5];
+                }
+                return iArr[7];
+            }
+            return iArr[1];
+        }
+        return iArr[1];
+    }
+
+    public final void b(Context context) {
+        SharedPreferences sharedPreferences = context.getSharedPreferences(context.getPackageName() + "_preferences", 0);  // 原 c0.x.a(context)
+        for (int i4 = 0; i4 < 9; i4++) {
+            this.f665a[i4] = sharedPreferences.getInt(f663b[i4], f664d[i4]);
+        }
+    }
+}