feat: default TLE source order with LAPAN-A2 (Kaggle) first, R4UAB second

Passwords for the release keystore were committed in plaintext to a
public repo. Move them to gitignored local.properties with an
environment-variable fallback. Keystore file itself stays in $HOME.

.gitignore

@@ -18,6 +18,7 @@ out/
 # Gradle files
 .gradle/
 build/
+.cxx/
 
 # Local configuration file (sdk path, etc)
 local.properties
@@ -67,3 +68,4 @@ fastlane/readme.md
 /app/release/output-metadata.json
 /app/release/
 /.kotlin/sessions/
+dist/

README.md

@@ -1,45 +1,38 @@
-# 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>
+- **双站过境匹配（Mutual Pass）** — 输入友台经纬度/网格，筛选双方同时可见的卫星过境，在地图上同时显示双方仰角曲线和地面轨迹，支持一键跳转雷达页查看详情
+- **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
+- **AMSAT 状态页** — 实时查看卫星的业余无线电转发器状态（开启/关闭/待机），支持 72 小时历史记录回放
+- **中文界面优化** — 翻译修正、UI 布局调整，系统语言自动切换
 
-### 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)。
 
 ## Star History
 
-<a href="https://www.star-history.com/?repos=rt-bishop%2FLook4Sat&type=timeline&legend=top-left">
+<a href="https://star-history.dera.page/#atsunatsu/Look4Sat&type=timeline&legend=top-left">
  <picture>
-   <source media="(prefers-color-scheme: dark)" srcset="https://api.star-history.com/chart?repos=rt-bishop/Look4Sat&type=timeline&theme=dark&legend=top-left" />
-   <source media="(prefers-color-scheme: light)" srcset="https://api.star-history.com/chart?repos=rt-bishop/Look4Sat&type=timeline&legend=top-left" />
-   <img alt="Star History Chart" src="https://api.star-history.com/chart?repos=rt-bishop/Look4Sat&type=timeline&legend=top-left" />
+   <source media="(prefers-color-scheme: dark)" srcset="https://star-history.dera.page/svg?repos=atsunatsu/Look4Sat&type=timeline&theme=dark&legend=top-left" />
+   <source media="(prefers-color-scheme: light)" srcset="https://star-history.dera.page/svg?repos=atsunatsu/Look4Sat&type=timeline&legend=top-left" />
+   <img alt="Star History Chart" src="https://star-history.dera.page/svg?repos=atsunatsu/Look4Sat&type=timeline&legend=top-left" />
  </picture>
 </a>

app/build.gradle.kts

@@ -1,12 +1,36 @@
+import java.io.FileInputStream
+import java.util.Properties
+
 plugins {
     alias(libs.plugins.convention.applicationPlugin)
 }
 
+// Release signing credentials live in local.properties (gitignored) or
+// environment variables — never hardcode passwords in VCS.
+val releaseProps = Properties().apply {
+    val propsFile = rootProject.file("local.properties")
+    if (propsFile.exists()) FileInputStream(propsFile).use { load(it) }
+}
+fun releaseCred(name: String): String =
+    releaseProps.getProperty(name) ?: System.getenv(name) ?: ""
+
 android {
-    // PR #1 CW decoder uses the Morse Expert native decoder, which ships only armeabi-v7a.
+    namespace = libs.versions.packageName.get()
     defaultConfig {
-        ndk {
-            abiFilters += listOf("armeabi-v7a")
+        applicationId = "cn.ba7opf.look4sat"
+        ndk { abiFilters.add("armeabi-v7a") }
+    }
+    signingConfigs {
+        create("release") {
+            storeFile = file(System.getProperty("user.home") + "/my-release-key.jks")
+            storePassword = releaseCred("RELEASE_STORE_PASSWORD")
+            keyAlias = releaseCred("RELEASE_KEY_ALIAS").ifEmpty { "look4sat" }
+            keyPassword = releaseCred("RELEASE_KEY_PASSWORD")
         }
     }
-}
+    buildTypes {
+        release {
+            signingConfig = signingConfigs.getByName("release")
+        }
+    }
+}

app/src/main/AndroidManifest.xml

@@ -13,6 +13,7 @@
     <uses-permission android:name="android.permission.BLUETOOTH_SCAN" />
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.RECORD_AUDIO" />
+    <uses-permission android:name="android.permission.REQUEST_INSTALL_PACKAGES" />
 
     <application
         android:name=".MainApplication"
@@ -45,5 +46,15 @@
             android:name="android.telephony.PROPERTY_SATELLITE_DATA_OPTIMIZED"
             android:value="com.rtbishop.look4sat" />
 
+        <provider
+            android:name="androidx.core.content.FileProvider"
+            android:authorities="${applicationId}.fileprovider"
+            android:exported="false"
+            android:grantUriPermissions="true">
+            <meta-data
+                android:name="android.support.FILE_PROVIDER_PATHS"
+                android:resource="@xml/file_paths" />
+        </provider>
+
     </application>
 </manifest>

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

@@ -49,7 +49,7 @@ class MainActivity : ComponentActivity() {
         super.onCreate(savedInstanceState)
         observeNightFilterState()
         setContent {
-            MainTheme(isDarkTheme = true) { MainScreen() }
+            MainTheme(isDarkTheme = true) { NavRoot() }
         }
     }
 

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

@@ -17,7 +17,10 @@
  */
 package com.rtbishop.look4sat
 
+import android.app.Activity
 import android.app.Application
+import android.app.Application.ActivityLifecycleCallbacks
+import android.os.Bundle
 import com.rtbishop.look4sat.core.data.injection.MainContainer
 import com.rtbishop.look4sat.core.domain.repository.IContainerProvider
 import com.rtbishop.look4sat.core.domain.repository.IMainContainer
@@ -35,12 +38,37 @@ class MainApplication : Application(), IContainerProvider {
     override fun onCreate() {
         super.onCreate()
         container = MainContainer(this)
+        clearAmSatCacheOnAppBackground()
         // trigger automatic update every 48 hours
         container.appScope.launch { checkAutoUpdate() }
         // load satellite data on every app start
         container.appScope.launch { container.satelliteRepo.initRepository() }
     }
 
+    private fun clearAmSatCacheOnAppBackground() {
+        registerActivityLifecycleCallbacks(object : ActivityLifecycleCallbacks {
+            private var startedActivityCount = 0
+
+            override fun onActivityStarted(activity: Activity) {
+                if (startedActivityCount == 0) {
+                    container.appScope.launch { container.amSatRepo.prefetchStatus() }
+                }
+                startedActivityCount += 1
+            }
+
+            override fun onActivityStopped(activity: Activity) {
+                startedActivityCount = (startedActivityCount - 1).coerceAtLeast(0)
+                if (startedActivityCount == 0) container.amSatRepo.clearStatusCache()
+            }
+
+            override fun onActivityCreated(activity: Activity, savedInstanceState: Bundle?) = Unit
+            override fun onActivityResumed(activity: Activity) = Unit
+            override fun onActivityPaused(activity: Activity) = Unit
+            override fun onActivitySaveInstanceState(activity: Activity, outState: Bundle) = Unit
+            override fun onActivityDestroyed(activity: Activity) = Unit
+        })
+    }
+
     private suspend fun checkAutoUpdate(timeNow: Long = System.currentTimeMillis()) {
         if (container.settingsRepo.otherSettings.value.stateOfAutoUpdate) {
             val timeDelta = timeNow - container.settingsRepo.databaseState.value.updateTimestamp

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

@@ -25,8 +25,6 @@ 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
@@ -44,7 +42,7 @@ 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.Surface
 import androidx.compose.material3.Text
 import androidx.compose.material3.adaptive.navigationsuite.NavigationSuiteDefaults
 import androidx.compose.material3.adaptive.navigationsuite.NavigationSuiteScaffold
@@ -53,6 +51,9 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.CompositionLocalProvider
 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.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
@@ -87,37 +88,53 @@ import com.rtbishop.look4sat.feature.passes.PassesDestination
 import com.rtbishop.look4sat.feature.radar.RadarDestination
 import com.rtbishop.look4sat.feature.satellites.SatellitesDestination
 import com.rtbishop.look4sat.feature.settings.SettingsDestination
+import com.rtbishop.look4sat.feature.status.SatStatusDestination
 
 @Composable
 fun NavRoot(deeplink: String? = null) {
     val rootBackStack = rememberNavBackStack(Screen.Passes)
     val deeplinkResolver = DeeplinkResolver()
+    var openMapRequest by remember { mutableIntStateOf(0) }
     LaunchedEffect(deeplink) {
-        deeplink?.let {
-            val destination = deeplinkResolver.resolve(it) // rootBackStack.clear()
-            rootBackStack.add(destination)
-        }
+        deeplink?.let { rootBackStack.add(deeplinkResolver.resolve(it)) }
     }
     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 })
+    val navigateToRadar: () -> Unit = { rootBackStack.add(RadarDestination) }
+    val navigateToMap: () -> Unit = {
+        while (rootBackStack.size > 1) rootBackStack.removeAt(rootBackStack.size - 1)
+        openMapRequest += 1
+    }
+    // Incoming screen slides in from the right, outgoing drifts left at 1/3 speed (API35+ style)
+    val pushTransition = slideInHorizontally(tween(300)) { it } togetherWith
+        slideOutHorizontally(tween(300)) { -it / 3 }
+    // Reverse: outgoing slides out to the right, incoming drifts in from the left
+    val popTransition = slideInHorizontally(tween(300)) { -it / 3 } togetherWith
+        slideOutHorizontally(tween(300)) { it }
     NavDisplay(
         modifier = Modifier.fillMaxSize(),
         backStack = rootBackStack,
         onBack = navigateBack,
-        transitionSpec = { slideInTransition },
-        popTransitionSpec = { slideOutTransition },
-        predictivePopTransitionSpec = { slideOutTransition },
+        transitionSpec = { pushTransition },
+        popTransitionSpec = { popTransition },
+        predictivePopTransitionSpec = { popTransition },
         entryDecorators = listOf(
-            rememberSaveableStateHolderNavEntryDecorator(), // Required for saving Compose state per entry
-            rememberViewModelStoreNavEntryDecorator() // Required for ViewModel scoping per entry
+            rememberSaveableStateHolderNavEntryDecorator(),
+            rememberViewModelStoreNavEntryDecorator()
         ),
         entryProvider = entryProvider {
-            entry<Screen.Passes> { MainScreen(navigateToRadar = { rootBackStack.add(RadarDestination) }) }
+            entry<Screen.Passes> {
+                MainScreen(
+                    navigateToRadar = navigateToRadar,
+                    openMapRequest = openMapRequest,
+                    onOpenMapRequestHandled = { openMapRequest = 0 }
+                )
+            }
             entry<RadarDestination> {
-                Scaffold { innerPadding ->
-                    RadarDestination(navigateUp = navigateBack)
-                    innerPadding.calculateTopPadding()
+                Surface(
+                    modifier = Modifier.fillMaxSize(),
+                    color = MaterialTheme.colorScheme.background
+                ) {
+                    RadarDestination(navigateUp = navigateBack, navigateToMap = navigateToMap)
                 }
             }
         }
@@ -125,12 +142,26 @@ fun NavRoot(deeplink: String? = null) {
 }
 
 @Composable
-fun MainScreen(navigateToRadar: () -> Unit = {}) {
+fun MainScreen(
+    navigateToRadar: () -> Unit = {},
+    openMapRequest: Int = 0,
+    onOpenMapRequestHandled: () -> Unit = {}
+) {
     val backStack = rememberNavBackStack(Screen.Passes)
     val currentKey = backStack.lastOrNull()
     val navigateBack: () -> Unit = { backStack.removeLastOrNull() }
+    val navigateToMap: () -> Unit = {
+        while (backStack.size > 1) backStack.removeAt(backStack.size - 1)
+        backStack.add(Screen.Map)
+    }
+    LaunchedEffect(openMapRequest) {
+        if (openMapRequest > 0) {
+            navigateToMap()
+            onOpenMapRequestHandled()
+        }
+    }
     val fadeTransition = fadeIn(animationSpec = tween(350)) togetherWith fadeOut(animationSpec = tween(350))
-    val navItems = listOf(Screen.Satellites, Screen.Passes, Screen.Radar, Screen.Mutual, Screen.Map, Screen.Settings)
+    val navItems = listOf(Screen.Satellites, Screen.Passes, Screen.AMSAT, Screen.Mutual, Screen.Settings)
 
     val context = LocalContext.current
     val container = (context.applicationContext as IContainerProvider).getMainContainer()
@@ -154,9 +185,9 @@ fun MainScreen(navigateToRadar: () -> Unit = {}) {
                     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.Passes
+                        is Screen.AMSAT -> screen is Screen.AMSAT
                         is Screen.Mutual -> screen is Screen.Mutual
-                        is Screen.Map -> screen is Screen.Map
                         is Screen.Settings -> screen is Screen.Settings
                         else -> false
                     }
@@ -165,7 +196,7 @@ fun MainScreen(navigateToRadar: () -> Unit = {}) {
                         label = { Text(stringResource(screen.titleResId)) },
                         selected = isSelected,
                         onClick = {
-                            if (isSelected) return@item
+                            if (isSelected && !(currentKey is Screen.Map && screen is Screen.Passes)) return@item
                             while (backStack.size > 1) backStack.removeAt(backStack.size - 1)
                             if (screen !is Screen.Passes) backStack.add(screen)
                         }
@@ -200,15 +231,14 @@ fun MainScreen(navigateToRadar: () -> Unit = {}) {
                             SatellitesDestination(navigateUp = navigateBack)
                         }
                         entry<Screen.Passes> {
-                            PassesDestination { catNum, aosTime ->
-                                container.setMutualPassData(MutualPassData())
-                                container.satelliteRepo.selectPass(catNum, aosTime)
-                                backStack.add(Screen.Radar)
-//                            navigateToRadar()
-                            }
-                        }
-                        entry<Screen.Radar> {
-                            RadarDestination(navigateUp = navigateBack)
+                            PassesDestination(
+                                navigateToRadar = { catNum, aosTime ->
+                                    container.setMutualPassData(MutualPassData())
+                                    container.satelliteRepo.selectPass(catNum, aosTime)
+                                    navigateToRadar()
+                                },
+                                navigateToMap = navigateToMap
+                            )
                         }
                         entry<Screen.Map> {
                             MapDestination()
@@ -216,14 +246,14 @@ fun MainScreen(navigateToRadar: () -> Unit = {}) {
                         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)
+                                    navigateToRadar()
                                 }
                             )
                         }
+                        entry<Screen.AMSAT> { SatStatusDestination() }
                         entry<Screen.Settings> {
                             SettingsDestination()
                         }
@@ -249,7 +279,7 @@ fun MainScreen(navigateToRadar: () -> Unit = {}) {
                                 if (pass != null) {
                                     container.setMutualPassData(MutualPassData())
                                     container.satelliteRepo.selectPass(pass.catNum, pass.aosTime)
-                                    backStack.add(Screen.Radar)
+                                    navigateToRadar()
                                 }
                             }
                             .padding(horizontal = 12.dp, vertical = 6.dp)

app/src/main/res/xml/file_paths.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<paths xmlns:android="http://schemas.android.com/apk/res/android">
+    <cache-path name="updates" path="." />
+</paths>

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

@@ -37,6 +37,7 @@ internal class ApplicationPlugin : Plugin<Project> {
             implementation(project(":feature:radar"))
             implementation(project(":feature:satellites"))
             implementation(project(":feature:settings"))
+            implementation(project(":feature:status"))
             implementation(libs.androidx.core.splashscreen)
             implementation(libs.compose.material3.adaptive)
             implementation(libs.compose.navigation3)

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

@@ -17,8 +17,10 @@
  */
 package com.rtbishop.look4sat.core.data.framework
 
+import com.rtbishop.look4sat.core.domain.model.Constants
 import com.rtbishop.look4sat.core.domain.repository.IReporter
 import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.sync.Mutex
 import kotlinx.coroutines.sync.withLock
@@ -31,18 +33,30 @@ class NetworkReporter(
     private val rotatorServer: String,
     private val rotatorPort: Int,
     private val frequencyServer: String,
-    private val frequencyPort: Int
+    private val frequencyPort: Int,
+    private val frequencyOffsetHz: Long = 0L
 ) : IReporter {
 
     private val writeMutex = Mutex()
+    private val connectionMutex = Mutex()
+    private val frequencyCommands = Channel<String>(Channel.CONFLATED)
 
     private var rotatorSocket: SocketChannel? = null
     private var rotatorConnected = false
-    private var rotatorConnecting = false
 
     private var frequencySocket: SocketChannel? = null
     private var frequencyConnected = false
-    private var frequencyConnecting = false
+
+    init {
+        // Keep only the latest frequency command to avoid stale backlog and effective lag.
+        reporterScope.launch {
+            for (command in frequencyCommands) {
+                ensureFrequencyConnected()
+                if (!frequencyConnected) continue
+                write(frequencySocket, command) { resetFrequencyConnection() }
+            }
+        }
+    }
 
     override fun reportRotation(format: String, azimuth: Double, elevation: Double) {
         reporterScope.launch {
@@ -53,51 +67,48 @@ class NetworkReporter(
                 .replace($$"$AZ", azimuth.toString())
                 .replace($$"$EL", el.toString())
                 .unescapeControlChars()
-            write(rotatorSocket, command) { rotatorConnected = false }
+            write(rotatorSocket, command) { resetRotatorConnection() }
         }
     }
 
     override fun reportFrequency(format: String, frequency: Long) {
-        reporterScope.launch {
-            ensureFrequencyConnected()
-            if (!frequencyConnected) return@launch
-            val command = format
-                .replace($$"$FREQ", frequency.toString())
-                .unescapeControlChars()
-            write(frequencySocket, command) { frequencyConnected = false }
-        }
+        val clampedOffset = frequencyOffsetHz.coerceIn(
+            Constants.FREQ_OFFSET_MIN_HZ,
+            Constants.FREQ_OFFSET_MAX_HZ
+        )
+        val correctedFreq = frequency.coerceAtLeast(0L).safeAdd(clampedOffset).coerceAtLeast(0L)
+        val command = format
+            .replace($$"$FREQ", correctedFreq.toString())
+            .unescapeControlChars()
+        frequencyCommands.trySend(command)
     }
 
-    private fun ensureRotatorConnected() {
-        if (rotatorConnected || rotatorConnecting || rotatorServer.isBlank()) return
-        reporterScope.launch {
+    private suspend fun ensureRotatorConnected() {
+        connectionMutex.withLock {
+            if (rotatorConnected || rotatorServer.isBlank()) return
             try {
-                rotatorConnecting = true
+                resetRotatorConnection()
                 rotatorSocket = SocketChannel.open(InetSocketAddress(rotatorServer, rotatorPort))
                 rotatorConnected = true
                 println("NetworkReporter: Rotator connected to $rotatorServer:$rotatorPort")
             } catch (e: Exception) {
                 println("NetworkReporter rotator connect error: ${e.message}")
-                rotatorConnected = false
-            } finally {
-                rotatorConnecting = false
+                resetRotatorConnection()
             }
         }
     }
 
-    private fun ensureFrequencyConnected() {
-        if (frequencyConnected || frequencyConnecting || frequencyServer.isBlank()) return
-        reporterScope.launch {
+    private suspend fun ensureFrequencyConnected() {
+        connectionMutex.withLock {
+            if (frequencyConnected || frequencyServer.isBlank()) return
             try {
-                frequencyConnecting = true
+                resetFrequencyConnection()
                 frequencySocket = SocketChannel.open(InetSocketAddress(frequencyServer, frequencyPort))
                 frequencyConnected = true
                 println("NetworkReporter: Frequency connected to $frequencyServer:$frequencyPort")
             } catch (e: Exception) {
                 println("NetworkReporter frequency connect error: ${e.message}")
-                frequencyConnected = false
-            } finally {
-                frequencyConnecting = false
+                resetFrequencyConnection()
             }
         }
     }
@@ -106,7 +117,9 @@ class NetworkReporter(
         try {
             writeMutex.withLock {
                 val buffer = ByteBuffer.wrap("$command\n".toByteArray())
-                socket?.write(buffer)
+                while (buffer.hasRemaining()) {
+                    socket?.write(buffer)
+                }
             }
         } catch (e: Exception) {
             println("NetworkReporter write error: ${e.message}")
@@ -114,6 +127,34 @@ class NetworkReporter(
         }
     }
 
+    private fun resetRotatorConnection() {
+        rotatorConnected = false
+        closeQuietly(rotatorSocket)
+        rotatorSocket = null
+    }
+
+    private fun resetFrequencyConnection() {
+        frequencyConnected = false
+        closeQuietly(frequencySocket)
+        frequencySocket = null
+    }
+
+    private fun closeQuietly(socket: SocketChannel?) {
+        try {
+            socket?.close()
+        } catch (_: Exception) {}
+    }
+
+    private fun Long.safeAdd(delta: Long): Long {
+        return when {
+            delta > 0 && this > Long.MAX_VALUE - delta -> Long.MAX_VALUE
+            delta < 0 && this < Long.MIN_VALUE - delta -> Long.MIN_VALUE
+            else -> this + delta
+        }
+    }
+
     private fun String.unescapeControlChars(): String =
-        replace("\\r", "\r").replace("\\n", "\n").replace("\\t", "\t")
+        replace("""\r""", 13.toChar().toString())
+            .replace("""\n""", 10.toChar().toString())
+            .replace("""\t""", 9.toChar().toString())
 }

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

@@ -29,11 +29,13 @@ 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.AmSatRepository
 import com.rtbishop.look4sat.core.data.repository.DatabaseRepo
 import com.rtbishop.look4sat.core.data.repository.SatelliteRepo
 import com.rtbishop.look4sat.core.data.repository.SelectionRepo
 import com.rtbishop.look4sat.core.data.repository.SensorsRepo
 import com.rtbishop.look4sat.core.data.repository.SettingsRepo
+import com.rtbishop.look4sat.core.data.repository.UpdateRepository
 import com.rtbishop.look4sat.core.data.source.LocalSource
 import com.rtbishop.look4sat.core.data.source.RemoteSource
 import com.rtbishop.look4sat.core.data.usecase.AddToCalendar
@@ -70,12 +72,15 @@ import okhttp3.OkHttpClient
 class MainContainer(private val context: Context) : IMainContainer {
 
     private val localSource = provideLocalSource()
+    private val remoteSource = provideRemoteSource()
     private val mainHandler = CoroutineExceptionHandler { _, error -> println("MainHandler: $error") }
     override val appScope = CoroutineScope(SupervisorJob() + Dispatchers.Default + mainHandler)
     override val settingsRepo = provideSettingsRepo()
     override val selectionRepo = provideSelectionRepo()
     override val satelliteRepo = provideSatelliteRepo()
     override val databaseRepo = provideDatabaseRepo()
+    override val amSatRepo by lazy { AmSatRepository(remoteSource, appScope) }
+    override val updateRepo by lazy { UpdateRepository(remoteSource) }
     override val radioTrackingService: IRadioTrackingService by lazy {
         val manager = context.getSystemService(Context.BLUETOOTH_SERVICE) as BluetoothManager
         RadioTrackingService(appScope, manager, satelliteRepo, settingsRepo)
@@ -114,7 +119,8 @@ class MainContainer(private val context: Context) : IMainContainer {
             rc.rotatorAddress,
             rc.rotatorPort.toIntOrNull() ?: 0,
             rc.frequencyAddress,
-            rc.frequencyPort.toIntOrNull() ?: 0
+            rc.frequencyPort.toIntOrNull() ?: 0,
+            rc.frequencyOffsetHz
         )
     }
 

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

@@ -0,0 +1,273 @@
+package com.rtbishop.look4sat.core.data.repository
+
+import com.rtbishop.look4sat.core.domain.model.AmSatReportSubmission
+import com.rtbishop.look4sat.core.domain.model.AmSatReportSubmitResult
+import com.rtbishop.look4sat.core.domain.model.SatDay
+import com.rtbishop.look4sat.core.domain.model.SatReport
+import com.rtbishop.look4sat.core.domain.model.SatSlot
+import com.rtbishop.look4sat.core.domain.model.SatStatus
+import com.rtbishop.look4sat.core.domain.model.SatStatusPage
+import com.rtbishop.look4sat.core.domain.repository.IAmSatRepository
+import com.rtbishop.look4sat.core.domain.source.IRemoteSource
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Deferred
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.async
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
+import kotlinx.coroutines.withContext
+import org.json.JSONObject
+import java.text.SimpleDateFormat
+import java.util.Calendar
+import java.util.Date
+import java.util.Locale
+import java.util.TimeZone
+
+/** One report from the AMSAT API (data layer model). */
+private data class ApiReport(
+    val id: String,
+    val name: String,
+    val callsign: String,
+    val report: String,
+    val gridSquare: String,
+    val reportedTimeUtcSec: Long
+)
+
+/** AMSAT status repository using RemoteSource (Clean Architecture: data layer handles HTTP). */
+class AmSatRepository(
+    private val remoteSource: IRemoteSource,
+    private val scope: CoroutineScope = CoroutineScope(SupervisorJob() + Dispatchers.IO)
+) : IAmSatRepository {
+
+    private val statusCacheMutex = Mutex()
+
+    @Volatile
+    private var statusCache: SatStatusPage? = null
+
+    @Volatile
+    private var statusFetchInFlight: Deferred<SatStatusPage?>? = null
+
+    @Volatile
+    private var cacheGeneration = 0
+
+    private val isoUtcFormat = SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'", Locale.US).apply {
+        timeZone = TimeZone.getTimeZone("UTC")
+    }
+
+    override fun getCachedStatus(): SatStatusPage? = statusCache
+
+    override suspend fun fetchStatus(forceRefresh: Boolean): SatStatusPage? {
+        if (!forceRefresh) statusCache?.let { return it }
+
+        var cachedPage: SatStatusPage? = null
+        val inFlightFetch = statusCacheMutex.withLock {
+            if (!forceRefresh) {
+                val cached = statusCache
+                if (cached != null) {
+                    cachedPage = cached
+                    return@withLock null
+                }
+            }
+
+            statusFetchInFlight ?: scope.async(Dispatchers.IO) {
+                fetchStatusFromRemote(cacheGeneration)
+            }.also { statusFetchInFlight = it }
+        }
+
+        cachedPage?.let { return it }
+        val fetch = inFlightFetch ?: return null
+        return try {
+            fetch.await()
+        } finally {
+            statusCacheMutex.withLock {
+                if (statusFetchInFlight === fetch && fetch.isCompleted) statusFetchInFlight = null
+            }
+        }
+    }
+
+    private suspend fun fetchStatusFromRemote(generation: Int): SatStatusPage? {
+        val nowSec = System.currentTimeMillis() / 1000
+        val catalogJson = remoteSource.getAmSatCatalog() ?: return null
+        // 72h = 3 days; API hard cap is limit=500 regardless of what we send.
+        // 500 records across ~100 catalog satellites ≈ ~1-5 reports/satellite/day — enough for 3 days.
+        // Upgrade path: paginate or request AMSAT to raise the cap if catalog grows beyond ~200 sats.
+        val reportsJson = remoteSource.getAmSatReports(hours = 72, limit = 500) ?: return null
+
+        val names = parseCatalog(catalogJson)
+        val reports = parseReports(reportsJson)
+
+        if (names.isEmpty() && reports.isEmpty()) return null
+
+        val statuses = buildStatuses(names, reports, nowSec)
+        val reportMap = reports.associate { it.id to toSatReport(it) }
+        return SatStatusPage(System.currentTimeMillis(), statuses, reportMap).also { page ->
+            if (generation == cacheGeneration) statusCache = page
+        }
+    }
+
+    override suspend fun prefetchStatus() {
+        fetchStatus(forceRefresh = false)
+    }
+
+    override fun clearStatusCache() {
+        cacheGeneration += 1
+        statusCache = null
+        statusFetchInFlight = null
+    }
+
+    override suspend fun submitReport(submission: AmSatReportSubmission): AmSatReportSubmitResult = withContext(Dispatchers.IO) {
+        val payload = JSONObject().apply {
+            put("name", submission.name)
+            put("report", submission.report)
+            put("callsign", submission.callsign)
+            put("reported_at", isoUtcFormat.format(Date(submission.reportedAtUtcMillis)))
+            if (submission.gridSquare.isNotBlank()) put("grid_square", submission.gridSquare)
+        }
+        val response = remoteSource.submitAmSatReport(payload.toString())
+            ?: return@withContext AmSatReportSubmitResult(success = false, message = "Network request failed")
+        val (code, body) = response
+        val errorMessage = parseSubmitError(body)
+        return@withContext if (code in 200..299 && errorMessage.isBlank()) {
+            AmSatReportSubmitResult(success = true, reportId = parseSubmitReportId(body))
+        } else {
+            AmSatReportSubmitResult(
+                success = false,
+                message = errorMessage.ifBlank { "HTTP $code" }
+            )
+        }
+    }
+
+    private fun parseSubmitError(json: String): String {
+        return try {
+            JSONObject(json).optJSONObject("error")?.optString("message").orEmpty()
+        } catch (_: Exception) {
+            ""
+        }
+    }
+
+    private fun parseSubmitReportId(json: String): String? {
+        return try {
+            val obj = JSONObject(json)
+            obj.optJSONObject("data")?.optString("id")?.takeIf { it.isNotBlank() }
+                ?: obj.optString("id").takeIf { it.isNotBlank() }
+        } catch (_: Exception) {
+            null
+        }
+    }
+
+    /** Parse catalog JSON to list of satellite names */
+    private fun parseCatalog(json: String): List<String> {
+        return try {
+            val arr = JSONObject(json).getJSONArray("data")
+            (0 until arr.length()).map { arr.getJSONObject(it).getString("name") }
+        } catch (_: Exception) {
+            emptyList()
+        }
+    }
+
+    /** Parse reports JSON to list of ApiReport domain objects */
+    private fun parseReports(json: String): List<ApiReport> {
+        return try {
+            val arr = JSONObject(json).getJSONArray("data")
+            (0 until arr.length()).mapNotNull { i ->
+                val o = arr.getJSONObject(i)
+                val iso = o.optString("reported_time", "")
+                if (iso.isEmpty()) null else ApiReport(
+                    id = o.optString("id", ""),
+                    name = o.optString("name", ""),
+                    callsign = o.optString("callsign", ""),
+                    report = o.optString("report", ""),
+                    gridSquare = o.optString("grid_square", ""),
+                    reportedTimeUtcSec = parseIsoUtcSec(iso)
+                )
+            }
+        } catch (_: Exception) {
+            emptyList()
+        }
+    }
+
+    /** Parse ISO 8601 UTC timestamp to epoch seconds (e.g., "2026-08-05T07:30:00Z") */
+    private fun parseIsoUtcSec(iso: String): Long {
+        return try {
+            (isoUtcFormat.parse(iso)?.time ?: 0L) / 1000
+        } catch (_: Exception) {
+            0L
+        }
+    }
+
+    /** Build one SatStatus (3 days x 12 slots) per catalog satellite, slotting reports by age. */
+    private fun buildStatuses(names: List<String>, reports: List<ApiReport>, nowSec: Long): List<SatStatus> {
+        val byName = reports.groupBy { it.name }
+        val utc = Calendar.getInstance(TimeZone.getTimeZone("UTC"))
+        val labels = (0 until 3).map { d ->
+            utc.timeInMillis = (nowSec - d * 86400L) * 1000
+            formatDayLabel(utc)
+        }
+        return names.map { name ->
+            val slots = (0 until 36).map { slotIdx ->
+                val slotStart = nowSec - (slotIdx + 1) * 7200L
+                val slotEnd = nowSec - slotIdx * 7200L
+                val inSlot = byName[name].orEmpty().filter { it.reportedTimeUtcSec in slotStart until slotEnd }
+                if (inSlot.isEmpty()) {
+                    SatSlot(statusColor = NO_REPORT_GRAY, count = 0)
+                } else {
+                    val newest = inSlot.maxByOrNull { it.reportedTimeUtcSec }!!
+                    SatSlot(
+                        statusColor = statusColorOf(newest.report),
+                        count = inSlot.size,
+                        reportIds = inSlot.map { it.id }
+                    )
+                }
+            }
+            val days = (0 until 3).map { d ->
+                SatDay(dateLabel = labels[d], slots = slots.subList(d * 12, (d + 1) * 12))
+            }
+            SatStatus(name = name, days = days)
+        }
+    }
+
+    private fun formatDayLabel(calendar: Calendar): String {
+        return if (Locale.getDefault().language == Locale.CHINESE.language) {
+            "${calendar.get(Calendar.MONTH) + 1}月${calendar.get(Calendar.DAY_OF_MONTH)}日"
+        } else {
+            val monthAbbr = arrayOf("Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec")
+            "${monthAbbr[calendar.get(Calendar.MONTH)]} ${calendar.get(Calendar.DAY_OF_MONTH)}"
+        }
+    }
+
+    private fun toSatReport(r: ApiReport): SatReport {
+        val cal = Calendar.getInstance(TimeZone.getTimeZone("UTC"))
+        cal.timeInMillis = r.reportedTimeUtcSec * 1000
+        val hh = cal.get(Calendar.HOUR_OF_DAY).toString().padStart(2, '0')
+        val mm = cal.get(Calendar.MINUTE).toString().padStart(2, '0')
+        val y = cal.get(Calendar.YEAR)
+        val mo = (cal.get(Calendar.MONTH) + 1).toString().padStart(2, '0')
+        val d = cal.get(Calendar.DAY_OF_MONTH).toString().padStart(2, '0')
+        return SatReport(
+            id = r.id,
+            statusText = r.report,
+            call = r.callsign,
+            grid = r.gridSquare,
+            dateUtc = "$y-$mo-$d",
+            timeUtc = "$hh:$mm UTC"
+        )
+    }
+
+    /** Map status text to color value (for UI rendering). */
+    private fun statusColorOf(report: String): Long = when (report.lowercase()) {
+        "heard", "crew active" -> ACTIVE_BLUE
+        "telemetry only" -> TLM_ORANGE
+        "not heard" -> NOT_HEARD_PINK
+        else -> CONFLICT_DEEP_ORANGE
+    }
+
+    companion object {
+        // AMSAT official status colors (from amsat.org/status)
+        private const val ACTIVE_BLUE = 0xFF648FFF
+        private const val TLM_ORANGE = 0xFFFFB000
+        private const val NOT_HEARD_PINK = 0xFFDC267F
+        private const val CONFLICT_DEEP_ORANGE = 0xFFFE6100
+        private const val NO_REPORT_GRAY = 0xFFC0C0C0
+    }
+}

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

@@ -66,28 +66,45 @@ class DatabaseRepo(
     }
 
     override suspend fun updateFromRemote() = withContext(dispatcher) {
-        val dataSourcesSettings = settingsRepo.dataSourcesSettings.value
-        val tleUrls = buildMap {
-            putAll(Sources.satelliteDataUrls)
-            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.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 })
-            }
-        }
-        val importedRadios = radioJobs.awaitAll().flatMap { (url, stream) ->
-            stream?.let { dataParser.parseJSONStream(unwrapIfZipped(url, it)) }.orEmpty()
-        }
+        val settings = settingsRepo.dataSourcesSettings.value
+        // Keep the raw URL as the status key (matches what the settings UI
+        // displays) while requesting with the normalized URL.
+        val tleUrls = settings.satelliteUrls
+            .filterIndexed { i, url -> url.isNotBlank() && settings.isSatelliteEnabled(i) }
+            .map { it to normalizeUrl(it) }
+            .distinctBy { it.second }
+        val radioUrls = settings.transceiversUrls
+            .filterIndexed { i, url -> url.isNotBlank() && settings.isTransceiverEnabled(i) }
+            .map { it to normalizeUrl(it) }
+            .distinctBy { it.second }
+        val builtinTypesByUrl = Sources.satelliteDataUrls
+            .filterValues { it.isNotBlank() }
+            .mapValues { normalizeUrl(it.value) }
+            .entries
+            .associate { (type, url) -> url to type }
+        val importedTypeIds = mutableMapOf<String, MutableList<Int>>()
+        // launch all network requests concurrently, keeping the raw url as key for status reporting
+        val tleJobs = tleUrls.map { (raw, norm) -> async { raw to remoteSource.getNetworkStream(norm) } }
+        val radioJobs = radioUrls.map { (raw, norm) -> async { raw to remoteSource.getNetworkStream(norm) } }
+        val tleResults = tleJobs.awaitAll()
+        val radioResults = radioJobs.awaitAll()
+        // report the HTTP status code of every source (200, 404, ...)
+        settingsRepo.updateDataSourcesStatus(
+            (tleResults + radioResults).associate { (url, result) -> url to result.code }
+        )
+        // parse fetched data concurrently and associate known built-in URLs with existing type filters.
+        val importedEntries = tleResults.flatMap { (rawUrl, result) ->
+            val normUrl = normalizeUrl(rawUrl)
+            val entries = result.stream?.let { parseSatelliteStream(normUrl, unwrapIfZipped(normUrl, it)) }.orEmpty()
+            val type = builtinTypesByUrl[normUrl] ?: customSourceType
+            importedTypeIds.getOrPut(type) { mutableListOf() }.addAll(entries.map { it.catnum })
+            entries
+        }.distinctBy { it.catnum }
+        importedTypeIds.forEach { (type, ids) -> settingsRepo.setSatelliteTypeIds(type, ids.distinct()) }
+        val importedRadios = radioResults.flatMap { (rawUrl, result) ->
+            val normUrl = normalizeUrl(rawUrl)
+            result.stream?.let { dataParser.parseJSONStream(unwrapIfZipped(normUrl, it)) }.orEmpty()
+        }.filter { it.uuid.isNotBlank() }.distinctBy { it.uuid }
         // insert parsed data into the database
         localSource.insertEntries(importedEntries)
         localSource.insertRadios(importedRadios)
@@ -100,6 +117,9 @@ class DatabaseRepo(
         setUpdateSuccessful(0L)
     }
 
+    private fun normalizeUrl(url: String): String =
+        if (url.startsWith("http", ignoreCase = true)) url else "https://$url"
+
     private suspend fun parseSatelliteStream(url: String, stream: InputStream): List<OrbitalData> {
         val bufferedStream = stream.buffered()
         return when {

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

@@ -34,6 +34,7 @@ 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
@@ -63,19 +64,23 @@ class SatelliteRepo(
     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 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
-            )
-        }
+        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 {

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

@@ -37,6 +37,10 @@ import com.rtbishop.look4sat.core.domain.utility.round
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.update
+import org.json.JSONObject
+import java.util.Locale
+import com.rtbishop.look4sat.core.domain.model.Constants
+import com.rtbishop.look4sat.core.domain.source.Sources
 
 class SettingsRepo(
     private val locationManager: LocationManager,
@@ -67,6 +71,7 @@ class SettingsRepo(
     private val keyFrequencyAddress = "frequencyAddress"
     private val keyFrequencyPort = "frequencyPort"
     private val keyFrequencyFormat = "frequencyFormat"
+    private val keyFrequencyOffsetHz = "frequencyOffsetHz"
     private val keySelectedIds = "selectedIds"
     private val keySelectedTypes = "selectedTypes"
     private val keySelectedModes = "selectedModes"
@@ -91,7 +96,15 @@ class SettingsRepo(
     private val keyUseCustomTransceivers = "useCustomTransceivers"
     private val keyTleUrl = "tleUrl"
     private val keyTransceiversUrl = "transceiversUrl"
+    private val keySatelliteUrls = "satelliteUrls"
+    private val keyTransceiversUrls = "transceiversUrls"
+    private val keySatelliteEnabled = "satelliteEnabled"
+    private val keyTransceiversEnabled = "transceiversEnabled"
+    private val keySatnogsTleSourceMigration = "satnogsTleSourceMigration"
     private val separatorComma = ","
+    private val separatorUrl = "\n"
+    private val legacyCelestrakSatnogsUrl =
+        "https://celestrak.org/NORAD/elements/gp.php?GROUP=satnogs&FORMAT=csv"
 
     //region # Satellites selection settings
     private val _satelliteSelection = MutableStateFlow(getSelectedIds())
@@ -298,6 +311,10 @@ class SettingsRepo(
     override val rcSettings: StateFlow<RCSettings> = _rcSettings
 
     override fun updateRCSettings(settings: RCSettings) {
+        val clampedFreqOffsetHz = settings.frequencyOffsetHz.coerceIn(
+            Constants.FREQ_OFFSET_MIN_HZ,
+            Constants.FREQ_OFFSET_MAX_HZ
+        )
         preferences.edit {
             putBoolean(keyRotatorState, settings.rotatorState)
             putString(keyRotatorAddress, settings.rotatorAddress)
@@ -307,6 +324,7 @@ class SettingsRepo(
             putString(keyFrequencyAddress, settings.frequencyAddress)
             putString(keyFrequencyPort, settings.frequencyPort)
             putString(keyFrequencyFormat, settings.frequencyFormat)
+            putLong(keyFrequencyOffsetHz, clampedFreqOffsetHz)
             putBoolean(keyBluetoothRotatorState, settings.bluetoothRotatorState)
             putString(keyBluetoothRotatorFormat, settings.bluetoothRotatorFormat)
             putString(keyBluetoothRotatorName, settings.bluetoothRotatorName)
@@ -315,7 +333,7 @@ class SettingsRepo(
             putString(keyBluetoothFrequencyFormat, settings.bluetoothFrequencyFormat)
             putString(keyBluetoothFrequencyAddress, settings.bluetoothFrequencyAddress)
         }
-        _rcSettings.value = settings
+        _rcSettings.value = settings.copy(frequencyOffsetHz = clampedFreqOffsetHz)
     }
 
     private fun getRCSettings(): RCSettings = RCSettings(
@@ -327,6 +345,8 @@ class SettingsRepo(
         frequencyAddress = preferences.getString(keyFrequencyAddress, null) ?: "127.0.0.1",
         frequencyPort = preferences.getString(keyFrequencyPort, null) ?: "4532",
         frequencyFormat = preferences.getString(keyFrequencyFormat, null) ?: $$"F $FREQ",
+        frequencyOffsetHz = preferences.getLong(keyFrequencyOffsetHz, 0L)
+            .coerceIn(Constants.FREQ_OFFSET_MIN_HZ, Constants.FREQ_OFFSET_MAX_HZ),
         bluetoothRotatorState = preferences.getBoolean(keyBluetoothRotatorState, false),
         bluetoothRotatorFormat = preferences.getString(keyBluetoothRotatorFormat, null) ?: $$"P $AZ $EL",
         bluetoothRotatorName = preferences.getString(keyBluetoothRotatorName, null) ?: "Default",
@@ -381,21 +401,108 @@ class SettingsRepo(
     override val dataSourcesSettings: StateFlow<DataSourcesSettings> = _dataSourcesSettings
 
     override fun updateDataSourcesSettings(settings: DataSourcesSettings) {
+        // Normalize the enabled lists so they are positionally aligned with the URL lists.
+        // Missing entries default to enabled (true), keeping the persisted "one flag per URL"
+        // invariant intact even when a default empty list is used to construct the model.
+        val normalized = settings.copy(
+            satelliteEnabled = alignFlags(settings.satelliteUrls, settings.satelliteEnabled),
+            transceiversEnabled = alignFlags(settings.transceiversUrls, settings.transceiversEnabled)
+        )
         preferences.edit {
-            putBoolean(keyUseCustomTle, settings.useCustomTLE)
-            putBoolean(keyUseCustomTransceivers, settings.useCustomTransceivers)
-            putString(keyTleUrl, settings.tleUrl)
-            putString(keyTransceiversUrl, settings.transceiversUrl)
+            putString(keySatelliteUrls, normalized.satelliteUrls.joinToString(separatorUrl))
+            putString(keyTransceiversUrls, normalized.transceiversUrls.joinToString(separatorUrl))
+            putString(keySatelliteEnabled, normalized.satelliteEnabled.joinToString(separatorComma))
+            putString(keyTransceiversEnabled, normalized.transceiversEnabled.joinToString(separatorComma))
+            putBoolean(keySatnogsTleSourceMigration, true)
         }
-        _dataSourcesSettings.value = settings
+        _dataSourcesSettings.value = normalized
     }
 
     private fun getDataSourcesSettings(): DataSourcesSettings = DataSourcesSettings(
-        useCustomTLE = preferences.getBoolean(keyUseCustomTle, false),
-        useCustomTransceivers = preferences.getBoolean(keyUseCustomTransceivers, false),
-        tleUrl = preferences.getString(keyTleUrl, "https://example.com/tle.txt") ?: "",
-        transceiversUrl = preferences.getString(keyTransceiversUrl, "https://example.com/radio.json") ?: ""
+        satelliteUrls = getDataSourceUrls(
+            key = keySatelliteUrls,
+            defaultUrls = Sources.satelliteDataUrls.values.filter { it.isNotBlank() },
+            legacyEnabledKey = keyUseCustomTle,
+            legacyUrlKey = keyTleUrl
+        ).migrateSatnogsTleSource(),
+        transceiversUrls = getDataSourceUrls(
+            key = keyTransceiversUrls,
+            defaultUrls = Sources.transceiversDataUrls.values.filter { it.isNotBlank() },
+            legacyEnabledKey = keyUseCustomTransceivers,
+            legacyUrlKey = keyTransceiversUrl
+        ),
+        satelliteEnabled = readEnabledFlags(keySatelliteEnabled),
+        transceiversEnabled = readEnabledFlags(keyTransceiversEnabled)
     )
+
+    /** Read the persisted per-source enabled flags (empty when never stored). */
+    private fun readEnabledFlags(key: String): List<Boolean> {
+        return preferences.getString(key, null)
+            ?.split(separatorComma)
+            ?.mapNotNull { it.trim() }
+            ?.filter { it == "true" || it == "false" }
+            ?.map { it == "true" }
+            ?: emptyList()
+    }
+
+    /** Keep the flags positionally aligned with the URL list, defaulting to enabled. */
+    private fun alignFlags(urls: List<String>, flags: List<Boolean>): List<Boolean> {
+        if (flags.size >= urls.size) return flags.take(urls.size)
+        return flags + List(urls.size - flags.size) { true }
+    }
+
+    private fun getDataSourceUrls(
+        key: String,
+        defaultUrls: List<String>,
+        legacyEnabledKey: String,
+        legacyUrlKey: String
+    ): List<String> {
+        val stored = preferences.getString(key, null)
+            ?.split(separatorUrl)
+            ?.map { it.trim() }
+            ?.filter { it.isNotBlank() }
+        if (stored != null) return stored
+        val legacyCustomUrl = preferences.getString(legacyUrlKey, null)?.trim().orEmpty()
+        return if (preferences.getBoolean(legacyEnabledKey, false) && legacyCustomUrl.isNotBlank()) {
+            (defaultUrls + legacyCustomUrl).distinct()
+        } else {
+            defaultUrls
+        }
+    }
+
+    private fun List<String>.migrateSatnogsTleSource(): List<String> {
+        if (preferences.getBoolean(keySatnogsTleSourceMigration, false)) return this
+        val satnogsTleUrl = Sources.satelliteDataUrls["SatNOGS"].orEmpty()
+        if (satnogsTleUrl.isBlank() || containsSourceUrl(satnogsTleUrl)) return this
+        val celestrakSatnogsIndex = indexOfFirst { isSameSourceUrl(it, legacyCelestrakSatnogsUrl) }
+        if (celestrakSatnogsIndex < 0) return this
+
+        val migrated = toMutableList().apply { add(celestrakSatnogsIndex + 1, satnogsTleUrl) }
+        preferences.edit {
+            putString(keySatelliteUrls, migrated.joinToString(separatorUrl))
+            putBoolean(keySatnogsTleSourceMigration, true)
+        }
+        return migrated
+    }
+
+    private fun List<String>.containsSourceUrl(url: String): Boolean = any { isSameSourceUrl(it, url) }
+
+    private fun isSameSourceUrl(first: String, second: String): Boolean =
+        normalizeSourceUrl(first).equals(normalizeSourceUrl(second), ignoreCase = true)
+
+    private fun normalizeSourceUrl(url: String): String {
+        val trimmed = url.trim()
+        return if (trimmed.startsWith("http", ignoreCase = true)) trimmed else "https://$trimmed"
+    }
+    //endregion
+
+    //region # Data sources status
+    private val _dataSourcesStatus = MutableStateFlow<Map<String, Int>>(emptyMap())
+    override val dataSourcesStatus: StateFlow<Map<String, Int>> = _dataSourcesStatus
+
+    override fun updateDataSourcesStatus(status: Map<String, Int>) {
+        _dataSourcesStatus.value = status
+    }
     //endregion
 
     //region # Radio control settings
@@ -436,4 +543,55 @@ class SettingsRepo(
         splitMode = preferences.getBoolean(keyRadioSplitMode, false)
     )
     //endregion
+
+    //region # Per-satellite calculator offset settings
+    private val keySatelliteOffsets = "satelliteOffsets"
+    private val keyLegacySatelliteOffsetPrefix = "offset_khz_"
+
+    override fun getSatelliteOffset(catnum: Int): String {
+        val json = preferences.getString(keySatelliteOffsets, "{}") ?: "{}"
+        val stored = try {
+            JSONObject(json).optString(catnum.toString(), "")
+        } catch (_: Exception) {
+            ""
+        }
+        if (stored.isNotEmpty()) return stored
+
+        // Lazy migration from the fork's old UI-layer implementation, which stored
+        // one SharedPreferences entry per satellite directly from TransceiversPage.
+        val legacyKey = "$keyLegacySatelliteOffsetPrefix$catnum"
+        val legacy = preferences.getString(legacyKey, "").orEmpty()
+        if (legacy.isNotEmpty()) {
+            setSatelliteOffset(catnum, legacy)
+        }
+        return legacy
+    }
+
+    override fun setSatelliteOffset(catnum: Int, offset: String) {
+        val json = preferences.getString(keySatelliteOffsets, "{}") ?: "{}"
+        val updated = try {
+            val obj = JSONObject(json)
+            if (offset.isEmpty()) obj.remove(catnum.toString()) else obj.put(catnum.toString(), offset)
+            obj.toString()
+        } catch (_: Exception) {
+            if (offset.isEmpty()) "{}" else """{"$catnum": "$offset"}"""
+        }
+        preferences.edit {
+            putString(keySatelliteOffsets, updated)
+            remove("$keyLegacySatelliteOffsetPrefix$catnum")
+        }
+    }
+    //endregion
+
+    //region # AMSAT status report settings
+    private val keyAmSatCallsign = "amSatCallsign"
+
+    override fun getAmSatCallsign(): String {
+        return preferences.getString(keyAmSatCallsign, "").orEmpty()
+    }
+
+    override fun setAmSatCallsign(callsign: String) {
+        preferences.edit { putString(keyAmSatCallsign, callsign.trim().uppercase(Locale.US)) }
+    }
+    //endregion
 }

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

@@ -0,0 +1,67 @@
+package com.rtbishop.look4sat.core.data.repository
+
+import com.rtbishop.look4sat.core.domain.model.LatestRelease
+import com.rtbishop.look4sat.core.domain.repository.IUpdateRepository
+import com.rtbishop.look4sat.core.domain.source.IRemoteSource
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import org.json.JSONObject
+import java.io.File
+
+class UpdateRepository(
+    private val remoteSource: IRemoteSource
+) : IUpdateRepository {
+
+    override suspend fun getLatestRelease(): LatestRelease? = withContext(Dispatchers.IO) {
+        val result = remoteSource.getNetworkStream(LATEST_RELEASE_URL)
+        val stream = result.stream ?: return@withContext null
+        try {
+            val json = stream.bufferedReader().use { it.readText() }
+            parseRelease(json)
+        } catch (e: Exception) {
+            println("UpdateRepository parse failure: $e")
+            null
+        }
+    }
+
+    override suspend fun downloadApk(url: String, dest: File): Boolean = withContext(Dispatchers.IO) {
+        if (url.isBlank()) return@withContext false
+        val result = remoteSource.getNetworkStream(url)
+        val stream = result.stream ?: return@withContext false
+        try {
+            dest.outputStream().use { out -> stream.use { it.copyTo(out) } }
+            true
+        } catch (e: Exception) {
+            println("UpdateRepository download failure: $e")
+            false
+        }
+    }
+
+    private fun parseRelease(json: String): LatestRelease? {
+        val obj = JSONObject(json)
+        val tag = obj.optString("tag_name")
+        if (tag.isBlank()) return null
+        val assets = obj.optJSONArray("assets")
+        var apkUrl: String? = null
+        if (assets != null) {
+            for (i in 0 until assets.length()) {
+                val asset = assets.optJSONObject(i) ?: continue
+                val name = asset.optString("name", "")
+                if (name.endsWith(".apk")) {
+                    apkUrl = asset.optString("browser_download_url", "").ifBlank { null }
+                    if (apkUrl != null) break
+                }
+            }
+        }
+        return LatestRelease(
+            versionTag = tag,
+            title = obj.optString("name", ""),
+            body = obj.optString("body", ""),
+            apkUrl = apkUrl
+        )
+    }
+
+    private companion object {
+        const val LATEST_RELEASE_URL = "https://api.github.com/repos/atsunatsu/Look4Sat/releases/latest"
+    }
+}

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

@@ -20,11 +20,13 @@ package com.rtbishop.look4sat.core.data.source
 import android.content.ContentResolver
 import androidx.core.net.toUri
 import com.rtbishop.look4sat.core.domain.source.IRemoteSource
+import com.rtbishop.look4sat.core.domain.source.NetworkResult
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.withContext
+import okhttp3.MediaType.Companion.toMediaType
 import okhttp3.OkHttpClient
 import okhttp3.Request
-import java.io.ByteArrayInputStream
+import okhttp3.RequestBody.Companion.toRequestBody
 import java.io.InputStream
 
 class RemoteSource(
@@ -43,15 +45,74 @@ class RemoteSource(
         }
     }
 
-    override suspend fun getNetworkStream(url: String): InputStream? = withContext(dispatcher) {
+    override suspend fun getNetworkStream(url: String): NetworkResult = withContext(dispatcher) {
         try {
             val networkRequest = Request.Builder().url(url).build()
-            httpClient.newCall(networkRequest).execute().use { response ->
-                if (!response.isSuccessful) return@withContext null
-                ByteArrayInputStream(response.body.bytes())
+            val response = httpClient.newCall(networkRequest).execute()
+            if (!response.isSuccessful) {
+                val code = response.code
+                response.close()
+                return@withContext NetworkResult(code, null)
             }
+            // Return the body stream directly as the caller is responsible for closing it.
+            // Closing the stream returns the connection to OkHttp's pool.
+            val body = response.body
+            if (body == null) {
+                response.close()
+                return@withContext NetworkResult(response.code, null)
+            }
+            NetworkResult(response.code, body.byteStream().buffered())
         } catch (exception: Exception) {
             println("RemoteSource network stream exception: $exception")
+            NetworkResult(NetworkResult.CONNECTION_ERROR, null)
+        }
+    }
+
+    override suspend fun getAmSatCatalog(): String? = withContext(dispatcher) {
+        try {
+            val request = Request.Builder()
+                .url("https://www.amsat.org/status/api/v1/catalog.php")
+                .header("User-Agent", "Look4Sat")
+                .build()
+            httpClient.newCall(request).execute().use { response ->
+                if (!response.isSuccessful) return@use null
+                response.body.string()
+            }
+        } catch (exception: Exception) {
+            println("RemoteSource getAmSatCatalog exception: $exception")
+            null
+        }
+    }
+
+    override suspend fun getAmSatReports(hours: Int, limit: Int): String? = withContext(dispatcher) {
+        try {
+            val request = Request.Builder()
+                .url("https://www.amsat.org/status/api/v1/reports.php?hours=$hours&limit=$limit")
+                .header("User-Agent", "Look4Sat")
+                .build()
+            httpClient.newCall(request).execute().use { response ->
+                if (!response.isSuccessful) return@use null
+                response.body.string()
+            }
+        } catch (exception: Exception) {
+            println("RemoteSource getAmSatReports exception: $exception")
+            null
+        }
+    }
+
+    override suspend fun submitAmSatReport(payloadJson: String): Pair<Int, String>? = withContext(dispatcher) {
+        try {
+            val body = payloadJson.toRequestBody("application/json; charset=utf-8".toMediaType())
+            val request = Request.Builder()
+                .url("https://www.amsat.org/status/api/v1/reports.php")
+                .header("User-Agent", "Look4Sat")
+                .post(body)
+                .build()
+            httpClient.newCall(request).execute().use { response ->
+                response.code to response.body.string()
+            }
+        } catch (exception: Exception) {
+            println("RemoteSource submitAmSatReport exception: $exception")
             null
         }
     }

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

@@ -0,0 +1,107 @@
+package com.rtbishop.look4sat.core.data.repository
+
+import com.rtbishop.look4sat.core.domain.model.SatStatus
+import com.rtbishop.look4sat.core.domain.model.SatStatusPage
+import com.rtbishop.look4sat.core.domain.source.IRemoteSource
+import com.rtbishop.look4sat.core.domain.source.NetworkResult
+import kotlinx.coroutines.async
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.test.runTest
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
+import org.junit.Assert.assertSame
+import org.junit.Test
+import java.io.InputStream
+
+class AmSatRepositoryTest {
+
+    @Test
+    fun fetchStatusReturnsSeededCacheUntilCacheIsCleared() = runTest {
+        val remoteSource = FakeAmSatRemoteSource()
+        val repository = AmSatRepository(remoteSource)
+        val cachedPage = SatStatusPage(
+            fetchedAtUtcMs = 123L,
+            statuses = listOf(SatStatus(name = "AO-7", days = emptyList())),
+            reports = emptyMap()
+        )
+        repository.seedStatusCache(cachedPage)
+
+        val firstPage = repository.fetchStatus()
+        val secondPage = repository.fetchStatus()
+
+        assertSame(cachedPage, firstPage)
+        assertSame(cachedPage, secondPage)
+        assertSame(cachedPage, repository.getCachedStatus())
+        assertEquals(0, remoteSource.catalogRequests)
+        assertEquals(0, remoteSource.reportRequests)
+
+        repository.clearStatusCache()
+        assertNull(repository.getCachedStatus())
+        repository.fetchStatus()
+
+        assertEquals(1, remoteSource.catalogRequests)
+        assertEquals(1, remoteSource.reportRequests)
+    }
+
+    @Test
+    fun forceRefreshBypassesCachedPage() = runTest {
+        val remoteSource = FakeAmSatRemoteSource()
+        val repository = AmSatRepository(remoteSource)
+        repository.seedStatusCache(
+            SatStatusPage(
+                fetchedAtUtcMs = 123L,
+                statuses = listOf(SatStatus(name = "AO-7", days = emptyList())),
+                reports = emptyMap()
+            )
+        )
+
+        repository.fetchStatus(forceRefresh = true)
+
+        assertEquals(1, remoteSource.catalogRequests)
+        assertEquals(1, remoteSource.reportRequests)
+    }
+
+    @Test
+    fun fetchStatusSharesStartupPrefetchRequest() = runTest {
+        val remoteSource = FakeAmSatRemoteSource(responseDelayMillis = 50)
+        val repository = AmSatRepository(remoteSource)
+
+        val prefetch = async { repository.prefetchStatus() }
+        val pageFetch = async { repository.fetchStatus() }
+        prefetch.await()
+        val page = pageFetch.await()
+
+        assertSame(page, repository.getCachedStatus())
+        assertEquals(1, remoteSource.catalogRequests)
+        assertEquals(1, remoteSource.reportRequests)
+    }
+}
+
+private fun AmSatRepository.seedStatusCache(page: SatStatusPage) {
+    val cacheField = AmSatRepository::class.java.getDeclaredField("statusCache")
+    cacheField.isAccessible = true
+    cacheField.set(this, page)
+}
+
+private class FakeAmSatRemoteSource(private val responseDelayMillis: Long = 0L) : IRemoteSource {
+    var catalogRequests = 0
+    var reportRequests = 0
+
+    override suspend fun getFileStream(uri: String): InputStream? = null
+
+    override suspend fun getNetworkStream(url: String): NetworkResult = NetworkResult(404, null)
+
+    override suspend fun getAmSatCatalog(): String? {
+        if (responseDelayMillis > 0L) delay(responseDelayMillis)
+        catalogRequests += 1
+        return """{"data":[{"name":"AO-7"}]}"""
+    }
+
+    override suspend fun getAmSatReports(hours: Int, limit: Int): String? {
+        if (responseDelayMillis > 0L) delay(responseDelayMillis)
+        reportRequests += 1
+        return """{"data":[]}"""
+    }
+
+    override suspend fun submitAmSatReport(payloadJson: String): Pair<Int, String>? = null
+}

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

@@ -31,6 +31,8 @@ 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.source.NetworkResult
+import com.rtbishop.look4sat.core.domain.source.Sources
 import com.rtbishop.look4sat.core.domain.utility.DataParser
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.MutableStateFlow
@@ -91,10 +93,8 @@ class DatabaseRepoTest {
         }
         val settingsRepo = FakeSettingsRepo(
             dataSources = DataSourcesSettings(
-                useCustomTLE = true,
-                useCustomTransceivers = false,
-                tleUrl = customCsvUrl,
-                transceiversUrl = ""
+                satelliteUrls = listOf(customCsvUrl),
+                transceiversUrls = emptyList()
             )
         )
         val repository = DatabaseRepo(dispatcher, dataParser, localSource, remoteSource, settingsRepo)
@@ -105,6 +105,27 @@ class DatabaseRepoTest {
         assertEquals(listOf(25544), settingsRepo.satelliteTypeIdsByType["Other"])
     }
 
+    @Test
+    fun `remote update imports satellites from real SatNOGS TLE source`() = runTest(dispatcher) {
+        val satnogsUrl = Sources.satelliteDataUrls.getValue("SatNOGS")
+        val localSource = FakeLocalSource()
+        val remoteSource = FakeRemoteSource().apply {
+            networkStreams[satnogsUrl] = { jamxTleStream() }
+        }
+        val settingsRepo = FakeSettingsRepo(
+            dataSources = DataSourcesSettings(
+                satelliteUrls = listOf(satnogsUrl),
+                transceiversUrls = emptyList()
+            )
+        )
+        val repository = DatabaseRepo(dispatcher, dataParser, localSource, remoteSource, settingsRepo)
+
+        repository.updateFromRemote()
+
+        assertTrue(localSource.insertedEntries.any { it.name == "JAMX-0825b" && it.catnum == 98248 })
+        assertEquals(listOf(98248), settingsRepo.satelliteTypeIdsByType["SatNOGS"])
+    }
+
     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
@@ -115,6 +136,12 @@ class DatabaseRepoTest {
         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 fun jamxTleStream(): InputStream = """
+        JAMX-0825b
+        1 98248U          26237.16675926  .00015724  00000-0  97477-3 0 00013
+        2 98248 097.5373 310.9694 0011309 278.1232 340.7230 15.09766181000012
+    """.trimIndent().byteInputStream()
 }
 
 private class FakeRemoteSource : IRemoteSource {
@@ -123,7 +150,14 @@ private class FakeRemoteSource : IRemoteSource {
 
     override suspend fun getFileStream(uri: String): InputStream? = fileStreams[uri]?.invoke()
 
-    override suspend fun getNetworkStream(url: String): InputStream? = networkStreams[url]?.invoke()
+    override suspend fun getNetworkStream(url: String): NetworkResult =
+        networkStreams[url]?.let { NetworkResult(200, it()) } ?: NetworkResult(404, null)
+
+    override suspend fun getAmSatCatalog(): String? = null
+
+    override suspend fun getAmSatReports(hours: Int, limit: Int): String? = null
+
+    override suspend fun submitAmSatReport(payloadJson: String): Pair<Int, String>? = null
 }
 
 private class FakeLocalSource : ILocalSource {
@@ -176,7 +210,7 @@ private class FakeSettingsRepo(dataSources: DataSourcesSettings = defaultDataSou
     override val databaseState: MutableStateFlow<DatabaseState> = MutableStateFlow(DatabaseState(0, 0, 0L))
 
     override val rcSettings: StateFlow<RCSettings> = MutableStateFlow(
-        RCSettings(false, "", "", "", false, "", "", "", false, "", "", "", false, "", "")
+        RCSettings(false, "", "", "", false, "", "", "", 0L, false, "", "", "", false, "", "")
     )
 
     override val otherSettings: StateFlow<OtherSettings> = MutableStateFlow(
@@ -221,14 +255,26 @@ private class FakeSettingsRepo(dataSources: DataSourcesSettings = defaultDataSou
         dataSourcesSettings.value = settings
     }
 
+    override val dataSourcesStatus: StateFlow<Map<String, Int>> = MutableStateFlow(emptyMap())
+
+    override fun updateDataSourcesStatus(status: Map<String, Int>) {
+        (dataSourcesStatus as? MutableStateFlow)?.value = status
+    }
+
     override fun updateRadioControlSettings(settings: RadioControlSettings) = Unit
+
+    override fun getSatelliteOffset(catnum: Int): String = ""
+
+    override fun setSatelliteOffset(catnum: Int, offset: String) = Unit
+
+    override fun getAmSatCallsign(): String = ""
+
+    override fun setAmSatCallsign(callsign: String) = Unit
 }
 
 private fun defaultDataSourcesSettings(): DataSourcesSettings {
     return DataSourcesSettings(
-        useCustomTLE = false,
-        useCustomTransceivers = false,
-        tleUrl = "",
-        transceiversUrl = ""
+        satelliteUrls = emptyList(),
+        transceiversUrls = emptyList()
     )
 }

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

@@ -0,0 +1,17 @@
+package com.rtbishop.look4sat.core.domain.model
+
+/** One public AMSAT satellite status report submission. */
+data class AmSatReportSubmission(
+    val name: String,
+    val report: String,
+    val callsign: String,
+    val gridSquare: String,
+    val reportedAtUtcMillis: Long
+)
+
+/** Result of submitting an AMSAT satellite status report. */
+data class AmSatReportSubmitResult(
+    val success: Boolean,
+    val message: String = "",
+    val reportId: String? = null
+)

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

@@ -0,0 +1,23 @@
+/*
+ * 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.model
+
+object Constants {
+    const val FREQ_OFFSET_MIN_HZ = -50_000L
+    const val FREQ_OFFSET_MAX_HZ = 50_000L
+}

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

@@ -0,0 +1,9 @@
+package com.rtbishop.look4sat.core.domain.model
+
+/** Latest release info fetched from the fork's GitHub releases API. */
+data class LatestRelease(
+    val versionTag: String, // e.g. "v4.4.6-ba7opf.6"
+    val title: String,      // release name, may be empty
+    val body: String,       // release notes / update description
+    val apkUrl: String?     // first .apk asset download URL, null if absent
+)

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

@@ -0,0 +1,37 @@
+package com.rtbishop.look4sat.core.domain.model
+
+/** One satellite status report (AMSAT site tooltip data) */
+data class SatReport(
+    val id: String,          // 报告 ID(a885153)
+    val statusText: String,  // Heard / Telemetry Only / Not Heard ...
+    val call: String,        // 呼号
+    val grid: String,        // 网格坐标(可为空)
+    val dateUtc: String,     // 2026-08-04
+    val timeUtc: String      // 2:46-:59 UTC
+)
+
+/** State of one 2-hour slot */
+data class SatSlot(
+    val statusColor: Long,   // ARGB 状态色(-1 = 无报告)
+    val count: Int,          // 报告数量(0 = 无)
+    val reportIds: List<String> = emptyList() // 该槽报告 ID 列表
+)
+
+/** One satellite day (12 two-hour slots) */
+data class SatDay(
+    val dateLabel: String,   // "Aug 4"
+    val slots: List<SatSlot> // 12 槽(00-02 ... 22-24)
+)
+
+/** One satellite, 3 days of state */
+data class SatStatus(
+    val name: String,        // "AO-123_[FM]"
+    val days: List<SatDay>   // 3 days (newest first)
+)
+
+/** Overall page parse result */
+data class SatStatusPage(
+    val fetchedAtUtcMs: Long,
+    val statuses: List<SatStatus>,
+    val reports: Map<String, SatReport> // id → 报告
+)

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

@@ -42,6 +42,7 @@ data class RCSettings(
     val frequencyAddress: String,
     val frequencyPort: String,
     val frequencyFormat: String,
+    val frequencyOffsetHz: Long = 0L,
     val bluetoothRotatorState: Boolean,
     val bluetoothRotatorFormat: String,
     val bluetoothRotatorName: String,
@@ -66,11 +67,14 @@ data class OtherSettings(
 )
 
 data class DataSourcesSettings(
-    val useCustomTLE: Boolean,
-    val useCustomTransceivers: Boolean,
-    val tleUrl: String,
-    val transceiversUrl: String
-)
+    val satelliteUrls: List<String>,
+    val transceiversUrls: List<String>,
+    val satelliteEnabled: List<Boolean> = emptyList(),
+    val transceiversEnabled: List<Boolean> = emptyList()
+) {
+    fun isSatelliteEnabled(index: Int): Boolean = satelliteEnabled.getOrElse(index) { true }
+    fun isTransceiverEnabled(index: Int): Boolean = transceiversEnabled.getOrElse(index) { true }
+}
 
 data class RadioControlSettings(
     val enabled: Boolean,

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

@@ -424,11 +424,15 @@ object CelestialComputer {
         }
         if (sunrise == 0.0) sunrise = daynum
 
-        // Phase 4: fast-forward through the day until sun drops back below threshold
-        daynum = sunrise
+        // Phase 4: fast-forward through the day until sun drops back below threshold.
+        // Start from just after sunrise (small offset) so the sun is clearly above
+        // the threshold. This prevents a bug where Phase 3 converges to a point
+        // slightly below -threshold, causing Phase 4 to skip and Phase 5 to converge
+        // to the same time as sunrise, producing identical sunrise/sunset times.
+        daynum = sunrise + 0.001
         sunPos = getSunPosition(observer, daynumToMillis(daynum))
         guard = 0
-        while (sunPos.elevation > -threshold && guard++ < 500) {
+        while (sunPos.elevation >= -threshold && guard++ < 500) {
             daynum += 0.008
             sunPos = getSunPosition(observer, daynumToMillis(daynum))
         }

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

@@ -0,0 +1,23 @@
+package com.rtbishop.look4sat.core.domain.repository
+
+import com.rtbishop.look4sat.core.domain.model.AmSatReportSubmission
+import com.rtbishop.look4sat.core.domain.model.AmSatReportSubmitResult
+import com.rtbishop.look4sat.core.domain.model.SatStatusPage
+
+/** AMSAT satellite status data source */
+interface IAmSatRepository {
+    /** Cached AMSAT status page for the current foreground session, if any. */
+    fun getCachedStatus(): SatStatusPage?
+
+    /** Fetch and parse the AMSAT status page; null on failure. */
+    suspend fun fetchStatus(forceRefresh: Boolean = false): SatStatusPage?
+
+    /** Warm the foreground-session cache without forcing a network reload. */
+    suspend fun prefetchStatus()
+
+    /** Clear the foreground-session status cache. */
+    fun clearStatusCache()
+
+    /** Submit a public AMSAT satellite status report. */
+    suspend fun submitReport(submission: AmSatReportSubmission): AmSatReportSubmitResult
+}

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

@@ -30,6 +30,8 @@ interface IMainContainer {
     val selectionRepo: ISelectionRepo
     val satelliteRepo: ISatelliteRepo
     val databaseRepo: IDatabaseRepo
+    val amSatRepo: IAmSatRepository
+    val updateRepo: IUpdateRepository
     val radioTrackingService: IRadioTrackingService
     val mutualPassData: StateFlow<MutualPassData>
     fun setMutualPassData(data: MutualPassData)

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

@@ -73,8 +73,23 @@ interface ISettingsRepo {
     fun updateDataSourcesSettings(settings: DataSourcesSettings)
     //endregion
 
+    //region # Data sources status
+    val dataSourcesStatus: StateFlow<Map<String, Int>>
+    fun updateDataSourcesStatus(status: Map<String, Int>)
+    //endregion
+
     //region # Radio control settings
     val radioControlSettings: StateFlow<RadioControlSettings>
     fun updateRadioControlSettings(settings: RadioControlSettings)
     //endregion
+
+    //region # Per-satellite calculator offset settings
+    fun getSatelliteOffset(catnum: Int): String
+    fun setSatelliteOffset(catnum: Int, offset: String)
+    //endregion
+
+    //region # AMSAT status report settings
+    fun getAmSatCallsign(): String
+    fun setAmSatCallsign(callsign: String)
+    //endregion
 }

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

@@ -0,0 +1,12 @@
+package com.rtbishop.look4sat.core.domain.repository
+
+import com.rtbishop.look4sat.core.domain.model.LatestRelease
+import java.io.File
+
+interface IUpdateRepository {
+    /** Fetch the latest release of the fork repo from GitHub; null on failure. */
+    suspend fun getLatestRelease(): LatestRelease?
+
+    /** Download the release APK from [url] into [dest]; true on success. */
+    suspend fun downloadApk(url: String, dest: File): Boolean
+}

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

@@ -19,7 +19,18 @@ package com.rtbishop.look4sat.core.domain.source
 
 import java.io.InputStream
 
+/** Result of a network download: the HTTP status code and the response body stream. */
+data class NetworkResult(val code: Int, val stream: InputStream?) {
+    companion object {
+        /** Code used when a request fails before any HTTP response is received. */
+        const val CONNECTION_ERROR = -1
+    }
+}
+
 interface IRemoteSource {
     suspend fun getFileStream(uri: String): InputStream?
-    suspend fun getNetworkStream(url: String): InputStream?
+    suspend fun getNetworkStream(url: String): NetworkResult
+    suspend fun getAmSatCatalog(): String?
+    suspend fun getAmSatReports(hours: Int, limit: Int): String?
+    suspend fun submitAmSatReport(payloadJson: String): Pair<Int, String>?
 }

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

@@ -19,7 +19,10 @@ package com.rtbishop.look4sat.core.domain.source
 
 object Sources {
     val satelliteDataUrls = mapOf(
+        "LAPAN-A2" to "https://www.kaggle.com/api/v1/datasets/download/muazamnugroho/lapan-a2-satellite-two-line-element-tle-dataset/LAPAN-A2_TLE_latest.txt",
+        "R4UAB" to "https://r4uab.ru/satonline.txt",
         "All" to "https://celestrak.org/NORAD/elements/gp.php?GROUP=active&FORMAT=csv",
+        "SatNOGS" to "https://db.satnogs.org/api/tle/?format=3le",
         "Amateur" to "https://celestrak.org/NORAD/elements/gp.php?GROUP=amateur&FORMAT=csv",
         "Brightest" to "https://celestrak.org/NORAD/elements/gp.php?GROUP=visual&FORMAT=csv",
         "Cubesat" to "https://celestrak.org/NORAD/elements/gp.php?GROUP=cubesat&FORMAT=csv",
@@ -35,7 +38,7 @@ object Sources {
         "OneWeb" to "https://celestrak.org/NORAD/elements/gp.php?GROUP=oneweb&FORMAT=csv",
         "Orbcomm" to "https://celestrak.org/NORAD/elements/gp.php?GROUP=orbcomm&FORMAT=csv",
         "Resource" to "https://celestrak.org/NORAD/elements/gp.php?GROUP=resource&FORMAT=csv",
-        "SatNOGS" to "https://celestrak.org/NORAD/elements/gp.php?GROUP=satnogs&FORMAT=csv",
+        "CelesTrak SatNOGS" to "https://celestrak.org/NORAD/elements/gp.php?GROUP=satnogs&FORMAT=csv",
         "Science" to "https://celestrak.org/NORAD/elements/gp.php?GROUP=science&FORMAT=csv",
         "Spire" to "https://celestrak.org/NORAD/elements/gp.php?GROUP=spire&FORMAT=csv",
         "Starlink" to "https://celestrak.org/NORAD/elements/gp.php?GROUP=starlink&FORMAT=csv",
@@ -45,10 +48,11 @@ object Sources {
         "Amsat" to "https://amsat.org/tle/current/nasabare.txt",
         "Classified" to "https://www.mmccants.org/tles/classfd.zip",
         "McCants" to "https://www.mmccants.org/tles/inttles.zip",
-        "R4UAB" to "https://r4uab.ru/satonline.txt",
+        "ARISS" to "https://live.ariss.org/iss.txt",
         "Other" to "" // key for sats filter
     )
     val transceiversDataUrls = mapOf(
-        "SatNOGS" to "https://db.satnogs.org/api/transmitters/?format=json&status=active"
+        "SatNOGS" to "https://db.satnogs.org/api/transmitters/?format=json&status=active",
+        "R4UAB" to "https://r4uab.ru/transmitters.json"
     )
 }

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

@@ -16,20 +16,28 @@ import java.util.Locale
 /**
  * Computes Doppler-corrected reciprocal frequencies for linear transponders.
  *
- * For a linear (passband) transponder, uplink and downlink frequencies are
- * related by a fixed passband offset. When the satellite moves, both are
- * Doppler-shifted. Given one, we compute the other:
+ * The full physical path:
  *
- *   downlink → uplink: mapDownlinkToUplink (passband) → getUplinkFreq (Doppler)
- *   uplink → downlink: mapUplinkToDownlink (passband) → getDownlinkFreq (Doppler)
+ * 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, compute the Doppler-corrected uplink frequency.
-     * Returns null if the transponder is not a linear passband type.
+     * 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,
@@ -37,17 +45,22 @@ object DopplerFrequencyCalculator {
         orbitalPos: OrbitalPos
     ): Long? {
         if (!isLinearTransponder(transponder)) return null
-        val baseUplink = TransponderMapper.mapDownlinkToUplink(downlinkHz, transponder) ?: return null
-        return orbitalPos.getUplinkFreq(baseUplink)
+        // 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, compute the Doppler-corrected uplink frequency
-     * with an offset applied to the downlink (in Hz).
-     * Returns null if the transponder is not a linear passband type.
+     * 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 mapping the downlink passband position back to the uplink.
+     * it before the inverse downlink Doppler.
      */
     fun computeUplinkFromDownlinkWithOffset(
         downlinkHz: Long,
@@ -56,13 +69,20 @@ object DopplerFrequencyCalculator {
         offsetHz: Long
     ): Long? {
         if (!isLinearTransponder(transponder)) return null
-        val baseUplink = TransponderMapper.mapDownlinkToUplink(downlinkHz - offsetHz, transponder) ?: return null
-        return orbitalPos.getUplinkFreq(baseUplink)
+        // 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, compute the Doppler-corrected downlink frequency.
-     * Returns null if the transponder is not a linear passband type.
+     * 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,
@@ -70,14 +90,19 @@ object DopplerFrequencyCalculator {
         orbitalPos: OrbitalPos
     ): Long? {
         if (!isLinearTransponder(transponder)) return null
-        val baseDownlink = TransponderMapper.mapUplinkToDownlink(uplinkHz, transponder) ?: return null
-        return orbitalPos.getDownlinkFreq(baseDownlink)
+        // 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, compute the Doppler-corrected downlink frequency
-     * with an offset applied to the downlink (in Hz).
-     * Returns null if the transponder is not a linear passband type.
+     * 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,
@@ -86,8 +111,13 @@ object DopplerFrequencyCalculator {
         offsetHz: Long
     ): Long? {
         if (!isLinearTransponder(transponder)) return null
-        val baseDownlink = TransponderMapper.mapUplinkToDownlink(uplinkHz, transponder) ?: return null
-        return orbitalPos.getDownlinkFreq(baseDownlink + offsetHz)
+        // 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. */
@@ -114,11 +144,30 @@ object DopplerFrequencyCalculator {
         val modes = listOfNotNull(transponder.downlinkMode, transponder.uplinkMode)
             .joinToString(separator = " ")
             .lowercase(Locale.ENGLISH)
-        val hasLinearName = info.contains("linear")
+        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)
+        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/QthConverter.kt

@@ -19,20 +19,43 @@ package com.rtbishop.look4sat.core.domain.utility
 
 import com.rtbishop.look4sat.core.domain.predict.GeoPos
 
+/**
+ * Convert a Maidenhead locator (4, 6 or 8 chars) to the position of its
+ * square / subsquare / extended-square centre. Longer input is truncated to
+ * 8 chars (the Maidenhead maximum); malformed or out-of-range input yields
+ * null.
+ */
 fun qthToPosition(locator: String): GeoPos? {
-    val trimmedQth = locator.take(6)
-    if (!isValidLocator(trimmedQth)) return null
-    val lonFirst = (trimmedQth[0].uppercaseChar().code - 65) * 20
-    val latFirst = (trimmedQth[1].uppercaseChar().code - 65) * 10
+    val trimmedQth = locator.trim().uppercase().take(8)
+    if (trimmedQth.length !in listOf(4, 6, 8) || !isValidLocator(trimmedQth)) return null
+    val lonFirst = (trimmedQth[0].code - 65) * 20
+    val latFirst = (trimmedQth[1].code - 65) * 10
     val lonSecond = trimmedQth[2].toString().toInt() * 2
     val latSecond = trimmedQth[3].toString().toInt()
-    val lonThird = (((trimmedQth[4].lowercaseChar().code - 97) / 12.0) + (1.0 / 24.0)) - 180
-    val latThird = (((trimmedQth[5].lowercaseChar().code - 97) / 24.0) + (1.0 / 48.0)) - 90
-    val longitude = (lonFirst + lonSecond + lonThird).round(4)
-    val latitude = (latFirst + latSecond + latThird).round(4)
-    return GeoPos(latitude, longitude)
+    // Start from the 4-char square centre, refine for 6/8-char subsquares.
+    var longitude = lonFirst + lonSecond + 1.0
+    var latitude = latFirst + latSecond + 0.5
+    if (trimmedQth.length >= 6) {
+        val lonSub = (trimmedQth[4].code - 65) * 5.0 / 60.0
+        val latSub = (trimmedQth[5].code - 65) * 2.5 / 60.0
+        if (lonSub < 0.0 || lonSub > 115.0 / 60.0 || latSub < 0.0 || latSub > 57.5 / 60.0) return null
+        longitude = lonFirst + lonSecond + lonSub + 2.5 / 60.0
+        latitude = latFirst + latSecond + latSub + 1.25 / 60.0
+        if (trimmedQth.length >= 8) {
+            val lonExt = (trimmedQth[6].code - 48) * 30.0 / 3600.0
+            val latExt = (trimmedQth[7].code - 48) * 15.0 / 3600.0
+            if (lonExt < 0.0 || lonExt > 270.0 / 3600.0 || latExt < 0.0 || latExt > 135.0 / 3600.0) return null
+            longitude += lonExt + 15.0 / 3600.0
+            latitude += latExt + 7.5 / 3600.0
+        }
+    }
+    return GeoPos((latitude - 90.0).round(4), (longitude - 180.0).round(4))
 }
 
+/**
+ * Convert a position to its 6-char Maidenhead locator, upper-cased (field,
+ * square and subsquare letters). Returns null for out-of-range positions.
+ */
 fun positionToQth(latitude: Double, longitude: Double): String? {
     if (!isValidPosition(latitude, longitude)) return null
     val newLongitude = if (longitude > 180.0) longitude else longitude + 180
@@ -41,8 +64,8 @@ fun positionToQth(latitude: Double, longitude: Double): String? {
     val latFirst = (65 + (newLatitude / 10)).toInt().toChar()
     val lonSecond = ((newLongitude / 2) % 10).toInt()
     val latSecond = (newLatitude % 10).toInt()
-    val lonThird = (65 + (newLongitude % 2) * 12).toInt().toChar().lowercaseChar()
-    val latThird = (65 + (newLatitude % 1) * 24).toInt().toChar().lowercaseChar()
+    val lonThird = (65 + (newLongitude % 2) * 12).toInt().toChar().uppercaseChar()
+    val latThird = (65 + (newLatitude % 1) * 24).toInt().toChar().uppercaseChar()
     return "$lonFirst$latFirst$lonSecond$latSecond$lonThird$latThird"
 }
 
@@ -51,5 +74,11 @@ private fun isValidPosition(lat: Double, lon: Double): Boolean {
 }
 
 private fun isValidLocator(locator: String): Boolean {
-    return locator.matches("[a-xA-X][a-xA-X]\\d\\d[a-xA-X][a-xA-X]".toRegex())
+    // 4 chars: [A-X][A-X]\d\d ; 6 chars: + [A-X][A-X] ; 8 chars: + \d\d
+    return when (locator.length) {
+        4 -> Regex("[A-X]{2}\\d{2}").matches(locator)
+        6 -> Regex("[A-X]{2}\\d{2}[A-X]{2}").matches(locator)
+        8 -> Regex("[A-X]{2}\\d{2}[A-X]{2}\\d{2}").matches(locator)
+        else -> false
+    }
 }

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

@@ -0,0 +1,44 @@
+package com.rtbishop.look4sat.core.domain.utility
+
+/**
+ * Compares two version strings of the form "<major>.<minor>.<patch>[-<build>]" used by the
+ * BA7OPF fork releases (e.g. "4.4.6-ba7opf.6" or "v4.4.6-ba7opf.7").
+ *
+ * The comparison is done on the numeric version segments first; when the base versions are
+ * equal, the trailing build number (if any) decides. This lets a "4.4.6-ba7opf.7" release be
+ * detected as newer than "4.4.6-ba7opf.6" while "4.5.0" trumps any "4.4.x" build.
+ */
+object VersionComparator {
+
+    /** True when [candidate] is a newer version than [current]. */
+    fun isNewer(candidate: String, current: String): Boolean {
+        val cand = parse(candidate)
+        val curr = parse(current)
+        val maxLen = maxOf(cand.first.size, curr.first.size)
+        for (i in 0 until maxLen) {
+            val c = cand.first.getOrElse(i) { 0 }
+            val k = curr.first.getOrElse(i) { 0 }
+            if (c != k) return c > k
+        }
+        return cand.second > curr.second
+    }
+
+    /**
+     * Parses a version string into (numeric base segments, trailing build number).
+     * "v4.4.6-ba7opf.7" -> ([4,4,6], 7); "4.4.6" -> ([4,4,6], 0); "4.4.6-ba7opf" -> ([4,4,6], 0).
+     */
+    fun parse(version: String): Pair<List<Int>, Int> {
+        val cleaned = version.trim().removePrefix("v")
+        val dashIndex = cleaned.indexOf('-')
+        val basePart = if (dashIndex >= 0) cleaned.substring(0, dashIndex) else cleaned
+        val suffixPart = if (dashIndex >= 0) cleaned.substring(dashIndex + 1) else ""
+        val base = basePart.split('.').mapNotNull { it.toIntOrNull() }
+        // The build number is the trailing numeric segment of the suffix (e.g. "ba7opf.7" -> 7).
+        val build = suffixPart
+            .split('.')
+            .lastOrNull()
+            ?.toIntOrNull()
+            ?: 0
+        return base to build
+    }
+}

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

@@ -9,6 +9,7 @@ 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,
@@ -18,7 +19,7 @@ class DopplerFrequencyCalculatorTest {
         downlinkMode: String? = "USB",
         uplinkMode: String? = "LSB"
     ) = SatRadio(
-        uuid = "linear", info = info, isAlive = true,
+        uuid = uuid, info = info, isAlive = true,
         downlinkLow = downLow, downlinkHigh = downHigh,
         downlinkMode = downlinkMode, uplinkLow = upLow, uplinkHigh = upHigh,
         uplinkMode = uplinkMode, isInverted = inverted, catnum = 12345
@@ -68,11 +69,93 @@ class DopplerFrequencyCalculatorTest {
         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()

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

@@ -1,20 +1,3 @@
-/*
- * 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
 
 import com.rtbishop.look4sat.core.domain.utility.positionToQth
@@ -22,25 +5,34 @@ import com.rtbishop.look4sat.core.domain.utility.qthToPosition
 import org.junit.Test
 
 class QthConverterTest {
-
     @Test
     fun `Given valid QTH returns correct POS`() {
+        // 8-char locator -> centre of the extended square (higher precision)
         var result = qthToPosition("io91VL39FX")
-        assert(result?.latitude == 51.4792 && result.longitude == -0.2083)
+        assert(result?.latitude == 51.5188 && result.longitude == -0.1792)
         result = qthToPosition("gf15vc")
         assert(result?.latitude == -34.8958 && result.longitude == -56.2083)
+        // 4-char locator -> centre of the 2deg x 1deg square
+        result = qthToPosition("JN58")
+        assert(result?.latitude == 48.5 && result.longitude == 11.0)
+        // lowercase input is accepted and normalised
+        result = qthToPosition("ol63pd")
+        assert(result?.latitude == 23.1458 && result.longitude == 113.2917)
     }
 
     @Test
     fun `Given invalid QTH returns null`() {
         assert(qthToPosition("ZZ00zz") == null)
-        assert(qthToPosition("JN58") == null)
+        assert(qthToPosition("JN5") == null) // odd length
+        assert(qthToPosition("JN58Z") == null) // 5 chars
+        assert(qthToPosition("JN58ZA") == null) // Z out of A-X range
     }
 
     @Test
     fun `Given valid POS returns correct QTH`() {
-        assert(positionToQth(51.4878, -0.2146) == "IO91vl")
-        assert(positionToQth(48.1466, 11.6083) == "JN58td")
+        assert(positionToQth(51.4878, -0.2146) == "IO91VL")
+        assert(positionToQth(48.1466, 11.6083) == "JN58TD")
+        assert(positionToQth(23.13, 113.26) == "OL63PD")
     }
 
     @Test

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

@@ -0,0 +1,48 @@
+package com.rtbishop.look4sat.core.domain
+
+import com.rtbishop.look4sat.core.domain.utility.VersionComparator
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+class VersionComparatorTest {
+
+    @Test
+    fun `newer build number wins when base version equal`() {
+        assertTrue(VersionComparator.isNewer("4.4.6-ba7opf.7", "4.4.6-ba7opf.6"))
+        assertTrue(VersionComparator.isNewer("v4.4.6-ba7opf.6", "4.4.6-ba7opf.5"))
+    }
+
+    @Test
+    fun `newer base version wins regardless of build number`() {
+        assertTrue(VersionComparator.isNewer("4.5.0", "4.4.6-ba7opf.99"))
+        assertTrue(VersionComparator.isNewer("4.4.7-ba7opf.1", "4.4.6-ba7opf.99"))
+    }
+
+    @Test
+    fun `older versions are not newer`() {
+        assertFalse(VersionComparator.isNewer("4.4.6-ba7opf.5", "4.4.6-ba7opf.6"))
+        assertFalse(VersionComparator.isNewer("4.4.5", "4.4.6-ba7opf.1"))
+        assertFalse(VersionComparator.isNewer("4.4.6-ba7opf.6", "4.4.6-ba7opf.6"))
+    }
+
+    @Test
+    fun `v prefix is ignored`() {
+        assertTrue(VersionComparator.isNewer("v4.4.7", "4.4.6"))
+        assertFalse(VersionComparator.isNewer("v4.4.6", "4.4.6-ba7opf.1"))
+    }
+
+    @Test
+    fun `non numeric suffix without number treated as zero build`() {
+        assertTrue(VersionComparator.isNewer("4.4.6-ba7opf.1", "4.4.6-ba7opf"))
+        assertFalse(VersionComparator.isNewer("4.4.6-ba7opf", "4.4.6-ba7opf.1"))
+    }
+
+    @Test
+    fun `parse extracts base and build number`() {
+        assertEquals(listOf(4, 4, 6) to 7, VersionComparator.parse("v4.4.6-ba7opf.7"))
+        assertEquals(listOf(4, 4, 6) to 0, VersionComparator.parse("4.4.6"))
+        assertEquals(listOf(4, 4, 6) to 0, VersionComparator.parse("4.4.6-ba7opf"))
+    }
+}

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

@@ -280,6 +280,40 @@ fun getDefaultPass(): OrbitalPass = OrbitalPass(
     altitude = 0, maxElevation = 0.0, orbitalObject = NearEarthObject(defaultOrbitalData), progress = 0f
 )
 
+@Composable
+fun InfoDialog(
+    title: String,
+    onDismiss: () -> Unit,
+    onAccept: () -> Unit,
+    extraAction: (@Composable () -> Unit)? = null,
+    content: @Composable () -> Unit
+) {
+    DialogShell(onDismissRequest = onDismiss) { padding ->
+        Row(
+            verticalAlignment = Alignment.CenterVertically,
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(start = padding, top = padding, end = padding)
+        ) {
+            Text(
+                text = title,
+                fontSize = 16.sp,
+                fontWeight = FontWeight.Medium,
+                color = MaterialTheme.colorScheme.primary,
+                maxLines = 1,
+                overflow = TextOverflow.Ellipsis,
+                modifier = Modifier.weight(1f)
+            )
+            extraAction?.let {
+                it()
+                Spacer(modifier = Modifier.width(8.dp))
+            }
+            CardButton(onClick = onAccept, text = stringResource(R.string.btn_accept))
+        }
+        content()
+    }
+}
+
 @Composable
 fun SharedDialog(
     title: String, onCancel: () -> Unit, onAccept: () -> Unit, content: @Composable () -> Unit

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

@@ -79,6 +79,10 @@ private val lightScheme = lightColorScheme(
     onSecondary = Color(0xFFFFFFFF),
     secondaryContainer = Color(0xFFF1E1BB),
     onSecondaryContainer = Color(0xFF221B04),
+    tertiary = Color(0xFF3C6FE0), // AMSAT Active (darker for light theme)
+    onTertiary = Color(0xFFFFFFFF),
+    tertiaryContainer = Color(0xFFE09800), // AMSAT Telemetry (darker)
+    onTertiaryContainer = Color(0xFF000000),
     background = Color(0xFFFFF8F0),
     onBackground = Color(0xFF1E1B13),
     surface = Color(0xFFFFF8F0),
@@ -101,10 +105,10 @@ private val darkScheme = darkColorScheme(
     onSecondary = Color(0xFF000000),
     secondaryContainer = Color(0xFF404040), // navBar indicator,
     onSecondaryContainer = Color(0xFFE0E0E0), // navBar active icon
-//    tertiary = Color(0xFF121212),
-//    onTertiary = Color(0xFF121212),
-//    tertiaryContainer = Color(0xFF121212),
-//    onTertiaryContainer = Color(0xFF121212),
+    tertiary = Color(0xFF648FFF), // AMSAT Active (from amsat.org/status)
+    onTertiary = Color(0xFF000000),
+    tertiaryContainer = Color(0xFFFFB000), // AMSAT Telemetry
+    onTertiaryContainer = Color(0xFF000000),
     background = Color(0xFF121212),
     onBackground = Color(0xFFE0E0E0),
     surface = Color(0xFF202020), // card background

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

@@ -29,14 +29,14 @@ sealed class Screen(val iconResId: Int, val titleResId: Int) : NavKey {
     @Serializable
     data object Passes : Screen(R.drawable.ic_passes, R.string.nav_pass)
 
-    @Serializable
-    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)
+    data object Mutual : Screen(R.drawable.ic_radio_tower, R.string.nav_mutual)
+
+    @Serializable
+    data object AMSAT : Screen(R.drawable.ic_satellite_alt, R.string.nav_amsat)
 
     @Serializable
     data object Settings : Screen(R.drawable.ic_settings, R.string.nav_prefs)

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

@@ -0,0 +1,3 @@
+<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="M19,13H13V19H11V13H5V11H11V5H13V11H19V13Z" />
+</vector>

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

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="960"
+    android:viewportHeight="960">
+    <path
+        android:fillColor="@android:color/white"
+        android:pathData="M240,320q-33,0 -56.5,-23.5T160,240q0,-33 23.5,-56.5T240,160q33,0 56.5,23.5T320,240q0,33 -23.5,56.5T240,320zM240,560q-33,0 -56.5,-23.5T160,480q0,-33 23.5,-56.5T240,400q33,0 56.5,23.5T320,480q0,33 -23.5,56.5T240,560zM240,800q-33,0 -56.5,-23.5T160,720q0,-33 23.5,-56.5T240,640q33,0 56.5,23.5T320,720q0,33 -23.5,56.5T240,800zM720,320q-33,0 -56.5,-23.5T640,240q0,-33 23.5,-56.5T720,160q33,0 56.5,23.5T800,240q0,33 -23.5,56.5T720,320zM720,560q-33,0 -56.5,-23.5T640,480q0,-33 23.5,-56.5T720,400q33,0 56.5,23.5T800,480q0,33 -23.5,56.5T720,560zM720,800q-33,0 -56.5,-23.5T640,720q0,-33 23.5,-56.5T720,640q33,0 56.5,23.5T800,720q0,33 -23.5,56.5T720,800z" />
+</vector>

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

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="utf-8"?>
+<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="#FF000000" android:pathData="M12,10A2,2 0 0,1 14,12C14,12.5 13.82,12.94 13.53,13.29L16.7,22H14.57L12,14.93L9.43,22H7.3L10.47,13.29C10.18,12.94 10,12.5 10,12A2,2 0 0,1 12,10M12,8A4,4 0 0,0 8,12C8,12.5 8.1,13 8.28,13.46L7.4,15.86C6.53,14.81 6,13.47 6,12A6,6 0 0,1 12,6A6,6 0 0,1 18,12C18,13.47 17.47,14.81 16.6,15.86L15.72,13.46C15.9,13 16,12.5 16,12A4,4 0 0,0 12,8M12,4A8,8 0 0,0 4,12C4,14.36 5,16.5 6.64,17.94L5.92,19.94C3.54,18.11 2,15.23 2,12A10,10 0 0,1 12,2A10,10 0 0,1 22,12C22,15.23 20.46,18.11 18.08,19.94L17.36,17.94C19,16.5 20,14.36 20,12A8,8 0 0,0 12,4Z" />
+</vector>

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

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Standard Material refresh icon (24dp viewport), centered geometry -->
+<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="#FF000000"
+        android:pathData="M17.65,6.35C16.2,4.9 14.21,4 12,4c-4.42,0 -7.99,3.58 -7.99,8s3.57,8 7.99,8c3.73,0 6.84,-2.55 7.73,-6h-2.08c-0.82,2.33 -3.04,4 -5.65,4 -3.31,0 -6,-2.69 -6,-6s2.69,-6 6,-6c1.66,0 3.14,0.69 4.22,1.78L13,11h7V4l-2.35,2.35z" />
+</vector>

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

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- AMSAT tab icon provided by rt-bishop (upstream author), original SVG asset -->
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <group
+        android:scaleX="0.242"
+        android:scaleY="0.242"
+        android:translateX="0.3"
+        android:translateY="-230.5">
+        <path android:fillColor="#FF000000" android:pathData="m 21.275553,967.35933 a 2.0000048,2.0000048 0 0 0 -1.1875,0.59375 l -13.5000003,13.5 a 2.0000048,2.0000048 0 0 0 0,2.8125 l 18.5625003,18.59382 a 2.0000048,2.0000048 0 0 0 1.2813,0.5625 l 5.5312,0.4375 -4.0312,4.0312 a 2.0000048,2.0000048 0 0 0 0,2.8126 l 13.6874,13.7187 a 2.0000048,2.0000048 0 0 0 2.8438,0 l 4.0312,-4.0312 0.4376,5.5312 a 2.0000048,2.0000048 0 0 0 0.5624,1.2813 l 18.5938,18.5625 a 2.0000048,2.0000048 0 0 0 2.8438,0 l 13.468705,-13.4688 a 2.0000048,2.0000048 0 0 0 0,-2.8437 l -18.562505,-18.5938 a 2.0000048,2.0000048 0 0 0 -1.2812,-0.5625 l -5.5313,-0.4375 4.0313,-4.0313 a 2.0000048,2.0000048 0 0 0 0,-2.8437 l -13.6876,-13.68757 a 2.0000048,2.0000048 0 0 0 -2.8437,0 l -4.0313,4.03125 -0.4374,-5.53125 a 2.0000048,2.0000048 0 0 0 -0.5626,-1.28125 l -18.5937,-18.5625 a 2.0000048,2.0000048 0 0 0 -1.4375,-0.59375 2.0000048,2.0000048 0 0 0 -0.1875,0 z m 0.2187,4.8125 16.6563,16.65625 0.5625,7.46875 -3.7812,3.78127 -7.4688,-0.59377 -16.6562,-16.625 z m 34.5626,41.46887 7.4687,0.5937 16.656305,16.625 -10.687605,10.6875 -16.625,-16.6562 -0.5937,-7.4688 z" />
+        <path android:fillColor="#FF000000" android:pathData="m 50.940553,966.18283 a 2.000005,2.000005 0 1 0 0,3.99969 c 7.9999,0 15.9734,3.03851 22.0884,9.15344 6.103605,6.10359 9.143805,14.08909 9.143805,22.07844 a 2.000005,2.000005 0 1 0 3.9994,0 c 0,-9.00692 -3.4462,-18.03775 -10.315,-24.90657 -6.877605,-6.8775 -15.900305,-10.325 -24.916605,-10.325 z" />
+        <path android:fillColor="#FF000000" android:pathData="m 50.940553,958.36533 a 2.000005,2.000005 0 1 0 0,3.99969 c 10.0021,0 19.9781,3.79987 27.613705,11.43562 7.6352,7.63517 11.4357,17.62207 11.4357,27.61376 a 2.000005,2.000005 0 1 0 3.9997,0 c 0,-11.00842 -4.207,-22.04171 -12.6072,-30.44188 -8.399505,-8.3996 -19.424005,-12.60719 -30.441905,-12.60719 z" />
+        <path android:fillColor="#FF000000" android:pathData="m 50.940553,973.94033 a 2.000005,2.000005 0 1 0 0,3.99938 c 6.0191,0 12.0105,2.279 16.6031,6.87156 4.5926,4.59255 6.881605,10.59683 6.881605,16.60313 a 2.000005,2.000005 0 1 0 3.9997,0 c 0,-7.02618 -2.6961,-14.07429 -8.053105,-19.43126 -5.3571,-5.35696 -12.398,-8.04281 -19.4313,-8.04281 z" />
+        <path android:fillColor="#FF000000" android:pathData="m 50.940553,981.77783 a 2.000005,2.000005 0 1 0 0,3.99938 c 4.0058,0 7.9968,1.51836 11.0578,4.57937 3.061,3.06099 4.5794,7.05193 4.5794,11.05782 a 2.000005,2.000005 0 1 0 3.9994,0 c 0,-5.02276 -1.9251,-10.06035 -5.7507,-13.88594 -3.8256,-3.82559 -8.8631,-5.75063 -13.8859,-5.75063 z" />
+    </group>
+</vector>

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

@@ -112,6 +112,13 @@
     <string name="prefs_data_update_success">Actualización completada con éxito</string>
 
     <string name="prefs_data_sources_title">Custom data sources</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_url_title" translatable="false">URL</string>
+    <string name="prefs_data_sources_satellites_label" translatable="false">Satellites data</string>
+    <string name="prefs_data_sources_transceivers_label" translatable="false">Transceivers data</string>
+    <string name="prefs_net_frequency_offset_hint" translatable="false">Frequency offset (Hz)</string>
+    <string name="prefs_net_frequency_offset_help" translatable="false">Range: -50000 to 50000 Hz. Positive values increase reported frequency; negative values decrease it.</string>
     <string name="prefs_data_sources_tle_switch">Custom TLE URL</string>
     <string name="prefs_data_sources_transceivers_switch">Custom transceivers URL</string>
 

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

@@ -111,6 +111,13 @@
     <string name="prefs_data_update_success">Обновление прошло успешно</string>
 
     <string name="prefs_data_sources_title">Свои источники данных</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_url_title" translatable="false">URL</string>
+    <string name="prefs_data_sources_satellites_label" translatable="false">Satellites data</string>
+    <string name="prefs_data_sources_transceivers_label" translatable="false">Transceivers data</string>
+    <string name="prefs_net_frequency_offset_hint" translatable="false">Frequency offset (Hz)</string>
+    <string name="prefs_net_frequency_offset_help" translatable="false">Range: -50000 to 50000 Hz. Positive values increase reported frequency; negative values decrease it.</string>
     <string name="prefs_data_sources_tle_switch">Custom TLE URL</string>
     <string name="prefs_data_sources_transceivers_switch">Custom Transceivers URL</string>
 

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

@@ -112,6 +112,13 @@
     <string name="prefs_data_update_success">යාවත්කාලීනය සම්පූර්ණ කිරීම සාර්ථකයි</string>
 
     <string name="prefs_data_sources_title">Custom data sources</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_url_title" translatable="false">URL</string>
+    <string name="prefs_data_sources_satellites_label" translatable="false">Satellites data</string>
+    <string name="prefs_data_sources_transceivers_label" translatable="false">Transceivers data</string>
+    <string name="prefs_net_frequency_offset_hint" translatable="false">Frequency offset (Hz)</string>
+    <string name="prefs_net_frequency_offset_help" translatable="false">Range: -50000 to 50000 Hz. Positive values increase reported frequency; negative values decrease it.</string>
     <string name="prefs_data_sources_tle_switch">Custom TLE URL</string>
     <string name="prefs_data_sources_transceivers_switch">Custom transceivers URL</string>
 

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

@@ -143,6 +143,12 @@
     <string name="prefs_data_update_success">Güncelleme başarıyla tamamlandı</string>
 
     <string name="prefs_data_sources_title">Özel veri kaynakları</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_satellites_label" translatable="false">Satellites data</string>
+    <string name="prefs_data_sources_transceivers_label" translatable="false">Transceivers data</string>
+    <string name="prefs_net_frequency_offset_hint" translatable="false">Frequency offset (Hz)</string>
+    <string name="prefs_net_frequency_offset_help" translatable="false">Range: -50000 to 50000 Hz. Positive values increase reported frequency; negative values decrease it.</string>
     <string name="prefs_data_sources_tle_switch">Özel TLE URL</string>
     <string name="prefs_data_sources_transceivers_switch">Özel transceiver URL</string>
     <string name="prefs_data_sources_url_title" translatable="false">URL (HTTPS)</string>
@@ -199,7 +205,8 @@
         \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

@@ -112,6 +112,13 @@
     <string name="prefs_data_update_success">Оновлення успішне</string>
 
     <string name="prefs_data_sources_title">Custom data sources</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_url_title" translatable="false">URL</string>
+    <string name="prefs_data_sources_satellites_label" translatable="false">Satellites data</string>
+    <string name="prefs_data_sources_transceivers_label" translatable="false">Transceivers data</string>
+    <string name="prefs_net_frequency_offset_hint" translatable="false">Frequency offset (Hz)</string>
+    <string name="prefs_net_frequency_offset_help" translatable="false">Range: -50000 to 50000 Hz. Positive values increase reported frequency; negative values decrease it.</string>
     <string name="prefs_data_sources_tle_switch">Custom TLE URL</string>
     <string name="prefs_data_sources_transceivers_switch">Custom transceivers URL</string>
 

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

@@ -39,6 +39,41 @@
     <string name="pass_welcome_title">欢迎来到 Look4Sat\!</string>
     <string name="pass_welcome_message">请务必在设置中通过GPS、经纬度或QTH定位您的位置\n建议至少每周更新一次数据库，以确保预测结果的准确性</string>
 
+    <!-- AMSAT Status screen -->
+    <string name="nav_amsat">AMSAT</string>
+    <string name="amsat_title">AMSAT 卫星状态</string>
+    <string name="amsat_refresh">刷新</string>
+    <string name="amsat_retry">重试</string>
+    <string name="amsat_updated">更新于：</string>
+    <string name="amsat_active">活跃</string>
+    <string name="amsat_tlm">遥测/信标</string>
+    <string name="amsat_not_heard">未听到</string>
+    <string name="amsat_conflict">冲突</string>
+    <string name="amsat_name">名称</string>
+    <string name="amsat_load_failed">加载失败 - 检查网络后重试</string>
+    <string name="amsat_no_reports">此时间段无报告</string>
+    <string name="amsat_close">关闭</string>
+    <string name="amsat_upload">上传</string>
+    <string name="amsat_upload_back">返回</string>
+    <string name="amsat_upload_report">上传报告到 AMSAT</string>
+    <string name="amsat_upload_status">状态</string>
+    <string name="amsat_upload_callsign">呼号</string>
+    <string name="amsat_upload_grid">网格</string>
+    <string name="amsat_upload_time_now">时间：当前 UTC %s</string>
+    <string name="amsat_upload_submit">提交到 AMSAT</string>
+    <string name="amsat_upload_confirm">确认上传</string>
+    <string name="amsat_upload_confirm_title">确认上传到 AMSAT</string>
+    <string name="amsat_upload_confirm_message">这条公开报告将上传到 AMSAT。\n卫星：%1$s\n状态：%2$s\n呼号：%3$s\n网格：%4$s</string>
+    <string name="amsat_upload_grid_none">未填写</string>
+    <string name="amsat_upload_success">报告已上传</string>
+    <string name="amsat_upload_failed">上传失败：%s</string>
+    <string name="amsat_upload_callsign_required">请填写呼号</string>
+    <string name="amsat_upload_grid_invalid">网格应为 4 或 6 位 Maidenhead 定位符</string>
+    <string name="amsat_upload_active">活跃</string>
+    <string name="amsat_upload_tlm">遥测/信标</string>
+    <string name="amsat_upload_not_heard">未听到</string>
+    <string name="amsat_upload_crew_active">ISS 语音</string>
+
     <!-- Radar screen -->
     <string name="radar_back">后退</string>
     <string name="radar_notify">通知</string>
@@ -92,7 +127,7 @@
     <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>
@@ -100,11 +135,11 @@
     <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>
@@ -119,8 +154,12 @@
     <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_restore">恢复默认数据源</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>
+    <string name="prefs_data_sources_url_title" translatable="false">URL</string>
+    <string name="prefs_data_sources_satellites_label">卫星数据</string>
+    <string name="prefs_data_sources_transceivers_label">收发器数据</string>
 
     <string name="prefs_data_output_title">数据输出</string>
     <string name="prefs_net_output">网络</string>
@@ -134,6 +173,8 @@
     <string name="prefs_net_frequency_switch">启用多普勒频率输出</string>
     <string name="prefs_net_frequency_address_hint">IP:端口</string>
     <string name="prefs_net_frequency_format_hint">数据格式</string>
+    <string name="prefs_net_frequency_offset_hint" translatable="false">频率偏移 (Hz)</string>
+    <string name="prefs_net_frequency_offset_help" translatable="false">范围：-50000 到 50000 Hz。正值提高上报频率，负值降低上报频率。</string>
 
     <string name="prefs_bt_title">蓝牙数据输出</string>
     <string name="prefs_bt_rotator_switch">启用方位俯仰角输出</string>
@@ -175,7 +216,52 @@
         \n• Alexandru Csete (Gpredict)
         \n• Dr T.S. Kelso (Celestrak)
         \n• Libre Space Foundation (SatNOGS)
-        \n• xdsopl 和 Robot36 贡献者!</string>
+        \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>
+    <string name="update_check_title">检查更新</string>
+    <string name="update_check_button">检查更新</string>
+    <string name="update_check_current">当前版本：%s</string>
+    <string name="update_check_latest">最新版本：%s</string>
+    <string name="update_check_up_to_date">已是最新版本</string>
+    <string name="update_check_available">发现新版本</string>
+    <string name="update_check_release_notes">更新内容</string>
+    <string name="update_check_download">下载并安装</string>
+    <string name="update_check_downloading">正在下载…</string>
+    <string name="update_check_error">检查更新失败，请检查网络连接。</string>
+    <string name="update_check_download_error">下载失败，请重试。</string>
+    <string name="update_check_no_apk">该版本未附带 APK 安装包。</string>
+
 </resources>

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

@@ -56,6 +56,41 @@
         \n\n* Added ACCESS_LOCAL_NETWORK permission check to support network data output
     </string>
 
+    <!-- AMSAT Status screen -->
+    <string name="nav_amsat">AMSAT</string>
+    <string name="amsat_title">AMSAT Satellite Status</string>
+    <string name="amsat_refresh">Refresh</string>
+    <string name="amsat_retry">Retry</string>
+    <string name="amsat_updated">Updated:</string>
+    <string name="amsat_active">Active</string>
+    <string name="amsat_tlm">TLM/Beacon</string>
+    <string name="amsat_not_heard">Not Heard</string>
+    <string name="amsat_conflict">Conflicting</string>
+    <string name="amsat_name">Name</string>
+    <string name="amsat_load_failed">Load failed - check network and retry</string>
+    <string name="amsat_no_reports">No reports for this period</string>
+    <string name="amsat_close">Close</string>
+    <string name="amsat_upload">Upload</string>
+    <string name="amsat_upload_back">Back</string>
+    <string name="amsat_upload_report">Upload report to AMSAT</string>
+    <string name="amsat_upload_status">Status</string>
+    <string name="amsat_upload_callsign">Callsign</string>
+    <string name="amsat_upload_grid">Grid</string>
+    <string name="amsat_upload_time_now">Time: current UTC %s</string>
+    <string name="amsat_upload_submit">Submit to AMSAT</string>
+    <string name="amsat_upload_confirm">Upload</string>
+    <string name="amsat_upload_confirm_title">Confirm AMSAT upload</string>
+    <string name="amsat_upload_confirm_message">This public report will be uploaded to AMSAT.\nSatellite: %1$s\nStatus: %2$s\nCallsign: %3$s\nGrid: %4$s</string>
+    <string name="amsat_upload_grid_none">Not provided</string>
+    <string name="amsat_upload_success">Report uploaded</string>
+    <string name="amsat_upload_failed">Upload failed: %s</string>
+    <string name="amsat_upload_callsign_required">Callsign is required</string>
+    <string name="amsat_upload_grid_invalid">Grid must be a 4 or 6 character Maidenhead locator</string>
+    <string name="amsat_upload_active">Active</string>
+    <string name="amsat_upload_tlm">TLM/Beacon</string>
+    <string name="amsat_upload_not_heard">Not Heard</string>
+    <string name="amsat_upload_crew_active">Crew Active</string>
+
     <!-- Radar screen -->
     <string name="radar_back">Back</string>
     <string name="radar_notify">Notify</string>
@@ -153,9 +188,12 @@
     <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_restore">Restore default sources</string>
     <string name="prefs_data_sources_tle_switch">Custom TLE URL</string>
     <string name="prefs_data_sources_transceivers_switch">Custom transceivers URL</string>
     <string name="prefs_data_sources_url_title" translatable="false">URL (HTTPS)</string>
+    <string name="prefs_data_sources_satellites_label">Satellites data</string>
+    <string name="prefs_data_sources_transceivers_label">Transceivers data</string>
 
     <string name="prefs_data_output_title">Data output</string>
     <string name="prefs_net_output">Network</string>
@@ -179,6 +217,8 @@
     <string name="prefs_net_frequency_switch">Enable frequency output</string>
     <string name="prefs_net_frequency_address_hint">IP:Port</string>
     <string name="prefs_net_frequency_format_hint">Format</string>
+    <string name="prefs_net_frequency_offset_hint" translatable="false">Frequency offset (Hz)</string>
+    <string name="prefs_net_frequency_offset_help" translatable="false">Range: -50000 to 50000 Hz. Positive values increase reported frequency; negative values decrease it.</string>
 
     <string name="prefs_bt_title">Bluetooth data output</string>
     <string name="prefs_bt_rotator_switch">Enable rotation output</string>
@@ -211,7 +251,52 @@
         \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>
+    <string name="update_check_title">Check for updates</string>
+    <string name="update_check_button">Check for updates</string>
+    <string name="update_check_current">Current version: %s</string>
+    <string name="update_check_latest">Latest version: %s</string>
+    <string name="update_check_up_to_date">You are up to date</string>
+    <string name="update_check_available">New version available</string>
+    <string name="update_check_release_notes">Release notes</string>
+    <string name="update_check_download">Download &amp; install</string>
+    <string name="update_check_downloading">Downloading…</string>
+    <string name="update_check_error">Failed to check for updates. Check your connection.</string>
+    <string name="update_check_download_error">Download failed. Try again.</string>
+    <string name="update_check_no_apk">No APK attached to this release.</string>
+
 </resources>

feature/cw/src/main/java/com/ve3nea/morse_expert/MainActivity.java

@@ -139,7 +139,7 @@ public class MainActivity {
     public void onResume() {
         android.content.SharedPreferences prefs = mActivity.getSharedPreferences(
             mActivity.getPackageName() + "_preferences", Context.MODE_PRIVATE);
-        String messageType = prefs.getString("message_type", "general_text");
+        String messageType = prefs.getString("message_type", "ham_radio_qso");
         b bVar = this.f11037F;
         if (bVar != null) {
             bVar.f623s.set(messageType.equals("ham_radio_qso"));

feature/mutual/src/main/java/com/rtbishop/look4sat/feature/mutual/ElevationCurveChart.kt

@@ -24,6 +24,7 @@ import androidx.compose.foundation.gestures.detectTapGestures
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
+import androidx.compose.ui.res.stringResource
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
@@ -40,6 +41,7 @@ import androidx.compose.ui.graphics.nativeCanvas
 import androidx.compose.ui.input.pointer.pointerInput
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
+import com.rtbishop.look4sat.core.presentation.R
 import java.text.SimpleDateFormat
 import java.util.Date
 import java.util.Locale
@@ -226,8 +228,8 @@ fun ElevationCurveChart(
             modifier = Modifier.fillMaxWidth().padding(horizontal = 8.dp, vertical = 4.dp),
             horizontalArrangement = Arrangement.SpaceEvenly
         ) {
-            Text("● 站点A", color = colorA, fontSize = 12.sp)
-            Text("● 站点B", color = colorB, fontSize = 12.sp)
+            Text(stringResource(R.string.mutual_station_a), color = colorA, fontSize = 12.sp)
+            Text(stringResource(R.string.mutual_station_b), color = colorB, fontSize = 12.sp)
         }
     }
 }

feature/mutual/src/main/java/com/rtbishop/look4sat/feature/mutual/MutualRadarView.kt

@@ -57,8 +57,8 @@ private const val STROKE_WIDTH = 2.5f
 fun MutualRadarView(
     trackSamples: List<TrackSample>,
     progress: Float = 0.5f,
-    labelA: String = "站点A",
-    labelB: String = "站点B",
+    labelA: String = "Station A",
+    labelB: String = "Station B",
     modifier: Modifier = Modifier
 ) {
     if (trackSamples.isEmpty()) return

feature/mutual/src/main/java/com/rtbishop/look4sat/feature/mutual/MutualScreen.kt

@@ -63,7 +63,6 @@ import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import com.rtbishop.look4sat.core.domain.repository.MutualPassData
 import com.rtbishop.look4sat.core.domain.repository.TrackSampleData
-import com.rtbishop.look4sat.core.presentation.IconCard
 import com.rtbishop.look4sat.core.presentation.R
 import com.rtbishop.look4sat.core.presentation.ScreenColumn
 import com.rtbishop.look4sat.core.presentation.TopBar
@@ -75,7 +74,6 @@ import java.util.Locale
 @Composable
 fun MutualScreen(
     viewModel: MutualViewModel,
-    navigateUp: () -> Unit = {},
     navigateToRadar: (Int, Long, MutualPassData?) -> Unit = { _, _, _ -> },
     modifier: Modifier = Modifier
 ) {
@@ -85,12 +83,10 @@ fun MutualScreen(
         topBar = { isVertical ->
             TopBar(
                 isVerticalLayout = isVertical,
-                startAction = {
-                    IconCard(action = navigateUp, resId = R.drawable.ic_back)
-                },
+                startAction = {},
                 topInfo = {
                     Text(
-                        text = "过境匹配",
+                        text = stringResource(R.string.mutual_title),
                         style = MaterialTheme.typography.titleMedium,
                         fontWeight = FontWeight.Bold
                     )
@@ -198,7 +194,7 @@ private fun MutualContent(
             ) {
                 if (isVertical) {
                     StationInputCard(
-                        title = "你的位置",
+                        title = stringResource(R.string.mutual_station_you),
                         titleColor = MaterialTheme.colorScheme.primary,
                         lat = state.stationALat,
                         lon = state.stationALon,
@@ -214,7 +210,7 @@ private fun MutualContent(
                         currentPositionAction = onUseCurrentPosition
                     )
                     StationInputCard(
-                        title = "友台位置",
+                        title = stringResource(R.string.mutual_station_opposite),
                         titleColor = MaterialTheme.colorScheme.tertiary,
                         lat = state.stationBLat,
                         lon = state.stationBLon,
@@ -234,7 +230,7 @@ private fun MutualContent(
                         horizontalArrangement = Arrangement.spacedBy(6.dp)
                     ) {
                         StationInputCard(
-                            title = "你的位置",
+                            title = stringResource(R.string.mutual_station_you),
                             titleColor = MaterialTheme.colorScheme.primary,
                             lat = state.stationALat,
                             lon = state.stationALon,
@@ -251,7 +247,7 @@ private fun MutualContent(
                             modifier = Modifier.weight(1f)
                         )
                         StationInputCard(
-                            title = "友台位置",
+                            title = stringResource(R.string.mutual_station_opposite),
                             titleColor = MaterialTheme.colorScheme.tertiary,
                             lat = state.stationBLat,
                             lon = state.stationBLon,
@@ -294,8 +290,8 @@ private fun MutualContent(
                 startTime = pass.startTime,
                 endTime = pass.endTime,
                 maxElev = maxOf(pass.maxElevationA, pass.maxElevationB, 10.0),
-                labelA = "你",
-                labelB = "友台"
+                labelA = stringResource(R.string.mutual_label_you),
+                labelB = stringResource(R.string.mutual_label_opposite)
             )
             MutualPassCard(
                 pass = pass,
@@ -341,20 +337,22 @@ private fun MutualStatusChip(state: MutualUiState) {
     }
 }
 
+@Composable
 private fun mutualStatusText(state: MutualUiState): String = when {
-    state.isCalculating -> "正在计算双方共同可见窗口…"
-    state.errorMessage != null -> "请修正提示后重新查询"
-    state.mutualPasses.isNotEmpty() -> "找到 ${state.mutualPasses.size} 个匹配 · 点击卡片展开曲线"
-    state.hasSearched -> "未找到共同可见窗口，调整时间或仰角后重试"
-    else -> "输入双方位置后点击查询"
+    state.isCalculating -> stringResource(R.string.mutual_status_calculating)
+    state.errorMessage != null -> stringResource(R.string.mutual_status_error)
+    state.mutualPasses.isNotEmpty() -> stringResource(R.string.mutual_status_matches, state.mutualPasses.size)
+    state.hasSearched -> stringResource(R.string.mutual_status_none)
+    else -> stringResource(R.string.mutual_status_idle)
 }
 
+@Composable
 private fun mutualStatusChipText(state: MutualUiState): String = when {
-    state.isCalculating -> "计算中"
-    state.errorMessage != null -> "有错误"
-    state.mutualPasses.isNotEmpty() -> "${state.mutualPasses.size}个匹配"
-    state.hasSearched -> "无匹配"
-    else -> "待查询"
+    state.isCalculating -> stringResource(R.string.mutual_chip_calculating)
+    state.errorMessage != null -> stringResource(R.string.mutual_chip_error)
+    state.mutualPasses.isNotEmpty() -> stringResource(R.string.mutual_chip_matches, state.mutualPasses.size)
+    state.hasSearched -> stringResource(R.string.mutual_chip_none)
+    else -> stringResource(R.string.mutual_chip_idle)
 }
 
 @Composable
@@ -393,7 +391,7 @@ private fun StationInputCard(
                 )
                 if (currentPositionAction != null) {
                     OutlinedButton(onClick = currentPositionAction) {
-                        Text("填入当前位置", style = MaterialTheme.typography.bodySmall)
+                        Text(stringResource(R.string.mutual_use_current), style = MaterialTheme.typography.bodySmall)
                     }
                 }
             }
@@ -405,7 +403,7 @@ private fun StationInputCard(
                 OutlinedTextField(
                     value = lat,
                     onValueChange = onLatChange,
-                    label = { Text("纬度") },
+                    label = { Text(stringResource(R.string.mutual_lat)) },
                     placeholder = { Text(latPlaceholder) },
                     keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Decimal),
                     singleLine = true,
@@ -414,7 +412,7 @@ private fun StationInputCard(
                 OutlinedTextField(
                     value = lon,
                     onValueChange = onLonChange,
-                    label = { Text("经度") },
+                    label = { Text(stringResource(R.string.mutual_lon)) },
                     placeholder = { Text(lonPlaceholder) },
                     keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Decimal),
                     singleLine = true,
@@ -425,15 +423,15 @@ private fun StationInputCard(
             OutlinedTextField(
                 value = grid,
                 onValueChange = onGridChange,
-                label = { Text("网格") },
+                label = { Text(stringResource(R.string.mutual_grid)) },
                 placeholder = { Text(gridPlaceholder) },
-                supportingText = { Text("支持 4/6/8 位 Maidenhead 网格；也可直接输入经纬度") },
+                supportingText = { Text(stringResource(R.string.mutual_grid_hint)) },
                 singleLine = true,
                 modifier = Modifier.fillMaxWidth()
             )
 
             Text(
-                text = "最小仰角：${minElev.toInt()}°",
+                text = stringResource(R.string.mutual_min_elevation, minElev.toInt()),
                 style = MaterialTheme.typography.bodySmall,
                 color = MaterialTheme.colorScheme.onSurfaceVariant
             )
@@ -461,7 +459,7 @@ private fun MatchSearchCard(
             verticalArrangement = Arrangement.spacedBy(10.dp)
         ) {
             Text(
-                text = "时间范围",
+                text = stringResource(R.string.mutual_time_range),
                 style = MaterialTheme.typography.titleSmall,
                 fontWeight = FontWeight.Medium
             )
@@ -492,7 +490,7 @@ private fun MatchSearchCard(
                     )
                     Spacer(Modifier.width(8.dp))
                 }
-                Text(if (isCalculating) "计算中..." else "查询匹配")
+                Text(if (isCalculating) stringResource(R.string.mutual_calculating) else stringResource(R.string.mutual_query))
             }
         }
     }
@@ -558,12 +556,12 @@ private fun MutualPassCard(
                 horizontalArrangement = Arrangement.SpaceBetween
             ) {
                 Text(
-                    text = "你: ${pass.maxElevationA}°",
+                    text = stringResource(R.string.mutual_elevation_you, pass.maxElevationA.toInt()),
                     style = MaterialTheme.typography.bodySmall,
                     color = MaterialTheme.colorScheme.primary
                 )
                 Text(
-                    text = "友台: ${pass.maxElevationB}°",
+                    text = stringResource(R.string.mutual_elevation_opposite, pass.maxElevationB.toInt()),
                     style = MaterialTheme.typography.bodySmall,
                     color = MaterialTheme.colorScheme.tertiary
                 )
@@ -579,7 +577,7 @@ private fun MutualPassCard(
                     // Dual-station radar track (polar plot)
                     if (visibleTracks.isNotEmpty()) {
                         Text(
-                            text = "双方轨迹",
+                            text = stringResource(R.string.mutual_both_tracks),
                             style = MaterialTheme.typography.titleSmall,
                             fontWeight = FontWeight.Medium,
                             color = MaterialTheme.colorScheme.onSurfaceVariant
@@ -587,8 +585,8 @@ private fun MutualPassCard(
                         MutualRadarView(
                             trackSamples = visibleTracks,
                             progress = dragProgress,
-                            labelA = "你",
-                            labelB = "友台"
+                            labelA = stringResource(R.string.mutual_label_you),
+                            labelB = stringResource(R.string.mutual_label_opposite)
                         )
                         Spacer(Modifier.height(8.dp))
                     }
@@ -613,7 +611,7 @@ private fun MutualPassCard(
                             modifier = Modifier.height(16.dp).width(16.dp)
                         )
                         Spacer(Modifier.width(6.dp))
-                        Text("查看雷达")
+                        Text(stringResource(R.string.mutual_open_radar))
                     }
                 }
             }

feature/mutual/src/main/java/com/rtbishop/look4sat/feature/mutual/MutualViewModel.kt

@@ -26,6 +26,9 @@ import com.rtbishop.look4sat.core.domain.predict.OrbitalPass
 import com.rtbishop.look4sat.core.domain.repository.IMainContainer
 import com.rtbishop.look4sat.core.domain.repository.ISatelliteRepo
 import com.rtbishop.look4sat.core.domain.repository.ISettingsRepo
+import com.rtbishop.look4sat.core.domain.utility.positionToQth
+import com.rtbishop.look4sat.core.domain.utility.qthToPosition
+import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
@@ -34,7 +37,6 @@ import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import kotlin.math.PI
-import kotlin.math.floor
 import kotlin.math.roundToInt
 
 data class MutualUiState(
@@ -56,7 +58,10 @@ data class MutualUiState(
 
 class MutualViewModel(
     private val satelliteRepo: ISatelliteRepo,
-    private val settingsRepo: ISettingsRepo
+    private val settingsRepo: ISettingsRepo,
+    // Injected so unit tests can run the pass computation on a test dispatcher;
+    // production callers keep the CPU-bound pool default.
+    private val computeDispatcher: CoroutineDispatcher = Dispatchers.Default
 ) : ViewModel() {
 
     private val _uiState = MutableStateFlow(MutualUiState())
@@ -66,7 +71,7 @@ class MutualViewModel(
         // Pre-fill station A with the user's current station position (as grid),
         // and default min elevation to the same value used by the main radar passes
         val pos = settingsRepo.stationPosition.value
-        val grid = latLonToGrid(pos.latitude, pos.longitude)
+        val grid = positionToQth(pos.latitude, pos.longitude) ?: ""
         _uiState.update { it.copy(
             stationAGrid = grid,
             stationALat = "%.4f".format(pos.latitude),
@@ -81,7 +86,9 @@ class MutualViewModel(
         val lat = value.toDoubleOrNull()
         val lon = _uiState.value.stationALon.toDoubleOrNull()
         if (lat != null && lon != null) {
-            _uiState.update { it.copy(stationAGrid = latLonToGrid(lat, lon)) }
+            positionToQth(lat, lon)?.let { grid ->
+                _uiState.update { it.copy(stationAGrid = grid) }
+            }
         }
     }
 
@@ -90,15 +97,18 @@ class MutualViewModel(
         val lat = _uiState.value.stationALat.toDoubleOrNull()
         val lon = value.toDoubleOrNull()
         if (lat != null && lon != null) {
-            _uiState.update { it.copy(stationAGrid = latLonToGrid(lat, lon)) }
+            positionToQth(lat, lon)?.let { grid ->
+                _uiState.update { it.copy(stationAGrid = grid) }
+            }
         }
     }
 
     fun onStationAGrid(value: String) {
         val old = _uiState.value.stationAGrid
-        _uiState.update { it.copy(stationAGrid = value) }
-        if (value.trim().uppercase() == old.trim().uppercase()) return
-        val pos = gridToLatLon(value.trim().uppercase())
+        val newGrid = value.trim().uppercase()
+        _uiState.update { it.copy(stationAGrid = newGrid) }
+        if (newGrid == old.trim().uppercase()) return
+        val pos = qthToPosition(newGrid)
         if (pos != null) {
             _uiState.update { it.copy(
                 stationALat = "%.4f".format(pos.latitude),
@@ -112,7 +122,9 @@ class MutualViewModel(
         val lat = value.toDoubleOrNull()
         val lon = _uiState.value.stationBLon.toDoubleOrNull()
         if (lat != null && lon != null) {
-            _uiState.update { it.copy(stationBGrid = latLonToGrid(lat, lon)) }
+            positionToQth(lat, lon)?.let { grid ->
+                _uiState.update { it.copy(stationBGrid = grid) }
+            }
         }
     }
 
@@ -121,15 +133,18 @@ class MutualViewModel(
         val lat = _uiState.value.stationBLat.toDoubleOrNull()
         val lon = value.toDoubleOrNull()
         if (lat != null && lon != null) {
-            _uiState.update { it.copy(stationBGrid = latLonToGrid(lat, lon)) }
+            positionToQth(lat, lon)?.let { grid ->
+                _uiState.update { it.copy(stationBGrid = grid) }
+            }
         }
     }
 
     fun onStationBGrid(value: String) {
         val old = _uiState.value.stationBGrid
-        _uiState.update { it.copy(stationBGrid = value) }
-        if (value.trim().uppercase() == old.trim().uppercase()) return
-        val pos = gridToLatLon(value.trim().uppercase())
+        val newGrid = value.trim().uppercase()
+        _uiState.update { it.copy(stationBGrid = newGrid) }
+        if (newGrid == old.trim().uppercase()) return
+        val pos = qthToPosition(newGrid)
         if (pos != null) {
             _uiState.update { it.copy(
                 stationBLat = "%.4f".format(pos.latitude),
@@ -144,7 +159,7 @@ class MutualViewModel(
         _uiState.update { it.copy(
             stationALat = "%.4f".format(pos.latitude),
             stationALon = "%.4f".format(pos.longitude),
-            stationAGrid = latLonToGrid(pos.latitude, pos.longitude)
+            stationAGrid = positionToQth(pos.latitude, pos.longitude) ?: ""
         ) }
     }
     fun onHoursAhead(value: Int) = _uiState.update { it.copy(hoursAhead = value) }
@@ -158,13 +173,13 @@ class MutualViewModel(
         var posB = resolvePosition(state.stationBLat, state.stationBLon, state.stationBGrid)
 
         if (posA == null || posB == null) {
-            _uiState.update { it.copy(errorMessage = "请输入有效的位置坐标或网格（4/6/8位）") }
+            _uiState.update { it.copy(errorMessage = "Please enter valid coordinates or a Maidenhead grid (4/6/8 chars)") }
             return
         }
 
         val satellites = satelliteRepo.satellites.value
         if (satellites.isEmpty()) {
-            _uiState.update { it.copy(errorMessage = "没有卫星数据，请先在卫星列表中选择卫星") }
+            _uiState.update { it.copy(errorMessage = "No satellite data. Select satellites from the list first.") }
             return
         }
 
@@ -184,7 +199,7 @@ class MutualViewModel(
             val minElevB = state.stationBMinElev
             val hours = state.hoursAhead
 
-            val results = withContext(Dispatchers.Default) {
+            val results = withContext(computeDispatcher) {
                 findMutualPasses(satellites, posA, posB, minElevA, minElevB, time, hours)
             }
 
@@ -193,9 +208,9 @@ class MutualViewModel(
                 val passCount = satelliteRepo.passes.value.size
                 val satCount = satellites.size
                 when {
-                    passCount == 0 -> "过境列表为空，请先在卫星列表中选择卫星"
-                    satCount == 0 -> "没有已选中的卫星"
-                    else -> "未找到共同过境（${passCount}个过境，${satCount}颗卫星）"
+                    passCount == 0 -> "Pass list is empty. Select satellites from the list first."
+                    satCount == 0 -> "No satellites selected."
+                    else -> "No mutual passes found (${passCount} passes, ${satCount} satellites)."
                 }
             } else null
 
@@ -213,83 +228,13 @@ class MutualViewModel(
     private fun resolvePosition(latText: String, lonText: String, gridText: String): GeoPos? {
         val trimmed = gridText.trim().uppercase()
         if (trimmed.length in listOf(4, 6, 8) && trimmed.all { it.isLetterOrDigit() }) {
-            return gridToLatLon(trimmed)
+            return qthToPosition(trimmed)
         }
         val lat = latText.toDoubleOrNull()
         val lon = lonText.toDoubleOrNull()
         return if (lat != null && lon != null) GeoPos(lat, lon) else null
     }
 
-    /** Convert lat/lon to Maidenhead grid (6-char). */
-    private fun latLonToGrid(lat: Double, lon: Double): String {
-        var adjLon = (lon + 180.0) % 360.0
-        var adjLat = (lat + 90.0) % 180.0
-
-        val fieldLon = (adjLon / 20.0).toInt()
-        val fieldLat = (adjLat / 10.0).toInt()
-        adjLon -= fieldLon * 20.0
-        adjLat -= fieldLat * 10.0
-
-        val squareLon = (adjLon / 2.0).toInt()
-        val squareLat = (adjLat / 1.0).toInt()
-        adjLon -= squareLon * 2.0
-        adjLat -= squareLat * 1.0
-
-        val subLon = (adjLon * 60.0 / 5.0).toInt()
-        val subLat = (adjLat * 60.0 / 2.5).toInt()
-
-        return buildString {
-            append('A' + fieldLon)
-            append('A' + fieldLat)
-            append('0' + squareLon)
-            append('0' + squareLat)
-            append('A' + subLon)
-            append('A' + subLat)
-        }
-    }
-
-    /** Convert Maidenhead grid (4, 6, or 8 chars) to lat/lon center of the square. */
-    private fun gridToLatLon(grid: String): GeoPos? {
-        val g = grid.uppercase()
-        if (g.length < 4) return null
-        val lonField = (g[0] - 'A').toDouble() * 20.0
-        val latField = (g[1] - 'A').toDouble() * 10.0
-        if (lonField < 0 || lonField > 340 || latField < 0 || latField > 170) return null
-
-        val lonSquare = (g[2] - '0').toDouble() * 2.0
-        val latSquare = (g[3] - '0').toDouble() * 1.0
-        if (lonSquare < 0 || lonSquare > 18 || latSquare < 0 || latSquare > 9) return null
-
-        var lon = lonField + lonSquare
-        var lat = latField + latSquare
-
-        if (g.length >= 6) {
-            val lonSub = (g[4] - 'A').toDouble() * 5.0 / 60.0
-            val latSub = (g[5] - 'A').toDouble() * 2.5 / 60.0
-            if (lonSub < 0 || lonSub > 115.0 / 60.0 || latSub < 0 || latSub > 57.5 / 60.0) return null
-            lon += lonSub
-            lat += latSub
-
-            if (g.length >= 8) {
-                val lonExt = (g[6] - '0').toDouble() * 30.0 / 3600.0
-                val latExt = (g[7] - '0').toDouble() * 15.0 / 3600.0
-                if (lonExt < 0 || lonExt > 270.0 / 3600.0 || latExt < 0 || latExt > 135.0 / 3600.0) return null
-                lon += lonExt + 15.0 / 3600.0
-                lat += latExt + 7.5 / 3600.0
-            } else {
-                lon += 2.5 / 60.0
-                lat += 1.25 / 60.0
-            }
-        } else {
-            lon += 1.0
-            lat += 0.5
-        }
-
-        lon = lon - 180.0
-        lat = lat - 90.0
-        return GeoPos(lat, lon)
-    }
-
     private fun findMutualPasses(
         satellites: List<OrbitalObject>,
         posA: GeoPos, posB: GeoPos,

feature/mutual/src/test/java/com/rtbishop/look4sat/feature/mutual/Fakes.kt

@@ -0,0 +1,96 @@
+package com.rtbishop.look4sat.feature.mutual
+
+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.SatRadio
+import com.rtbishop.look4sat.core.domain.predict.GeoPos
+import com.rtbishop.look4sat.core.domain.predict.OrbitalObject
+import com.rtbishop.look4sat.core.domain.predict.OrbitalPass
+import com.rtbishop.look4sat.core.domain.predict.OrbitalPos
+import com.rtbishop.look4sat.core.domain.repository.ISatelliteRepo
+import com.rtbishop.look4sat.core.domain.repository.ISettingsRepo
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+
+/**
+ * Test fake for ISatelliteRepo. Only `satellites` and `passes` are backed by
+ * mutable state; everything else the ViewModel never touches fails loudly.
+ */
+class FakeSatelliteRepo(
+    satellites: List<OrbitalObject> = emptyList(),
+    passes: List<OrbitalPass> = emptyList()
+) : ISatelliteRepo {
+
+    override val satellites = MutableStateFlow(satellites)
+    override val passes = MutableStateFlow(passes)
+    override val isCalculating = MutableStateFlow(false)
+    override val selectedPass = MutableStateFlow(Pair(0, 0L))
+
+    override fun selectPass(catNum: Int, aosTime: Long) = TODO()
+    override suspend fun initRepository() = TODO()
+    override suspend fun calculatePasses(
+        time: Long, hoursAhead: Int, minElevation: Double,
+        aosStartMinute: Int, aosEndMinute: Int,
+        invertAosTimeWindow: Boolean, modes: List<String>
+    ) = TODO()
+    override suspend fun getPosition(sat: OrbitalObject, pos: GeoPos, time: Long): OrbitalPos = TODO()
+    override suspend fun getTrack(sat: OrbitalObject, pos: GeoPos, start: Long, end: Long): List<OrbitalPos> = TODO()
+    override suspend fun getRadios(sat: OrbitalObject, pos: GeoPos, radios: List<SatRadio>, time: Long): List<SatRadio> = TODO()
+    override suspend fun getRadiosWithId(id: Int): List<SatRadio> = TODO()
+}
+
+/**
+ * Test fake for ISettingsRepo. Only [stationPosition] is backed by mutable
+ * state; everything else the ViewModel never touches fails loudly.
+ */
+class FakeSettingsRepo(initialPosition: GeoPos = GeoPos(23.13, 113.26)) : ISettingsRepo {
+
+    override val stationPosition = MutableStateFlow(initialPosition)
+
+    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 databaseState: StateFlow<DatabaseState> = MutableStateFlow(DatabaseState(0, 0, 0L))
+    override val rcSettings: StateFlow<RCSettings> = MutableStateFlow(
+        RCSettings(false, "", "", "", false, "", "", "", 0L, false, "", "", "", false, "", "")
+    )
+    override val otherSettings: StateFlow<OtherSettings> = MutableStateFlow(
+        OtherSettings(false, false, false, false, false, false, false, false)
+    )
+    override val dataSourcesSettings: StateFlow<DataSourcesSettings> = MutableStateFlow(
+        DataSourcesSettings(satelliteUrls = emptyList(), transceiversUrls = emptyList())
+    )
+    override val radioControlSettings: StateFlow<RadioControlSettings> = MutableStateFlow(
+        RadioControlSettings(false, RadioControlSettings.MODEL_YAESU_FT817, "", "", "", "", 9600)
+    )
+
+    override fun setSelectedIds(ids: List<Int>) = TODO()
+    override fun setSelectedTypes(types: List<String>) = TODO()
+    override fun setPassesSettings(settings: PassesSettings) = TODO()
+    override fun setStationPosition(latitude: Double, longitude: Double, altitude: Double): Boolean = TODO()
+    override fun setStationPosition(): Boolean = TODO()
+    override fun setStationPosition(locator: String): Boolean = TODO()
+    override fun getSatelliteTypesIds(types: List<String>): List<Int> = TODO()
+    override fun setSatelliteTypeIds(type: String, ids: List<Int>) = TODO()
+    override fun updateDatabaseState(state: DatabaseState) = TODO()
+    override fun updateRCSettings(settings: RCSettings) = TODO()
+    override fun updateOtherSettings(transform: (OtherSettings) -> OtherSettings) = TODO()
+    override fun updateDataSourcesSettings(settings: DataSourcesSettings) = TODO()
+
+    override val dataSourcesStatus: StateFlow<Map<String, Int>> = MutableStateFlow(emptyMap())
+
+    override fun updateDataSourcesStatus(status: Map<String, Int>) = TODO()
+
+    override fun updateRadioControlSettings(settings: RadioControlSettings) = TODO()
+    override fun getSatelliteOffset(catnum: Int): String = ""
+    override fun setSatelliteOffset(catnum: Int, offset: String) = TODO()
+    override fun getAmSatCallsign(): String = ""
+    override fun setAmSatCallsign(callsign: String) = TODO()
+}

feature/mutual/src/test/java/com/rtbishop/look4sat/feature/mutual/MainDispatcherRule.kt

@@ -0,0 +1,25 @@
+package com.rtbishop.look4sat.feature.mutual
+
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.TestDispatcher
+import kotlinx.coroutines.test.StandardTestDispatcher
+import kotlinx.coroutines.test.resetMain
+import kotlinx.coroutines.test.setMain
+import org.junit.rules.TestWatcher
+import org.junit.runner.Description
+
+/**
+ * Swaps the Main dispatcher for a [StandardTestDispatcher] so that
+ * `viewModelScope.launch` work can be driven deterministically with
+ * `runTest` / `advanceUntilIdle()` instead of racing real threads.
+ */
+@OptIn(ExperimentalCoroutinesApi::class)
+class MainDispatcherRule(
+    val dispatcher: TestDispatcher = StandardTestDispatcher()
+) : TestWatcher() {
+
+    override fun starting(description: Description) = Dispatchers.setMain(dispatcher)
+
+    override fun finished(description: Description) = Dispatchers.resetMain()
+}

feature/mutual/src/test/java/com/rtbishop/look4sat/feature/mutual/MutualViewModelTest.kt

@@ -0,0 +1,288 @@
+package com.rtbishop.look4sat.feature.mutual
+
+import com.rtbishop.look4sat.core.domain.predict.GeoPos
+import com.rtbishop.look4sat.core.domain.predict.OrbitalObject
+import com.rtbishop.look4sat.core.domain.predict.OrbitalPass
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.StandardTestDispatcher
+import kotlinx.coroutines.test.TestScope
+import kotlinx.coroutines.test.advanceUntilIdle
+import kotlinx.coroutines.test.runTest
+import kotlin.random.Random
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertNotEquals
+import org.junit.Assert.assertNull
+import org.junit.Assert.assertTrue
+import org.junit.Rule
+import org.junit.Test
+
+@OptIn(ExperimentalCoroutinesApi::class)
+class MutualViewModelTest {
+
+    @get:Rule
+    val mainDispatcherRule = MainDispatcherRule()
+
+    /**
+     * ViewModel wired to fakes and a test dispatcher that shares the runTest
+     * scheduler, so [advanceUntilIdle] deterministically drains both the
+     * viewModelScope (Main) queue and the compute dispatcher.
+     */
+    private fun TestScope.createVm(
+        satellites: List<OrbitalObject> = emptyList(),
+        passes: List<OrbitalPass> = emptyList(),
+        position: GeoPos = TestOrbits.GUANGZHOU
+    ): MutualViewModel = MutualViewModel(
+        satelliteRepo = FakeSatelliteRepo(satellites, passes),
+        settingsRepo = FakeSettingsRepo(position),
+        computeDispatcher = StandardTestDispatcher(mainDispatcherRule.dispatcher.scheduler)
+    )
+
+    private fun TestScope.queryAndSettle(vm: MutualViewModel) {
+        vm.queryMutualPasses()
+        advanceUntilIdle()
+    }
+
+    // ---------------------------------------------------------------- init
+
+    @Test
+    fun `init prefills station A with the current position`() = runTest(mainDispatcherRule.dispatcher.scheduler) {
+        val vm = createVm(position = TestOrbits.GUANGZHOU)
+        val state = vm.uiState.value
+
+        assertEquals("23.1300", state.stationALat)
+        assertEquals("113.2600", state.stationALon)
+        assertEquals(6, state.stationAGrid.length)
+        assertTrue(state.stationAGrid.startsWith("OL63"))
+        assertTrue(state.stationAGrid.uppercase() == state.stationAGrid)
+        assertEquals(0.0, state.stationAMinElev, 0.0)
+    }
+
+    // ------------------------------------------------------- station input
+
+    @Test
+    fun `entering latitude recomputes the maidenhead grid`() = runTest(mainDispatcherRule.dispatcher.scheduler) {
+        val vm = createVm(position = TestOrbits.SHENZHEN) // station A pre-filled with SZ
+        vm.onStationALat("23.5")
+
+        // 23.5N 114.06E -> field OL, square 73 (Shenzhen), subsquare AM
+        assertEquals("OL73AM", vm.uiState.value.stationAGrid)
+        // raw input string is stored verbatim, not reformatted
+        assertEquals("23.5", vm.uiState.value.stationALat)
+    }
+
+    @Test
+    fun `entering longitude recomputes the maidenhead grid`() = runTest(mainDispatcherRule.dispatcher.scheduler) {
+        val vm = createVm(position = TestOrbits.GUANGZHOU)
+        vm.onStationALon("113.5")
+
+        // 23.13N 113.5E -> Guangzhou field OL63, subsquare SD
+        assertEquals("OL63SD", vm.uiState.value.stationAGrid)
+        // raw input string is stored verbatim, not reformatted
+        assertEquals("113.5", vm.uiState.value.stationALon)
+    }
+
+    @Test
+    fun `entering a lowercase grid normalises to uppercase and updates lat lon`() = runTest(mainDispatcherRule.dispatcher.scheduler) {
+        val vm = createVm(position = TestOrbits.NEW_YORK)
+        vm.onStationAGrid("ol63")
+
+        val state = vm.uiState.value
+        // The grid is normalised to upper case on input (Bug fix: raw input
+        // used to be stored verbatim, e.g. "ol63" stayed lowercase).
+        assertEquals("OL63", state.stationAGrid)
+        // 4-char grid resolves to the square centre
+        assertEquals(23.5, state.stationALat.toDouble(), 1e-9)
+        assertEquals(113.0, state.stationALon.toDouble(), 1e-9)
+    }
+
+    @Test
+    fun `invalid grid leaves lat and lon untouched`() = runTest(mainDispatcherRule.dispatcher.scheduler) {
+        val vm = createVm(position = TestOrbits.GUANGZHOU)
+        val before = vm.uiState.value.stationALat
+        vm.onStationAGrid("ZZ99") // valid shape, out-of-range letters
+
+        assertEquals("ZZ99", vm.uiState.value.stationAGrid)
+        assertEquals(before, vm.uiState.value.stationALat)
+    }
+
+    @Test
+    fun `use current position restores station A from settings`() = runTest(mainDispatcherRule.dispatcher.scheduler) {
+        val vm = createVm(position = TestOrbits.GUANGZHOU)
+        vm.onStationALat("10.0")
+        vm.onStationALon("20.0")
+        assertNotEquals("23.1300", vm.uiState.value.stationALat)
+
+        vm.onUseCurrentPosition()
+
+        val state = vm.uiState.value
+        assertEquals("23.1300", state.stationALat)
+        assertEquals("113.2600", state.stationALon)
+        assertTrue(state.stationAGrid.startsWith("OL63"))
+    }
+
+    @Test
+    fun `station B independent from station A`() = runTest(mainDispatcherRule.dispatcher.scheduler) {
+        val vm = createVm()
+        vm.onStationBLat("22.54")
+        vm.onStationBLon("114.06")
+
+        // 22.54N 114.06E is Shenzhen: OL72 field (lon square 7, lat square 2)
+        assertEquals("OL72", vm.uiState.value.stationBGrid.take(4))
+        assertTrue(vm.uiState.value.stationBGrid.length == 6)
+    }
+
+    // ------------------------------------------------------ query: errors
+
+    @Test
+    fun `query with invalid coordinates sets an error and does not search`() = runTest(mainDispatcherRule.dispatcher.scheduler) {
+        val vm = createVm(satellites = listOf(TestOrbits.ISS), passes = TestOrbits.findPassWindows())
+        vm.onStationAGrid("ZZ99")
+        vm.onStationBGrid("ZZ99")
+
+        queryAndSettle(vm)
+
+        val state = vm.uiState.value
+        assertTrue(state.errorMessage != null)
+        assertFalse(state.hasSearched)
+        assertFalse(state.isCalculating)
+        assertTrue(state.mutualPasses.isEmpty())
+    }
+
+    @Test
+    fun `query with no satellites sets an error`() = runTest(mainDispatcherRule.dispatcher.scheduler) {
+        val vm = createVm(satellites = emptyList())
+        vm.onStationBGrid("OL62")
+
+        queryAndSettle(vm)
+
+        assertEquals(
+            "No satellite data. Select satellites from the list first.",
+            vm.uiState.value.errorMessage
+        )
+    }
+
+    @Test
+    fun `query with everything empty reports empty pass list`() = runTest(mainDispatcherRule.dispatcher.scheduler) {
+        val vm = createVm(satellites = listOf(TestOrbits.ISS), passes = emptyList())
+        vm.onStationBGrid("OL62")
+        vm.onStationAMinElev(89.0)
+        vm.onStationBMinElev(89.0)
+        vm.onHoursAhead(2)
+
+        queryAndSettle(vm)
+
+        val state = vm.uiState.value
+        assertFalse(state.isCalculating)
+        assertEquals("Pass list is empty. Select satellites from the list first.", state.errorMessage)
+    }
+
+    // --------------------------------------------------- query: happy path
+
+    @Test
+    fun `query finds mutual passes reusing the main pass list`() = runTest(mainDispatcherRule.dispatcher.scheduler) {
+        val windows = TestOrbits.findPassWindows(hoursAhead = 12)
+        assertTrue("test fixture must produce ISS passes over Guangzhou", windows.isNotEmpty())
+
+        val vm = createVm(
+            satellites = listOf(TestOrbits.ISS),
+            passes = windows
+        )
+        vm.onStationBGrid("OL62")
+        vm.onHoursAhead(12)
+
+        queryAndSettle(vm)
+
+        val state = vm.uiState.value
+        assertNull(state.errorMessage)
+        assertTrue(state.hasSearched)
+        assertFalse(state.isCalculating)
+        assertTrue("expected at least one mutual pass", state.mutualPasses.isNotEmpty())
+        assertTrue(state.mutualPasses.all { it.catNum == 25544 })
+        assertTrue(state.mutualPasses.all { it.name == "ISS (ZARYA)" })
+        // AOS/LOS within the searched horizon
+        val now = System.currentTimeMillis()
+        assertTrue(state.mutualPasses.all { it.startTime >= now - 120_000L })
+        assertTrue(state.mutualPasses.all { it.endTime <= now + 12 * 3600_000L + 120_000L })
+    }
+
+    @Test
+    fun `query results are sorted by start time even when input is shuffled`() = runTest(mainDispatcherRule.dispatcher.scheduler) {
+        // A 24h horizon reliably yields several windows per satellite (ISS +
+        // staggered variant), guaranteeing >= 2 distinct passes.
+        val windows = TestOrbits.findPassWindows(hoursAhead = 24) +
+            TestOrbits.findPassWindows(sat = TestOrbits.ISS_VARIANT, hoursAhead = 24)
+        assertTrue("fixture must produce at least two windows", windows.size >= 2)
+
+        val shuffled = windows.shuffled(Random(42))
+        val vm = createVm(
+            satellites = listOf(TestOrbits.ISS, TestOrbits.ISS_VARIANT),
+            passes = shuffled
+        )
+        vm.onStationBGrid("OL62")
+        vm.onHoursAhead(24)
+
+        queryAndSettle(vm)
+
+        val starts = vm.uiState.value.mutualPasses.map { it.startTime }
+        assertEquals(starts.sorted(), starts)
+        // Refined AOS must not drift far from the coarse window
+        val byAos = windows.associateBy { it.aosTime }
+        vm.uiState.value.mutualPasses.forEach { mp ->
+            assertTrue("refined AOS ${mp.startTime} near a coarse AOS", byAos.keys.any { kotlin.math.abs(it - mp.startTime) < 5 * 60_000L })
+        }
+    }
+
+    // -------------------------------------------------- query: fallback
+
+    @Test
+    fun `query falls back to independent search when pass list is empty`() = runTest(mainDispatcherRule.dispatcher.scheduler) {
+        // Two satellites (ISS + staggered variant) raise the odds of a window
+        // within the fallback horizon while keeping the search realistic.
+        val vm = createVm(
+            satellites = listOf(TestOrbits.ISS, TestOrbits.ISS_VARIANT),
+            passes = emptyList()
+        )
+        vm.onStationBGrid("OL62")
+        vm.onHoursAhead(12)
+
+        queryAndSettle(vm)
+
+        val state = vm.uiState.value
+        assertFalse(state.isCalculating)
+        assertTrue(state.hasSearched)
+        // GZ + SZ are ~100km apart: a 12h ISS window must yield at least one mutual pass
+        assertNull(state.errorMessage)
+        assertTrue("fallback should find mutual passes", state.mutualPasses.isNotEmpty())
+    }
+
+    @Test
+    fun `query over antipodal stations finds no mutual passes`() = runTest(mainDispatcherRule.dispatcher.scheduler) {
+        val vm = createVm(satellites = listOf(TestOrbits.ISS), passes = emptyList())
+        vm.onStationBLat("40.71")
+        vm.onStationBLon("-74.01")
+        vm.onHoursAhead(2)
+
+        queryAndSettle(vm)
+
+        val state = vm.uiState.value
+        assertFalse(state.isCalculating)
+        assertTrue(state.mutualPasses.isEmpty())
+        assertTrue(state.errorMessage != null)
+    }
+
+    // -------------------------------------------------------------- misc
+
+    @Test
+    fun `clearError resets the error message`() = runTest(mainDispatcherRule.dispatcher.scheduler) {
+        val vm = createVm()
+        vm.onStationAGrid("ZZ99")
+        vm.onStationBGrid("ZZ99")
+        queryAndSettle(vm)
+        assertTrue(vm.uiState.value.errorMessage != null)
+
+        vm.clearError()
+
+        assertNull(vm.uiState.value.errorMessage)
+    }
+}

feature/mutual/src/test/java/com/rtbishop/look4sat/feature/mutual/TestOrbits.kt

@@ -0,0 +1,104 @@
+package com.rtbishop.look4sat.feature.mutual
+
+import com.rtbishop.look4sat.core.domain.predict.GeoPos
+import com.rtbishop.look4sat.core.domain.predict.NearEarthObject
+import com.rtbishop.look4sat.core.domain.predict.OrbitalData
+import com.rtbishop.look4sat.core.domain.predict.OrbitalObject
+import com.rtbishop.look4sat.core.domain.predict.OrbitalPass
+import kotlin.math.PI
+
+/**
+ * Deterministic orbital test fixtures: real ISS TLE elements (2024-03-09,
+ * same source as DataParserTest) so SGP4 propagation produces genuine
+ * visibility windows instead of fabricated numbers.
+ */
+object TestOrbits {
+
+    /** ISS (ZARYA) from the 2024-03-09 TLE used in DataParserTest. */
+    val ISS: OrbitalObject = NearEarthObject(
+        OrbitalData(
+            name = "ISS (ZARYA)",
+            epoch = 24069.23963816,
+            meanmo = 15.49756209,
+            eccn = 0.0005741,
+            incl = 51.6418,
+            raan = 90.7424,
+            argper = 343.9724,
+            meanan = 92.8274,
+            catnum = 25544,
+            bstar = 0.00025016
+        )
+    )
+
+    /** Guangzhou (default BA7OPF grid OL62/OL63 area). */
+    val GUANGZHOU = GeoPos(23.13, 113.26)
+
+    /** Shenzhen, ~100 km from Guangzhou — nearly every LEO pass is mutual. */
+    val SHENZHEN = GeoPos(22.54, 114.06)
+
+    /** New York — on the opposite side of the globe, never mutual with GZ. */
+    val NEW_YORK = GeoPos(40.71, -74.01)
+
+    /**
+     * Second LEO with the same ISS elements but a different argument of
+     * perigee, so its visibility windows land at different times. Gives tests
+     * two distinct passes to exercise ordering/aggregation logic.
+     */
+    val ISS_VARIANT: OrbitalObject = NearEarthObject(
+        OrbitalData(
+            name = "ISS-V2",
+            epoch = 24069.23963816,
+            meanmo = 15.49756209,
+            eccn = 0.0005741,
+            incl = 51.6418,
+            raan = 90.7424,
+            argper = 100.0,
+            meanan = 92.8274,
+            catnum = 25545,
+            bstar = 0.00025016
+        )
+    )
+
+    /**
+     * Coarse pass-window search (30s steps) producing OrbitalPass entries with
+     * honest AOS/LOS times. Mirrors the coarse phase of SatelliteRepo.getLeoPass;
+     * the ViewModel under test re-refines the edges to ~1s itself.
+     */
+    fun findPassWindows(
+        sat: OrbitalObject = ISS,
+        pos: GeoPos = GUANGZHOU,
+        time: Long = System.currentTimeMillis(),
+        hoursAhead: Int = 12
+    ): List<OrbitalPass> {
+        if (!sat.willBeSeen(pos)) return emptyList()
+        val passes = mutableListOf<OrbitalPass>()
+        val step = 30_000L
+        val end = time + hoursAhead * 3600_000L
+        var t = time
+        var inWindow = false
+        var aos = 0L
+        var maxElev = 0.0
+        while (t < end) {
+            val elev = sat.getElevation(pos, t) * 180.0 / PI
+            if (elev > 0.0 && !inWindow) {
+                inWindow = true
+                aos = t
+                maxElev = 0.0
+            }
+            if (inWindow && elev > maxElev) maxElev = elev
+            if (elev <= 0.0 && inWindow) {
+                inWindow = false
+                passes.add(
+                    OrbitalPass(
+                        aosTime = aos,
+                        losTime = t,
+                        maxElevation = maxElev,
+                        orbitalObject = sat
+                    )
+                )
+            }
+            t += step
+        }
+        return passes
+    }
+}

feature/passes/src/main/java/com/rtbishop/look4sat/feature/passes/PassesScreen.kt

@@ -84,19 +84,23 @@ import java.util.Locale
 import java.util.TimeZone
 
 @Composable
-fun PassesDestination(navigateToRadar: (Int, Long) -> Unit) {
+fun PassesDestination(
+    navigateToRadar: (Int, Long) -> Unit,
+    navigateToMap: () -> Unit
+) {
     val context = LocalContext.current
     val container = (context.applicationContext as IContainerProvider).getMainContainer()
     val viewModel: PassesViewModel = viewModel(factory = PassesViewModel.factory(container))
     val uiState = viewModel.uiState.collectAsStateWithLifecycle().value
-    PassesScreen(uiState, viewModel::onAction, navigateToRadar)
+    PassesScreen(uiState, viewModel::onAction, navigateToRadar, navigateToMap)
 }
 
 @Composable
 private fun PassesScreen(
     uiState: PassesState,
     onAction: (PassesAction) -> Unit,
-    navigateToRadar: (Int, Long) -> Unit
+    navigateToRadar: (Int, Long) -> Unit,
+    navigateToMap: () -> Unit
 ) {
     if (uiState.isPassesDialogShown) {
         PassesFilterDialog(
@@ -163,7 +167,7 @@ private fun PassesScreen(
                     NextPassRow(pass = uiState.nextPass, isUtc = uiState.isUtc)
                 },
                 endAction = {
-                    IconCard(action = { onAction(PassesAction.ToggleRadiosDialog) }, resId = R.drawable.ic_radios)
+                    IconCard(action = navigateToMap, resId = R.drawable.ic_map)
                 }
             )
         }

feature/passes/src/main/java/com/rtbishop/look4sat/feature/passes/PassesViewModel.kt

@@ -23,6 +23,7 @@ import androidx.lifecycle.viewmodel.initializer
 import androidx.lifecycle.viewmodel.viewModelFactory
 import com.rtbishop.look4sat.core.domain.model.PassesSettings
 import com.rtbishop.look4sat.core.domain.predict.CelestialComputer
+import com.rtbishop.look4sat.core.domain.predict.GeoPos
 import com.rtbishop.look4sat.core.domain.predict.OrbitalPass
 import com.rtbishop.look4sat.core.domain.repository.IMainContainer
 import com.rtbishop.look4sat.core.domain.repository.ISatelliteRepo
@@ -167,6 +168,7 @@ class PassesViewModel(
     // CelestialComputer.findSunRiseSet() returns the next rise/set after the supplied time, so pass
     // the calendar day's 00:00 in the same timezone used by the visible date group. Passing a pass's
     // AOS time can jump to the following day's sunrise/sunset when that AOS is after the local event.
+    // For white nights / polar day edge cases, we fall back to searching from the previous day.
     private fun computeSunTimes(passes: List<OrbitalPass>, isUtc: Boolean): Map<String, Pair<String, String>> {
         val stationPos = settingsRepo.stationPosition.value
         val tz = if (isUtc) TimeZone.getTimeZone("UTC") else TimeZone.getDefault()
@@ -175,7 +177,7 @@ class PassesViewModel(
         val result = LinkedHashMap<String, Pair<String, String>>()
         // DeepSpace group always shows today's sun times
         if (passes.any { it.isDeepSpace }) {
-            val riseSet = CelestialComputer.findSunRiseSet(stationPos, startOfDayMillis(System.currentTimeMillis(), tz))
+            val riseSet = findTodaySunRiseSet(stationPos, startOfDayMillis(System.currentTimeMillis(), tz))
             val rise = if (riseSet.riseTimeMillis > 0) sdfTime.format(Date(riseSet.riseTimeMillis)) else "--:--"
             val set = if (riseSet.setTimeMillis > 0) sdfTime.format(Date(riseSet.setTimeMillis)) else "--:--"
             result["DeepSpace (period >225min)"] = rise to set
@@ -184,7 +186,7 @@ class PassesViewModel(
             if (pass.isDeepSpace) continue
             val label = sdfDate.format(Date(pass.aosTime))
             if (label in result) continue
-            val riseSet = CelestialComputer.findSunRiseSet(stationPos, startOfDayMillis(pass.aosTime, tz))
+            val riseSet = findTodaySunRiseSet(stationPos, startOfDayMillis(pass.aosTime, tz))
             val rise = if (riseSet.riseTimeMillis > 0) sdfTime.format(Date(riseSet.riseTimeMillis)) else "--:--"
             val set = if (riseSet.setTimeMillis > 0) sdfTime.format(Date(riseSet.setTimeMillis)) else "--:--"
             result[label] = rise to set
@@ -192,6 +194,33 @@ class PassesViewModel(
         return result
     }
 
+    /**
+     * Find today's sunrise and sunset by starting from local midnight.
+     * Handles the white nights / polar day edge case where the sun is still above
+     * the -0.8333° threshold at midnight: in that case we search from the previous
+     * day's midnight to find a valid sunrise/sunset pair within the target day.
+     */
+    private fun findTodaySunRiseSet(observer: GeoPos, localMidnightMillis: Long): CelestialComputer.RiseSetTimes {
+        val threshold = 0.8333
+        val sunPos = CelestialComputer.getSunPosition(observer, localMidnightMillis)
+        if (sunPos.elevation > -threshold) {
+            // White nights / polar day: the sun is too high at midnight.
+            // Search from earlier days so the algorithm goes through a full
+            // sunset → sunrise → sunset cycle, landing in the target day.
+            val dayEnd = localMidnightMillis + 86400000L
+            for (offset in 1..3) {
+                val result = CelestialComputer.findSunRiseSet(observer, localMidnightMillis - offset * 86400000L)
+                if (result.riseTimeMillis in localMidnightMillis..dayEnd &&
+                    result.setTimeMillis in localMidnightMillis..dayEnd) {
+                    return result
+                }
+            }
+            // No valid pair found (midnight sun / polar day)
+            return CelestialComputer.RiseSetTimes(0L, 0L)
+        }
+        return CelestialComputer.findSunRiseSet(observer, localMidnightMillis)
+    }
+
     private fun startOfDayMillis(timeMillis: Long, tz: TimeZone): Long {
         return Calendar.getInstance(tz, Locale.getDefault()).apply {
             timeInMillis = timeMillis

feature/radar/src/main/java/com/rtbishop/look4sat/feature/radar/RadarScreen.kt

@@ -84,7 +84,7 @@ private enum class RadarPage(val title: String) {
 }
 
 @Composable
-fun RadarDestination(navigateUp: () -> Unit) {
+fun RadarDestination(navigateUp: () -> Unit, navigateToMap: () -> Unit) {
     val context = LocalContext.current
     val container = (context.applicationContext as IContainerProvider).getMainContainer()
     val viewModel: RadarViewModel = viewModel(factory = RadarViewModel.factory(container))
@@ -96,6 +96,12 @@ fun RadarDestination(navigateUp: () -> Unit) {
         }
         navigateUp()
     }
+    val navigateToMapAndClearMutual = {
+        if (container.mutualPassData.value.endTime > 0L) {
+            container.setMutualPassData(MutualPassData())
+        }
+        navigateToMap()
+    }
     LaunchedEffect(mutualData.endTime) {
         if (mutualData.endTime <= 0L) return@LaunchedEffect
         while (true) {
@@ -121,7 +127,7 @@ fun RadarDestination(navigateUp: () -> Unit) {
         viewModel.onAction(RadarAction.SstvPermissionResult(granted))
         viewModel.onAction(RadarAction.CwPermissionResult(granted))
     }
-    RadarScreen(uiState, viewModel::onAction, navigateUpAndClearMutual, mutualData, requestMicPermission = {
+    RadarScreen(uiState, viewModel::onAction, navigateUpAndClearMutual, navigateToMapAndClearMutual, mutualData, requestMicPermission = {
         permissionLauncher.launch(Manifest.permission.RECORD_AUDIO)
     })
 }
@@ -131,13 +137,11 @@ private fun RadarScreen(
     uiState: RadarState,
     onAction: (RadarAction) -> Unit,
     navigateUp: () -> Unit,
+    navigateToMap: () -> Unit,
     mutualData: MutualPassData,
     requestMicPermission: () -> Unit
 ) {
     val upcomingPass = uiState.currentPass ?: getDefaultPass()
-    val addToCalendar: () -> Unit = {
-        uiState.currentPass?.let { onAction(RadarAction.AddToCalendar(it.name, it.aosTime, it.losTime)) }
-    }
     // Station-B overlay: full track line (only where B's elevation > 0) + live position dot
     // at the current moment, same display mode as the local station.
     val trackB = remember(mutualData.trackSamples) {
@@ -173,7 +177,7 @@ private fun RadarScreen(
             TopBar {
                 IconCard(action = navigateUp, resId = R.drawable.ic_back)
                 TimerRow(timeString = uiState.currentTime, isTimeAos = uiState.isTimeAos)
-                IconCard(action = addToCalendar, resId = R.drawable.ic_calendar)
+                IconCard(action = navigateToMap, resId = R.drawable.ic_map)
             }
             TopBar { NextPassRow(pass = upcomingPass, isUtc = uiState.isUtc) }
         } else {
@@ -181,7 +185,7 @@ private fun RadarScreen(
                 IconCard(action = navigateUp, resId = R.drawable.ic_back)
                 TimerRow(timeString = uiState.currentTime, isTimeAos = uiState.isTimeAos)
                 NextPassRow(pass = upcomingPass, modifier = Modifier.weight(1f), isUtc = uiState.isUtc)
-                IconCard(action = addToCalendar, resId = R.drawable.ic_calendar)
+                IconCard(action = navigateToMap, resId = R.drawable.ic_map)
             }
         }
         if (isVertical) {
@@ -249,6 +253,7 @@ private fun PagerCard(
                         selectedUuid = uiState.transceivers.selectedUuid,
                         orbitalPos = uiState.orbitalPos,
                         cw = uiState.cw,
+                        calculatorOffsetKHz = uiState.calculatorOffsetKHz,
                         onAction = onAction,
                         requestMicPermission = requestMicPermission
                     )

feature/radar/src/main/java/com/rtbishop/look4sat/feature/radar/RadarState.kt

@@ -69,7 +69,8 @@ data class RadarState(
     val mutualEndTime: Long = 0L,
     val mutualMaxElev: Double = 10.0,
     val mutualLabelA: String = "你",
-    val mutualLabelB: String = "友台"
+    val mutualLabelB: String = "友台",
+    val calculatorOffsetKHz: String = ""
 )
 
 enum class SstvStatus { Idle, Recording }
@@ -124,4 +125,7 @@ sealed interface RadarAction {
     data class CwSetToneFreq(val freq: Float) : RadarAction
     data class CwToggleExpanded(val expanded: Boolean) : RadarAction
     data class CwPermissionResult(val granted: Boolean) : RadarAction
+
+    // Calculator actions
+    data class ChangeCalculatorOffset(val offsetKHz: String) : RadarAction
 }

feature/radar/src/main/java/com/rtbishop/look4sat/feature/radar/RadarViewModel.kt

@@ -151,7 +151,13 @@ class RadarViewModel(
         transponders = allRadios.filter { it.downlinkLow != null }
         if (allRadios.isNotEmpty()) {
             val firstUuid = allRadios.first().uuid
-            _uiState.update { it.copy(transceivers = it.transceivers.copy(selectedUuid = firstUuid)) }
+            val offsetKHz = allRadios.first().catnum?.let { settingsRepo.getSatelliteOffset(it) } ?: ""
+            _uiState.update {
+                it.copy(
+                    transceivers = it.transceivers.copy(selectedUuid = firstUuid),
+                    calculatorOffsetKHz = offsetKHz
+                )
+            }
             transponders.find { it.uuid == firstUuid }?.let { trackingService.setTransponder(it) }
         }
         if (!pass.isDeepSpace) {
@@ -228,7 +234,16 @@ class RadarViewModel(
                 // Compute toggle state before the update so we don't read post-update value
                 val isTogglingOff = _uiState.value.transceivers.selectedUuid == action.uuid
                 val newUuid = if (isTogglingOff) null else action.uuid
-                _uiState.update { it.copy(transceivers = it.transceivers.copy(selectedUuid = newUuid)) }
+                val offsetKHz = if (!isTogglingOff) {
+                    transponders.find { it.uuid == action.uuid }
+                        ?.catnum?.let { settingsRepo.getSatelliteOffset(it) } ?: ""
+                } else ""
+                _uiState.update {
+                    it.copy(
+                        transceivers = it.transceivers.copy(selectedUuid = newUuid),
+                        calculatorOffsetKHz = offsetKHz
+                    )
+                }
                 // Only update the tracking service when selecting a different transponder to
                 // avoid resetting a user-adjusted TX base on re-expand
                 if (!isTogglingOff) {
@@ -296,6 +311,15 @@ class RadarViewModel(
             is RadarAction.CwToggleExpanded -> {
                 _uiState.update { it.copy(cw = it.cw.copy(isExpanded = action.expanded)) }
             }
+            is RadarAction.ChangeCalculatorOffset -> {
+                val catnum = _uiState.value.transceivers.selectedUuid?.let { uuid ->
+                    transponders.find { it.uuid == uuid }?.catnum
+                }
+                if (catnum != null) {
+                    settingsRepo.setSatelliteOffset(catnum, action.offsetKHz)
+                }
+                _uiState.update { it.copy(calculatorOffsetKHz = action.offsetKHz) }
+            }
         }
     }
 

feature/radar/src/main/java/com/rtbishop/look4sat/feature/radar/TransceiversPage.kt

@@ -23,14 +23,20 @@ import androidx.compose.animation.AnimatedVisibility
 import androidx.compose.animation.expandVertically
 import androidx.compose.animation.shrinkVertically
 import androidx.compose.foundation.background
+import androidx.compose.foundation.border
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.interaction.MutableInteractionSource
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.verticalScroll
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.text.BasicTextField
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.FlowRow
+import androidx.compose.foundation.layout.IntrinsicSize
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxHeight
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
@@ -41,6 +47,7 @@ import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.foundation.lazy.itemsIndexed
 import androidx.compose.foundation.lazy.rememberLazyListState
 import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.foundation.layout.PaddingValues
 import androidx.compose.foundation.text.KeyboardOptions
 import androidx.compose.material3.Button
 import androidx.compose.material3.FilterChip
@@ -49,22 +56,31 @@ import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.OutlinedButton
 import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.Slider
 import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.material3.ElevatedCard
+import androidx.compose.material3.CardDefaults
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.DisposableEffect
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableIntStateOf
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
+import androidx.compose.ui.draw.drawBehind
 import androidx.compose.ui.draw.rotate
+import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.TextStyle
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.input.KeyboardType
 import androidx.compose.ui.text.style.TextAlign
@@ -128,12 +144,14 @@ fun CalculatorPage(
     selectedUuid: String?,
     orbitalPos: OrbitalPos?,
     cw: CwSubState,
+    calculatorOffsetKHz: String = "",
     onAction: (RadarAction) -> Unit,
     requestMicPermission: () -> Unit = {},
     modifier: Modifier = Modifier
 ) {
     val calculatorTransceivers = remember(transceivers) {
         transceivers.filter(DopplerFrequencyCalculator::isNamedLinearTransponder)
+            .let(DopplerFrequencyCalculator::deduplicateTransponders)
     }
     val selectedTransceiver = remember(calculatorTransceivers, selectedUuid) {
         calculatorTransceivers.firstOrNull { it.uuid == selectedUuid }
@@ -145,61 +163,55 @@ fun CalculatorPage(
         return
     }
 
-    LazyColumn(
+    Column(
         modifier = modifier
             .fillMaxSize()
-            .padding(8.dp),
+            .verticalScroll(rememberScrollState()),
         verticalArrangement = Arrangement.spacedBy(10.dp)
     ) {
         if (calculatorTransceivers.size > 1) {
-            item {
-                FlowRow(
-                    horizontalArrangement = Arrangement.spacedBy(6.dp),
-                    verticalArrangement = Arrangement.spacedBy(4.dp),
-                    modifier = Modifier.fillMaxWidth()
-                ) {
-                    calculatorTransceivers.forEach { radio ->
-                        FilterChip(
-                            selected = radio.uuid == selectedTransceiver.uuid,
-                            onClick = {
-                                if (radio.uuid != selectedUuid) onAction(RadarAction.SelectTransmitter(radio.uuid))
-                            },
-                            label = {
-                                Text(
-                                    text = transceiverTitle(radio),
-                                    maxLines = 1,
-                                    overflow = TextOverflow.Ellipsis
-                                )
-                            }
-                        )
-                    }
+            FlowRow(
+                horizontalArrangement = Arrangement.spacedBy(6.dp),
+                verticalArrangement = Arrangement.spacedBy(4.dp),
+                modifier = Modifier.fillMaxWidth()
+            ) {
+                calculatorTransceivers.forEach { radio ->
+                    FilterChip(
+                        selected = radio.uuid == selectedTransceiver.uuid,
+                        onClick = {
+                            if (radio.uuid != selectedUuid) onAction(RadarAction.SelectTransmitter(radio.uuid))
+                        },
+                        label = {
+                            Text(
+                                text = transceiverTitle(radio),
+                                maxLines = 1,
+                                overflow = TextOverflow.Ellipsis
+                            )
+                        }
+                    )
                 }
             }
         }
 
-        item {
-            DopplerFrequencyCalculator(
-                transponder = selectedTransceiver,
-                orbitalPos = orbitalPos,
-                modifier = Modifier.fillMaxWidth()
-            )
-        }
+        DopplerFrequencyCalculator(
+            transponder = selectedTransceiver,
+            orbitalPos = orbitalPos,
+            offsetKHz = calculatorOffsetKHz,
+            onOffsetChange = { onAction(RadarAction.ChangeCalculatorOffset(it)) },
+            modifier = Modifier.fillMaxWidth()
+        )
 
-        item {
-            HorizontalDivider(
-                thickness = 1.dp,
-                color = MaterialTheme.colorScheme.outline.copy(alpha = 0.3f)
-            )
-        }
+        HorizontalDivider(
+            thickness = 1.dp,
+            color = MaterialTheme.colorScheme.outline.copy(alpha = 0.3f)
+        )
 
-        item {
-            CwDecoderPanel(
-                cw = cw,
-                onAction = onAction,
-                requestMicPermission = requestMicPermission,
-                modifier = Modifier.fillMaxWidth()
-            )
-        }
+        CwDecoderPanel(
+            cw = cw,
+            onAction = onAction,
+            requestMicPermission = requestMicPermission,
+            modifier = Modifier.fillMaxWidth()
+        )
     }
 }
 
@@ -532,152 +544,365 @@ private fun ExpandedRadioControl(
     }
 }
 
+private enum class EditedField { TX, PASSBAND, RX }
+
 @Composable
 private fun DopplerFrequencyCalculator(
     transponder: SatRadio,
     orbitalPos: OrbitalPos?,
+    offsetKHz: String = "",
+    onOffsetChange: (String) -> Unit = {},
     modifier: Modifier = Modifier
 ) {
     if (orbitalPos == null || !DopplerFrequencyCalculator.isLinearTransponder(transponder)) return
 
-    var txInputMHz by remember { mutableStateOf("") }
-    var rxInputMHz by remember { mutableStateOf("") }
-    var offsetKHz by remember { mutableStateOf("") }
-    var lastEditedBy by remember { mutableStateOf(EditedField.TX) }
+    var lastEditedField by rememberSaveable(transponder.uuid) { mutableStateOf(EditedField.TX) }
+    var txFrequencyHz by rememberSaveable(transponder.uuid) { mutableStateOf(0L) }
+    var rxFrequencyHz by rememberSaveable(transponder.uuid) { mutableStateOf(0L) }
+    var passbandPosition by rememberSaveable(transponder.uuid) { mutableStateOf(0.5f) }
+    var stepSizeKHz by remember { mutableIntStateOf(1) }
 
     val offsetHz = offsetKHz.toDoubleOrNull()?.let { it * 1000 }?.toLong() ?: 0L
 
-    // Real-time refresh: when orbitalPos changes (1Hz), recompute the opposite field
+    val txLow = transponder.uplinkLow ?: return
+    val txHigh = transponder.uplinkHigh ?: return
+    val rxLow = transponder.downlinkLow ?: return
+    val rxHigh = transponder.downlinkHigh ?: return
+    val txRange = txHigh - txLow
+    val rxRange = rxHigh - rxLow
+    if (txRange <= 0L || rxRange <= 0L) return
+
+    // 原始转发器值（逆转多普勒），用于 passband 映射计算
+    val rawTxLow = orbitalPos.getDownlinkFreq(txLow)
+    val rawTxHigh = orbitalPos.getDownlinkFreq(txHigh)
+    val rawRxLow = orbitalPos.getUplinkFreq(rxLow)
+    val rawRxHigh = orbitalPos.getUplinkFreq(rxHigh)
+    val rawTxRange = rawTxHigh - rawTxLow
+    val rawRxRange = rawRxHigh - rawRxLow
+    val rawTransponder = transponder.copy(
+        uplinkLow = rawTxLow, uplinkHigh = rawTxHigh,
+        downlinkLow = rawRxLow, downlinkHigh = rawRxHigh
+    )
+
+    // 初始化
+    LaunchedEffect(Unit) {
+        if (txFrequencyHz == 0L) {
+            txFrequencyHz = txLow + txRange / 2
+            rxFrequencyHz = DopplerFrequencyCalculator.computeDownlinkFromUplinkWithOffset(
+                txFrequencyHz, rawTransponder, orbitalPos, offsetHz
+            ) ?: (rxLow + rxRange / 2)
+        }
+    }
+
+    // 实时重算：卫星移动时，锚点侧不变，重算另一侧
     LaunchedEffect(orbitalPos) {
-        if (lastEditedBy == EditedField.TX) {
-            val txMHz = txInputMHz.toDoubleOrNull()
-            if (txMHz != null && txMHz > 0) {
-                val txHz = (txMHz * 1_000_000).toLong()
-                val rxHz = DopplerFrequencyCalculator.computeDownlinkFromUplinkWithOffset(
-                    txHz, transponder, orbitalPos, offsetHz
-                )
-                if (rxHz != null) {
-                    rxInputMHz = String.format(Locale.ENGLISH, "%.6f", rxHz / 1_000_000.0)
-                }
+        if (lastEditedField == EditedField.TX) {
+            // TX 是锚点，不变；重算 RX
+            rxFrequencyHz = DopplerFrequencyCalculator.computeDownlinkFromUplinkWithOffset(
+                txFrequencyHz, rawTransponder, orbitalPos, offsetHz
+            ) ?: rxFrequencyHz
+        } else if (lastEditedField == EditedField.RX) {
+            // RX 是锚点，不变；重算 TX
+            txFrequencyHz = DopplerFrequencyCalculator.computeUplinkFromDownlinkWithOffset(
+                rxFrequencyHz, rawTransponder, orbitalPos, offsetHz
+            ) ?: txFrequencyHz
+        } else if (lastEditedField == EditedField.PASSBAND) {
+            // 相对位置不变（passbandPosition），TX 用地面频率，RX 经 Transceiver 完整路径计算
+            txFrequencyHz = txLow + (passbandPosition * txRange).toLong()
+            rxFrequencyHz = DopplerFrequencyCalculator.computeDownlinkFromUplinkWithOffset(
+                txFrequencyHz, rawTransponder, orbitalPos, offsetHz
+            ) ?: rxFrequencyHz
+        }
+    }
+
+    val txSliderValue = if (lastEditedField == EditedField.PASSBAND) {
+        passbandPosition
+    } else {
+        ((txFrequencyHz - txLow).toFloat() / txRange).coerceIn(0f, 1f)
+    }
+    val rxSliderValue = if (lastEditedField == EditedField.PASSBAND) {
+        ((rxFrequencyHz - rxLow).toFloat() / rxRange).coerceIn(0f, 1f)
+    } else {
+        ((rxFrequencyHz - rxLow).toFloat() / rxRange).coerceIn(0f, 1f)
+    }
+
+    fun updateTx(newTxHz: Long) {
+        when (lastEditedField) {
+            EditedField.PASSBAND -> {
+                // Passband 模式：滑块位置 → passbandPosition → 地面频率，RX 经 Transceiver 计算
+                val pos = ((newTxHz - txLow).toFloat() / txRange).coerceIn(0f, 1f)
+                passbandPosition = pos
+                txFrequencyHz = txLow + (pos * txRange).toLong()
+                rxFrequencyHz = DopplerFrequencyCalculator.computeDownlinkFromUplinkWithOffset(
+                    txFrequencyHz, rawTransponder, orbitalPos, offsetHz
+                ) ?: rxFrequencyHz
             }
-        } else {
-            val rxMHz = rxInputMHz.toDoubleOrNull()
-            if (rxMHz != null && rxMHz > 0) {
-                val rxHz = (rxMHz * 1_000_000).toLong()
-                val txHz = DopplerFrequencyCalculator.computeUplinkFromDownlinkWithOffset(
-                    rxHz, transponder, orbitalPos, offsetHz
+            else -> {
+                txFrequencyHz = newTxHz.coerceIn(txLow, txHigh)
+                rxFrequencyHz = DopplerFrequencyCalculator.computeDownlinkFromUplinkWithOffset(
+                    txFrequencyHz, rawTransponder, orbitalPos, offsetHz
+                ) ?: rxFrequencyHz
+            }
+        }
+    }
+
+    fun updateRx(newRxHz: Long) {
+        when (lastEditedField) {
+            EditedField.PASSBAND -> {
+                // Passband 模式：从 RX 经完整往返路径（含多普勒补偿）反推 TX 位置
+                val txFromRx = DopplerFrequencyCalculator.computeUplinkFromDownlinkWithOffset(
+                    newRxHz, rawTransponder, orbitalPos, offsetHz
                 )
-                if (txHz != null) {
-                    txInputMHz = String.format(Locale.ENGLISH, "%.6f", txHz / 1_000_000.0)
+                passbandPosition = if (txFromRx != null) {
+                    ((txFromRx - txLow).toFloat() / txRange).coerceIn(0f, 1f)
+                } else {
+                    ((rxFrequencyHz - rxLow).toFloat() / rxRange).coerceIn(0f, 1f)
                 }
+                txFrequencyHz = txLow + (passbandPosition * txRange).toLong()
+                rxFrequencyHz = DopplerFrequencyCalculator.computeDownlinkFromUplinkWithOffset(
+                    txFrequencyHz, rawTransponder, orbitalPos, offsetHz
+                ) ?: rxFrequencyHz
+            }
+            else -> {
+                rxFrequencyHz = newRxHz.coerceIn(rxLow, rxHigh)
+                txFrequencyHz = DopplerFrequencyCalculator.computeUplinkFromDownlinkWithOffset(
+                    rxFrequencyHz, rawTransponder, orbitalPos, offsetHz
+                ) ?: txFrequencyHz
             }
         }
     }
 
     Column(
-        modifier = modifier,
-        verticalArrangement = Arrangement.spacedBy(4.dp)
+        modifier = modifier.fillMaxWidth().padding(top = 16.dp),
+        verticalArrangement = Arrangement.spacedBy(12.dp)
     ) {
-        Text(
-            text = stringResource(R.string.radar_doppler_calc),
-            fontSize = 14.sp,
-            fontWeight = FontWeight.Medium,
-            color = MaterialTheme.colorScheme.primary
-        )
-        Text(
-            text = stringResource(R.string.radar_doppler_info),
-            fontSize = 12.sp,
-            color = MaterialTheme.colorScheme.onSurfaceVariant
-        )
-
-        // Offset input
-        OutlinedTextField(
-            value = offsetKHz,
-            onValueChange = { newVal ->
-                offsetKHz = newVal
-                // Trigger recompute based on last edited field
-                if (lastEditedBy == EditedField.TX) {
-                    val txMHz = txInputMHz.toDoubleOrNull()
-                    if (txMHz != null && txMHz > 0) {
-                        val txHz = (txMHz * 1_000_000).toLong()
-                        val rxHz = DopplerFrequencyCalculator.computeDownlinkFromUplinkWithOffset(
-                            txHz, transponder, orbitalPos, offsetHz
-                        )
-                        rxInputMHz = if (rxHz != null) String.format(Locale.ENGLISH, "%.6f", rxHz / 1_000_000.0) else ""
-                    }
-                } else {
-                    val rxMHz = rxInputMHz.toDoubleOrNull()
-                    if (rxMHz != null && rxMHz > 0) {
-                        val rxHz = (rxMHz * 1_000_000).toLong()
-                        val txHz = DopplerFrequencyCalculator.computeUplinkFromDownlinkWithOffset(
-                            rxHz, transponder, orbitalPos, offsetHz
-                        )
-                        txInputMHz = if (txHz != null) String.format(Locale.ENGLISH, "%.6f", txHz / 1_000_000.0) else ""
-                    }
+            Row(
+                modifier = Modifier.fillMaxWidth().height(IntrinsicSize.Min),
+                verticalAlignment = Alignment.CenterVertically,
+                horizontalArrangement = Arrangement.spacedBy(6.dp)
+            ) {
+                // 左半边: TX + RX 按钮
+                Row(
+                    modifier = Modifier.weight(1f),
+                    horizontalArrangement = Arrangement.spacedBy(4.dp),
+                    verticalAlignment = Alignment.CenterVertically
+                ) {
+                    FilterChip(
+                        selected = lastEditedField == EditedField.TX,
+                        onClick = {
+                            when (lastEditedField) {
+                                EditedField.TX -> {
+                                    passbandPosition = ((txFrequencyHz - txLow).toFloat() / txRange).coerceIn(0f, 1f)
+                                    lastEditedField = EditedField.PASSBAND
+                                    rxFrequencyHz = DopplerFrequencyCalculator.computeDownlinkFromUplinkWithOffset(
+                                        txFrequencyHz, rawTransponder, orbitalPos, offsetHz
+                                    ) ?: rxFrequencyHz
+                                }
+                                EditedField.PASSBAND -> { lastEditedField = EditedField.TX }
+                                else -> { lastEditedField = EditedField.TX }
+                            }
+                        },
+                        label = {
+                            Text("TX", fontSize = 13.sp, textAlign = TextAlign.Center,
+                                modifier = Modifier.fillMaxWidth())
+                        },
+                        modifier = Modifier.weight(1f).fillMaxHeight()
+                    )
+                    FilterChip(
+                        selected = lastEditedField == EditedField.RX,
+                        onClick = {
+                            when (lastEditedField) {
+                                EditedField.RX -> {
+                                    txFrequencyHz = DopplerFrequencyCalculator.computeUplinkFromDownlinkWithOffset(
+                                        rxFrequencyHz, rawTransponder, orbitalPos, offsetHz
+                                    ) ?: txFrequencyHz
+                                    passbandPosition = ((txFrequencyHz - txLow).toFloat() / txRange).coerceIn(0f, 1f)
+                                    lastEditedField = EditedField.PASSBAND
+                                }
+                                EditedField.PASSBAND -> {
+                                    lastEditedField = EditedField.RX
+                                    txFrequencyHz = DopplerFrequencyCalculator.computeUplinkFromDownlinkWithOffset(
+                                        rxFrequencyHz, rawTransponder, orbitalPos, offsetHz
+                                    ) ?: txFrequencyHz
+                                }
+                                else -> { lastEditedField = EditedField.RX }
+                            }
+                        },
+                        label = {
+                            Text("RX", fontSize = 13.sp, textAlign = TextAlign.Center,
+                                modifier = Modifier.fillMaxWidth())
+                        },
+                        modifier = Modifier.weight(1f).fillMaxHeight()
+                    )
                 }
-            },
-            label = { Text(stringResource(R.string.radar_doppler_offset_hint)) },
-            singleLine = true,
-            keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Text),
-            modifier = Modifier.fillMaxWidth()
-        )
+                // 右半边: Offset 输入框（带细线边框）
+                Box(
+                    modifier = Modifier
+                        .weight(1f)
+                        .height(48.dp)
+                        .border(1.dp, MaterialTheme.colorScheme.outline, MaterialTheme.shapes.small),
+                    contentAlignment = Alignment.Center
+                ) {
+                    BasicTextField(
+                        value = offsetKHz,
+                        onValueChange = onOffsetChange,
+                        singleLine = true,
+                        textStyle = TextStyle(
+                            fontSize = 16.sp,
+                            textAlign = TextAlign.Center,
+                            color = MaterialTheme.colorScheme.onSurface
+                        ),
+                        decorationBox = { innerTextField ->
+                            if (offsetKHz.isEmpty()) {
+                                Text(
+                                    text = "Offset (kHz)",
+                                    fontSize = 16.sp,
+                                    color = MaterialTheme.colorScheme.onSurfaceVariant
+                                )
+                            }
+                            innerTextField()
+                        }
+                    )
+                }
+            }
 
-        // TX and RX inputs on the same row
-        Row(
-            horizontalArrangement = Arrangement.spacedBy(8.dp),
-            modifier = Modifier.fillMaxWidth()
-        ) {
-            // TX input → compute RX
-            OutlinedTextField(
-                value = txInputMHz,
-                onValueChange = { newVal ->
-                    txInputMHz = newVal
-                    lastEditedBy = EditedField.TX
-                    val mhz = newVal.toDoubleOrNull()
-                    if (mhz != null && mhz > 0) {
-                        val txHz = (mhz * 1_000_000).toLong()
-                        val rxHz = DopplerFrequencyCalculator.computeDownlinkFromUplinkWithOffset(
-                            txHz, transponder, orbitalPos, offsetHz
+            // TX 行
+            Column(modifier = Modifier.fillMaxWidth()) {
+                Row(verticalAlignment = Alignment.CenterVertically) {
+                    OutlinedButton(
+                        onClick = { updateTx(txFrequencyHz - stepSizeKHz * 1000L) },
+                        modifier = Modifier.width(32.dp).height(28.dp),
+                        contentPadding = PaddingValues(0.dp),
+                        shape = MaterialTheme.shapes.extraSmall
+                    ) { Text("−", fontSize = 14.sp) }
+
+                    Slider(
+                        value = txSliderValue,
+                        onValueChange = { norm ->
+                            val rawFreq = txLow + (txRange * norm).toLong()
+                            val snapped = ((rawFreq + 500) / 1000L) * 1000L
+                            updateTx(snapped.coerceIn(txLow, txHigh))
+                        },
+                        valueRange = 0f..1f,
+                        modifier = Modifier.weight(1f).height(20.dp).padding(horizontal = 4.dp)
+                    )
+
+                    OutlinedButton(
+                        onClick = { updateTx(txFrequencyHz + stepSizeKHz * 1000L) },
+                        modifier = Modifier.width(32.dp).height(28.dp),
+                        contentPadding = PaddingValues(0.dp),
+                        shape = MaterialTheme.shapes.extraSmall
+                    ) { Text("+", fontSize = 14.sp) }
+                }
+                Row(
+                    modifier = Modifier.fillMaxWidth().padding(horizontal = 4.dp),
+                    verticalAlignment = Alignment.CenterVertically
+                ) {
+                    Text(
+                        text = String.format(Locale.ENGLISH, "%.4f", txLow / 1_000_000.0),
+                        fontSize = 12.sp,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant,
+                        modifier = Modifier.weight(1f)
+                    )
+                    Row(
+                        verticalAlignment = Alignment.CenterVertically,
+                        horizontalArrangement = Arrangement.Center
+                    ) {
+                        Text(
+                            text = String.format(Locale.ENGLISH, "%.6f", txFrequencyHz / 1_000_000.0),
+                            fontSize = 20.sp,
+                            fontWeight = FontWeight.Bold,
+                            color = MaterialTheme.colorScheme.primary
+                        )
+                        Text(
+                            text = " MHz",
+                            fontSize = 20.sp,
+                            fontWeight = FontWeight.Bold,
+                            color = MaterialTheme.colorScheme.primary
                         )
-                        rxInputMHz = if (rxHz != null) String.format(Locale.ENGLISH, "%.6f", rxHz / 1_000_000.0) else ""
-                    } else if (newVal.isEmpty()) {
-                        rxInputMHz = ""
                     }
-                },
-                label = { Text(stringResource(R.string.radar_doppler_tx_hint)) },
-                singleLine = true,
-                keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Decimal),
-                modifier = Modifier.weight(1f)
+                    Text(
+                        text = String.format(Locale.ENGLISH, "%.4f", txHigh / 1_000_000.0),
+                        fontSize = 12.sp,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant,
+                        modifier = Modifier.weight(1f),
+                        textAlign = TextAlign.End
+                    )
+                }
+            }
+
+            HorizontalDivider(
+                thickness = 0.5.dp,
+                color = MaterialTheme.colorScheme.outline.copy(alpha = 0.3f)
             )
 
-            // RX input → compute TX
-            OutlinedTextField(
-                value = rxInputMHz,
-                onValueChange = { newVal ->
-                    rxInputMHz = newVal
-                    lastEditedBy = EditedField.RX
-                    val mhz = newVal.toDoubleOrNull()
-                    if (mhz != null && mhz > 0) {
-                        val rxHz = (mhz * 1_000_000).toLong()
-                        val txHz = DopplerFrequencyCalculator.computeUplinkFromDownlinkWithOffset(
-                            rxHz, transponder, orbitalPos, offsetHz
+            // RX 行
+            Column(modifier = Modifier.fillMaxWidth()) {
+                Row(verticalAlignment = Alignment.CenterVertically) {
+                    OutlinedButton(
+                        onClick = { updateRx(rxFrequencyHz - stepSizeKHz * 1000L) },
+                        modifier = Modifier.width(32.dp).height(28.dp),
+                        contentPadding = PaddingValues(0.dp),
+                        shape = MaterialTheme.shapes.extraSmall
+                    ) { Text("−", fontSize = 14.sp) }
+
+                    Slider(
+                        value = rxSliderValue,
+                        onValueChange = { norm ->
+                            val rawFreq = rxLow + (rxRange * norm).toLong()
+                            val snapped = ((rawFreq + 500) / 1000L) * 1000L
+                            updateRx(snapped.coerceIn(rxLow, rxHigh))
+                        },
+                        valueRange = 0f..1f,
+                        modifier = Modifier.weight(1f).height(20.dp).padding(horizontal = 4.dp)
+                    )
+
+                    OutlinedButton(
+                        onClick = { updateRx(rxFrequencyHz + stepSizeKHz * 1000L) },
+                        modifier = Modifier.width(32.dp).height(28.dp),
+                        contentPadding = PaddingValues(0.dp),
+                        shape = MaterialTheme.shapes.extraSmall
+                    ) { Text("+", fontSize = 14.sp) }
+                }
+                Row(
+                    modifier = Modifier.fillMaxWidth().padding(horizontal = 4.dp),
+                    verticalAlignment = Alignment.CenterVertically
+                ) {
+                    Text(
+                        text = String.format(Locale.ENGLISH, "%.4f", rxLow / 1_000_000.0),
+                        fontSize = 12.sp,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant,
+                        modifier = Modifier.weight(1f)
+                    )
+                    Row(
+                        verticalAlignment = Alignment.CenterVertically,
+                        horizontalArrangement = Arrangement.Center
+                    ) {
+                        Text(
+                            text = String.format(Locale.ENGLISH, "%.6f", rxFrequencyHz / 1_000_000.0),
+                            fontSize = 20.sp,
+                            fontWeight = FontWeight.Bold,
+                            color = MaterialTheme.colorScheme.primary
+                        )
+                        Text(
+                            text = " MHz",
+                            fontSize = 20.sp,
+                            fontWeight = FontWeight.Bold,
+                            color = MaterialTheme.colorScheme.primary
                         )
-                        txInputMHz = if (txHz != null) String.format(Locale.ENGLISH, "%.6f", txHz / 1_000_000.0) else ""
-                    } else if (newVal.isEmpty()) {
-                        txInputMHz = ""
                     }
-                },
-                label = { Text(stringResource(R.string.radar_doppler_rx_hint)) },
-                singleLine = true,
-                keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Decimal),
-                modifier = Modifier.weight(1f)
-            )
+                    Text(
+                        text = String.format(Locale.ENGLISH, "%.4f", rxHigh / 1_000_000.0),
+                        fontSize = 12.sp,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant,
+                        modifier = Modifier.weight(1f),
+                        textAlign = TextAlign.End
+                    )
+                }
+            }
         }
-    }
 }
 
-private enum class EditedField { TX, RX }
-
 @Composable
 private fun CwDecoderPanel(
     cw: CwSubState,
@@ -717,30 +942,36 @@ private fun CwDecoderPanel(
             // PR #1 Morse Expert engine: mini layout with waterfall + decoded text.
             // Keep the old Kotlin decoder state/actions as fallback code, but this panel no longer feeds it.
             val context = LocalContext.current
-            val activity = remember { context as? Activity }
+            val activity = remember(context) {
+                context as? Activity ?: error("CwDecoderPanel must be hosted in an Activity")
+            }
             val controller = remember { MainActivity() }
-            val rootView = remember {
-                LayoutInflater.from(context).inflate(CwR.layout.cw_panel_main, null) as ConstraintLayout
+            val rootView = remember(context) {
+                LayoutInflater.from(context).inflate(CwR.layout.activity_main, null) as ConstraintLayout
             }
             var initialized by remember { mutableStateOf(false) }
             var listening by remember { mutableStateOf(false) }
 
-            DisposableEffect(Unit) {
-                if (activity != null) {
-                    controller.onCreate(activity, rootView, false)
-                }
-                onDispose {
-                    controller.onPause()
-                    controller.onDestroy()
-                }
-            }
-
-            LaunchedEffect(cw.hasPermission) {
-                if (cw.hasPermission && !initialized) {
+            // 重要: 不在展开时初始化控制器(避免"一展开就崩溃")。
+            // controller.onCreate/onResume/onPermissionGranted 全部推迟到用户点 Start 才执行。
+            fun startDecoding() {
+                if (!initialized) {
+                    controller.onCreate(activity, rootView)
                     controller.onPermissionGranted()
                     controller.onResume()
                     initialized = true
-                    listening = true
+                } else {
+                    controller.onResume()
+                }
+                listening = true
+            }
+
+            DisposableEffect(Unit) {
+                onDispose {
+                    if (initialized) {
+                        controller.onPause()
+                        controller.onDestroy()
+                    }
                 }
             }
 
@@ -754,14 +985,8 @@ private fun CwDecoderPanel(
                             onClick = {
                                 if (!cw.hasPermission) {
                                     requestMicPermission()
-                                } else if (!initialized) {
-                                    controller.onPermissionGranted()
-                                    controller.onResume()
-                                    initialized = true
-                                    listening = true
                                 } else {
-                                    controller.onResume()
-                                    listening = true
+                                    startDecoding()
                                 }
                             },
                             modifier = Modifier.weight(1f)
@@ -780,19 +1005,23 @@ private fun CwDecoderPanel(
                         }
                     }
                     OutlinedButton(
-                        onClick = { controller.clearDecoded() },
+                        onClick = { if (initialized) controller.clearDecoded() },
                         modifier = Modifier.weight(1f)
                     ) {
                         Text(stringResource(R.string.radar_cw_reset))
                     }
                 }
 
-                AndroidView(
-                    factory = { rootView },
+                Box(
                     modifier = Modifier
                         .fillMaxWidth()
                         .height(150.dp)
-                )
+                ) {
+                    AndroidView(
+                        factory = { rootView },
+                        modifier = Modifier.fillMaxSize()
+                    )
+                }
             }
         }
     }

feature/settings/src/main/java/com/rtbishop/look4sat/feature/settings/SettingsDialog.kt

@@ -19,39 +19,83 @@ package com.rtbishop.look4sat.feature.settings
 
 import android.bluetooth.BluetoothManager
 import android.content.Context
+import androidx.compose.animation.core.Animatable
+import androidx.compose.animation.core.Spring
+import androidx.compose.animation.core.animateFloatAsState
+import androidx.compose.animation.core.spring
+import androidx.compose.animation.core.tween
+import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
+import androidx.compose.foundation.gestures.detectDragGesturesAfterLongPress
+import androidx.compose.foundation.gestures.scrollBy
 import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.ExperimentalLayoutApi
 import androidx.compose.foundation.layout.FlowRow
+import androidx.compose.foundation.layout.PaddingValues
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxHeight
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.LazyListScope
+import androidx.compose.foundation.lazy.LazyListState
+import androidx.compose.foundation.lazy.itemsIndexed
+import androidx.compose.foundation.lazy.rememberLazyListState
+import androidx.compose.material3.Checkbox
 import androidx.compose.material3.FilterChip
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.OutlinedTextField
 import androidx.compose.material3.Switch
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.MutableFloatState
+import androidx.compose.runtime.MutableState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableFloatStateOf
 import androidx.compose.runtime.mutableIntStateOf
+import androidx.compose.runtime.mutableLongStateOf
+import androidx.compose.runtime.mutableStateMapOf
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.saveable.rememberSaveable
+import androidx.compose.runtime.toMutableStateList
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.shadow
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.graphicsLayer
+import androidx.compose.ui.input.pointer.pointerInput
+import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.IntOffset
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
+import androidx.compose.ui.zIndex
+import com.rtbishop.look4sat.core.domain.model.Constants
 import com.rtbishop.look4sat.core.domain.model.RCSettings
 import com.rtbishop.look4sat.core.domain.model.RadioControlSettings
+import com.rtbishop.look4sat.core.domain.source.NetworkResult
+import com.rtbishop.look4sat.core.domain.source.Sources
 import com.rtbishop.look4sat.core.presentation.CardButton
+import com.rtbishop.look4sat.core.presentation.IconCard
 import com.rtbishop.look4sat.core.presentation.LocalSpacing
 import com.rtbishop.look4sat.core.presentation.MainTheme
 import com.rtbishop.look4sat.core.presentation.R
 import com.rtbishop.look4sat.core.presentation.SharedDialog
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
 
 @Preview(showBackground = true)
 @Composable
@@ -116,11 +160,19 @@ fun LocatorDialog(qthLocator: String, dismiss: () -> Unit, save: (String) -> Uni
 private fun TransceiversDialogPreview() {
     MainTheme {
         DataSourcesDialog(
-            useCustomTle = true,
-            useCustomTransceivers = true,
-            tleUrl = "https://example.com/tle.txt",
-            transceiversUrl = "https://example.com/tx.json",
-            requestCustomSourcesPermission = { onGranted, _ -> onGranted() },
+            satelliteUrls = listOf(
+                "celestrak.org/NORAD/elements/gp.php?GROUP=active&FORMAT=csv",
+                "amsat.org/tle/current/nasabare.txt"
+            ),
+            transceiversUrls = listOf(
+                "db.satnogs.org/api/transmitters/?format=json&status=active"
+            ),
+            satelliteEnabled = listOf(true, false),
+            transceiversEnabled = listOf(true),
+            statusCodes = mapOf(
+                "celestrak.org/NORAD/elements/gp.php?GROUP=active&FORMAT=csv" to 200,
+                "amsat.org/tle/current/nasabare.txt" to 404
+            ),
             onImportTle = {},
             onImportTransceivers = {},
             onDismiss = {},
@@ -131,111 +183,404 @@ private fun TransceiversDialogPreview() {
 
 @Composable
 fun DataSourcesDialog(
-    useCustomTle: Boolean,
-    useCustomTransceivers: Boolean,
-    tleUrl: String,
-    transceiversUrl: String,
-    requestCustomSourcesPermission: (onGranted: () -> Unit, onDenied: () -> Unit) -> Unit,
+    satelliteUrls: List<String>,
+    transceiversUrls: List<String>,
+    satelliteEnabled: List<Boolean>,
+    transceiversEnabled: List<Boolean>,
+    statusCodes: Map<String, Int>,
     onImportTle: () -> Unit,
     onImportTransceivers: () -> Unit,
     onDismiss: () -> Unit,
-    onSave: (Boolean, Boolean, String, String) -> Unit
+    onSave: (List<String>, List<String>, List<Boolean>, List<Boolean>) -> Unit
 ) {
     val padding = LocalSpacing.current.large
-    val isEnabledCustomTle = rememberSaveable { mutableStateOf(useCustomTle) }
-    val isEnabledCustomTransceivers = rememberSaveable { mutableStateOf(useCustomTransceivers) }
-    val urlTle = rememberSaveable { mutableStateOf(tleUrl) }
-    val urlTransceivers = rememberSaveable { mutableStateOf(transceiversUrl) }
-    val onAccept = {
-        onSave(isEnabledCustomTle.value, isEnabledCustomTransceivers.value, urlTle.value, urlTransceivers.value)
-        onDismiss()
+    // Stable Long IDs avoid key collisions when several entries are empty or duplicated.
+    val nextId = remember { mutableLongStateOf((satelliteUrls.size + transceiversUrls.size).toLong()) }
+    val satUrls = remember {
+        satelliteUrls.mapIndexed { i, url -> i.toLong() to url }.toMutableStateList()
     }
-    val onCancel = { onDismiss() }
-    SharedDialog(
-        title = stringResource(id = R.string.prefs_data_sources_title),
-        onCancel = onCancel,
-        onAccept = onAccept,
-    ) {
-        Column(modifier = Modifier.padding(horizontal = padding)) {
-            Row(horizontalArrangement = Arrangement.spacedBy(6.dp)) {
-                CardButton(
-                    onClick = {
-                        onImportTle()
-                        onDismiss()
-                    },
-                    text = "TLE/3LE (.txt)\nOMM (.csv)",
-                    modifier = Modifier.weight(1f)
-                )
-                CardButton(
-                    onClick = {
-                        onImportTransceivers()
-                        onDismiss()
-                    },
-                    text = "Transceivers\nSatNOGS (.json)",
-                    modifier = Modifier.weight(1f)
-                )
-            }
-            Spacer(modifier = Modifier.height(6.dp))
-            Row(
-                horizontalArrangement = Arrangement.SpaceBetween,
-                verticalAlignment = Alignment.CenterVertically,
-                modifier = Modifier.fillMaxWidth()
-            ) {
-                Text(text = stringResource(id = R.string.prefs_data_sources_tle_switch))
-                Switch(
-                    checked = isEnabledCustomTle.value,
-                    onCheckedChange = { enabled ->
-                        if (!enabled) {
-                            isEnabledCustomTle.value = false
-                        } else {
-                            requestCustomSourcesPermission(
-                                { isEnabledCustomTle.value = true },
-                                { isEnabledCustomTle.value = false }
-                            )
-                        }
-                    }
-                )
-            }
-            OutlinedTextField(
-                value = urlTle.value,
-                onValueChange = { urlTle.value = it },
-                label = { Text(text = stringResource(id = R.string.prefs_data_sources_url_title)) },
-                singleLine = true,
-                modifier = Modifier.fillMaxWidth(),
-                enabled = isEnabledCustomTle.value,
-            )
-            Spacer(modifier = Modifier.height(6.dp))
-            Row(
-                horizontalArrangement = Arrangement.SpaceBetween,
-                verticalAlignment = Alignment.CenterVertically,
-                modifier = Modifier.fillMaxWidth()
-            ) {
-                Text(text = stringResource(id = R.string.prefs_data_sources_transceivers_switch))
-                Switch(
-                    checked = isEnabledCustomTransceivers.value,
-                    onCheckedChange = { enabled ->
-                        if (!enabled) {
-                            isEnabledCustomTransceivers.value = false
-                        } else {
-                            requestCustomSourcesPermission(
-                                { isEnabledCustomTransceivers.value = true },
-                                { isEnabledCustomTransceivers.value = false }
-                            )
-                        }
-                    }
-                )
-            }
-            OutlinedTextField(
-                value = urlTransceivers.value,
-                onValueChange = { urlTransceivers.value = it },
-                label = { Text(text = stringResource(id = R.string.prefs_data_sources_url_title)) },
-                singleLine = true,
-                modifier = Modifier.fillMaxWidth(),
-                enabled = isEnabledCustomTransceivers.value,
-            )
-            Spacer(modifier = Modifier.height(12.dp))
+    val txUrls = remember {
+        transceiversUrls.mapIndexed { i, url -> (satelliteUrls.size + i).toLong() to url }.toMutableStateList()
+    }
+    val satEnabled = remember {
+        mutableStateMapOf<Long, Boolean>().apply {
+            satUrls.forEachIndexed { i, (id, _) -> this[id] = satelliteEnabled.getOrElse(i) { true } }
         }
     }
+    val txEnabled = remember {
+        mutableStateMapOf<Long, Boolean>().apply {
+            txUrls.forEachIndexed { i, (id, _) -> this[id] = transceiversEnabled.getOrElse(i) { true } }
+        }
+    }
+    val onRestoreDefaults = {
+        val satDefaults = Sources.satelliteDataUrls.values.filter { it.isNotBlank() }
+        val txDefaults = Sources.transceiversDataUrls.values.filter { it.isNotBlank() }
+        nextId.longValue = (satDefaults.size + txDefaults.size).toLong()
+        satUrls.clear()
+        satUrls.addAll(satDefaults.mapIndexed { i, url -> i.toLong() to url })
+        txUrls.clear()
+        txUrls.addAll(txDefaults.mapIndexed { i, url -> (satDefaults.size + i).toLong() to url })
+        satEnabled.clear()
+        txEnabled.clear()
+        Unit
+    }
+    val listState = rememberLazyListState()
+    val satDraggedId = remember { mutableStateOf(-1L) }
+    val txDraggedId = remember { mutableStateOf(-1L) }
+    val onAccept = {
+        val satFiltered = satUrls.filter { it.second.trim().isNotBlank() }
+        val txFiltered = txUrls.filter { it.second.trim().isNotBlank() }
+        onSave(
+            satFiltered.map { it.second.trim() },
+            txFiltered.map { it.second.trim() },
+            satFiltered.map { satEnabled[it.first] ?: true },
+            txFiltered.map { txEnabled[it.first] ?: true }
+        )
+        onDismiss()
+    }
+    SharedDialog(
+        title = stringResource(id = R.string.prefs_data_sources_title),
+        onCancel = onDismiss,
+        onAccept = onAccept,
+    ) {
+        LazyColumn(
+            state = listState,
+            modifier = Modifier
+                .fillMaxHeight(0.84f)
+                .padding(horizontal = padding),
+            verticalArrangement = Arrangement.spacedBy(4.dp),
+            contentPadding = PaddingValues(vertical = 6.dp)
+        ) {
+            item {
+                Row(
+                    horizontalArrangement = Arrangement.spacedBy(6.dp),
+                    modifier = Modifier.fillMaxWidth()
+                ) {
+                    CardButton(
+                        onClick = { onImportTle(); onDismiss() },
+                        text = "TLE/3LE (.txt)\nOMM (.csv)",
+                        modifier = Modifier.weight(1f)
+                    )
+                    CardButton(
+                        onClick = { onImportTransceivers(); onDismiss() },
+                        text = "Transceivers\nSatNOGS (.json)",
+                        modifier = Modifier.weight(1f)
+                    )
+                }
+            }
+            item {
+                CardButton(
+                    onClick = onRestoreDefaults,
+                    text = stringResource(R.string.prefs_data_sources_restore),
+                    modifier = Modifier.fillMaxWidth()
+                )
+            }
+            sourceSection(
+                sectionKey = "sat",
+                labelResId = R.string.prefs_data_sources_satellites_label,
+                urls = satUrls,
+                listState = listState,
+                draggedId = satDraggedId,
+                statusCodes = statusCodes,
+                enabledMap = satEnabled,
+                onToggle = { id -> satEnabled[id] = !(satEnabled[id] ?: true) },
+                onAdd = { satUrls.add(nextId.longValue++ to "") },
+                onMove = { from, to -> satUrls.add(to, satUrls.removeAt(from)) },
+                onRemove = { i -> satUrls.removeAt(i) },
+                onUrlChange = { i, v -> satUrls[i] = satUrls[i].first to v }
+            )
+            sourceSection(
+                sectionKey = "tx",
+                labelResId = R.string.prefs_data_sources_transceivers_label,
+                urls = txUrls,
+                listState = listState,
+                draggedId = txDraggedId,
+                statusCodes = statusCodes,
+                enabledMap = txEnabled,
+                onToggle = { id -> txEnabled[id] = !(txEnabled[id] ?: true) },
+                onAdd = { txUrls.add(nextId.longValue++ to "") },
+                onMove = { from, to -> txUrls.add(to, txUrls.removeAt(from)) },
+                onRemove = { i -> txUrls.removeAt(i) },
+                onUrlChange = { i, v -> txUrls[i] = txUrls[i].first to v }
+            )
+        }
+    }
+}
+
+private fun LazyListScope.sourceSection(
+    sectionKey: String,
+    labelResId: Int,
+    urls: List<Pair<Long, String>>,
+    listState: LazyListState,
+    draggedId: MutableState<Long>,
+    statusCodes: Map<String, Int>,
+    enabledMap: Map<Long, Boolean>,
+    onToggle: (Long) -> Unit,
+    onAdd: () -> Unit,
+    onMove: (Int, Int) -> Unit,
+    onRemove: (Int) -> Unit,
+    onUrlChange: (Int, String) -> Unit
+) {
+    item {
+        Spacer(modifier = Modifier.height(6.dp))
+        Row(verticalAlignment = Alignment.CenterVertically, modifier = Modifier.fillMaxWidth()) {
+            Text(
+                text = stringResource(labelResId),
+                fontWeight = FontWeight.Medium,
+                color = MaterialTheme.colorScheme.primary,
+                modifier = Modifier.weight(1f)
+            )
+            IconCard(action = onAdd, resId = R.drawable.ic_add)
+        }
+    }
+    itemsIndexed(urls, key = { _, entry -> "$sectionKey-${entry.first}" }) { index, (id, url) ->
+        val enabledTint = MaterialTheme.colorScheme.onSurfaceVariant
+        val enabled = enabledMap[id] ?: true
+        val rowState = remember { DragRowState() }
+        val scope = rememberCoroutineScope()
+        val isDragging = draggedId.value == id
+        val isLifted = isDragging || rowState.isSettling.value
+        LaunchedEffect(isDragging) {
+            if (!isDragging) return@LaunchedEffect
+            autoScroll(listState, rowState.startCenterY, rowState.fingerOffset, rowState.scrollComp)
+        }
+        Row(
+            verticalAlignment = Alignment.CenterVertically,
+            modifier = Modifier
+                .fillMaxWidth()
+                .draggedVisual(
+                    isLifted = isLifted,
+                    translationY = if (rowState.isSettling.value) {
+                        rowState.settleAnim.value
+                    } else {
+                        rowState.offsetY.floatValue + rowState.scrollComp.floatValue
+                    }
+                )
+                .animateItem(
+                    fadeInSpec = spring(),
+                    // The dragged row repositions instantly, while its neighbours spring
+                    // out of the way (the "squeeze" effect).
+                    placementSpec = if (isDragging) {
+                        tween<IntOffset>(durationMillis = 0)
+                    } else {
+                        spring(
+                            dampingRatio = Spring.DampingRatioMediumBouncy,
+                            stiffness = Spring.StiffnessMediumLow
+                        )
+                    },
+                    fadeOutSpec = spring()
+                )
+        ) {
+            Box(
+                contentAlignment = Alignment.Center,
+                modifier = Modifier
+                    .size(40.dp)
+                    .dragHandle(listState, sectionKey, id, urls, draggedId, rowState, scope, onMove)
+            ) {
+                Icon(
+                    painter = painterResource(R.drawable.ic_drag_handle),
+                    contentDescription = null,
+                    tint = enabledTint
+                )
+            }
+            OutlinedTextField(
+                value = url,
+                onValueChange = { onUrlChange(index, it) },
+                label = { Text(stringResource(R.string.prefs_data_sources_url_title)) },
+                supportingText = statusCodes[url]?.let { code ->
+                    { Text(statusLabel(code), color = statusColor(code), fontSize = 12.sp) }
+                },
+                trailingIcon = {
+                    IconButton(onClick = { onRemove(index) }) {
+                        Icon(
+                            painter = painterResource(R.drawable.ic_delete),
+                            contentDescription = null
+                        )
+                    }
+                },
+                singleLine = true,
+                enabled = enabled,
+                modifier = Modifier.weight(1f)
+            )
+            Checkbox(
+                checked = enabled,
+                onCheckedChange = { onToggle(id) }
+            )
+        }
+    }
+}
+
+/**
+ * Per-row drag state, kept in one object to keep the drag-handle modifier signature small.
+ *
+ * [offsetY] is the compensated visual displacement during a drag (finger travel minus the
+ * heights of already-swapped neighbours), so the row stays glued to the finger. [fingerOffset]
+ * tracks the raw finger travel for edge auto-scroll and swap detection. [settleAnim] smoothly
+ * flies the lifted row back into its slot once the finger is released.
+ */
+private class DragRowState {
+    val offsetY = mutableFloatStateOf(0f)
+    val fingerOffset = mutableFloatStateOf(0f)
+    val scrollComp = mutableFloatStateOf(0f)
+    val startCenterY = mutableFloatStateOf(0f)
+    val settleAnim = Animatable(0f)
+    val isSettling = mutableStateOf(false)
+}
+
+/** Spring shared by neighbour "squeeze" and the settle-back animation: soft and slightly bouncy. */
+private val reorderSpring = spring<Float>(
+    dampingRatio = Spring.DampingRatioMediumBouncy,
+    stiffness = Spring.StiffnessMediumLow
+)
+
+/**
+ * Drag handle gesture that performs live reordering while dragging.
+ */
+@Composable
+private fun Modifier.dragHandle(
+    listState: LazyListState,
+    sectionKey: String,
+    entryId: Long,
+    urls: List<Pair<Long, String>>,
+    draggedId: MutableState<Long>,
+    rowState: DragRowState,
+    scope: CoroutineScope,
+    onMove: (from: Int, to: Int) -> Unit
+): Modifier = pointerInput(entryId, sectionKey) {
+    fun reorderLive() {
+        val myIndex = urls.indexOfFirst { it.first == entryId }
+        if (myIndex !in urls.indices) return
+        val myCenter = rowState.startCenterY.floatValue + rowState.fingerOffset.floatValue
+        val visible = listState.layoutInfo.visibleItemsInfo
+        // Dragging down: swap when the dragged centre passes the next row's midpoint.
+        if (myIndex < urls.lastIndex) {
+            val next = visible.firstOrNull { it.key == "$sectionKey-${urls[myIndex + 1].first}" }
+            if (next != null && myCenter > next.offset + next.size / 2f) {
+                onMove(myIndex, myIndex + 1)
+                rowState.offsetY.floatValue -= next.size.toFloat()
+                return
+            }
+        }
+        // Dragging up: swap when the dragged centre passes the previous row's midpoint.
+        if (myIndex > 0) {
+            val prev = visible.firstOrNull { it.key == "$sectionKey-${urls[myIndex - 1].first}" }
+            if (prev != null && myCenter < prev.offset + prev.size / 2f) {
+                onMove(myIndex, myIndex - 1)
+                rowState.offsetY.floatValue += prev.size.toFloat()
+            }
+        }
+    }
+
+    // Reset the drag bookkeeping and fly the lifted row back into its slot.
+    fun finishDrag() {
+        val lastOffset = rowState.offsetY.floatValue + rowState.scrollComp.floatValue
+        if (kotlin.math.abs(lastOffset) < 1f) {
+            rowState.fingerOffset.floatValue = 0f
+            rowState.offsetY.floatValue = 0f
+            rowState.scrollComp.floatValue = 0f
+            draggedId.value = -1L
+            return
+        }
+        scope.launch {
+            rowState.settleAnim.snapTo(lastOffset)
+            rowState.isSettling.value = true
+            rowState.fingerOffset.floatValue = 0f
+            rowState.offsetY.floatValue = 0f
+            rowState.scrollComp.floatValue = 0f
+            draggedId.value = -1L
+            rowState.settleAnim.animateTo(0f, reorderSpring)
+            rowState.isSettling.value = false
+        }
+    }
+
+    detectDragGesturesAfterLongPress(
+        onDragStart = {
+            rowState.isSettling.value = false
+            val layout = listState.layoutInfo.visibleItemsInfo.firstOrNull { it.key == "$sectionKey-$entryId" }
+            rowState.startCenterY.floatValue = (layout?.offset ?: 0) + (layout?.size ?: 0) / 2f
+            rowState.fingerOffset.floatValue = 0f
+            rowState.offsetY.floatValue = 0f
+            rowState.scrollComp.floatValue = 0f
+            draggedId.value = entryId
+        },
+        onDragEnd = ::finishDrag,
+        onDragCancel = ::finishDrag
+    ) { change, dragAmount ->
+        change.consume()
+        if (draggedId.value != entryId) return@detectDragGesturesAfterLongPress
+        rowState.fingerOffset.floatValue += dragAmount.y
+        rowState.offsetY.floatValue += dragAmount.y
+        reorderLive()
+    }
+}
+
+@Composable
+private fun Modifier.draggedVisual(isLifted: Boolean, translationY: Float): Modifier {
+    val shape = MaterialTheme.shapes.small
+    // Smoothly scale the row up/down as the lifted card appears and disappears.
+    val scale by animateFloatAsState(
+        targetValue = if (isLifted) 1.02f else 1f,
+        animationSpec = spring(stiffness = Spring.StiffnessMediumLow),
+        label = "dragScale"
+    )
+    return this
+        .graphicsLayer {
+            if (isLifted) {
+                this.translationY = translationY
+                scaleX = scale
+                scaleY = scale
+            }
+        }
+        .then(
+            if (isLifted) {
+                // Solid card on top so the lifted row fully covers the row beneath it
+                // instead of showing a translucent overlap of both rows.
+                Modifier
+                    .zIndex(1f)
+                    .shadow(8.dp, shape, clip = false)
+                    .background(MaterialTheme.colorScheme.surface, shape)
+            } else {
+                Modifier
+            }
+        )
+}
+
+/**
+ * Scrolls the list while dragging so the entry follows the finger past the viewport edges.
+ * The visual centre is tracked independently of the entry's layout slot (which can scroll out
+ * of [LazyListState.layoutInfo.visibleItemsInfo] during a long drag); [startCenterY] is the
+ * entry's viewport centre captured at drag start and [fingerOffset] is the raw finger delta.
+ */
+private suspend fun autoScroll(
+    listState: LazyListState,
+    startCenterY: MutableFloatState,
+    fingerOffset: MutableFloatState,
+    scrollComp: MutableFloatState
+) {
+    val threshold = 48f
+    val maxSpeed = 24f
+    while (true) {
+        val info = listState.layoutInfo
+        val center = startCenterY.floatValue + fingerOffset.floatValue
+        val top = info.viewportStartOffset + threshold
+        val bottom = info.viewportEndOffset - threshold
+        val delta = when {
+            center < top -> -(top - center).coerceAtMost(maxSpeed)
+            center > bottom -> (center - bottom).coerceAtMost(maxSpeed)
+            else -> 0f
+        }
+        if (delta != 0f) scrollComp.floatValue += listState.scrollBy(delta)
+        delay(16L)
+    }
+}
+
+private fun statusLabel(code: Int): String = if (code == NetworkResult.CONNECTION_ERROR) "ERR" else code.toString()
+
+@Composable
+private fun statusColor(code: Int): Color = when {
+    code == NetworkResult.CONNECTION_ERROR -> MaterialTheme.colorScheme.error
+    code in 200..299 -> Color(0xFF66BB6A)
+    else -> MaterialTheme.colorScheme.error
 }
 
 @Preview(showBackground = true)
@@ -252,6 +597,7 @@ fun PreviewNetworkOutputDialog() {
                 frequencyAddress = "127.0.0.1",
                 frequencyPort = "4532",
                 frequencyFormat = $$"F $FREQ",
+                frequencyOffsetHz = 0L,
                 bluetoothRotatorState = false,
                 bluetoothRotatorFormat = $$"P $AZ $EL",
                 bluetoothRotatorName = "Default",
@@ -261,7 +607,7 @@ fun PreviewNetworkOutputDialog() {
                 bluetoothFrequencyFormat = $$"F $FREQ"
             ),
             onDismiss = {},
-            onSave = { _, _, _, _, _, _, _, _ -> }
+            onSave = { _, _, _, _, _, _, _, _, _ -> }
         )
     }
 }
@@ -272,7 +618,7 @@ fun NetworkOutputDialog(
     onDismiss: () -> Unit,
     onSave: (
         Boolean, String, String, String,
-        Boolean, String, String, String
+        Boolean, String, String, String, Long
     ) -> Unit
 ) {
     val padding = LocalSpacing.current.large
@@ -286,12 +632,15 @@ fun NetworkOutputDialog(
         mutableStateOf("${initialSettings.frequencyAddress}:${initialSettings.frequencyPort}")
     }
     val frequencyFormat = rememberSaveable { mutableStateOf(initialSettings.frequencyFormat) }
+    val frequencyOffsetHz = rememberSaveable { mutableStateOf(initialSettings.frequencyOffsetHz.toString()) }
     val onAccept = {
         val (rotIp, rotPort) = splitAddress(rotatorAddress.value)
         val (freqIp, freqPort) = splitAddress(frequencyAddress.value)
+        val offsetHz = (frequencyOffsetHz.value.trim().toLongOrNull() ?: 0L)
+            .coerceIn(Constants.FREQ_OFFSET_MIN_HZ, Constants.FREQ_OFFSET_MAX_HZ)
         onSave(
             rotatorState.value, rotIp, rotPort, rotatorFormat.value,
-            frequencyState.value, freqIp, freqPort, frequencyFormat.value
+            frequencyState.value, freqIp, freqPort, frequencyFormat.value, offsetHz
         )
         onDismiss()
     }
@@ -324,6 +673,24 @@ fun NetworkOutputDialog(
                 onFormatChange = { frequencyFormat.value = it },
                 formatLabel = stringResource(R.string.prefs_net_frequency_format_hint)
             )
+            Spacer(modifier = Modifier.height(6.dp))
+            OutlinedTextField(
+                value = frequencyOffsetHz.value,
+                onValueChange = { frequencyOffsetHz.value = it },
+                singleLine = true,
+                label = { Text(stringResource(R.string.prefs_net_frequency_offset_hint)) },
+                supportingText = { Text(stringResource(R.string.prefs_net_frequency_offset_help)) },
+                trailingIcon = {
+                    IconButton(
+                        onClick = { frequencyOffsetHz.value = "0" },
+                        enabled = frequencyState.value && frequencyOffsetHz.value != "0"
+                    ) {
+                        Icon(painter = painterResource(R.drawable.ic_close), contentDescription = null)
+                    }
+                },
+                modifier = Modifier.fillMaxWidth(),
+                enabled = frequencyState.value
+            )
             Spacer(modifier = Modifier.height(12.dp))
         }
     }
@@ -352,6 +719,7 @@ fun PreviewBluetoothOutputDialog() {
                 frequencyAddress = "127.0.0.1",
                 frequencyPort = "4532",
                 frequencyFormat = $$"F $FREQ",
+                frequencyOffsetHz = 0L,
                 bluetoothRotatorState = false,
                 bluetoothRotatorFormat = $$"P $AZ $EL",
                 bluetoothRotatorName = "Default",

feature/settings/src/main/java/com/rtbishop/look4sat/feature/settings/SettingsScreen.kt

@@ -61,6 +61,7 @@ import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.lifecycle.viewmodel.compose.viewModel
+import com.rtbishop.look4sat.core.domain.model.DataSourcesSettings
 import com.rtbishop.look4sat.core.domain.model.OtherSettings
 import com.rtbishop.look4sat.core.domain.predict.GeoPos
 import com.rtbishop.look4sat.core.domain.repository.IContainerProvider
@@ -81,13 +82,25 @@ import java.util.Locale
 fun SettingsDestination() {
     val context = LocalContext.current
     val container = (context.applicationContext as IContainerProvider).getMainContainer()
-    val viewModel: SettingsViewModel = viewModel(factory = SettingsViewModel.factory(container))
+    val viewModel: SettingsViewModel = viewModel(factory = SettingsViewModel.factory(container, context))
     val uiState by viewModel.uiState.collectAsStateWithLifecycle()
     SettingsScreen(uiState, viewModel::onAction)
 }
 
 @Composable
 private fun SettingsScreen(uiState: SettingsState, onAction: (SettingsAction) -> Unit) {
+    var showUpdateChecker by rememberSaveable { mutableStateOf(false) }
+    if (showUpdateChecker) {
+        UpdateCheckerScreen(
+            currentVersion = uiState.appVersionName,
+            state = uiState.updateChecker,
+            onBack = { showUpdateChecker = false },
+            onCheck = { onAction(SettingsAction.CheckForUpdate) },
+            onDownload = { onAction(SettingsAction.DownloadUpdate) },
+            onConsumeApk = { onAction(SettingsAction.ConsumeDownloadedApk) }
+        )
+        return
+    }
     val dialogs = rememberDialogVisibility()
     val pendingCustomSourcesGrant = remember { mutableStateOf<(() -> Unit)?>(null) }
     val pendingCustomSourcesDeny = remember { mutableStateOf<(() -> Unit)?>(null) }
@@ -125,30 +138,23 @@ private fun SettingsScreen(uiState: SettingsState, onAction: (SettingsAction) ->
     }
     if (dialogs.dataSources) {
         DataSourcesDialog(
-            useCustomTle = uiState.dataSourcesSettings.useCustomTLE,
-            useCustomTransceivers = uiState.dataSourcesSettings.useCustomTransceivers,
-            tleUrl = uiState.dataSourcesSettings.tleUrl,
-            transceiversUrl = uiState.dataSourcesSettings.transceiversUrl,
-            requestCustomSourcesPermission = { onGranted, onDenied ->
-                pendingCustomSourcesGrant.value = onGranted
-                pendingCustomSourcesDeny.value = onDenied
-                permissions.launchCustomSourcesPermission()
-            },
+            satelliteUrls = uiState.dataSourcesSettings.satelliteUrls,
+            transceiversUrls = uiState.dataSourcesSettings.transceiversUrls,
+            satelliteEnabled = uiState.dataSourcesSettings.satelliteEnabled,
+            transceiversEnabled = uiState.dataSourcesSettings.transceiversEnabled,
+            statusCodes = uiState.dataSourcesStatus,
             onImportTle = { permissions.launchTleImport(); dialogs.dataSources = false },
             onImportTransceivers = { permissions.launchTransceiverImport(); dialogs.dataSources = false },
             onDismiss = { dialogs.dataSources = false },
-            onSave = { useCustomTle, useCustomTransceivers, tleUrl, transceiversUrl ->
-                val current = uiState.dataSourcesSettings
-                val newSettings = current.copy(
-                    useCustomTLE = if (!useCustomTle || tleUrl.isNotBlank()) useCustomTle else current.useCustomTLE,
-                    tleUrl = if (!useCustomTle || tleUrl.isNotBlank()) tleUrl else current.tleUrl,
-                    useCustomTransceivers = if (!useCustomTransceivers || transceiversUrl.isNotBlank()) useCustomTransceivers else current.useCustomTransceivers,
-                    transceiversUrl = if (!useCustomTransceivers || transceiversUrl.isNotBlank()) transceiversUrl else current.transceiversUrl
+            onSave = { satUrls, txUrls, satEnabled, txEnabled ->
+                val newSettings = DataSourcesSettings(
+                    satelliteUrls = satUrls,
+                    transceiversUrls = txUrls,
+                    satelliteEnabled = satEnabled,
+                    transceiversEnabled = txEnabled
                 )
-                if (newSettings != current) onAction(SettingsAction.UpdateDataSources(newSettings))
-                if (newSettings.useCustomTLE || newSettings.useCustomTransceivers) {
-                    onAction(SettingsAction.UpdateFromWeb)
-                }
+                if (newSettings != uiState.dataSourcesSettings) onAction(SettingsAction.UpdateDataSources(newSettings))
+                onAction(SettingsAction.UpdateFromWeb)
             }
         )
     }
@@ -156,14 +162,15 @@ private fun SettingsScreen(uiState: SettingsState, onAction: (SettingsAction) ->
         NetworkOutputDialog(
             initialSettings = uiState.rcSettings,
             onDismiss = { dialogs.network = false },
-            onSave = { rotState, rotAddr, rotPort, rotFmt, freqState, freqAddr, freqPort, freqFmt ->
+            onSave = { rotState, rotAddr, rotPort, rotFmt, freqState, freqAddr, freqPort, freqFmt, freqOffsetHz ->
                 onAction(
                     SettingsAction.UpdateRC(
                         uiState.rcSettings.copy(
                             rotatorState = rotState, rotatorAddress = rotAddr,
                             rotatorPort = rotPort, rotatorFormat = rotFmt,
                             frequencyState = freqState, frequencyAddress = freqAddr,
-                            frequencyPort = freqPort, frequencyFormat = freqFmt
+                            frequencyPort = freqPort, frequencyFormat = freqFmt,
+                            frequencyOffsetHz = freqOffsetHz
                         )
                     )
                 )
@@ -300,6 +307,13 @@ private fun SettingsScreen(uiState: SettingsState, onAction: (SettingsAction) ->
             }
             item { OtherCard(uiState.otherSettings, onAction) }
             item { CardCredits() }
+            item(span = { GridItemSpan(maxLineSpan) }) {
+                CardButton(
+                    onClick = { showUpdateChecker = true },
+                    text = stringResource(R.string.update_check_button),
+                    modifier = Modifier.fillMaxWidth()
+                )
+            }
         }
     }
 }

feature/settings/src/main/java/com/rtbishop/look4sat/feature/settings/SettingsState.kt

@@ -18,10 +18,12 @@
 package com.rtbishop.look4sat.feature.settings
 
 import com.rtbishop.look4sat.core.domain.model.DataSourcesSettings
+import com.rtbishop.look4sat.core.domain.model.LatestRelease
 import com.rtbishop.look4sat.core.domain.model.OtherSettings
 import com.rtbishop.look4sat.core.domain.model.RCSettings
 import com.rtbishop.look4sat.core.domain.model.RadioControlSettings
 import com.rtbishop.look4sat.core.domain.predict.GeoPos
+import java.io.File
 
 data class PositionSettings(
     val isUpdating: Boolean, val stationPos: GeoPos, val messageResId: Int
@@ -34,6 +36,15 @@ data class DataSettings(
     val timestamp: Long
 )
 
+data class UpdateCheckerState(
+    val isChecking: Boolean = false,
+    val release: LatestRelease? = null,
+    val hasUpdate: Boolean = false,
+    val isDownloading: Boolean = false,
+    val apkFile: File? = null,
+    val errorResId: Int? = null
+)
+
 data class SettingsState(
     val appVersionName: String,
     val positionSettings: PositionSettings,
@@ -41,7 +52,9 @@ data class SettingsState(
     val otherSettings: OtherSettings,
     val rcSettings: RCSettings,
     val radioControlSettings: RadioControlSettings,
-    val dataSourcesSettings: DataSourcesSettings
+    val dataSourcesSettings: DataSourcesSettings,
+    val dataSourcesStatus: Map<String, Int> = emptyMap(),
+    val updateChecker: UpdateCheckerState = UpdateCheckerState()
 )
 
 sealed interface SettingsAction {
@@ -72,6 +85,11 @@ sealed interface SettingsAction {
     // Data sources
     data class UpdateDataSources(val settings: DataSourcesSettings) : SettingsAction
 
+    // Update checker
+    data object CheckForUpdate : SettingsAction
+    data object DownloadUpdate : SettingsAction
+    data object ConsumeDownloadedApk : SettingsAction
+
     // System
     data class ShowToast(val message: String) : SettingsAction
 }

feature/settings/src/main/java/com/rtbishop/look4sat/feature/settings/SettingsViewModel.kt

@@ -17,6 +17,7 @@
  */
 package com.rtbishop.look4sat.feature.settings
 
+import android.content.Context
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import androidx.lifecycle.viewmodel.initializer
@@ -24,16 +25,21 @@ import androidx.lifecycle.viewmodel.viewModelFactory
 import com.rtbishop.look4sat.core.domain.repository.IDatabaseRepo
 import com.rtbishop.look4sat.core.domain.repository.IMainContainer
 import com.rtbishop.look4sat.core.domain.repository.ISettingsRepo
+import com.rtbishop.look4sat.core.domain.repository.IUpdateRepository
 import com.rtbishop.look4sat.core.domain.usecase.IShowToast
+import com.rtbishop.look4sat.core.domain.utility.VersionComparator
 import com.rtbishop.look4sat.core.presentation.R
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
+import java.io.File
 
 class SettingsViewModel(
     private val databaseRepo: IDatabaseRepo,
     private val settingsRepo: ISettingsRepo,
+    private val updateRepo: IUpdateRepository,
+    private val apkFile: File,
     private val showToast: IShowToast
 ) : ViewModel() {
 
@@ -47,7 +53,8 @@ class SettingsViewModel(
             otherSettings = settingsRepo.otherSettings.value,
             rcSettings = settingsRepo.rcSettings.value,
             radioControlSettings = settingsRepo.radioControlSettings.value,
-            dataSourcesSettings = settingsRepo.dataSourcesSettings.value
+            dataSourcesSettings = settingsRepo.dataSourcesSettings.value,
+            dataSourcesStatus = settingsRepo.dataSourcesStatus.value
         )
     )
 
@@ -90,6 +97,11 @@ class SettingsViewModel(
                 _uiState.update { it.copy(dataSourcesSettings = settings) }
             }
         }
+        viewModelScope.launch {
+            settingsRepo.dataSourcesStatus.collect { status ->
+                _uiState.update { it.copy(dataSourcesStatus = status) }
+            }
+        }
         viewModelScope.launch {
             settingsRepo.radioControlSettings.collect { settings ->
                 _uiState.update { it.copy(radioControlSettings = settings) }
@@ -125,11 +137,59 @@ class SettingsViewModel(
             is SettingsAction.UpdateRC -> settingsRepo.updateRCSettings(action.settings)
             is SettingsAction.UpdateRadioControl -> settingsRepo.updateRadioControlSettings(action.settings)
             is SettingsAction.UpdateDataSources -> settingsRepo.updateDataSourcesSettings(action.settings)
+            // Update checker
+            SettingsAction.CheckForUpdate -> checkForUpdate()
+            SettingsAction.DownloadUpdate -> downloadUpdate()
+            SettingsAction.ConsumeDownloadedApk -> consumeDownloadedApk()
             // System
             is SettingsAction.ShowToast -> showToast(action.message)
         }
     }
 
+    // region Update checker
+
+    private fun checkForUpdate() {
+        _uiState.update { it.copy(updateChecker = it.updateChecker.copy(isChecking = true, errorResId = null)) }
+        viewModelScope.launch {
+            val release = updateRepo.getLatestRelease()
+            val hasUpdate = release != null &&
+                VersionComparator.isNewer(release.versionTag, settingsRepo.appVersionName)
+            _uiState.update {
+                it.copy(
+                    updateChecker = it.updateChecker.copy(
+                        isChecking = false,
+                        release = release,
+                        hasUpdate = hasUpdate,
+                        errorResId = if (release == null) R.string.update_check_error else null
+                    )
+                )
+            }
+        }
+    }
+
+    private fun downloadUpdate() {
+        val url = _uiState.value.updateChecker.release?.apkUrl ?: return
+        _uiState.update { it.copy(updateChecker = it.updateChecker.copy(isDownloading = true, errorResId = null)) }
+        viewModelScope.launch {
+            val success = updateRepo.downloadApk(url, apkFile)
+            _uiState.update {
+                it.copy(
+                    updateChecker = it.updateChecker.copy(
+                        isDownloading = false,
+                        apkFile = if (success) apkFile else null,
+                        errorResId = if (success) null else R.string.update_check_download_error
+                    )
+                )
+            }
+        }
+    }
+
+    private fun consumeDownloadedApk() {
+        _uiState.update { it.copy(updateChecker = it.updateChecker.copy(apkFile = null)) }
+    }
+
+    // endregion
+
     // region Position helpers — consolidated from 3 near-identical functions
 
     private fun setGpsPosition() {
@@ -201,11 +261,13 @@ class SettingsViewModel(
 
     companion object {
 
-        fun factory(container: IMainContainer) = viewModelFactory {
+        fun factory(container: IMainContainer, context: Context) = viewModelFactory {
             initializer {
                 SettingsViewModel(
                     databaseRepo = container.databaseRepo,
                     settingsRepo = container.settingsRepo,
+                    updateRepo = container.updateRepo,
+                    apkFile = File(context.cacheDir, "look4sat-update.apk"),
                     showToast = container.provideShowToast()
                 )
             }

feature/settings/src/main/java/com/rtbishop/look4sat/feature/settings/UpdateCheckerScreen.kt

@@ -0,0 +1,236 @@
+/*
+ * 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.feature.settings
+
+import android.content.Intent
+import android.net.Uri
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Arrangement
+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.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material3.CircularProgressIndicator
+import androidx.compose.material3.ElevatedCard
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.draw.rotate
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.painterResource
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import androidx.core.content.FileProvider
+import com.rtbishop.look4sat.core.presentation.CardButton
+import com.rtbishop.look4sat.core.presentation.IconCard
+import com.rtbishop.look4sat.core.presentation.R
+import com.rtbishop.look4sat.core.presentation.ScreenColumn
+import com.rtbishop.look4sat.core.presentation.TopBar
+
+@Composable
+fun UpdateCheckerScreen(
+    currentVersion: String,
+    state: UpdateCheckerState,
+    onBack: () -> Unit,
+    onCheck: () -> Unit,
+    onDownload: () -> Unit,
+    onConsumeApk: () -> Unit
+) {
+    val context = LocalContext.current
+
+    // When the APK finishes downloading, hand it to the system installer.
+    LaunchedEffect(state.apkFile) {
+        val file = state.apkFile ?: return@LaunchedEffect
+        val uri: Uri = FileProvider.getUriForFile(context, "${context.packageName}.fileprovider", file)
+        val intent = Intent(Intent.ACTION_VIEW).apply {
+            setDataAndType(uri, "application/vnd.android.package-archive")
+            addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
+            addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
+        }
+        context.startActivity(intent)
+        onConsumeApk()
+    }
+
+    ScreenColumn(
+        topBar = { isVerticalLayout ->
+            TopBar {
+                IconCard(
+                    action = onBack,
+                    resId = R.drawable.ic_arrow,
+                    modifier = Modifier.rotate(180f)
+                )
+                Text(
+                    text = stringResource(R.string.update_check_title),
+                    style = MaterialTheme.typography.titleMedium,
+                    modifier = Modifier.weight(1f)
+                )
+            }
+        }
+    ) {
+        Column(
+            verticalArrangement = Arrangement.spacedBy(10.dp),
+            modifier = Modifier
+                .fillMaxSize()
+                .padding(10.dp)
+        ) {
+            ElevatedCard(modifier = Modifier.fillMaxWidth()) {
+                Column(
+                    horizontalAlignment = Alignment.CenterHorizontally,
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .padding(horizontal = 12.dp, vertical = 10.dp)
+                ) {
+                    Text(
+                        text = stringResource(R.string.update_check_current, currentVersion),
+                        color = MaterialTheme.colorScheme.primary,
+                        fontWeight = FontWeight.Medium
+                    )
+                    Spacer(modifier = Modifier.height(8.dp))
+                    CardButton(
+                        onClick = onCheck,
+                        text = stringResource(R.string.update_check_button),
+                        modifier = Modifier.fillMaxWidth()
+                    )
+                }
+            }
+
+            when {
+                state.isChecking -> StatusRow(showSpinner = true)
+                state.errorResId != null -> StatusRow(showSpinner = false, message = stringResource(state.errorResId))
+                state.release == null -> Unit // not checked yet
+                !state.hasUpdate -> StatusRow(showSpinner = false, message = stringResource(R.string.update_check_up_to_date))
+                else -> ReleaseCard(
+                    state = state,
+                    onDownload = onDownload,
+                    modifier = Modifier.weight(1f)
+                )
+            }
+        }
+    }
+}
+
+@Composable
+private fun StatusRow(showSpinner: Boolean, message: String? = null) {
+    Row(
+        horizontalArrangement = Arrangement.Center,
+        verticalAlignment = Alignment.CenterVertically,
+        modifier = Modifier.fillMaxWidth()
+    ) {
+        if (showSpinner) {
+            CircularProgressIndicator(modifier = Modifier.size(20.dp))
+            Spacer(modifier = Modifier.width(8.dp))
+        }
+        if (message != null) {
+            Text(
+                text = message,
+                textAlign = TextAlign.Center,
+                color = MaterialTheme.colorScheme.onSurfaceVariant
+            )
+        }
+    }
+}
+
+@Composable
+private fun ReleaseCard(state: UpdateCheckerState, onDownload: () -> Unit, modifier: Modifier = Modifier) {
+    val release = state.release ?: return
+    ElevatedCard(modifier = modifier.fillMaxWidth()) {
+        Column(
+            modifier = Modifier
+                .fillMaxSize()
+                .padding(horizontal = 12.dp, vertical = 10.dp)
+        ) {
+            Text(
+                text = stringResource(R.string.update_check_available),
+                color = MaterialTheme.colorScheme.primary,
+                fontWeight = FontWeight.Medium
+            )
+            Spacer(modifier = Modifier.height(4.dp))
+            Text(
+                text = stringResource(R.string.update_check_latest, release.versionTag.removePrefix("v")),
+                fontSize = 14.sp
+            )
+            if (release.title.isNotBlank() && release.title != release.versionTag) {
+                Text(text = release.title, fontSize = 12.sp, color = MaterialTheme.colorScheme.onSurfaceVariant)
+            }
+            if (release.body.isNotBlank()) {
+                Spacer(modifier = Modifier.height(8.dp))
+                Text(
+                    text = stringResource(R.string.update_check_release_notes),
+                    fontWeight = FontWeight.Medium,
+                    fontSize = 13.sp
+                )
+                Box(
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .weight(1f)
+                        .padding(top = 4.dp)
+                        .clip(RoundedCornerShape(12.dp))
+                        .background(MaterialTheme.colorScheme.surfaceVariant.copy(alpha = 0.45f))
+                        .verticalScroll(rememberScrollState())
+                        .padding(10.dp)
+                ) {
+                    Text(
+                        text = release.body,
+                        fontSize = 12.sp,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant
+                    )
+                }
+            } else {
+                Spacer(modifier = Modifier.weight(1f))
+            }
+            Spacer(modifier = Modifier.height(10.dp))
+            when {
+                release.apkUrl == null -> Text(
+                    text = stringResource(R.string.update_check_no_apk),
+                    color = MaterialTheme.colorScheme.error,
+                    fontSize = 12.sp
+                )
+                state.isDownloading -> Row(
+                    horizontalArrangement = Arrangement.Center,
+                    verticalAlignment = Alignment.CenterVertically,
+                    modifier = Modifier.fillMaxWidth()
+                ) {
+                    CircularProgressIndicator(modifier = Modifier.size(18.dp))
+                    Spacer(modifier = Modifier.width(8.dp))
+                    Text(text = stringResource(R.string.update_check_downloading))
+                }
+                else -> CardButton(
+                    onClick = onDownload,
+                    text = stringResource(R.string.update_check_download),
+                    modifier = Modifier.fillMaxWidth()
+                )
+            }
+        }
+    }
+}

feature/status/build.gradle.kts

@@ -0,0 +1,17 @@
+import com.android.build.api.dsl.LibraryExtension
+
+plugins {
+    alias(libs.plugins.convention.featurePlugin)
+}
+
+android {
+    namespace = "com.rtbishop.look4sat.feature.status"
+    compileOptions {
+        encoding = "UTF-8"
+    }
+}
+
+dependencies {
+    implementation(project(":core:domain"))
+    implementation(project(":core:presentation"))
+}

feature/status/src/main/java/com/rtbishop/look4sat/feature/status/SatStatusScreen.kt

@@ -0,0 +1,628 @@
+package com.rtbishop.look4sat.feature.status
+
+import androidx.compose.animation.AnimatedVisibility
+import androidx.compose.foundation.Image
+import androidx.compose.foundation.background
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.FlowRow
+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.height
+import androidx.compose.foundation.layout.heightIn
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.AlertDialog
+import androidx.compose.material3.Button
+import androidx.compose.material3.CircularProgressIndicator
+import androidx.compose.material3.FilterChip
+import androidx.compose.material3.FilterChipDefaults
+import androidx.compose.material3.HorizontalDivider
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.DisposableEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.ColorFilter
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.painterResource
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import androidx.lifecycle.Lifecycle
+import androidx.lifecycle.LifecycleEventObserver
+import androidx.lifecycle.compose.LocalLifecycleOwner
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import androidx.lifecycle.viewmodel.compose.viewModel
+import com.rtbishop.look4sat.core.domain.model.SatDay
+import com.rtbishop.look4sat.core.domain.model.SatReport
+import com.rtbishop.look4sat.core.domain.model.SatSlot
+import com.rtbishop.look4sat.core.domain.model.SatStatus
+import com.rtbishop.look4sat.core.domain.repository.IContainerProvider
+import com.rtbishop.look4sat.core.presentation.CardButton
+import com.rtbishop.look4sat.core.presentation.InfoDialog
+import com.rtbishop.look4sat.core.presentation.R
+import com.rtbishop.look4sat.core.presentation.layoutPadding
+import java.text.SimpleDateFormat
+import java.util.Calendar
+import java.util.Date
+import java.util.Locale
+import java.util.TimeZone
+
+/** Fixed width per day tile — tablet-safe; name column absorbs remaining space. */
+private val TILE_WIDTH: Dp = 64.dp
+
+private data class UploadOption(
+    val apiValue: String,
+    val labelResId: Int,
+    val color: Color
+)
+
+private val UPLOAD_OPTIONS = listOf(
+    UploadOption(AMSAT_REPORT_HEARD, R.string.amsat_upload_active, Color(0xFF648FFF)),
+    UploadOption(AMSAT_REPORT_TELEMETRY_ONLY, R.string.amsat_upload_tlm, Color(0xFFFFB000)),
+    UploadOption(AMSAT_REPORT_NOT_HEARD, R.string.amsat_upload_not_heard, Color(0xFFDC267F)),
+    UploadOption(AMSAT_REPORT_CREW_ACTIVE, R.string.amsat_upload_crew_active, Color(0xFFFE6100))
+)
+
+/**
+ * Map AMSAT status text to Material3 colorScheme colors.
+ * Addresses PR #233 review: use colorScheme instead of hardcoded Color() constants.
+ */
+@Composable
+private fun statusColorOf(statusText: String): Color {
+    return when {
+        statusText.contains("Heard", ignoreCase = true) && !statusText.contains("Not", ignoreCase = true) ->
+            MaterialTheme.colorScheme.tertiary
+        statusText.contains("Telemetry", ignoreCase = true) || statusText.contains("Beacon", ignoreCase = true) ->
+            MaterialTheme.colorScheme.tertiaryContainer
+        statusText.contains("Not Heard", ignoreCase = true) ->
+            Color(0xFFDC267F)
+        else ->
+            MaterialTheme.colorScheme.error
+    }
+}
+
+@Composable
+fun SatStatusDestination() {
+    val context = LocalContext.current
+    val container = (context.applicationContext as IContainerProvider).getMainContainer()
+    val viewModel: SatStatusViewModel = viewModel(factory = SatStatusViewModel.factory(container))
+    val lifecycleOwner = LocalLifecycleOwner.current
+    val uiState by viewModel.uiState.collectAsStateWithLifecycle()
+    DisposableEffect(lifecycleOwner, viewModel) {
+        var skipInitialStart = true
+        val observer = LifecycleEventObserver { _, event ->
+            if (event == Lifecycle.Event.ON_START) {
+                if (skipInitialStart) {
+                    skipInitialStart = false
+                } else {
+                    viewModel.fetch()
+                }
+            }
+        }
+        lifecycleOwner.lifecycle.addObserver(observer)
+        onDispose { lifecycleOwner.lifecycle.removeObserver(observer) }
+    }
+    SatStatusScreen(
+        uiState = uiState,
+        refresh = viewModel::refresh,
+        onToggleUpload = viewModel::toggleUploadPanel,
+        onUploadReportChange = viewModel::setUploadReport,
+        onUploadCallsignChange = viewModel::setUploadCallsign,
+        onUploadGridChange = viewModel::setUploadGrid,
+        onRequestSubmitUpload = viewModel::requestSubmitConfirmation,
+        onConfirmSubmitUpload = viewModel::confirmSubmitReport,
+        onDismissSubmitConfirmation = viewModel::dismissSubmitConfirmation,
+        onDismissUpload = viewModel::collapseUploadPanel
+    )
+}
+
+@Composable
+private fun SatStatusScreen(
+    uiState: SatStatusUiState,
+    refresh: () -> Unit,
+    onToggleUpload: () -> Unit,
+    onUploadReportChange: (String) -> Unit,
+    onUploadCallsignChange: (String) -> Unit,
+    onUploadGridChange: (String) -> Unit,
+    onRequestSubmitUpload: () -> Unit,
+    onConfirmSubmitUpload: (String) -> Unit,
+    onDismissSubmitConfirmation: () -> Unit,
+    onDismissUpload: () -> Unit
+) {
+    var selectedDay by remember { mutableStateOf<Pair<SatStatus, SatDay>?>(null) }
+    Column(modifier = Modifier.fillMaxSize().layoutPadding()) {
+        StatusHeader(fetchedAtUtcMs = uiState.fetchedAtUtcMs, isRefreshing = uiState.isRefreshing, onRefresh = refresh)
+        LegendRow()
+
+        when {
+            uiState.isLoading -> {
+                Box(modifier = Modifier.fillMaxSize(), contentAlignment = Alignment.Center) {
+                    CircularProgressIndicator()
+                }
+            }
+            uiState.error != null && uiState.statuses.isEmpty() -> {
+                Column(
+                    modifier = Modifier.fillMaxSize(),
+                    verticalArrangement = Arrangement.Center,
+                    horizontalAlignment = Alignment.CenterHorizontally
+                ) {
+                    Text(text = stringResource(id = R.string.amsat_load_failed), color = MaterialTheme.colorScheme.error)
+                    TextButton(onClick = refresh) { Text(text = stringResource(id = R.string.amsat_retry)) }
+                }
+            }
+            else -> {
+                HeaderRow(statuses = uiState.statuses)
+                HorizontalDivider(thickness = 1.dp)
+                LazyColumn(modifier = Modifier.fillMaxSize()) {
+                    items(uiState.statuses, key = { it.name }) { status ->
+                        StatusRow(status = status, onClickDay = { day -> selectedDay = status to day })
+                    }
+                }
+            }
+        }
+    }
+
+    selectedDay?.let { (status, day) ->
+        ReportDialog(
+            statusName = status.name,
+            day = day,
+            reports = uiState.reports,
+            upload = uiState.upload,
+            onToggleUpload = onToggleUpload,
+            onReportChange = onUploadReportChange,
+            onCallsignChange = onUploadCallsignChange,
+            onGridChange = onUploadGridChange,
+            onRequestSubmitReport = onRequestSubmitUpload,
+            onConfirmSubmitReport = { onConfirmSubmitUpload(status.name) },
+            onDismissSubmitConfirmation = onDismissSubmitConfirmation,
+            onDismiss = {
+                selectedDay = null
+                onDismissUpload()
+            }
+        )
+    }
+}
+
+/** Top: update time + refresh button (spinner while loading) */
+@Composable
+private fun StatusHeader(fetchedAtUtcMs: Long, isRefreshing: Boolean, onRefresh: () -> Unit) {
+    Row(
+        modifier = Modifier.fillMaxWidth().padding(vertical = 4.dp),
+        verticalAlignment = Alignment.CenterVertically
+    ) {
+        Text(
+            text = if (fetchedAtUtcMs > 0)
+                stringResource(id = R.string.amsat_updated) + " " + formatFetchedAt(fetchedAtUtcMs)
+            else
+                stringResource(id = R.string.amsat_title),
+            fontSize = 14.sp,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+            modifier = Modifier.weight(1f)
+        )
+        Box(
+            modifier = Modifier
+                .size(32.dp)
+                .clip(CircleShape)
+                .background(MaterialTheme.colorScheme.surfaceVariant)
+                .clickable(onClick = onRefresh),
+            contentAlignment = Alignment.Center
+        ) {
+            if (isRefreshing) {
+                CircularProgressIndicator(modifier = Modifier.size(16.dp), strokeWidth = 2.dp)
+            } else {
+                Image(
+                    painter = painterResource(id = R.drawable.ic_refresh),
+                    contentDescription = stringResource(id = R.string.amsat_refresh),
+                    modifier = Modifier.size(16.dp),
+                    colorFilter = ColorFilter.tint(MaterialTheme.colorScheme.primary)
+                )
+            }
+        }
+    }
+}
+
+/** Legend: FlowRow of colored chips — wraps to two lines on narrow screens, stays one line when wide. */
+@Composable
+private fun LegendRow() {
+    val legend = listOf(
+        stringResource(id = R.string.amsat_active) to Color(0xFF648FFF),
+        stringResource(id = R.string.amsat_tlm) to Color(0xFFFFB000),
+        stringResource(id = R.string.amsat_not_heard) to Color(0xFFDC267F),
+        stringResource(id = R.string.amsat_conflict) to Color(0xFFFE6100)
+    )
+    FlowRow(
+        modifier = Modifier.fillMaxWidth().padding(bottom = 6.dp),
+        horizontalArrangement = Arrangement.spacedBy(6.dp),
+        verticalArrangement = Arrangement.spacedBy(6.dp)
+    ) {
+        legend.forEach { (label, color) ->
+            val alphaColor = color.copy(alpha = 0.25f)
+            Row(
+                modifier = Modifier
+                    .clip(RoundedCornerShape(32.dp))
+                    .background(alphaColor)
+                    .padding(horizontal = 12.dp, vertical = 4.dp),
+                verticalAlignment = Alignment.CenterVertically
+            ) {
+                Box(
+                    modifier = Modifier
+                        .size(8.dp)
+                        .clip(RoundedCornerShape(4.dp))
+                        .background(color)
+                )
+                Spacer(modifier = Modifier.width(6.dp))
+                Text(
+                    text = label,
+                    fontSize = 14.sp,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant
+                )
+            }
+        }
+    }
+}
+
+/** Header: satellite name column + fixed-width date labels aligned to tiles. */
+@Composable
+private fun HeaderRow(statuses: List<SatStatus>) {
+    val dates = statuses.firstOrNull()?.days?.map { it.dateLabel } ?: emptyList()
+    Row(
+        modifier = Modifier.fillMaxWidth().padding(vertical = 2.dp),
+        verticalAlignment = Alignment.CenterVertically
+    ) {
+        Text(
+            text = stringResource(id = R.string.amsat_name),
+            fontSize = 12.sp,
+            fontWeight = FontWeight.Medium,
+            color = MaterialTheme.colorScheme.primary,
+            modifier = Modifier.weight(1f).padding(start = 4.dp)
+        )
+        dates.forEach { date ->
+            Text(
+                text = date,
+                fontSize = 12.sp,
+                fontWeight = FontWeight.Medium,
+                textAlign = TextAlign.Center,
+                color = MaterialTheme.colorScheme.primary,
+                modifier = Modifier.width(TILE_WIDTH)
+            )
+        }
+    }
+}
+
+/** Satellite row: name takes remaining width; day tiles are fixed-width (tablet-safe). */
+@Composable
+private fun StatusRow(status: SatStatus, onClickDay: (SatDay) -> Unit) {
+    val noReportGray = 0xFFC0C0C0L
+    Row(
+        modifier = Modifier.fillMaxWidth().padding(vertical = 2.dp),
+        verticalAlignment = Alignment.CenterVertically
+    ) {
+        Text(
+            text = status.name,
+            fontSize = 14.sp,
+            maxLines = 1,
+            overflow = TextOverflow.Ellipsis,
+            modifier = Modifier.weight(1f).padding(end = 4.dp)
+        )
+        status.days.forEach { day ->
+            val slot = day.slots.firstOrNull { it.statusColor != noReportGray } ?: day.slots.first()
+            DayCell(
+                slot = slot,
+                modifier = Modifier.width(TILE_WIDTH).padding(horizontal = 2.dp),
+                onClick = { onClickDay(day) }
+            )
+        }
+    }
+}
+
+/** Day block: newest reported status among the day's 12 slots; gray when none. */
+@Composable
+private fun DayCell(slot: SatSlot, modifier: Modifier, onClick: () -> Unit) {
+    val color = Color(slot.statusColor)
+    Box(
+        modifier = modifier
+            .height(28.dp)
+            .clip(RoundedCornerShape(4.dp))
+            .background(color)
+            .clickable(onClick = onClick),
+        contentAlignment = Alignment.Center
+    ) {
+        if (slot.count > 0) {
+            Text(text = slot.count.toString(), fontSize = 13.sp, fontWeight = FontWeight.Bold, color = Color.White)
+        }
+    }
+}
+
+/** Report detail dialog (callsign / date / time / grid) */
+@Composable
+private fun ReportDialog(
+    statusName: String,
+    day: SatDay,
+    reports: Map<String, SatReport>,
+    upload: AmSatUploadUiState,
+    onToggleUpload: () -> Unit,
+    onReportChange: (String) -> Unit,
+    onCallsignChange: (String) -> Unit,
+    onGridChange: (String) -> Unit,
+    onRequestSubmitReport: () -> Unit,
+    onConfirmSubmitReport: () -> Unit,
+    onDismissSubmitConfirmation: () -> Unit,
+    onDismiss: () -> Unit
+) {
+    val dayReports = day.slots.flatMap { it.reportIds }.mapNotNull { reports[it] }
+    InfoDialog(
+        title = "$statusName · ${day.dateLabel}",
+        onDismiss = onDismiss,
+        onAccept = onDismiss,
+        extraAction = {
+            CardButton(
+                onClick = onToggleUpload,
+                text = stringResource(if (upload.isExpanded) R.string.amsat_upload_back else R.string.amsat_upload)
+            )
+        }
+    ) {
+        AnimatedVisibility(visible = upload.isExpanded) {
+            AmSatUploadPanel(
+                statusName = statusName,
+                upload = upload,
+                onReportChange = onReportChange,
+                onCallsignChange = onCallsignChange,
+                onGridChange = onGridChange,
+                onRequestSubmitReport = onRequestSubmitReport
+            )
+        }
+        if (upload.isConfirmingSubmit) {
+            AmSatUploadConfirmDialog(
+                statusName = statusName,
+                upload = upload,
+                onConfirm = onConfirmSubmitReport,
+                onDismiss = onDismissSubmitConfirmation
+            )
+        }
+        if (dayReports.isEmpty()) {
+            Text(
+                text = stringResource(id = R.string.amsat_no_reports),
+                modifier = Modifier.padding(horizontal = 16.dp, vertical = 8.dp)
+            )
+            Spacer(modifier = Modifier.height(8.dp))
+        } else {
+            LazyColumn(modifier = Modifier.heightIn(max = 480.dp)) {
+                items(dayReports) { report ->
+                    Column(modifier = Modifier.fillMaxWidth().padding(horizontal = 16.dp, vertical = 8.dp)) {
+                        Row(verticalAlignment = Alignment.CenterVertically) {
+                            Box(
+                                modifier = Modifier
+                                    .size(8.dp)
+                                    .clip(CircleShape)
+                                    .background(statusColorOf(report.statusText))
+                            )
+                            Spacer(modifier = Modifier.width(6.dp))
+                            Text(text = report.statusText, fontSize = 14.sp, fontWeight = FontWeight.Bold)
+                        }
+                        Text(
+                            text = "${report.call}  ${report.dateUtc}  ${report.timeUtc}" +
+                                if (report.grid.isNotBlank() && report.grid != "-") "  ${report.grid}" else "",
+                            fontSize = 14.sp,
+                            color = MaterialTheme.colorScheme.onSurfaceVariant
+                        )
+                    }
+                    HorizontalDivider(thickness = 0.5.dp)
+                }
+            }
+        }
+    }
+}
+
+@Composable
+private fun AmSatUploadPanel(
+    statusName: String,
+    upload: AmSatUploadUiState,
+    onReportChange: (String) -> Unit,
+    onCallsignChange: (String) -> Unit,
+    onGridChange: (String) -> Unit,
+    onRequestSubmitReport: () -> Unit
+) {
+    val options = remember(statusName) {
+        if (statusName.startsWith("ISS")) UPLOAD_OPTIONS else UPLOAD_OPTIONS.filter { it.apiValue != AMSAT_REPORT_CREW_ACTIVE }
+    }
+    Column(
+        modifier = Modifier
+            .fillMaxWidth()
+            .padding(horizontal = 16.dp, vertical = 8.dp)
+            .clip(RoundedCornerShape(16.dp))
+            .background(MaterialTheme.colorScheme.surfaceVariant.copy(alpha = 0.45f))
+            .padding(12.dp),
+        verticalArrangement = Arrangement.spacedBy(10.dp)
+    ) {
+        Text(
+            text = stringResource(R.string.amsat_upload_report),
+            fontSize = 16.sp,
+            fontWeight = FontWeight.Medium,
+            color = MaterialTheme.colorScheme.primary
+        )
+        Text(
+            text = stringResource(R.string.amsat_upload_time_now, formatUtcNowForUpload(System.currentTimeMillis())),
+            fontSize = 12.sp,
+            color = MaterialTheme.colorScheme.onSurfaceVariant
+        )
+        Text(
+            text = stringResource(R.string.amsat_upload_status),
+            fontSize = 12.sp,
+            color = MaterialTheme.colorScheme.onSurfaceVariant
+        )
+        FlowRow(
+            horizontalArrangement = Arrangement.spacedBy(6.dp),
+            verticalArrangement = Arrangement.spacedBy(4.dp)
+        ) {
+            options.forEach { option ->
+                val selected = upload.selectedReport == option.apiValue
+                FilterChip(
+                    selected = selected,
+                    onClick = { onReportChange(option.apiValue) },
+                    label = {
+                        Row(verticalAlignment = Alignment.CenterVertically) {
+                            Box(
+                                modifier = Modifier
+                                    .size(8.dp)
+                                    .clip(CircleShape)
+                                    .background(if (selected) Color.White else option.color)
+                            )
+                            Spacer(modifier = Modifier.width(6.dp))
+                            Text(stringResource(option.labelResId), maxLines = 1)
+                        }
+                    },
+                    colors = FilterChipDefaults.filterChipColors(
+                        containerColor = option.color.copy(alpha = 0.10f),
+                        labelColor = MaterialTheme.colorScheme.onSurface,
+                        selectedContainerColor = option.color,
+                        selectedLabelColor = Color.White
+                    ),
+                    border = FilterChipDefaults.filterChipBorder(
+                        enabled = true,
+                        selected = selected,
+                        borderColor = option.color.copy(alpha = 0.60f),
+                        selectedBorderColor = option.color
+                    )
+                )
+            }
+        }
+        Row(horizontalArrangement = Arrangement.spacedBy(8.dp), modifier = Modifier.fillMaxWidth()) {
+            OutlinedTextField(
+                value = upload.callsign,
+                onValueChange = onCallsignChange,
+                label = { Text(stringResource(R.string.amsat_upload_callsign)) },
+                singleLine = true,
+                modifier = Modifier.weight(1f)
+            )
+            OutlinedTextField(
+                value = upload.gridSquare,
+                onValueChange = onGridChange,
+                label = { Text(stringResource(R.string.amsat_upload_grid)) },
+                singleLine = true,
+                modifier = Modifier.weight(1f)
+            )
+        }
+        Button(
+            onClick = onRequestSubmitReport,
+            enabled = !upload.isSubmitting && upload.callsign.isNotBlank(),
+            modifier = Modifier.fillMaxWidth()
+        ) {
+            if (upload.isSubmitting) {
+                CircularProgressIndicator(modifier = Modifier.size(16.dp), strokeWidth = 2.dp)
+            } else {
+                Text(stringResource(R.string.amsat_upload_submit))
+            }
+        }
+        upload.message?.let { message ->
+            if (message == UPLOAD_MESSAGE_SUCCESS) {
+                Text(
+                    text = stringResource(R.string.amsat_upload_success),
+                    fontSize = 12.sp,
+                    color = MaterialTheme.colorScheme.primary
+                )
+            }
+        }
+        upload.error?.let { error ->
+            Text(
+                text = uploadErrorText(error),
+                fontSize = 12.sp,
+                color = MaterialTheme.colorScheme.error
+            )
+        }
+    }
+}
+
+@Composable
+private fun AmSatUploadConfirmDialog(
+    statusName: String,
+    upload: AmSatUploadUiState,
+    onConfirm: () -> Unit,
+    onDismiss: () -> Unit
+) {
+    val option = UPLOAD_OPTIONS.firstOrNull { it.apiValue == upload.selectedReport } ?: UPLOAD_OPTIONS.first()
+    val statusLabel = stringResource(option.labelResId)
+    val grid = upload.gridSquare.ifBlank { stringResource(R.string.amsat_upload_grid_none) }
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        title = { Text(stringResource(R.string.amsat_upload_confirm_title)) },
+        text = {
+            Text(
+                text = stringResource(
+                    R.string.amsat_upload_confirm_message,
+                    statusName,
+                    statusLabel,
+                    upload.callsign,
+                    grid
+                )
+            )
+        },
+        confirmButton = {
+            TextButton(onClick = onConfirm, enabled = !upload.isSubmitting) {
+                Text(stringResource(R.string.amsat_upload_confirm))
+            }
+        },
+        dismissButton = {
+            TextButton(onClick = onDismiss, enabled = !upload.isSubmitting) {
+                Text(stringResource(R.string.btn_cancel))
+            }
+        }
+    )
+}
+
+@Composable
+private fun uploadErrorText(error: String): String {
+    return when (error) {
+        UPLOAD_ERROR_CALLSIGN_REQUIRED -> stringResource(R.string.amsat_upload_callsign_required)
+        UPLOAD_ERROR_GRID_INVALID -> stringResource(R.string.amsat_upload_grid_invalid)
+        else -> stringResource(R.string.amsat_upload_failed, error)
+    }
+}
+
+private val MONTH_ABBR = arrayOf("Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec")
+
+private fun formatFetchedAt(utcMs: Long): String {
+    val cal = Calendar.getInstance()
+    cal.timeInMillis = utcMs
+    val day = cal.get(Calendar.DAY_OF_MONTH)
+    val monthIndex = cal.get(Calendar.MONTH)
+    val year = cal.get(Calendar.YEAR)
+    val hh = cal.get(Calendar.HOUR_OF_DAY).toString().padStart(2, '0')
+    val mm = cal.get(Calendar.MINUTE).toString().padStart(2, '0')
+    val ss = cal.get(Calendar.SECOND).toString().padStart(2, '0')
+    return if (Locale.getDefault().language == Locale.CHINESE.language) {
+        "${year}年${monthIndex + 1}月${day}日 - $hh:$mm:$ss"
+    } else {
+        "$day${MONTH_ABBR[monthIndex]} $year - $hh:$mm:$ss"
+    }
+}
+
+private fun formatUtcNowForUpload(utcMs: Long): String {
+    val formatter = SimpleDateFormat("yyyy-MM-dd HH:mm", Locale.US).apply {
+        timeZone = TimeZone.getTimeZone("UTC")
+    }
+    return formatter.format(Date(utcMs))
+}

feature/status/src/main/java/com/rtbishop/look4sat/feature/status/SatStatusViewModel.kt

@@ -0,0 +1,294 @@
+package com.rtbishop.look4sat.feature.status
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import androidx.lifecycle.viewmodel.initializer
+import androidx.lifecycle.viewmodel.viewModelFactory
+import com.rtbishop.look4sat.core.domain.model.AmSatReportSubmission
+import com.rtbishop.look4sat.core.domain.model.SatReport
+import com.rtbishop.look4sat.core.domain.model.SatStatus
+import com.rtbishop.look4sat.core.domain.model.SatStatusPage
+import com.rtbishop.look4sat.core.domain.repository.IAmSatRepository
+import com.rtbishop.look4sat.core.domain.repository.IMainContainer
+import com.rtbishop.look4sat.core.domain.repository.ISettingsRepo
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.update
+import kotlinx.coroutines.launch
+import java.util.Locale
+
+const val AMSAT_REPORT_HEARD = "Heard"
+const val AMSAT_REPORT_TELEMETRY_ONLY = "Telemetry Only"
+const val AMSAT_REPORT_NOT_HEARD = "Not Heard"
+const val AMSAT_REPORT_CREW_ACTIVE = "Crew Active"
+
+const val UPLOAD_ERROR_CALLSIGN_REQUIRED = "callsign_required"
+const val UPLOAD_ERROR_GRID_INVALID = "grid_invalid"
+const val UPLOAD_MESSAGE_SUCCESS = "success"
+
+data class AmSatUploadUiState(
+    val isExpanded: Boolean = false,
+    val selectedReport: String = AMSAT_REPORT_HEARD,
+    val callsign: String = "",
+    val gridSquare: String = "",
+    val isSubmitting: Boolean = false,
+    val isConfirmingSubmit: Boolean = false,
+    val message: String? = null,
+    val error: String? = null
+)
+
+data class SatStatusUiState(
+    val isLoading: Boolean = false,
+    val isRefreshing: Boolean = false,
+    val statuses: List<SatStatus> = emptyList(),
+    val reports: Map<String, SatReport> = emptyMap(),
+    val fetchedAtUtcMs: Long = 0L,
+    val error: String? = null,
+    val upload: AmSatUploadUiState = AmSatUploadUiState()
+)
+
+class SatStatusViewModel(
+    private val amSatRepo: IAmSatRepository,
+    private val settingsRepo: ISettingsRepo
+) : ViewModel() {
+
+    private val cachedStatusPage = amSatRepo.getCachedStatus()
+    private val _uiState = MutableStateFlow(cachedStatusPage?.toUiState() ?: SatStatusUiState(isLoading = true))
+    val uiState: StateFlow<SatStatusUiState> = _uiState
+
+    init {
+        if (cachedStatusPage == null) fetch()
+    }
+
+    fun fetch() {
+        amSatRepo.getCachedStatus()?.let { page ->
+            applyStatusPage(page)
+            return
+        }
+        viewModelScope.launch {
+            _uiState.update { it.copy(isLoading = true, error = null) }
+            try {
+                val page = amSatRepo.fetchStatus()
+                if (page != null && page.statuses.isNotEmpty()) {
+                    applyStatusPage(page)
+                } else {
+                    _uiState.update {
+                        it.copy(isLoading = false, isRefreshing = false, error = "fetch_failed")
+                    }
+                }
+            } catch (exception: Exception) {
+                _uiState.update {
+                    it.copy(isLoading = false, isRefreshing = false, error = exception.message ?: "fetch_failed")
+                }
+            }
+        }
+    }
+
+    fun refresh() {
+        if (_uiState.value.isRefreshing) return
+        _uiState.update { it.copy(isRefreshing = true, error = null) }
+        viewModelScope.launch {
+            try {
+                val page = amSatRepo.fetchStatus(forceRefresh = true)
+                if (page != null && page.statuses.isNotEmpty()) {
+                    applyStatusPage(page)
+                } else {
+                    _uiState.update { it.copy(isRefreshing = false, error = "fetch_failed") }
+                }
+            } catch (exception: Exception) {
+                _uiState.update { it.copy(isRefreshing = false, error = exception.message ?: "fetch_failed") }
+            }
+        }
+    }
+
+    private fun applyStatusPage(page: SatStatusPage) {
+        _uiState.update {
+            it.copy(
+                isLoading = false,
+                isRefreshing = false,
+                statuses = page.statuses,
+                reports = page.reports,
+                fetchedAtUtcMs = page.fetchedAtUtcMs,
+                error = null
+            )
+        }
+    }
+
+    fun toggleUploadPanel() {
+        val storedCallsign = settingsRepo.getAmSatCallsign()
+        val defaultGrid = defaultGridSquare()
+        _uiState.update { state ->
+            val upload = state.upload
+            val expanded = !upload.isExpanded
+            state.copy(
+                upload = if (expanded) {
+                    upload.copy(
+                        isExpanded = true,
+                        callsign = upload.callsign.ifBlank { storedCallsign },
+                        gridSquare = upload.gridSquare.ifBlank { defaultGrid },
+                        message = null,
+                        error = null
+                    )
+                } else {
+                    upload.copy(isExpanded = false, isConfirmingSubmit = false, message = null, error = null)
+                }
+            )
+        }
+    }
+
+    fun collapseUploadPanel() {
+        _uiState.update { it.copy(upload = it.upload.copy(isExpanded = false, isConfirmingSubmit = false, message = null, error = null)) }
+    }
+
+    fun setUploadReport(report: String) {
+        _uiState.update { it.copy(upload = it.upload.copy(selectedReport = report, isConfirmingSubmit = false, message = null, error = null)) }
+    }
+
+    fun setUploadCallsign(callsign: String) {
+        val normalized = callsign.trim().uppercase(Locale.US)
+        settingsRepo.setAmSatCallsign(normalized)
+        _uiState.update { it.copy(upload = it.upload.copy(callsign = normalized, isConfirmingSubmit = false, message = null, error = null)) }
+    }
+
+    fun setUploadGrid(grid: String) {
+        val normalized = grid.trim().uppercase(Locale.US)
+        _uiState.update { it.copy(upload = it.upload.copy(gridSquare = normalized, isConfirmingSubmit = false, message = null, error = null)) }
+    }
+
+    fun requestSubmitConfirmation() {
+        val prepared = validateUpload(_uiState.value.upload) ?: return
+        _uiState.update {
+            it.copy(
+                upload = it.upload.copy(
+                    callsign = prepared.callsign,
+                    gridSquare = prepared.grid,
+                    isConfirmingSubmit = true,
+                    message = null,
+                    error = null
+                )
+            )
+        }
+    }
+
+    fun dismissSubmitConfirmation() {
+        _uiState.update { it.copy(upload = it.upload.copy(isConfirmingSubmit = false)) }
+    }
+
+    fun confirmSubmitReport(satelliteName: String) {
+        val upload = _uiState.value.upload
+        if (upload.isSubmitting) return
+        val prepared = validateUpload(upload) ?: return
+
+        settingsRepo.setAmSatCallsign(prepared.callsign)
+        _uiState.update {
+            it.copy(
+                upload = it.upload.copy(
+                    callsign = prepared.callsign,
+                    gridSquare = prepared.grid,
+                    isSubmitting = true,
+                    isConfirmingSubmit = false,
+                    error = null,
+                    message = null
+                )
+            )
+        }
+        viewModelScope.launch {
+            val result = amSatRepo.submitReport(
+                AmSatReportSubmission(
+                    name = satelliteName,
+                    report = prepared.report,
+                    callsign = prepared.callsign,
+                    gridSquare = prepared.grid,
+                    reportedAtUtcMillis = System.currentTimeMillis()
+                )
+            )
+            if (result.success) {
+                _uiState.update {
+                    it.copy(
+                        upload = it.upload.copy(
+                            isSubmitting = false,
+                            callsign = prepared.callsign,
+                            gridSquare = prepared.grid,
+                            message = UPLOAD_MESSAGE_SUCCESS,
+                            error = null
+                        )
+                    )
+                }
+                refresh()
+            } else {
+                _uiState.update {
+                    it.copy(
+                        upload = it.upload.copy(
+                            isSubmitting = false,
+                            message = null,
+                            error = result.message.ifBlank { "Upload failed" }
+                        )
+                    )
+                }
+            }
+        }
+    }
+
+    private fun validateUpload(upload: AmSatUploadUiState): PreparedUpload? {
+        val callsign = upload.callsign.trim().uppercase(Locale.US)
+        val grid = upload.gridSquare.trim().uppercase(Locale.US)
+        return when {
+            callsign.isBlank() -> {
+                _uiState.update {
+                    it.copy(
+                        upload = it.upload.copy(
+                            isConfirmingSubmit = false,
+                            error = UPLOAD_ERROR_CALLSIGN_REQUIRED,
+                            message = null
+                        )
+                    )
+                }
+                null
+            }
+            grid.isNotBlank() && !MAIDENHEAD_GRID.matches(grid) -> {
+                _uiState.update {
+                    it.copy(
+                        upload = it.upload.copy(
+                            isConfirmingSubmit = false,
+                            error = UPLOAD_ERROR_GRID_INVALID,
+                            message = null
+                        )
+                    )
+                }
+                null
+            }
+            else -> PreparedUpload(
+                report = upload.selectedReport,
+                callsign = callsign,
+                grid = grid
+            )
+        }
+    }
+
+    private fun defaultGridSquare(): String {
+        val grid = settingsRepo.stationPosition.value.qthLocator.trim().uppercase(Locale.US)
+        return grid.takeUnless { it == "JJ00AA" }.orEmpty()
+    }
+
+    companion object {
+        fun factory(container: IMainContainer) = viewModelFactory {
+            initializer {
+                SatStatusViewModel(container.amSatRepo, container.settingsRepo)
+            }
+        }
+    }
+}
+
+private fun SatStatusPage.toUiState() = SatStatusUiState(
+    statuses = statuses,
+    reports = reports,
+    fetchedAtUtcMs = fetchedAtUtcMs
+)
+
+private data class PreparedUpload(
+    val report: String,
+    val callsign: String,
+    val grid: String
+)
+
+private val MAIDENHEAD_GRID = Regex("^[A-R]{2}[0-9]{2}([A-X]{2})?$")

gradle/libs.versions.toml

@@ -1,8 +1,8 @@
 [versions]
 #noinspection UnusedVersionCatalogEntry
-appVersionCode = "443"
+appVersionCode = "451"
 #noinspection UnusedVersionCatalogEntry
-appVersionName = "4.4.3"
+appVersionName = "4.4.6-ba7opf.7"
 #noinspection UnusedVersionCatalogEntry
 compileSdk = "37"
 #noinspection UnusedVersionCatalogEntry
@@ -23,7 +23,7 @@ compose-activity = "1.13.0"
 compose-lifecycle = "2.11.0"
 compose-navigation3 = "1.1.5"
 
-google-ksp = "2.3.8"
+google-ksp = "2.3.10"
 
 kotlin = "2.4.10"
 kotlin-coroutines = "1.11.0"

settings.gradle.kts

@@ -27,5 +27,6 @@ include(
     ":feature:passes",
     ":feature:radar",
     ":feature:satellites",
-    ":feature:settings"
+    ":feature:settings",
+    ":feature:status"
 )