v4.3.0 - Sticky header, sun/moon positions, red night mode

Co-authored-by: Arty Bishop <44072814+rt-bishop@users.noreply.github.com>

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

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

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

@@ -25,19 +25,17 @@ 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.togetherWith
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
 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.WindowInsets
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
-import androidx.compose.foundation.layout.statusBars
 import androidx.compose.foundation.layout.width
-import androidx.compose.foundation.layout.windowInsetsPadding
 import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
@@ -58,128 +56,162 @@ import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
-import androidx.navigation.NavHostController
-import androidx.navigation.compose.NavHost
-import androidx.navigation.compose.currentBackStackEntryAsState
-import androidx.navigation.compose.rememberNavController
+import androidx.lifecycle.viewmodel.navigation3.rememberViewModelStoreNavEntryDecorator
+import androidx.navigation3.runtime.entryProvider
+import androidx.navigation3.runtime.rememberNavBackStack
+import androidx.navigation3.runtime.rememberSaveableStateHolderNavEntryDecorator
+import androidx.navigation3.ui.NavDisplay
+import com.rtbishop.look4sat.core.domain.repository.IContainerProvider
 import com.rtbishop.look4sat.core.presentation.Screen
 import com.rtbishop.look4sat.core.presentation.hasEnoughHeight
 import com.rtbishop.look4sat.core.presentation.hasEnoughWidth
-import com.rtbishop.look4sat.core.domain.repository.IContainerProvider
-import com.rtbishop.look4sat.feature.map.mapDestination
-import com.rtbishop.look4sat.feature.passes.passesDestination
-import com.rtbishop.look4sat.feature.radar.radarDestination
-import com.rtbishop.look4sat.feature.radiocontrol.radioControlDestination
-import com.rtbishop.look4sat.feature.satellites.satellitesDestination
-import com.rtbishop.look4sat.feature.settings.settingsDestination
+import com.rtbishop.look4sat.feature.map.MapDestination
+import com.rtbishop.look4sat.feature.passes.PassesDestination
+import com.rtbishop.look4sat.feature.radar.RadarDestination
+import com.rtbishop.look4sat.feature.radiocontrol.RadioControlDestination
+import com.rtbishop.look4sat.feature.satellites.SatellitesDestination
+import com.rtbishop.look4sat.feature.settings.SettingsDestination
 
 @Composable
-fun MainScreen(navController: NavHostController = rememberNavController()) {
-    val items = listOf(Screen.Satellites, Screen.Passes, Screen.Radar, Screen.Map, Screen.Settings)
-    val currentDestination = navController.currentBackStackEntryAsState().value?.destination?.route
-    val startDestination = Screen.Passes.route
+fun MainScreen() {
+    val backStack = rememberNavBackStack(Screen.Passes)
+    val currentKey = backStack.lastOrNull()
+    val navigateBack: () -> Unit = { backStack.removeAt(backStack.size - 1) }
+    val fadeTransition = fadeIn(animationSpec = tween(350)) togetherWith fadeOut(animationSpec = tween(350))
+//    val slideInTransition = slideInHorizontally(initialOffsetX = { it }) togetherWith scaleOut(targetScale = 0.9f)
+//    val slideOutTransition = scaleIn(initialScale = 0.9f) togetherWith slideOutHorizontally(targetOffsetX = { it })
+    val navItems = listOf(Screen.Satellites, Screen.Passes, Screen.Radar(), Screen.Map, Screen.Settings)
 
-    // Observe radio tracking state for the status bar
     val context = LocalContext.current
     val container = (context.applicationContext as IContainerProvider).getMainContainer()
     val trackingState by container.radioTrackingService.state.collectAsStateWithLifecycle()
 
     NavigationSuiteScaffold(
         navigationSuiteItems = {
-            items.forEach {
+            navItems.forEach { screen ->
+                val isSelected = when (currentKey) {
+                    is Screen.Satellites -> screen is Screen.Satellites
+                    is Screen.Passes -> screen is Screen.Passes
+                    is Screen.Radar -> screen is Screen.Radar
+                    is Screen.Map -> screen is Screen.Map
+                    is Screen.Settings -> screen is Screen.Settings
+                    else -> false
+                }
                 item(
-                    icon = { Icon(painterResource(it.iconResId), stringResource(it.titleResId)) },
-                    label = { Text(stringResource(it.titleResId)) },
-                    selected = currentDestination?.contains(it.route) ?: false,
+                    icon = { Icon(painterResource(screen.iconResId), stringResource(screen.titleResId)) },
+                    label = { Text(stringResource(screen.titleResId)) },
+                    selected = isSelected,
                     onClick = {
-                        if (currentDestination?.contains(it.route) ?: false) return@item
-                        navController.navigate(it.route) {
-                            popUpTo(startDestination) { saveState = false }
-                            launchSingleTop = true
-                            restoreState = false
-                        }
-                    })
+                        if (isSelected) return@item
+                        while (backStack.size > 1) backStack.removeAt(backStack.size - 1)
+                        if (screen !is Screen.Passes) backStack.add(screen)
+                    }
+                )
             }
-        }, navigationSuiteColors = NavigationSuiteDefaults.colors(
+        },
+        navigationSuiteColors = NavigationSuiteDefaults.colors(
             navigationRailContainerColor = MaterialTheme.colorScheme.surfaceContainer
-        ), layoutType = when {
+        ),
+        layoutType = when {
             !hasEnoughHeight() && hasEnoughWidth() -> NavigationSuiteType.NavigationRail
             !hasEnoughWidth() -> NavigationSuiteType.ShortNavigationBarCompact
             else -> NavigationSuiteType.ShortNavigationBarMedium
         }
     ) {
         Column {
-        NavHost(
-            navController = navController,
-            startDestination = startDestination,
-            enterTransition =  { fadeIn(animationSpec = tween(350)) },
-            exitTransition = { fadeOut(animationSpec = tween(350)) },
-            modifier = Modifier.weight(1f)
-        ) {
-            satellitesDestination { navController.navigateUp() }
-            passesDestination { catNum: Int, aosTime: Long ->
-                val radarRoute = "${Screen.Radar.route}?catNum=${catNum}&aosTime=${aosTime}"
-                navController.navigate(radarRoute)
-            }
-            radarDestination(
-                navigateUp = { navController.navigateUp() },
-                navigateToRadioControl = { catNum, aosTime ->
-                    val route = "${Screen.RadioControl.route}?catNum=$catNum&aosTime=$aosTime"
-                    navController.navigate(route)
-                }
-            )
-            radioControlDestination { navController.navigateUp() }
-            mapDestination()
-            settingsDestination()
-        }
-
-        // Radio tracking status banner (above bottom navigation)
-        if (trackingState.isActive) {
-            val infiniteTransition = rememberInfiniteTransition(label = "trackingPulse")
-            val alpha by infiniteTransition.animateFloat(
-                initialValue = 1f, targetValue = 0.4f,
-                animationSpec = infiniteRepeatable(
-                    animation = tween(1000, easing = LinearEasing),
-                    repeatMode = RepeatMode.Reverse
-                ), label = "pulseAlpha"
-            )
-            Row(
-                verticalAlignment = Alignment.CenterVertically,
-                modifier = Modifier
-                    .fillMaxWidth()
-                    .background(MaterialTheme.colorScheme.primaryContainer)
-                    .clickable {
-                        val pass = trackingState.currentPass
-                        if (pass != null) {
-                            val route = "${Screen.RadioControl.route}?catNum=${pass.catNum}&aosTime=${pass.aosTime}"
-                            navController.navigate(route)
+            NavDisplay(
+                backStack = backStack,
+                modifier = Modifier.weight(1f),
+                onBack = navigateBack,
+                transitionSpec = { fadeTransition },
+                popTransitionSpec = { fadeTransition },
+                predictivePopTransitionSpec = { fadeTransition },
+                entryDecorators = listOf(
+                    // Required for saving Compose state per entry
+                    rememberSaveableStateHolderNavEntryDecorator(),
+                    // Required for ViewModel scoping per entry
+                    rememberViewModelStoreNavEntryDecorator()
+                ),
+                entryProvider = entryProvider {
+                    entry<Screen.Satellites> {
+                        SatellitesDestination(navigateUp = navigateBack)
+                    }
+                    entry<Screen.Passes> {
+                        PassesDestination { catNum, aosTime ->
+                            backStack.add(Screen.Radar(catNum, aosTime))
                         }
                     }
-                    .padding(horizontal = 12.dp, vertical = 6.dp)
-            ) {
-                Box(
+                    entry<Screen.Radar> { route ->
+                        RadarDestination(
+                            catNum = route.catNum,
+                            aosTime = route.aosTime,
+                            navigateUp = navigateBack,
+                            navigateToRadioControl = { catNum, aosTime ->
+                                backStack.add(Screen.RadioControl(catNum, aosTime))
+                            }
+                        )
+                    }
+                    entry<Screen.RadioControl> { route ->
+                        RadioControlDestination(
+                            catNum = route.catNum,
+                            aosTime = route.aosTime,
+                            navigateUp = navigateBack
+                        )
+                    }
+                    entry<Screen.Map> {
+                        MapDestination()
+                    }
+                    entry<Screen.Settings> {
+                        SettingsDestination()
+                    }
+                }
+            )
+            // Radio tracking status banner
+            if (trackingState.isActive) {
+                val infiniteTransition = rememberInfiniteTransition(label = "trackingPulse")
+                val alpha by infiniteTransition.animateFloat(
+                    initialValue = 1f, targetValue = 0.4f,
+                    animationSpec = infiniteRepeatable(
+                        animation = tween(1000, easing = LinearEasing),
+                        repeatMode = RepeatMode.Reverse
+                    ), label = "pulseAlpha"
+                )
+                Row(
+                    verticalAlignment = Alignment.CenterVertically,
                     modifier = Modifier
-                        .size(8.dp)
-                        .clip(CircleShape)
-                        .background(Color(0xFF4CAF50).copy(alpha = alpha))
-                )
-                Spacer(modifier = Modifier.width(8.dp))
-                Text(
-                    text = "Tracking: ${trackingState.currentPass?.name ?: ""}",
-                    fontSize = 13.sp,
-                    fontWeight = FontWeight.Medium,
-                    color = MaterialTheme.colorScheme.onPrimaryContainer,
-                    modifier = Modifier.weight(1f)
-                )
-                val txOk = if (trackingState.txConnected) "TX" else ""
-                val rxOk = if (trackingState.rxConnected) "RX" else ""
-                Text(
-                    text = listOf(txOk, rxOk).filter { it.isNotBlank() }.joinToString("/"),
-                    fontSize = 12.sp,
-                    color = MaterialTheme.colorScheme.onPrimaryContainer
-                )
+                        .fillMaxWidth()
+                        .background(MaterialTheme.colorScheme.primaryContainer)
+                        .clickable {
+                            val pass = trackingState.currentPass
+                            if (pass != null) {
+                                backStack.add(Screen.RadioControl(pass.catNum, pass.aosTime))
+                            }
+                        }
+                        .padding(horizontal = 12.dp, vertical = 6.dp)
+                ) {
+                    Box(
+                        modifier = Modifier
+                            .size(8.dp)
+                            .clip(CircleShape)
+                            .background(Color(0xFF4CAF50).copy(alpha = alpha))
+                    )
+                    Spacer(modifier = Modifier.width(8.dp))
+                    Text(
+                        text = "Tracking: ${trackingState.currentPass?.name ?: ""}",
+                        fontSize = 13.sp,
+                        fontWeight = FontWeight.Medium,
+                        color = MaterialTheme.colorScheme.onPrimaryContainer,
+                        modifier = Modifier.weight(1f)
+                    )
+                    val txOk = if (trackingState.txConnected) "TX" else ""
+                    val rxOk = if (trackingState.rxConnected) "RX" else ""
+                    Text(
+                        text = listOf(txOk, rxOk).filter { it.isNotBlank() }.joinToString("/"),
+                        fontSize = 12.sp,
+                        color = MaterialTheme.colorScheme.onPrimaryContainer
+                    )
+                }
             }
         }
-        } // end Column
     }
 }

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

@@ -38,6 +38,8 @@ internal class ApplicationPlugin : Plugin<Project> {
             implementation(project(":feature:satellites"))
             implementation(project(":feature:settings"))
             implementation(libs.androidx.core.splashscreen)
+            implementation(libs.compose.material3.adaptive)
+            implementation(libs.compose.navigation3)
             androidTestImplementation(libs.bundles.androidTest)
         }
     }

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

@@ -33,7 +33,7 @@ internal class CoreDataPlugin : Plugin<Project> {
             implementation(libs.androidx.room)
             implementation(libs.androidx.room.runtime)
             ksp(libs.androidx.room.compiler)
-            implementation(libs.other.coroutines)
+            implementation(libs.kotlin.coroutines)
             implementation(libs.other.okhttp)
         }
     }

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

@@ -25,10 +25,11 @@ import org.gradle.kotlin.dsl.dependencies
 internal class CoreDomainPlugin : Plugin<Project> {
     override fun apply(target: Project) = with(target) {
         applyPlugin(libs.plugins.kotlin.jvm)
+        applyPlugin(libs.plugins.kotlin.serialization)
         setupKotlin()
         dependencies {
-            implementation(libs.other.coroutines)
-            implementation(libs.other.json)
+            implementation(libs.kotlin.coroutines)
+            implementation(libs.kotlin.serialization)
         }
     }
 }

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

@@ -24,12 +24,15 @@ import org.gradle.kotlin.dsl.dependencies
 @Suppress("Unused")
 internal class CorePresentationPlugin : Plugin<Project> {
     override fun apply(target: Project) = with(target) {
+        applyPlugin(libs.plugins.kotlin.serialization)
         setupAndroidLib()
         setupCompose()
         setupKotlin()
         dependencies {
             implementation(project(":core:domain"))
             implementation(libs.androidx.core.splashscreen)
+            implementation(libs.kotlin.serialization)
+            implementation(libs.compose.material3.adaptive)
         }
     }
 }

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

@@ -74,7 +74,7 @@ internal fun Project.setupAndroidApp() {
         }
         androidResources {
             generateLocaleConfig = true
-            localeFilters.addAll(listOf("en", "es", "ru", "si", "uk", "zh"))
+            localeFilters.addAll(listOf("en", "es", "ru", "si", "tr", "uk", "zh"))
         }
         packaging { resources { excludes += listOf("META-INF/*") } }
     }

build.gradle.kts

@@ -4,6 +4,7 @@ plugins {
     alias(libs.plugins.compose.compiler) apply false
     alias(libs.plugins.google.ksp) apply false
     alias(libs.plugins.kotlin.jvm) apply false
+    alias(libs.plugins.kotlin.serialization) apply false
 }
 
 tasks.register("clean", Delete::class.java) {

core/data/src/main/java/com/rtbishop/look4sat/core/data/database/entity/SatRadio.kt

@@ -25,11 +25,11 @@ data class SatRadio(
     @PrimaryKey val uuid: String,
     val info: String,
     val isAlive: Boolean,
-    var downlinkLow: Long?,
-    var downlinkHigh: Long?,
+    val downlinkLow: Long?,
+    val downlinkHigh: Long?,
     val downlinkMode: String?,
-    var uplinkLow: Long?,
-    var uplinkHigh: Long?,
+    val uplinkLow: Long?,
+    val uplinkHigh: Long?,
     val uplinkMode: String?,
     val isInverted: Boolean,
     val catnum: Int?

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

@@ -72,6 +72,7 @@ class SettingsRepo(
     private val keyStateOfSweep = "stateOfSweep"
     private val keyStateOfUtc = "stateOfUtc"
     private val keyStateOfLightTheme = "stateOfLightTheme"
+    private val keyStateOfNightMode = "stateOfNightMode"
     private val keyStationAltitude = "stationAltitude"
     private val keyStationLatitude = "stationLatitude"
     private val keyStationLongitude = "stationLongitude"
@@ -329,6 +330,7 @@ class SettingsRepo(
                 putBoolean(keyStateOfSweep, new.stateOfSweep)
                 putBoolean(keyStateOfUtc, new.stateOfUtc)
                 putBoolean(keyStateOfLightTheme, new.stateOfLightTheme)
+                putBoolean(keyStateOfNightMode, new.stateOfNightMode)
                 putBoolean(keyShouldSeeWarning, new.shouldSeeWarning)
                 putBoolean(keyShouldSeeWhatsNew, new.shouldSeeWhatsNew)
             }
@@ -342,6 +344,7 @@ class SettingsRepo(
         stateOfSweep = preferences.getBoolean(keyStateOfSweep, true),
         stateOfUtc = preferences.getBoolean(keyStateOfUtc, false),
         stateOfLightTheme = preferences.getBoolean(keyStateOfLightTheme, false),
+        stateOfNightMode = preferences.getBoolean(keyStateOfNightMode, false),
         shouldSeeWarning = preferences.getBoolean(keyShouldSeeWarning, true),
         shouldSeeWhatsNew = preferences.getBoolean(keyShouldSeeWhatsNew, true)
     )

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

@@ -17,16 +17,20 @@
  */
 package com.rtbishop.look4sat.core.domain.model
 
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+@Serializable
 data class SatRadio(
-    val uuid: String,
-    val info: String,
-    val isAlive: Boolean,
-    var downlinkLow: Long?,
-    var downlinkHigh: Long?,
-    val downlinkMode: String?,
-    var uplinkLow: Long?,
-    var uplinkHigh: Long?,
-    val uplinkMode: String?,
-    val isInverted: Boolean,
-    val catnum: Int?
+    @SerialName("uuid") val uuid: String,
+    @SerialName("description") val info: String,
+    @SerialName("alive") val isAlive: Boolean,
+    @SerialName("downlink_low") val downlinkLow: Long?,
+    @SerialName("downlink_high") val downlinkHigh: Long?,
+    @SerialName("mode") val downlinkMode: String?,
+    @SerialName("uplink_low") val uplinkLow: Long?,
+    @SerialName("uplink_high") val uplinkHigh: Long?,
+    @SerialName("uplink_mode") val uplinkMode: String?,
+    @SerialName("invert") val isInverted: Boolean,
+    @SerialName("norad_cat_id") val catnum: Int?
 )

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

@@ -54,6 +54,7 @@ data class OtherSettings(
     val stateOfSweep: Boolean,
     val stateOfUtc: Boolean,
     val stateOfLightTheme: Boolean,
+    val stateOfNightMode: Boolean = false,
     val shouldSeeWarning: Boolean,
     val shouldSeeWhatsNew: Boolean
 )

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

@@ -0,0 +1,666 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.domain.predict
+
+import com.rtbishop.look4sat.core.domain.utility.toDegrees
+import com.rtbishop.look4sat.core.domain.utility.toRadians
+import kotlin.math.PI
+import kotlin.math.abs
+import kotlin.math.acos
+import kotlin.math.asin
+import kotlin.math.atan
+import kotlin.math.atan2
+import kotlin.math.cos
+import kotlin.math.floor
+import kotlin.math.log10
+import kotlin.math.pow
+import kotlin.math.sin
+import kotlin.math.sqrt
+import kotlin.math.tan
+
+/**
+ * Standalone celestial computations extracted from PREDICT v2.2.5.
+ * Provides Sun position, Moon position, satellite visibility classification,
+ * orbital metadata, RA/Dec conversion, and rise/set finding for Sun and Moon.
+ *
+ * All angles are in degrees unless noted. Time is Unix epoch milliseconds.
+ *
+ * Shared math utilities (thetaGJD, modulus, mod2PI, deltaET, millisToDaynum,
+ * solarPositionECI, eciToGeodetic) live in OrbitalMath.kt in the same package.
+ */
+object CelestialComputer {
+
+    // ── Result types ──
+
+    /** Sun position as seen from a ground observer. */
+    data class SunPosition(
+        val azimuth: Double,         // degrees, 0=N, 90=E
+        val elevation: Double,       // degrees, >0 above horizon
+        val distance: Double,        // normalized: 1.0 + ((range - AU) / AU)
+        val rangeRate: Double,       // km/s
+        val latitude: Double,        // sub-solar point latitude, degrees
+        val longitude: Double,       // sub-solar point longitude, degrees
+        val rightAscension: Double,  // degrees
+        val declination: Double      // degrees
+    )
+
+    /** Moon position as seen from a ground observer. */
+    data class MoonPosition(
+        val azimuth: Double,         // degrees, 0=N, 90=E
+        val elevation: Double,       // degrees
+        val rightAscension: Double,  // degrees
+        val declination: Double,     // degrees
+        val gha: Double,             // Greenwich Hour Angle, degrees
+        val angularDiameter: Double, // apparent diameter relative to Earth's diameter
+        val radialVelocity: Double   // m/s, Doppler radial velocity for EME
+    )
+
+    /**
+     * 3-state satellite visibility classification.
+     * - [VISIBLE]: satellite is sunlit, observer is in darkness (sun below -12°) — optically visible
+     * - [DAYLIGHT]: satellite is sunlit, observer is in daylight
+     * - [ECLIPSED]: satellite is in Earth's shadow
+     */
+    enum class SatVisibility { VISIBLE, DAYLIGHT, ECLIPSED }
+
+    /** Orbital metadata not typically included in pass data. */
+    data class OrbitalMetadata(
+        val footprintDiameter: Double, // km, ground coverage circle diameter
+        val orbitNumber: Long,         // current orbit/revolution number
+        val betaAngle: Double,         // degrees, angle between orbital plane and Sun
+        val orbitalPhase: Double       // 0-256 phase within current orbit
+    )
+
+    // ── Sun position ──
+
+    /**
+     * Compute the Sun's full position as seen from [observer] at [timeMillis].
+     * Includes az/el, RA/Dec, sub-solar lat/lon, range, and range rate.
+     * Based on FindSun() from PREDICT v2.2.5.
+     */
+    fun getSunPosition(observer: GeoPos, timeMillis: Long): SunPosition {
+        val daynum = millisToDaynum(timeMillis)
+        val julUtc = daynum + 2444238.5
+        val sunVec = solarPositionECI(julUtc)
+        val zeroVel = doubleArrayOf(0.0, 0.0, 0.0)
+        val obsGeo = observerGeodetic(observer)
+
+        // Az, El, Range, RangeRate
+        val obsSet = computeObsAngles(julUtc, sunVec, zeroVel, obsGeo)
+
+        // Lat/Lon of sub-solar point
+        val latLon = eciToGeodetic(julUtc, sunVec)
+
+        // RA/Dec
+        val raDec = calculateRADec(julUtc, sunVec, zeroVel, obsGeo)
+
+        return SunPosition(
+            azimuth = obsSet[0].toDegrees(),
+            elevation = obsSet[1].toDegrees(),
+            distance = 1.0 + ((obsSet[2] - ASTRONOMICAL_UNIT) / ASTRONOMICAL_UNIT),
+            rangeRate = 1000.0 * obsSet[3],
+            latitude = latLon[0].toDegrees(),
+            longitude = latLon[1].toDegrees().let { if (it > 180.0) it - 360.0 else it },
+            rightAscension = raDec[0].toDegrees(),
+            declination = raDec[1].toDegrees()
+        )
+    }
+
+    // ── Moon position ──
+
+    /**
+     * Compute the Moon's position as seen from [observer] at [timeMillis].
+     * Full Meeus lunar ephemeris from PREDICT v2.2.5 with expanded terms
+     * and radial velocity approximation for EME Doppler.
+     */
+    fun getMoonPosition(observer: GeoPos, timeMillis: Long): MoonPosition {
+        val daynum = millisToDaynum(timeMillis)
+        val jd = daynum + 2444238.5
+        var t = (jd - 2415020.0) / 36525.0
+        val t2 = t * t
+        val t3 = t2 * t
+
+        var l1 = 270.434164 + 481267.8831 * t - 0.001133 * t2 + 0.0000019 * t3
+        var mSun = 358.475833 + 35999.0498 * t - 0.00015 * t2 - 0.0000033 * t3
+        var m1 = 296.104608 + 477198.8491 * t + 0.009192 * t2 + 0.0000144 * t3
+        var d = 350.737486 + 445267.1142 * t - 0.001436 * t2 + 0.0000019 * t3
+        var ff = 11.250889 + 483202.0251 * t - 0.003211 * t2 - 0.0000003 * t3
+        val om = (259.183275 - 1934.142 * t + 0.002078 * t2 + 0.0000022 * t3) * DEG2RAD
+
+        val correction512 = sin((51.2 + 20.2 * t) * DEG2RAD)
+        val ss = 0.003964 * sin((346.56 + 132.87 * t - 0.0091731 * t2) * DEG2RAD)
+        l1 += 0.000233 * correction512 + ss + 0.001964 * sin(om)
+        mSun -= 0.001778 * correction512
+        m1 += 0.000817 * correction512 + ss + 0.002541 * sin(om)
+        d += 0.002011 * correction512 + ss + 0.001964 * sin(om)
+        ff += ss - 0.024691 * sin(om) - 0.004328 * sin(om + (275.05 - 2.3 * t) * DEG2RAD)
+
+        val ex = 1.0 - 0.002495 * t - 0.00000752 * t2
+        l1 = primeAngle(l1); mSun = primeAngle(mSun); m1 = primeAngle(m1)
+        d = primeAngle(d); ff = primeAngle(ff)
+
+        val mR = mSun * DEG2RAD
+        val m1R = m1 * DEG2RAD
+        val dR = d * DEG2RAD
+        val ffR = ff * DEG2RAD
+
+        // Ecliptic longitude — expanded v225 terms
+        var l = l1 + 6.28875 * sin(m1R) + 1.274018 * sin(2 * dR - m1R) + 0.658309 * sin(2 * dR)
+        l += 0.213616 * sin(2 * m1R) - ex * 0.185596 * sin(mR) - 0.114336 * sin(2 * ffR)
+        l += 0.058793 * sin(2 * dR - 2 * m1R) + ex * 0.057212 * sin(2 * dR - mR - m1R) + 0.05332 * sin(2 * dR + m1R)
+        l += ex * 0.045874 * sin(2 * dR - mR) + ex * 0.041024 * sin(m1R - mR) - 0.034718 * sin(dR)
+        l -= ex * 0.030465 * sin(mR + m1R) + 0.015326 * sin(2 * dR - 2 * ffR) - 0.012528 * sin(2 * ffR + m1R)
+        l -= 0.01098 * sin(2 * ffR - m1R) + 0.010674 * sin(4 * dR - m1R) + 0.010034 * sin(3 * m1R)
+        l += 0.008548 * sin(4 * dR - 2 * m1R) - ex * 0.00791 * sin(mR - m1R + 2 * dR)
+        l -= ex * 0.006783 * sin(2 * dR + mR)
+        l += 0.005162 * sin(m1R - dR) + ex * 0.005 * sin(mR + dR) + ex * 0.004049 * sin(m1R - mR + 2 * dR)
+        l += 0.003996 * sin(2 * m1R + 2 * dR) + 0.003862 * sin(4 * dR) + 0.003665 * sin(2 * dR - 3 * m1R)
+        l += ex * 0.002695 * sin(2 * m1R - mR) + 0.002602 * sin(m1R - 2 * ffR - 2 * dR)
+        l += ex * 0.002396 * sin(2 * dR - mR - 2 * m1R)
+        l -= 0.002349 * sin(m1R + dR) + ex * ex * 0.002249 * sin(2 * dR - 2 * mR)
+        l -= ex * 0.002125 * sin(2 * m1R + mR)
+        l -= ex * ex * 0.002079 * sin(2 * mR) + ex * ex * 0.002059 * sin(2 * dR - m1R - 2 * mR)
+        l -= 0.001773 * sin(m1R + 2 * dR - 2 * ffR)
+        l += ex * 0.00122 * sin(4 * dR - mR - m1R) - 0.00111 * sin(2 * m1R + 2 * ffR) + 0.000892 * sin(m1R - 3 * dR)
+        l -= ex * 0.000811 * sin(mR + m1R + 2 * dR) + ex * 0.000761 * sin(4 * dR - mR - 2 * m1R)
+        l += ex * ex * 0.000717 * sin(m1R - 2 * mR)
+        l += ex * ex * 0.000704 * sin(m1R - 2 * mR - 2 * dR) + ex * 0.000693 * sin(mR - 2 * m1R + 2 * dR)
+        l += ex * 0.000598 * sin(2 * dR - mR - 2 * ffR) + 0.00055 * sin(m1R + 4 * dR)
+        l += 0.000538 * sin(4 * m1R) + ex * 0.000521 * sin(4 * dR - mR) + 0.000486 * sin(2 * m1R - dR)
+        l -= 0.001595 * sin(2 * ffR + 2 * dR)
+
+        // Ecliptic latitude — expanded v225 terms
+        var b =
+            5.128189 * sin(ffR) + 0.280606 * sin(m1R + ffR) + 0.277693 * sin(m1R - ffR) + 0.173238 * sin(2 * dR - ffR)
+        b += 0.055413 * sin(2 * dR + ffR - m1R) + 0.046272 * sin(2 * dR - ffR - m1R) + 0.032573 * sin(2 * dR + ffR)
+        b += 0.017198 * sin(2 * m1R + ffR) + 9.266999e-03 * sin(2 * dR + m1R - ffR) + 0.008823 * sin(2 * m1R - ffR)
+        b += ex * 0.008247 * sin(2 * dR - mR - ffR) + 0.004323 * sin(2 * dR - ffR - 2 * m1R)
+        b += 0.0042 * sin(2 * dR + ffR + m1R)
+        b += ex * 0.003372 * sin(ffR - mR - 2 * dR) + ex * 0.002472 * sin(2 * dR + ffR - mR - m1R)
+        b += ex * 0.002222 * sin(2 * dR + ffR - mR)
+        b += 0.002072 * sin(2 * dR - ffR - mR - m1R) + ex * 0.001877 * sin(ffR - mR + m1R)
+        b += 0.001828 * sin(4 * dR - ffR - m1R)
+        b -= ex * 0.001803 * sin(ffR + mR) - 0.00175 * sin(3 * ffR)
+        b += ex * 0.00157 * sin(m1R - mR - ffR) - 0.001487 * sin(ffR + dR)
+        b -= ex * 0.001481 * sin(ffR + mR + m1R) + ex * 0.001417 * sin(ffR - mR - m1R)
+        b += ex * 0.00135 * sin(ffR - mR) + 0.00133 * sin(ffR - dR)
+        b += 0.001106 * sin(ffR + 3 * m1R) + 0.00102 * sin(4 * dR - ffR) + 0.000833 * sin(ffR + 4 * dR - m1R)
+        b += 0.000781 * sin(m1R - 3 * ffR) + 0.00067 * sin(ffR + 4 * dR - 2 * m1R)
+        b += 0.000606 * sin(2 * dR - 3 * ffR)
+        b += 0.000597 * sin(2 * dR + 2 * m1R - ffR) + ex * 0.000492 * sin(2 * dR + m1R - mR - ffR)
+        b += 0.00045 * sin(2 * m1R - ffR - 2 * dR)
+        b += 0.000439 * sin(3 * m1R - ffR) + 0.000423 * sin(ffR + 2 * dR + 2 * m1R)
+        b += 0.000422 * sin(2 * dR - ffR - 3 * m1R)
+        b -= ex * 0.000367 * sin(mR + ffR + 2 * dR - m1R) - ex * 0.000353 * sin(mR + ffR + 2 * dR)
+        b += 0.000331 * sin(ffR + 4 * dR)
+        b += ex * 0.000317 * sin(2 * dR + ffR - mR + m1R) + ex * ex * 0.000306 * sin(2 * dR - 2 * mR - ffR)
+        b -= 0.000283 * sin(m1R + 3 * ffR)
+
+        val w1 = 0.0004664 * cos(om)
+        val w2 = 0.0000754 * cos(om + (275.05 - 2.3 * t) * DEG2RAD)
+        val bt = b * (1.0 - w1 - w2)
+
+        // Parallax — expanded v225 terms
+        var p =
+            0.950724 + 0.051818 * cos(m1R) + 0.009531 * cos(2 * dR - m1R) + 0.007843 * cos(2 * dR) + 0.002824 * cos(2 * m1R)
+        p += 0.000857 * cos(2 * dR + m1R) + ex * 0.000533 * cos(2 * dR - mR) + ex * 0.000401 * cos(2 * dR - mR - m1R)
+        p += 0.000173 * cos(3 * m1R) + 0.000167 * cos(4 * dR - m1R) - ex * 0.000111 * cos(mR)
+        p += 0.000103 * cos(4 * dR - 2 * m1R) - 0.000084 * cos(2 * m1R - 2 * dR) - ex * 0.000083 * cos(2 * dR + mR)
+        p += 0.000079 * cos(2 * dR + 2 * m1R)
+        p += 0.000072 * cos(4 * dR) + ex * 0.000064 * cos(2 * dR - mR + m1R) - ex * 0.000063 * cos(2 * dR + mR - m1R)
+        p += ex * 0.000041 * cos(mR + dR) + ex * 0.000035 * cos(2 * m1R - mR) - 0.000033 * cos(3 * m1R - 2 * dR)
+        p -= 0.00003 * cos(m1R + dR) - 0.000029 * cos(2 * ffR - 2 * dR) - ex * 0.000029 * cos(2 * m1R + mR)
+        p += ex * ex * 0.000026 * cos(2 * dR - 2 * mR) - 0.000023 * cos(2 * ffR - 2 * dR + m1R)
+        p += ex * 0.000019 * cos(4 * dR - mR - m1R)
+
+        val bRad = bt * DEG2RAD
+        val lm = l * DEG2RAD
+        val moonDx = 3.0 / (PI * p)
+
+        // Ecliptic → equatorial
+        val z = (jd - 2415020.5) / 365.2422
+        val ob = (23.452294 - (0.46845 * z + 5.9e-07 * z * z) / 3600.0).toRadians()
+        val dec = asin(sin(bRad) * cos(ob) + cos(bRad) * sin(ob) * sin(lm))
+        var ra = acos(cos(bRad) * cos(lm) / cos(dec)); if (lm > PI) ra = TWO_PI - ra
+
+        val n = observer.latitude * DEG2RAD
+        t = (jd - 2451545.0) / 36525.0
+        var teg = 280.46061837 + 360.98564736629 * (jd - 2451545.0) + (0.000387933 * t - t * t / 38710000.0) * t
+        while (teg > 360.0) teg -= 360.0
+        val th = fixAngle((teg - observer.longitude) * DEG2RAD)
+        val h = th - ra
+        val azVal = atan2(sin(h), cos(h) * sin(n) - tan(dec) * cos(n)) + PI
+        val el = asin(sin(n) * sin(dec) + cos(n) * cos(dec) * cos(h))
+
+        // Moon radial velocity approximation (from "Amateur Radio Software", GM4ANB, RSGB 1985)
+        val mm = fixAngle(1.319238 + daynum * 0.228027135)
+        val radT2 = 0.10976
+        val radT1 = mm + radT2 * sin(mm)
+        var dv = 0.01255 * moonDx * moonDx * sin(radT1) * (1.0 + radT2 * cos(mm))
+        dv *= 4449.0
+        val earthR = 6378.0
+        val moonDist = 384401.0
+        val radT3 = earthR * moonDist * (cos(dec) * cos(n) * sin(h)) /
+            sqrt(moonDist * moonDist - moonDist * earthR * sin(el))
+        val moonDv = dv + radT3 * 0.0753125
+
+        val moonRa = ra / DEG2RAD
+        var moonGha = teg - moonRa
+        if (moonGha < 0.0) moonGha += 360.0
+
+        return MoonPosition(
+            azimuth = azVal / DEG2RAD,
+            elevation = el / DEG2RAD,
+            rightAscension = moonRa,
+            declination = dec / DEG2RAD,
+            gha = moonGha,
+            angularDiameter = moonDx,
+            radialVelocity = moonDv
+        )
+    }
+
+    // ── Satellite visibility ──
+
+    /**
+     * Classify satellite visibility given its eclipse state and the Sun's elevation
+     * at the observer's location.
+     *
+     * @param isEclipsed whether the satellite is in Earth's shadow
+     * @param sunElevationDeg Sun elevation at observer in degrees
+     * @param satElevationDeg satellite elevation at observer in degrees (must be >= 0)
+     */
+    fun classifyVisibility(
+        isEclipsed: Boolean,
+        sunElevationDeg: Double,
+        satElevationDeg: Double
+    ): SatVisibility {
+        if (isEclipsed) return SatVisibility.ECLIPSED
+        return if (sunElevationDeg <= -12.0 && satElevationDeg >= 0.0) SatVisibility.VISIBLE
+        else SatVisibility.DAYLIGHT
+    }
+
+    // ── Orbital metadata ──
+
+    /**
+     * Compute orbital metadata for a satellite at its current position.
+     *
+     * @param altitudeKm satellite altitude in km
+     * @param meanMotion revolutions per day from TLE
+     * @param bstar drag term from TLE
+     * @param meanAnomaly mean anomaly at epoch (radians)
+     * @param revNumAtEpoch revolution number at TLE epoch
+     * @param ageDays days since TLE epoch (julUTC - julEpoch)
+     * @param phase orbital phase in radians (from SGP4/SDP4 output)
+     * @param satPosECI satellite ECI position [x, y, z]
+     * @param satVelECI satellite ECI velocity [vx, vy, vz]
+     * @param sunPosECI sun ECI position [x, y, z]
+     */
+    fun computeOrbitalMetadata(
+        altitudeKm: Double,
+        meanMotion: Double,
+        bstar: Double,
+        meanAnomaly: Double,
+        revNumAtEpoch: Int,
+        ageDays: Double,
+        phase: Double,
+        satPosECI: DoubleArray,
+        satVelECI: DoubleArray,
+        sunPosECI: DoubleArray
+    ): OrbitalMetadata {
+        // Footprint diameter (km)
+        val footprint = 12756.33 * acos(EARTH_RADIUS / (EARTH_RADIUS + altitudeKm))
+
+        // Orbit number
+        val xmnpda = 1.44E3
+        val orbitNum = floor(
+            (meanMotion * xmnpda / TWO_PI + ageDays * bstar) * ageDays + meanAnomaly / TWO_PI
+        ).toLong() + revNumAtEpoch
+
+        // Beta angle: angle between orbital plane and Sun direction
+        // Orbital plane normal = cross(pos, vel)
+        val nx = satPosECI[1] * satVelECI[2] - satPosECI[2] * satVelECI[1]
+        val ny = satPosECI[2] * satVelECI[0] - satPosECI[0] * satVelECI[2]
+        val nz = satPosECI[0] * satVelECI[1] - satPosECI[1] * satVelECI[0]
+        val nMag = sqrt(nx * nx + ny * ny + nz * nz)
+        val sMag = sqrt(sunPosECI[0] * sunPosECI[0] + sunPosECI[1] * sunPosECI[1] + sunPosECI[2] * sunPosECI[2])
+        val dotNS = nx * sunPosECI[0] + ny * sunPosECI[1] + nz * sunPosECI[2]
+        val betaAngle = if (nMag > 0 && sMag > 0) {
+            (PI / 2.0 - acos(dotNS / (nMag * sMag))).toDegrees()
+        } else 0.0
+
+        // Phase (0-256 scale, matching PREDICT convention)
+        val orbitalPhase = 256.0 * (phase / TWO_PI)
+
+        return OrbitalMetadata(footprint, orbitNum, betaAngle, orbitalPhase)
+    }
+
+    // ── Satellite status checks ──
+
+    /** Check if a satellite is geostationary (mean motion ≈ 1.0027 rev/day). */
+    fun isGeostationary(meanMotion: Double): Boolean = abs(meanMotion - 1.0027) < 0.0002
+
+    /**
+     * Check if a satellite has likely decayed based on drag and time since epoch.
+     *
+     * @param meanMotion revolutions per day
+     * @param drag first derivative of mean motion / 2 (from TLE line 1)
+     * @param epochDaynum TLE epoch as daynum (days since 31Dec79)
+     * @param currentDaynum current time as daynum
+     */
+    fun hasDecayed(meanMotion: Double, drag: Double, epochDaynum: Double, currentDaynum: Double): Boolean {
+        return epochDaynum + ((16.666666 - meanMotion) / (10.0 * abs(drag))) < currentDaynum
+    }
+
+    // ── Rise/Set finding ──
+
+    /** Rise and set times for a celestial body. */
+    data class RiseSetTimes(
+        val riseTimeMillis: Long,  // 0 if not found
+        val setTimeMillis: Long    // 0 if not found
+    )
+
+    /**
+     * Find the next sunrise and sunset times from [startMillis] for [observer].
+     * Uses elevation threshold of -0.8333° to match the standard civil definition:
+     * upper limb on geometric horizon with standard atmospheric refraction (~0.57°)
+     * and solar semidiameter (~0.27°) corrections applied, matching USNO/timeanddate.com.
+     */
+    fun findSunRiseSet(observer: GeoPos, startMillis: Long): RiseSetTimes {
+        // Standard civil threshold: center elevation when upper limb meets geometric horizon
+        // -0.8333° = standard refraction (~0.5667°) + solar semidiameter (~0.2667°)
+        val threshold = 0.8333
+        var daynum = millisToDaynum(startMillis)
+        var sunPos = getSunPosition(observer, daynumToMillis(daynum))
+
+        // Phase 1: if sun is above threshold, fast-forward to well past sunset into night
+        if (sunPos.elevation > -threshold) {
+            var guard = 0
+            while (sunPos.elevation > -threshold && guard++ < 500) {
+                daynum += 0.008  // fixed ~11.5 min steps past the setting sun
+                sunPos = getSunPosition(observer, daynumToMillis(daynum))
+            }
+            // Now advance until sun is clearly below minimum (deep night)
+            guard = 0
+            while (sunPos.elevation > -12.0 && guard++ < 500) {
+                daynum += 0.02
+                sunPos = getSunPosition(observer, daynumToMillis(daynum))
+            }
+        }
+
+        // Phase 2: advance until sun starts rising toward threshold (elevation increasing)
+        var guard = 0
+        while (sunPos.elevation < -threshold && guard++ < 500) {
+            daynum += 0.008
+            sunPos = getSunPosition(observer, daynumToMillis(daynum))
+        }
+
+        // Phase 3: converge symmetrically on elevation = -threshold (sunrise)
+        var sunrise = 0.0
+        guard = 0
+        while (sunrise == 0.0 && guard++ < 200) {
+            val delta = sunPos.elevation + threshold
+            if (abs(delta) < 0.01) {
+                sunrise = daynum
+            } else {
+                daynum -= 0.004 * delta
+                sunPos = getSunPosition(observer, daynumToMillis(daynum))
+            }
+        }
+        if (sunrise == 0.0) sunrise = daynum
+
+        // Phase 4: fast-forward through the day until sun drops back below threshold
+        daynum = sunrise
+        sunPos = getSunPosition(observer, daynumToMillis(daynum))
+        guard = 0
+        while (sunPos.elevation > -threshold && guard++ < 500) {
+            daynum += 0.008
+            sunPos = getSunPosition(observer, daynumToMillis(daynum))
+        }
+
+        // Phase 5: converge symmetrically on elevation = -threshold (sunset)
+        var sunset = 0.0
+        guard = 0
+        while (sunset == 0.0 && guard++ < 200) {
+            val delta = sunPos.elevation + threshold
+            if (abs(delta) < 0.01) {
+                sunset = daynum
+            } else {
+                daynum += 0.004 * delta
+                sunPos = getSunPosition(observer, daynumToMillis(daynum))
+            }
+        }
+        if (sunset == 0.0) sunset = daynum
+
+        return RiseSetTimes(daynumToMillis(sunrise), daynumToMillis(sunset))
+    }
+
+    /**
+     * Find the next moonrise and moonset times from [startMillis] for [observer].
+     * Uses the adaptive iteration from PREDICT v2.2.5's PredictMoon().
+     */
+    fun findMoonRiseSet(observer: GeoPos, startMillis: Long): RiseSetTimes {
+        var daynum = millisToDaynum(startMillis)
+        var moonPos = getMoonPosition(observer, daynumToMillis(daynum))
+
+        // If moon is already up, move forward until it sets
+        var guard = 0
+        if (moonPos.elevation > 0) {
+            while (moonPos.elevation > 0 && guard++ < 1000) {
+                daynum += 0.004 * sin(DEG2RAD * (moonPos.elevation + 0.5))
+                moonPos = getMoonPosition(observer, daynumToMillis(daynum))
+            }
+            daynum += 0.4
+            moonPos = getMoonPosition(observer, daynumToMillis(daynum))
+        }
+        // Find moonrise
+        var moonrise = 0.0
+        guard = 0
+        while (moonrise == 0.0 && guard++ < 1000) {
+            if (abs(moonPos.elevation) < 0.03) {
+                moonrise = daynum
+            } else {
+                daynum -= 0.004 * moonPos.elevation
+                moonPos = getMoonPosition(observer, daynumToMillis(daynum))
+            }
+        }
+        if (moonrise == 0.0) moonrise = daynum
+
+        // Find moonset from moonrise
+        daynum = moonrise
+        moonPos = getMoonPosition(observer, daynumToMillis(daynum))
+        guard = 0
+        while (moonPos.elevation > -1 && guard++ < 1000) {
+            daynum += 0.04 * cos(DEG2RAD * (moonPos.elevation + 0.5))
+            moonPos = getMoonPosition(observer, daynumToMillis(daynum))
+        }
+        var moonset = 0.0
+        guard = 0
+        while (moonset == 0.0 && guard++ < 1000) {
+            if (abs(moonPos.elevation) < 0.03) {
+                moonset = daynum
+            } else {
+                daynum += 0.004 * moonPos.elevation
+                moonPos = getMoonPosition(observer, daynumToMillis(daynum))
+            }
+        }
+        if (moonset == 0.0) moonset = daynum
+
+        return RiseSetTimes(daynumToMillis(moonrise), daynumToMillis(moonset))
+    }
+
+    // ── Visual magnitude estimation ──
+
+    /**
+     * Estimate the apparent visual magnitude of a satellite.
+     *
+     * Uses the standard formula from McCants/Heavens-Above:
+     *   apparentMag = stdMag + 5 * log10(range / 1000) - 15 * log10(cos(phaseAngle / 2))
+     *
+     * @param rangeKm slant range from observer to satellite in km
+     * @param phaseAngleDeg Sun-satellite-observer angle in degrees
+     * @param stdMag intrinsic/standard magnitude (default 4.0)
+     * @return estimated apparent visual magnitude
+     */
+    fun estimateVisualMagnitude(rangeKm: Double, phaseAngleDeg: Double, stdMag: Double = 4.0): Double {
+        if (rangeKm <= 0) return stdMag
+        val halfPhaseRad = phaseAngleDeg.toRadians() / 2.0
+        val cosHalfPhase = cos(halfPhaseRad)
+        val phaseTerm = if (cosHalfPhase > 1e-6) -15.0 * log10(cosHalfPhase) else 99.0
+        return stdMag + 5.0 * log10(rangeKm / 1000.0) + phaseTerm
+    }
+
+    /**
+     * Compute the phase angle (Sun-satellite-observer) in degrees.
+     *
+     * @param satPosECI satellite ECI position [x, y, z] in km
+     * @param sunPosECI sun ECI position [x, y, z] in km
+     * @param obsPosECI observer ECI position [x, y, z] in km
+     * @return phase angle in degrees (0 = fully illuminated face toward observer)
+     */
+    fun computePhaseAngle(satPosECI: DoubleArray, sunPosECI: DoubleArray, obsPosECI: DoubleArray): Double {
+        val toSunX = sunPosECI[0] - satPosECI[0]
+        val toSunY = sunPosECI[1] - satPosECI[1]
+        val toSunZ = sunPosECI[2] - satPosECI[2]
+        val toObsX = obsPosECI[0] - satPosECI[0]
+        val toObsY = obsPosECI[1] - satPosECI[1]
+        val toObsZ = obsPosECI[2] - satPosECI[2]
+        val dot = toSunX * toObsX + toSunY * toObsY + toSunZ * toObsZ
+        val magSun = sqrt(toSunX * toSunX + toSunY * toSunY + toSunZ * toSunZ)
+        val magObs = sqrt(toObsX * toObsX + toObsY * toObsY + toObsZ * toObsZ)
+        if (magSun == 0.0 || magObs == 0.0) return 90.0
+        val cosAngle = (dot / (magSun * magObs)).coerceIn(-1.0, 1.0)
+        return acos(cosAngle).toDegrees()
+    }
+
+    // ── Doppler ──
+
+    /**
+     * Compute Doppler shift for a given base frequency and range rate.
+     *
+     * @param frequencyHz base frequency in Hz
+     * @param rangeRateKmS range rate in km/s (negative = approaching)
+     * @return shifted frequency in Hz
+     */
+    fun dopplerShift(frequencyHz: Double, rangeRateKmS: Double): Double {
+        return frequencyHz * (299792.458 - rangeRateKmS) / 299792.458
+    }
+
+    // ── Internal helpers ──
+
+    private fun observerGeodetic(pos: GeoPos): DoubleArray {
+        // [lat_rad, lon_rad, alt_km]  — longitude negated so that
+        // mod2PI(thetaGJD + obsGeo[1]) == mod2PI(thetaGJD + lon_rad)
+        return doubleArrayOf(pos.latitude * DEG2RAD, -pos.longitude * DEG2RAD, pos.altitude / 1000.0)
+    }
+
+    /**
+     * Convert az/el observation to Right Ascension / Declination.
+     * Returns [ra_rad, dec_rad].
+     * Based on Calculate_RADec() from PREDICT v2.2.5 (Escobal method).
+     */
+    private fun calculateRADec(
+        julUtc: Double,
+        targetPos: DoubleArray,
+        targetVel: DoubleArray,
+        obsGeo: DoubleArray
+    ): DoubleArray {
+        val obsSet = computeObsAngles(julUtc, targetPos, targetVel, obsGeo)
+        val az = obsSet[0]
+        val el = obsSet[1]
+        val phi = obsGeo[0]
+        val theta = mod2PI(thetaGJD(julUtc) + obsGeo[1])
+        val sinTheta = sin(theta)
+        val cosTheta = cos(theta)
+        val sinPhi = sin(phi)
+        val cosPhi = cos(phi)
+        val lxh = -cos(az) * cos(el)
+        val lyh = sin(az) * cos(el)
+        val lzh = sin(el)
+        val sx = sinPhi * cosTheta
+        val ex2 = -sinTheta
+        val zx = cosTheta * cosPhi
+        val sy = sinPhi * sinTheta
+        val zy = sinTheta * cosPhi
+        val sz = -cosPhi
+        val lx = sx * lxh + ex2 * lyh + zx * lzh
+        val ly = sy * lxh + cosTheta * lyh + zy * lzh
+        val lz = sz * lxh + 0.0 * lyh + sinPhi * lzh
+        val dec = asin(lz)
+        val cosDelta = sqrt(1.0 - lz * lz)
+        val sinAlpha = ly / cosDelta
+        val cosAlpha = lx / cosDelta
+        val ra = mod2PI(atan2(sinAlpha, cosAlpha))
+        return doubleArrayOf(ra, dec)
+    }
+
+    /**
+     * Compute observer look-angles (az, el, range, rangeRate) to a target at ECI position.
+     * Returns [azimuth_rad, elevation_rad, range_km, rangeRate_km/s].
+     * Azimuth is north-referenced (0=N, π/2=E), matching OrbitalObject's convention.
+     */
+    private fun computeObsAngles(
+        julUtc: Double,
+        targetPos: DoubleArray,
+        targetVel: DoubleArray,
+        obsGeo: DoubleArray // [lat_rad, lon_rad, alt_km]
+    ): DoubleArray {
+        val theta = mod2PI(thetaGJD(julUtc) + obsGeo[1])
+        val c = 1.0 / sqrt(1 + FLAT_FACT * (FLAT_FACT - 2) * sin(obsGeo[0]).pow(2))
+        val sq = (1 - FLAT_FACT).pow(2) * c
+        val achcp = (EARTH_RADIUS * c + obsGeo[2]) * cos(obsGeo[0])
+        val ox = achcp * cos(theta)
+        val oy = achcp * sin(theta)
+        val oz = (EARTH_RADIUS * sq + obsGeo[2]) * sin(obsGeo[0])
+        val ovx = -MFACTOR * oy
+        val ovy = MFACTOR * ox
+
+        val rx = targetPos[0] - ox
+        val ry = targetPos[1] - oy
+        val rz = targetPos[2] - oz
+        val rMag = sqrt(rx * rx + ry * ry + rz * rz)
+        val rvx = targetVel[0] - ovx
+        val rvy = targetVel[1] - ovy
+        val rvz = targetVel[2]
+
+        val sinLat = sin(obsGeo[0])
+        val cosLat = cos(obsGeo[0])
+        val sinTheta = sin(theta)
+        val cosTheta = cos(theta)
+        val topS = sinLat * cosTheta * rx + sinLat * sinTheta * ry - cosLat * rz
+        val topE = -sinTheta * rx + cosTheta * ry
+        val topZ = cosLat * cosTheta * rx + cosLat * sinTheta * ry + sinLat * rz
+
+        // Match north-based convention (0=N, 90=E) used by OrbitalObject.calculateObs
+        // Must use atan(-topE / topS) not atan2(-topE, topS) — they differ in quadrant handling
+        var azim = atan(-topE / topS)
+        if (topS > 0.0) azim += PI
+        if (azim < 0.0) azim += TWO_PI
+        val el = asin(topZ / rMag)
+        val rangeRate = (rx * rvx + ry * rvy + rz * rvz) / rMag
+
+        return doubleArrayOf(azim, el, rMag, rangeRate)
+    }
+
+    private const val MFACTOR = 7.292115E-5
+
+    private fun primeAngle(x: Double) = x - 360.0 * floor(x / 360.0)
+
+    private fun fixAngle(x: Double): Double {
+        var a = x; while (a > TWO_PI) a -= TWO_PI; return a
+    }
+}

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

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

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

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

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

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

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

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

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

@@ -21,13 +21,19 @@ import com.rtbishop.look4sat.core.domain.model.SatRadio
 import com.rtbishop.look4sat.core.domain.predict.OrbitalData
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.withContext
-import org.json.JSONArray
-import org.json.JSONObject
+import kotlinx.serialization.json.Json
+import kotlinx.serialization.json.JsonArray
+import kotlinx.serialization.json.decodeFromJsonElement
 import java.io.InputStream
 import kotlin.math.pow
 
 class DataParser(private val dispatcher: CoroutineDispatcher) {
 
+    private val json = Json {
+        ignoreUnknownKeys = true
+        coerceInputValues = true
+    }
+
     suspend fun parseCSVStream(stream: InputStream): List<OrbitalData> = withContext(dispatcher) {
         stream.bufferedReader().useLines { lines ->
             lines.drop(1).mapNotNull { parseCSV(it.split(",")) }.toList()
@@ -43,8 +49,12 @@ class DataParser(private val dispatcher: CoroutineDispatcher) {
 
     suspend fun parseJSONStream(stream: InputStream): List<SatRadio> = withContext(dispatcher) {
         runCatching {
-            val jsonArray = JSONArray(stream.bufferedReader().readText())
-            (0 until jsonArray.length()).mapNotNull { parseJSON(jsonArray.getJSONObject(it)) }
+            val root = json.parseToJsonElement(stream.bufferedReader().readText())
+            (root as? JsonArray)?.mapNotNull { element ->
+                runCatching { json.decodeFromJsonElement<SatRadio>(element) }
+                    .onFailure { println("JSON parsing exception: $it") }
+                    .getOrNull()
+            } ?: emptyList()
         }.getOrDefault(emptyList())
     }
 
@@ -95,26 +105,6 @@ class DataParser(private val dispatcher: CoroutineDispatcher) {
         )
     }.onFailure { println("TLE parsing exception: $it") }.getOrNull()
 
-    private fun parseJSON(json: JSONObject): SatRadio? = runCatching {
-        SatRadio(
-            uuid = json.getString("uuid"),
-            info = json.getString("description"),
-            isAlive = json.getBoolean("alive"),
-            downlinkLow = json.optLongOrNull("downlink_low"),
-            downlinkHigh = json.optLongOrNull("downlink_high"),
-            downlinkMode = json.optStringOrNull("mode"),
-            uplinkLow = json.optLongOrNull("uplink_low"),
-            uplinkHigh = json.optLongOrNull("uplink_high"),
-            uplinkMode = json.optStringOrNull("uplink_mode"),
-            isInverted = json.getBoolean("invert"),
-            catnum = json.optIntOrNull("norad_cat_id")
-        )
-    }.onFailure { println("JSON parsing exception: $it") }.getOrNull()
-
-    private fun JSONObject.optStringOrNull(key: String): String? = if (isNull(key)) null else getString(key)
-    private fun JSONObject.optLongOrNull(key: String): Long? = if (isNull(key)) null else getLong(key)
-    private fun JSONObject.optIntOrNull(key: String): Int? = if (isNull(key)) null else getInt(key)
-
     private fun getDayOfYear(year: Int, month: Int, dayOfMonth: Int): Int {
         val daysInMonth = intArrayOf(31, if (isLeapYear(year)) 29 else 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31)
         return daysInMonth.take(month - 1).sum() + dayOfMonth

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

@@ -19,9 +19,14 @@ package com.rtbishop.look4sat.core.domain.utility
 
 import com.rtbishop.look4sat.core.domain.predict.DEG2RAD
 import com.rtbishop.look4sat.core.domain.predict.RAD2DEG
+import kotlin.math.acos
+import kotlin.math.atan2
+import kotlin.math.cos
 import kotlin.math.max
 import kotlin.math.min
+import kotlin.math.sin
 
+private const val AVG_EARTH_RADIUS_KM = 6371.009
 private const val MIN_LATITUDE = -85.05112877980658
 private const val MAX_LATITUDE = 85.05112877980658
 private const val MIN_LONGITUDE = -180.0
@@ -48,6 +53,27 @@ fun Double.toRadians(): Double = this * DEG2RAD
 //    return MIN_LONGITUDE + (MAX_LONGITUDE - MIN_LONGITUDE) * this
 //}
 
+// Great-circle distance between two positions in kilometers using the spherical law of cosines.
+fun greatCircleDistanceKm(lat1: Double, lon1: Double, lat2: Double, lon2: Double): Double {
+    val lat1R = lat1.toRadians()
+    val lat2R = lat2.toRadians()
+    val lon1R = lon1.toRadians()
+    val lon2R = lon2.toRadians()
+    return acos(
+        sin(lat1R) * sin(lat2R) + cos(lat1R) * cos(lat2R) * cos(lon2R - lon1R)
+    ) * AVG_EARTH_RADIUS_KM
+}
+
+// Initial bearing (azimuth) from position 1 to position 2, in degrees (0-360).
+fun bearingDeg(lat1: Double, lon1: Double, lat2: Double, lon2: Double): Double {
+    val lat1R = lat1.toRadians()
+    val lat2R = lat2.toRadians()
+    val dLon = (lon2 - lon1).toRadians()
+    val y = sin(dLon) * cos(lat2R)
+    val x = cos(lat1R) * sin(lat2R) - sin(lat1R) * cos(lat2R) * cos(dLon)
+    return (atan2(y, x).toDegrees() + 360) % 360
+}
+
 fun clipLat(latitude: Double): Double {
     return clip(latitude, MIN_LATITUDE, MAX_LATITUDE)
 }

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

@@ -2,9 +2,9 @@ package com.rtbishop.look4sat.core.domain
 
 import com.rtbishop.look4sat.core.domain.model.SatRadio
 import com.rtbishop.look4sat.core.domain.utility.TransponderMapper
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
 import org.junit.Test
-import kotlin.test.assertEquals
-import kotlin.test.assertNull
 
 class TransponderMapperTest {
 

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

@@ -1,10 +1,43 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
 package com.rtbishop.look4sat.core.presentation
 
-sealed class Screen(val route: String, val iconResId: Int, val titleResId: Int) {
-    data object Satellites : Screen("satellites", R.drawable.ic_satellites, R.string.nav_sat)
-    data object Passes : Screen("passes", R.drawable.ic_passes, R.string.nav_pass)
-    data object Radar : Screen("radar", R.drawable.ic_radar, R.string.nav_radar)
-    data object Map : Screen("map", R.drawable.ic_map, R.string.nav_map)
-    data object Settings : Screen("settings", R.drawable.ic_settings, R.string.nav_prefs)
-    data object RadioControl : Screen("radiocontrol", R.drawable.ic_radios, R.string.nav_radiocontrol)
+import androidx.navigation3.runtime.NavKey
+import kotlinx.serialization.Serializable
+
+@Serializable
+sealed class Screen(val iconResId: Int, val titleResId: Int) : NavKey {
+
+    @Serializable
+    data object Satellites : Screen(R.drawable.ic_satellites, R.string.nav_sat)
+
+    @Serializable
+    data object Passes : Screen(R.drawable.ic_passes, R.string.nav_pass)
+
+    @Serializable
+    data class Radar(val catNum: Int = 0, val aosTime: Long = 0L) : Screen(R.drawable.ic_radar, R.string.nav_radar)
+
+    @Serializable
+    data class RadioControl(val catNum: Int = 0, val aosTime: Long = 0L) : Screen(0, 0)
+
+    @Serializable
+    data object Map : Screen(R.drawable.ic_map, R.string.nav_map)
+
+    @Serializable
+    data object Settings : Screen(R.drawable.ic_settings, R.string.nav_prefs)
 }

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

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

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

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

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

@@ -31,7 +31,7 @@
     <!-- Passes screen -->
     <string name="pass_filter_title">Geçişleri filtrele</string>
     <string name="pass_filter_elev">Minimum yükseklik açısı</string>
-    <string name="pass_filter_hours">İlerideki saatler</string>
+    <string name="pass_filter_hours">Gösterilecek saat aralığı</string>
     <string name="pass_time_placeholder" translatable="false"> -- : -- : -- </string>
     <string name="pass_modes_title">Modulasyon türü seçin</string>
     <string name="pass_satId" translatable="false">%05d</string>
@@ -66,7 +66,7 @@
     <string name="radar_alt_value" translatable="false">%.0f km</string>
     <string name="radar_dist_text">Mesafe</string>
     <string name="radar_dist_value" translatable="false">%.0f km</string>
-    <string name="radar_eclipsed">Tutulumda</string>
+    <string name="radar_eclipsed">Gölgede</string>
     <string name="radar_downlink">Downlink</string>
     <string name="radar_uplink">Uplink</string>
     <string name="radar_link_low" translatable="false">%.4f</string>
@@ -93,7 +93,7 @@
     <string name="map_longitude">Boylam: %.1f°</string>
     <string name="map_qth" translatable="false">QTH: %s</string>
     <string name="map_phase">Faz: %.1f°</string>
-    <string name="map_eclipsed">Tutulumda</string>
+    <string name="map_eclipsed">Gölgede</string>
     <string name="map_period">Periyot: %.0f dk</string>
     <string name="map_velocity">Hız: %.2f km/s</string>
     <string name="map_visibility">Görünürlük: %s</string>
@@ -182,7 +182,7 @@
     <string name="prefs_other_switch_sweep">Radar taramasını etkinleştir</string>
     <string name="prefs_other_switch_sensors">Radar görünümünü döndürmek için sensörleri kullan</string>
 
-    <string name="prefs_outro_title">Teşekkür etmek istiyorum</string>
+    <string name="prefs_outro_title">Teşekkürler</string>
     <string name="prefs_outro_thanks" translatable="false">
         • Look4Sat users and contributors!
         \n• David A. B. Johnson (predict4java)

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

@@ -49,10 +49,12 @@
         \n\nPlease update the database at least weekly to get accurate predictions.</string>
     <string name="pass_whatsnew_title" translatable="false">What\'s new in Look4Sat</string>
     <string name="pass_whatsnew_message" translatable="false">
-        * Added Turkish translation, by Emre Can Akdaş (TA3ECR)
-        \n* Added DeepSpace passes filter option to the dialog
-        \n* Fixed the radar blip disappearing while eclipsed
-        \n* Fixed (hopefully) the refresh indicator being stuck
+        * Added fixes for Turkish translation, by Emre Can Akdaş (TA3ECR)
+        \n* Added passes sticky header with sunrise/sunset times
+        \n* Added current moon/sun positions to the Radar Screen
+        \n* Added current moon/sun positions to the Map Screen
+        \n* Added red night mode filter overlay for the whole app
+
     </string>
 
     <!-- Radar screen -->
@@ -181,6 +183,7 @@
     <string name="prefs_other_switch_update">Enable automatic data update</string>
     <string name="prefs_other_switch_sweep">Enable radar sweep animation</string>
     <string name="prefs_other_switch_sensors">Use sensors to rotate radar view</string>
+    <string name="prefs_other_switch_night_mode">Enable red night mode filter</string>
 
     <string name="prefs_outro_title">I would like to say thanks to</string>
     <string name="prefs_outro_thanks" translatable="false">

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

@@ -1,4 +1,5 @@
-* Added Turkish translation, by Emre Can Akdaş (TA3ECR)
-* Added DeepSpace passes filter option to the dialog
-* Fixed the radar blip disappearing while eclipsed
-* Fixed (hopefully) the refresh indicator being stuck
+* Added fixes for Turkish translation, by Emre Can Akdaş (TA3ECR)
+* Added passes sticky header with sunrise/sunset times
+* Added current moon/sun positions to the Radar Screen
+* Added current moon/sun positions to the Map Screen
+* Added red night mode filter overlay for the whole app

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

@@ -1,4 +1,5 @@
-* Added Turkish translation, by Emre Can Akdaş (TA3ECR)
-* Added DeepSpace passes filter option to the dialog
-* Fixed the radar blip disappearing while eclipsed
-* Fixed (hopefully) the refresh indicator being stuck
+* Added fixes for Turkish translation, by Emre Can Akdaş (TA3ECR)
+* Added passes sticky header with sunrise/sunset times
+* Added current moon/sun positions to the Radar Screen
+* Added current moon/sun positions to the Map Screen
+* Added red night mode filter overlay for the whole app

feature/map/src/main/java/com/rtbishop/look4sat/feature/map/MapNightOverlay.kt

@@ -0,0 +1,152 @@
+/*
+ * 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.map
+
+import android.graphics.Canvas
+import android.graphics.Color
+import android.graphics.Paint
+import android.graphics.RectF
+import org.osmdroid.views.MapView
+import org.osmdroid.views.overlay.Overlay
+import kotlin.math.cos
+import kotlin.math.sin
+
+/**
+ * Custom osmdroid overlay that shades the night side of the globe.
+ *
+ * Works entirely in screen-pixel space: for each vertical strip on screen it
+ * asks osmdroid for the geographic coordinate, then tests whether that point is
+ * in the night half-sphere relative to the sub-solar point.  Because the
+ * computation happens during draw() the result is always correct regardless
+ * of zoom level or map scroll position — no polygon winding issues possible.
+ *
+ * A point (latRad, lonRad) is in night when the angle to the sub-solar point
+ * exceeds 90°, i.e. the dot product of the two unit vectors is negative:
+ *   dot = sin(lat)*sin(sunLat) + cos(lat)*cos(sunLat)*cos(lon - sunLon) < 0
+ *
+ * Performance: we sample one column per [stepPx] pixels (default 4) and draw
+ * filled vertical rectangles.  On a 1080-wide screen this means ~270 trig
+ * evaluations per row, which is imperceptible.
+ */
+class MapNightOverlay : Overlay() {
+
+    /** Sub-solar latitude in degrees. */
+    var sunLatDeg: Double = 0.0
+
+    /** Sub-solar longitude in degrees. */
+    var sunLonDeg: Double = 0.0
+
+    private val nightPaint = Paint(Paint.ANTI_ALIAS_FLAG).apply {
+        style = Paint.Style.FILL
+        color = Color.argb(75, 0, 0, 0)
+    }
+
+    private val rect = RectF()
+
+    override fun draw(canvas: Canvas, mapView: MapView, shadow: Boolean) {
+        if (shadow) return
+
+        val proj = mapView.projection
+        val sunLatRad = Math.toRadians(sunLatDeg)
+        val sunLonRad = Math.toRadians(sunLonDeg)
+        val sinSunLat = sin(sunLatRad)
+        val cosSunLat = cos(sunLatRad)
+
+        val w = mapView.width
+        val h = mapView.height
+        val stepPx = 4 // sample every N pixels — balance quality vs CPU
+
+        // We scan column by column. For each column we determine the longitude,
+        // then find the latitude range that is in night and shade it.
+        // Since longitude is constant along a vertical strip and the day/night
+        // boundary at a given longitude is at most two latitudes, we can do a
+        // scan-line fill efficiently.
+
+        var x = 0
+        while (x < w) {
+            // Get the geographic coordinate at the top and bottom of this column.
+            val geoTop = proj.fromPixels(x, 0) ?: run { x += stepPx; continue }
+            val geoBot = proj.fromPixels(x, h - 1) ?: run { x += stepPx; continue }
+
+            val lonRad = Math.toRadians(geoTop.longitude)
+            val cosLonDiff = cos(lonRad - sunLonRad)
+
+            // Top pixel geographic lat
+            val latTopRad = Math.toRadians(geoTop.latitude)
+            // Bottom pixel geographic lat (osmdroid: y=0 is top of screen, higher y = lower lat)
+            val latBotRad = Math.toRadians(geoBot.latitude)
+
+            // dot(sunVec, pointVec) < 0 → night
+            // dot = sin(lat)*sinSunLat + cos(lat)*cosSunLat*cosLonDiff
+            val dotTop = sin(latTopRad) * sinSunLat + cos(latTopRad) * cosSunLat * cosLonDiff
+            val dotBot = sin(latBotRad) * sinSunLat + cos(latBotRad) * cosSunLat * cosLonDiff
+
+            when {
+                dotTop < 0 && dotBot < 0 -> {
+                    // Entire column is night — shade from top to bottom
+                    rect.set(x.toFloat(), 0f, (x + stepPx).toFloat(), h.toFloat())
+                    canvas.drawRect(rect, nightPaint)
+                }
+
+                dotTop >= 0 && dotBot >= 0 -> {
+                    // Entire column is day — nothing to draw
+                }
+
+                else -> {
+                    // Terminator crosses this column — find the crossing pixel by binary search
+                    val crossY = findCrossingY(proj, x, 0, h - 1, sinSunLat, cosSunLat, cosLonDiff)
+                    if (dotTop < 0) {
+                        // Night at top, day at bottom
+                        rect.set(x.toFloat(), 0f, (x + stepPx).toFloat(), crossY.toFloat())
+                        canvas.drawRect(rect, nightPaint)
+                    } else {
+                        // Day at top, night at bottom
+                        rect.set(x.toFloat(), crossY.toFloat(), (x + stepPx).toFloat(), h.toFloat())
+                        canvas.drawRect(rect, nightPaint)
+                    }
+                }
+            }
+            x += stepPx
+        }
+    }
+
+    /**
+     * Binary-search for the pixel row where the day/night boundary crosses column [x].
+     * [yTop] is in day, [yBot] is in night (or vice versa).
+     */
+    private fun findCrossingY(
+        proj: org.osmdroid.views.Projection,
+        x: Int,
+        yTop: Int,
+        yBot: Int,
+        sinSunLat: Double,
+        cosSunLat: Double,
+        cosLonDiff: Double
+    ): Int {
+        var lo = yTop
+        var hi = yBot
+        while (hi - lo > 1) {
+            val mid = (lo + hi) / 2
+            val geo = proj.fromPixels(x, mid) ?: return mid
+            val latRad = Math.toRadians(geo.latitude)
+            val dot = sin(latRad) * sinSunLat + cos(latRad) * cosSunLat * cosLonDiff
+            if (dot < 0) hi = mid else lo = mid
+        }
+        return (lo + hi) / 2
+    }
+}

feature/map/src/main/java/com/rtbishop/look4sat/feature/map/MapScreen.kt

@@ -60,15 +60,13 @@ import androidx.lifecycle.LifecycleEventObserver
 import androidx.lifecycle.compose.LocalLifecycleOwner
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.lifecycle.viewmodel.compose.viewModel
-import androidx.navigation.NavGraphBuilder
-import androidx.navigation.compose.composable
 import com.rtbishop.look4sat.core.domain.predict.GeoPos
 import com.rtbishop.look4sat.core.domain.predict.OrbitalObject
 import com.rtbishop.look4sat.core.domain.predict.OrbitalPos
+import com.rtbishop.look4sat.core.domain.repository.IContainerProvider
 import com.rtbishop.look4sat.core.presentation.IconCard
 import com.rtbishop.look4sat.core.presentation.NextPassRow
 import com.rtbishop.look4sat.core.presentation.R
-import com.rtbishop.look4sat.core.presentation.Screen
 import com.rtbishop.look4sat.core.presentation.TimerRow
 import com.rtbishop.look4sat.core.presentation.TopBar
 import com.rtbishop.look4sat.core.presentation.isVerticalLayout
@@ -86,7 +84,10 @@ private const val OVERLAY_STATION = 0
 private const val OVERLAY_TRACK = 1
 private const val OVERLAY_FOOTPRINT = 2
 private const val OVERLAY_POSITIONS = 3
-private const val OVERLAY_COUNT = 4
+private const val OVERLAY_TERMINATOR = 4
+private const val OVERLAY_SUN = 5
+private const val OVERLAY_MOON = 6
+private const val OVERLAY_COUNT = 7
 
 private val minLat = MapView.getTileSystem().minLatitude
 private val maxLat = MapView.getTileSystem().maxLatitude
@@ -109,14 +110,26 @@ private val textPaint = Paint(Paint.ANTI_ALIAS_FLAG).apply {
     setShadowLayer(3f, 3f, 3f, Color.BLACK)
 }
 private val iconCache = LruCache<String, Drawable>(128)
+private val sunIconPaint = Paint(Paint.ANTI_ALIAS_FLAG).apply {
+    colorFilter =
+        android.graphics.PorterDuffColorFilter("#FFE082".toColorInt(), android.graphics.PorterDuff.Mode.SRC_IN)
+}
+private val moonIconPaint = Paint(Paint.ANTI_ALIAS_FLAG).apply {
+    colorFilter =
+        android.graphics.PorterDuffColorFilter("#E0E0E0".toColorInt(), android.graphics.PorterDuff.Mode.SRC_IN)
+}
 
-fun NavGraphBuilder.mapDestination() {
-    composable(Screen.Map.route) {
-        val viewModel = viewModel(MapViewModel::class.java, factory = MapViewModel.Factory)
-        val uiState by viewModel.uiState.collectAsStateWithLifecycle()
-        val mapView = rememberMapViewWithLifecycle()
-        MapScreen(uiState, viewModel::onAction, mapView)
-    }
+@Composable
+fun MapDestination() {
+    val context = LocalContext.current
+    val container = (context.applicationContext as IContainerProvider).getMainContainer()
+    val viewModel = viewModel(
+        modelClass = MapViewModel::class.java,
+        factory = MapViewModel.factory(container)
+    )
+    val uiState by viewModel.uiState.collectAsStateWithLifecycle()
+    val mapView = rememberMapViewWithLifecycle()
+    MapScreen(uiState, viewModel::onAction, mapView)
 }
 
 @Composable
@@ -153,6 +166,9 @@ private fun MapScreen(uiState: MapState, onAction: (MapAction) -> Unit, mapView:
                     uiState.track?.let { setSatelliteTrack(it, view) }
                     uiState.footprint?.let { setFootprint(it, view) }
                     uiState.positions?.let { setPositions(it, view) { item -> onAction(MapAction.SelectItem(item)) } }
+                    setTerminator(uiState.sunLatDeg, uiState.sunLonDeg, view)
+                    setSubSolarPoint(uiState.sunLatDeg, uiState.sunLonDeg, view)
+                    setMoonPosition(uiState.moonLatDeg, uiState.moonLonDeg, view)
                     view.invalidate()
                 }
                 uiState.mapData?.let { mapData ->
@@ -366,14 +382,12 @@ private var footprintPoints: ArrayList<GeoPoint>? = null
 private fun setFootprint(orbitalPos: OrbitalPos, mapView: MapView) {
     try {
         val rangeCircle = orbitalPos.getRangeCircle()
-        // Lazily initialize the reusable point list and polyline
         var pts = footprintPoints
         if (pts == null || pts.size != rangeCircle.size) {
             pts = ArrayList(rangeCircle.size)
             for (gp in rangeCircle) pts.add(GeoPoint(gp.latitude, gp.longitude))
             footprintPoints = pts
         } else {
-            // Update coordinates in-place — zero allocations
             for (i in rangeCircle.indices) {
                 pts[i].latitude = rangeCircle[i].latitude
                 pts[i].longitude = rangeCircle[i].longitude
@@ -389,6 +403,83 @@ private fun setFootprint(orbitalPos: OrbitalPos, mapView: MapView) {
         println(e)
     }
 }
+
+/**
+ * Update the NightOverlay with the current sub-solar position.
+ * The overlay is created once and kept in OVERLAY_TERMINATOR; only its
+ * sunLatDeg/sunLonDeg fields are updated each tick so osmdroid redraws it.
+ */
+private fun setTerminator(sunLatDeg: Double, sunLonDeg: Double, mapView: MapView) {
+    try {
+        val overlay = mapView.overlays[OVERLAY_TERMINATOR]
+        if (overlay is MapNightOverlay) {
+            overlay.sunLatDeg = sunLatDeg
+            overlay.sunLonDeg = sunLonDeg
+        } else {
+            mapView.overlays[OVERLAY_TERMINATOR] = MapNightOverlay().apply {
+                this.sunLatDeg = sunLatDeg
+                this.sunLonDeg = sunLonDeg
+            }
+        }
+    } catch (e: Exception) {
+        println(e)
+    }
+}
+
+/** Place an ic_sun icon marker at the sub-solar point. */
+private fun setSubSolarPoint(sunLatDeg: Double, sunLonDeg: Double, mapView: MapView) {
+    try {
+        val overlay = mapView.overlays[OVERLAY_SUN]
+        val sunPos = GeoPoint(sunLatDeg, sunLonDeg)
+        if (overlay is Marker) {
+            overlay.position = sunPos
+        } else {
+            val iconSize = 48
+            val bmp = createBitmap(iconSize, iconSize)
+            ContextCompat.getDrawable(mapView.context, R.drawable.ic_sun)?.apply {
+                setBounds(0, 0, iconSize, iconSize)
+                colorFilter = sunIconPaint.colorFilter
+                draw(Canvas(bmp))
+            }
+            mapView.overlays[OVERLAY_SUN] = Marker(mapView).apply {
+                setInfoWindow(null)
+                setAnchor(Marker.ANCHOR_CENTER, Marker.ANCHOR_CENTER)
+                icon = bmp.toDrawable(mapView.context.resources)
+                position = sunPos
+            }
+        }
+    } catch (e: Exception) {
+        println(e)
+    }
+}
+
+/** Place an ic_moon icon marker at the sub-lunar point. */
+private fun setMoonPosition(moonLatDeg: Double, moonLonDeg: Double, mapView: MapView) {
+    try {
+        val overlay = mapView.overlays[OVERLAY_MOON]
+        val moonPos = GeoPoint(moonLatDeg, moonLonDeg)
+        if (overlay is Marker) {
+            overlay.position = moonPos
+        } else {
+            val iconSize = 48
+            val bmp = createBitmap(iconSize, iconSize)
+            val c = Canvas(bmp)
+            ContextCompat.getDrawable(mapView.context, R.drawable.ic_moon)?.apply {
+                setBounds(0, 0, iconSize, iconSize)
+                colorFilter = moonIconPaint.colorFilter
+                draw(c)
+            }
+            mapView.overlays[OVERLAY_MOON] = Marker(mapView).apply {
+                setInfoWindow(null)
+                setAnchor(Marker.ANCHOR_CENTER, Marker.ANCHOR_CENTER)
+                icon = bmp.toDrawable(mapView.context.resources)
+                position = moonPos
+            }
+        }
+    } catch (e: Exception) {
+        println(e)
+    }
+}
 // endregion
 
 // region MapView lifecycle

feature/map/src/main/java/com/rtbishop/look4sat/feature/map/MapState.kt

@@ -30,7 +30,11 @@ data class MapState(
     val orbitalPass: OrbitalPass,
     val track: List<List<GeoPos>>? = null,
     val footprint: OrbitalPos? = null,
-    val positions: Map<OrbitalObject, GeoPos>? = null
+    val positions: Map<OrbitalObject, GeoPos>? = null,
+    val sunLatDeg: Double = 0.0,
+    val sunLonDeg: Double = 0.0,
+    val moonLatDeg: Double = 0.0,
+    val moonLonDeg: Double = 0.0
 )
 
 sealed interface MapAction {

feature/map/src/main/java/com/rtbishop/look4sat/feature/map/MapViewModel.kt

@@ -18,15 +18,15 @@
 package com.rtbishop.look4sat.feature.map
 
 import androidx.lifecycle.ViewModel
-import androidx.lifecycle.ViewModelProvider
 import androidx.lifecycle.viewModelScope
 import androidx.lifecycle.viewmodel.initializer
 import androidx.lifecycle.viewmodel.viewModelFactory
+import com.rtbishop.look4sat.core.domain.predict.CelestialComputer
 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.IContainerProvider
+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.clipLat
@@ -49,8 +49,10 @@ import kotlinx.coroutines.isActive
 import kotlinx.coroutines.launch
 import java.util.Date
 
-class MapViewModel(private val satelliteRepo: ISatelliteRepo, private val settingsRepo: ISettingsRepo) :
-    ViewModel() {
+class MapViewModel(
+    private val satelliteRepo: ISatelliteRepo,
+    private val settingsRepo: ISettingsRepo
+) : ViewModel() {
 
     private val stationPos = settingsRepo.stationPosition.value
     private val defaultPass = getDefaultPass()
@@ -177,10 +179,12 @@ class MapViewModel(private val satelliteRepo: ISatelliteRepo, private val settin
             }
         }
 
-        // 2. Derive footprint and info data from the already-computed selected position
+        // 2. Derive footprint, info data, sun and moon position from already-computed state
         val satPos = selectedSatPos ?: satelliteRepo.getPosition(selected, pos, date.time)
         val footprint = satPos
         val mapData = buildMapData(selected, satPos, date)
+        val sunPos = CelestialComputer.getSunPosition(stationPos, date.time)
+        val moonPos = CelestialComputer.getMoonPosition(stationPos, date.time)
 
         // 3. Single atomic state update — one recomposition per cycle
         _uiState.update {
@@ -188,7 +192,11 @@ class MapViewModel(private val satelliteRepo: ISatelliteRepo, private val settin
                 positions = positionsMap,
                 footprint = footprint,
                 mapData = mapData.first,
-                orbitalPass = mapData.second
+                orbitalPass = mapData.second,
+                sunLatDeg = sunPos.latitude,
+                sunLonDeg = sunPos.longitude,
+                moonLatDeg = moonPos.declination, // sub-lunar latitude = declination
+                moonLonDeg = if (moonPos.gha <= 180.0) -moonPos.gha else 360.0 - moonPos.gha
             )
         }
     }
@@ -286,11 +294,12 @@ class MapViewModel(private val satelliteRepo: ISatelliteRepo, private val settin
         /** Number of parallel chunks for satellite position computation */
         private const val PARALLEL_CHUNKS = 4
 
-        val Factory: ViewModelProvider.Factory = viewModelFactory {
-            val applicationKey = ViewModelProvider.AndroidViewModelFactory.APPLICATION_KEY
+        fun factory(container: IMainContainer) = viewModelFactory {
             initializer {
-                val container = (this[applicationKey] as IContainerProvider).getMainContainer()
-                MapViewModel(container.satelliteRepo, container.settingsRepo)
+                MapViewModel(
+                    satelliteRepo = container.satelliteRepo,
+                    settingsRepo = container.settingsRepo
+                )
             }
         }
     }

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

@@ -29,6 +29,7 @@ import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.lazy.grid.GridCells
+import androidx.compose.foundation.lazy.grid.GridItemSpan
 import androidx.compose.foundation.lazy.grid.LazyGridState
 import androidx.compose.foundation.lazy.grid.LazyVerticalGrid
 import androidx.compose.foundation.lazy.grid.items
@@ -44,9 +45,12 @@ import androidx.compose.material3.pulltorefresh.PullToRefreshBox
 import androidx.compose.material3.pulltorefresh.PullToRefreshDefaults
 import androidx.compose.material3.pulltorefresh.rememberPullToRefreshState
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.derivedStateOf
+import androidx.compose.runtime.getValue
 import androidx.compose.runtime.remember
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+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
@@ -56,19 +60,17 @@ import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.lifecycle.viewmodel.compose.viewModel
-import androidx.navigation.NavGraphBuilder
-import androidx.navigation.compose.composable
 import com.rtbishop.look4sat.core.domain.predict.DeepSpaceObject
 import com.rtbishop.look4sat.core.domain.predict.NearEarthObject
 import com.rtbishop.look4sat.core.domain.predict.OrbitalData
 import com.rtbishop.look4sat.core.domain.predict.OrbitalPass
+import com.rtbishop.look4sat.core.domain.repository.IContainerProvider
 import com.rtbishop.look4sat.core.presentation.EmptyListCard
 import com.rtbishop.look4sat.core.presentation.IconCard
 import com.rtbishop.look4sat.core.presentation.InfoDialog
 import com.rtbishop.look4sat.core.presentation.MainTheme
 import com.rtbishop.look4sat.core.presentation.NextPassRow
 import com.rtbishop.look4sat.core.presentation.R
-import com.rtbishop.look4sat.core.presentation.Screen
 import com.rtbishop.look4sat.core.presentation.ScreenColumn
 import com.rtbishop.look4sat.core.presentation.TimerRow
 import com.rtbishop.look4sat.core.presentation.TopBar
@@ -79,15 +81,16 @@ import java.util.Date
 import java.util.Locale
 import java.util.TimeZone
 
-fun NavGraphBuilder.passesDestination(navigateToRadar: (Int, Long) -> Unit) {
-    composable(Screen.Passes.route) {
-        val viewModel = viewModel(
-            modelClass = PassesViewModel::class.java,
-            factory = PassesViewModel.Factory
-        )
-        val uiState = viewModel.uiState.collectAsStateWithLifecycle().value
-        PassesScreen(uiState, viewModel::onAction, navigateToRadar)
-    }
+@Composable
+fun PassesDestination(navigateToRadar: (Int, Long) -> Unit) {
+    val context = LocalContext.current
+    val container = (context.applicationContext as IContainerProvider).getMainContainer()
+    val viewModel = viewModel(
+        modelClass = PassesViewModel::class.java,
+        factory = PassesViewModel.factory(container)
+    )
+    val uiState = viewModel.uiState.collectAsStateWithLifecycle().value
+    PassesScreen(uiState, viewModel::onAction, navigateToRadar)
 }
 
 @Composable
@@ -148,7 +151,8 @@ private fun PassesScreen(
             passes = uiState.itemsList,
             navigateToRadar = navigateToRadar,
             refreshPasses = { onAction(PassesAction.RefreshPasses) },
-            gridState = gridState
+            gridState = gridState,
+            sunTimes = uiState.sunTimes
         )
     }
 }
@@ -161,10 +165,43 @@ private fun PassesList(
     passes: List<OrbitalPass>,
     navigateToRadar: (Int, Long) -> Unit,
     refreshPasses: () -> Unit,
-    gridState: LazyGridState
+    gridState: LazyGridState,
+    sunTimes: Map<String, Pair<String, String>>
 ) {
     val isVerticalLayout = isVerticalLayout()
     val refreshState = rememberPullToRefreshState()
+    val timeZone = remember(isUtc) { if (isUtc) TimeZone.getTimeZone("UTC") else TimeZone.getDefault() }
+    val sdfDate = remember(isUtc) {
+        SimpleDateFormat("EEE, dd MMM yyyy", Locale.ENGLISH).also { it.timeZone = timeZone }
+    }
+
+    // Group passes by calendar day so we know where headers go
+    val groupedPasses = remember(passes, isUtc) {
+        passes.filter { !it.isDeepSpace }.groupBy { sdfDate.format(Date(it.aosTime)) } +
+            if (passes.any { it.isDeepSpace }) mapOf("Deep Space" to passes.filter { it.isDeepSpace }) else emptyMap()
+    }
+
+    // Derive the sticky header label from the first visible item index
+    val stickyHeader by remember(gridState, groupedPasses) {
+        derivedStateOf {
+            val firstVisible = gridState.firstVisibleItemIndex
+            var itemIndex = 0
+            var header = groupedPasses.keys.firstOrNull() ?: ""
+            for ((key, items) in groupedPasses) {
+                header = key
+                itemIndex += 1 + items.size
+                if (itemIndex > firstVisible) break
+            }
+            header
+        }
+    }
+
+    // The sticky overlay should only show when the first in-list header has scrolled out of view.
+    // firstVisibleItemIndex == 0 means the first header is still visible — hide the overlay.
+    val showStickyOverlay by remember(gridState) {
+        derivedStateOf { gridState.firstVisibleItemIndex > 0 || gridState.firstVisibleItemScrollOffset > 0 }
+    }
+
     ElevatedCard(modifier = Modifier.fillMaxSize()) {
         PullToRefreshBox(
             isRefreshing = isRefreshing,
@@ -183,19 +220,33 @@ private fun PassesList(
             if (passes.isEmpty()) {
                 EmptyListCard(message = stringResource(R.string.pass_empty_list_message))
             } else {
-                LazyVerticalGrid(
-                    state = gridState,
-                    columns = GridCells.Adaptive(320.dp),
-                    modifier = Modifier.fillMaxSize()
-                ) {
-                    items(items = passes, key = { item -> item.catNum + item.aosTime }) { pass ->
-                        PassItem(
-                            pass = pass,
-                            navigateToRadar = navigateToRadar,
-                            modifier = Modifier.animateItem(),
-                            isVerticalLayout = isVerticalLayout,
-                            isUtc = isUtc
-                        )
+                Column {
+                    // Sticky header overlay — only visible once the in-list header scrolls away
+                    if (showStickyOverlay) {
+                        val (rise, set) = sunTimes[stickyHeader] ?: ("--:--" to "--:--")
+                        StickyDateHeader(label = stickyHeader, sunriseTime = rise, sunsetTime = set)
+                    }
+                    LazyVerticalGrid(
+                        state = gridState,
+                        columns = GridCells.Adaptive(320.dp),
+                        modifier = Modifier.fillMaxSize()
+                    ) {
+                        for ((dateLabel, dayPasses) in groupedPasses) {
+                            // In-list section header (scrolls away, drives the sticky overlay)
+                            item(span = { GridItemSpan(maxLineSpan) }) {
+                                val (rise, set) = sunTimes[dateLabel] ?: ("--:--" to "--:--")
+                                StickyDateHeader(label = dateLabel, sunriseTime = rise, sunsetTime = set)
+                            }
+                            items(items = dayPasses, key = { item -> item.catNum + item.aosTime }) { pass ->
+                                PassItem(
+                                    pass = pass,
+                                    navigateToRadar = navigateToRadar,
+                                    modifier = Modifier.animateItem(),
+                                    isVerticalLayout = isVerticalLayout,
+                                    isUtc = isUtc
+                                )
+                            }
+                        }
                     }
                 }
             }
@@ -203,6 +254,45 @@ private fun PassesList(
     }
 }
 
+@Composable
+private fun StickyDateHeader(label: String, sunriseTime: String, sunsetTime: String) {
+    Row(
+        verticalAlignment = Alignment.CenterVertically,
+        horizontalArrangement = Arrangement.SpaceBetween,
+        modifier = Modifier
+            .fillMaxWidth()
+            .background(MaterialTheme.colorScheme.surfaceContainerHighest)
+            .padding(horizontal = 12.dp, vertical = 4.dp)
+    ) {
+        Text(
+            text = label,
+            fontSize = 14.sp,
+            fontWeight = FontWeight.Normal,
+            color = MaterialTheme.colorScheme.primary
+        )
+        Row(horizontalArrangement = Arrangement.spacedBy(12.dp)) {
+            Row(verticalAlignment = Alignment.CenterVertically, horizontalArrangement = Arrangement.spacedBy(4.dp)) {
+                Icon(
+                    painter = painterResource(R.drawable.ic_sun),
+                    contentDescription = null,
+                    tint = MaterialTheme.colorScheme.primary,
+                    modifier = Modifier.size(16.dp)
+                )
+                Text(text = sunriseTime, fontSize = 14.sp, color = MaterialTheme.colorScheme.onSurface)
+            }
+            Row(verticalAlignment = Alignment.CenterVertically, horizontalArrangement = Arrangement.spacedBy(4.dp)) {
+                Icon(
+                    painter = painterResource(R.drawable.ic_moon),
+                    contentDescription = null,
+                    tint = MaterialTheme.colorScheme.onSurface,
+                    modifier = Modifier.size(16.dp)
+                )
+                Text(text = sunsetTime, fontSize = 14.sp, color = MaterialTheme.colorScheme.onSurface)
+            }
+        }
+    }
+}
+
 @Preview(showBackground = true)
 @Composable
 private fun DeepSpacePassPreview() {
@@ -234,15 +324,15 @@ private fun PassItem(
     val timeZone = remember(isUtc) {
         if (isUtc) TimeZone.getTimeZone("UTC") else TimeZone.getDefault()
     }
-    val sdfDate = remember(isUtc) {
-        SimpleDateFormat("EEE dd MMM", Locale.ENGLISH).also { it.timeZone = timeZone }
-    }
     val sdfTime = remember(isUtc) {
         SimpleDateFormat("HH:mm:ss", Locale.ENGLISH).also { it.timeZone = timeZone }
     }
-    val aosDateStr = remember(pass.aosTime, isUtc) { sdfDate.format(Date(pass.aosTime)) }
     val aosTimeStr = remember(pass.aosTime, isUtc) { sdfTime.format(Date(pass.aosTime)) }
     val losTimeStr = remember(pass.losTime, isUtc) { sdfTime.format(Date(pass.losTime)) }
+    val durationStr = remember(pass.aosTime, pass.losTime) {
+        val seconds = (pass.losTime - pass.aosTime) / 1000
+        "${seconds / 60}m ${seconds % 60}s"
+    }
 
     Column(
         modifier = modifier.clickable { navigateToRadar(pass.catNum, pass.aosTime) }
@@ -299,7 +389,7 @@ private fun PassItem(
                             color = MaterialTheme.colorScheme.onSurface
                         )
                     } else {
-                        Text(text = aosDateStr, fontSize = 15.sp, color = MaterialTheme.colorScheme.onSurface)
+                        Text(text = durationStr, fontSize = 15.sp, color = MaterialTheme.colorScheme.onSurface)
                     }
                 }
                 Row(

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

@@ -32,7 +32,9 @@ data class PassesState(
     val showDeepSpace: Boolean = true,
     val modes: List<String> = emptyList(),
     val itemsList: List<OrbitalPass> = emptyList(),
-    val shouldSeeWhatsNew: Boolean = false
+    val shouldSeeWhatsNew: Boolean = false,
+    // Map of dateLabel -> Pair(sunriseTime, sunsetTime) for each day group
+    val sunTimes: Map<String, Pair<String, String>> = emptyMap()
 )
 
 sealed interface PassesAction {

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

@@ -18,13 +18,13 @@
 package com.rtbishop.look4sat.feature.passes
 
 import androidx.lifecycle.ViewModel
-import androidx.lifecycle.ViewModelProvider
 import androidx.lifecycle.viewModelScope
 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.OrbitalPass
-import com.rtbishop.look4sat.core.domain.repository.IContainerProvider
+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.round
@@ -37,6 +37,10 @@ import kotlinx.coroutines.flow.collectLatest
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.isActive
 import kotlinx.coroutines.launch
+import java.text.SimpleDateFormat
+import java.util.Date
+import java.util.Locale
+import java.util.TimeZone
 
 class PassesViewModel(
     private val satelliteRepo: ISatelliteRepo,
@@ -64,36 +68,45 @@ class PassesViewModel(
                 _uiState.update { it.copy(isRefreshing = calculating) }
             }
         }
-        // Local tick loop — computes pass progress and countdown timer every second
+        // React to settings changes: update UTC flag and whatsNew
         viewModelScope.launch {
+            settingsRepo.otherSettings.collectLatest { settings ->
+                _uiState.update { it.copy(isUtc = settings.stateOfUtc, shouldSeeWhatsNew = settings.shouldSeeWhatsNew) }
+            }
+        }
+        // Local tick loop — computes pass progress, countdown timer, and per-day sun times every second
+        viewModelScope.launch {
+            var lastSunTimesKey = "" // track when we need to recompute sun times
             while (isActive) {
                 val timeNow = System.currentTimeMillis()
+                val isUtc = _uiState.value.isUtc
                 val showDeepSpace = _uiState.value.showDeepSpace
                 val allPasses = satelliteRepo.passes.value
                 val filtered = if (showDeepSpace) allPasses else allPasses.filter { !it.isDeepSpace }
                 val processed = computePassProgress(filtered, timeNow)
                 val (nextPass, nextTime, isAos) = resolveNextPass(processed, timeNow)
+
+                // Recompute per-day sun times only when passes list or UTC setting changes
+                val sunTimesKey = "${processed.firstOrNull()?.aosTime}-${processed.lastOrNull()?.aosTime}-$isUtc"
+                val sunTimes = if (sunTimesKey != lastSunTimesKey) {
+                    lastSunTimesKey = sunTimesKey
+                    computeSunTimes(processed, isUtc)
+                } else {
+                    _uiState.value.sunTimes
+                }
+
                 _uiState.update {
                     it.copy(
                         itemsList = processed,
                         nextPass = nextPass,
                         nextTime = nextTime,
-                        isNextTimeAos = isAos
+                        isNextTimeAos = isAos,
+                        sunTimes = sunTimes
                     )
                 }
                 delay(1000)
             }
         }
-        viewModelScope.launch {
-            settingsRepo.otherSettings.collectLatest { settings ->
-                _uiState.update {
-                    it.copy(
-                        isUtc = settings.stateOfUtc,
-                        shouldSeeWhatsNew = settings.shouldSeeWhatsNew
-                    )
-                }
-            }
-        }
     }
 
     fun onAction(action: PassesAction) {
@@ -101,18 +114,35 @@ class PassesViewModel(
             PassesAction.DismissWhatsNew -> settingsRepo.setWhatsNewDismissed()
             is PassesAction.FilterPasses ->
                 applyFilter(action.hoursAhead, action.minElevation, action.showDeepSpace, _uiState.value.modes)
-
             is PassesAction.FilterRadios ->
                 applyFilter(_uiState.value.hours, _uiState.value.elevation, _uiState.value.showDeepSpace, action.modes)
             PassesAction.RefreshPasses -> refreshPasses()
             PassesAction.TogglePassesDialog ->
                 _uiState.update { it.copy(isPassesDialogShown = !it.isPassesDialogShown) }
-
             PassesAction.ToggleRadiosDialog ->
                 _uiState.update { it.copy(isRadiosDialogShown = !it.isRadiosDialogShown) }
         }
     }
 
+    /** Computes sunrise/sunset strings for each unique calendar day in the pass list. */
+    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()
+        val sdfDate = SimpleDateFormat("EEE, dd MMM yyyy", Locale.ENGLISH).also { it.timeZone = tz }
+        val sdfTime = SimpleDateFormat("HH:mm", Locale.ENGLISH).also { it.timeZone = tz }
+        val result = LinkedHashMap<String, Pair<String, String>>()
+        for (pass in passes) {
+            if (pass.isDeepSpace) continue
+            val label = sdfDate.format(Date(pass.aosTime))
+            if (label in result) continue
+            val riseSet = CelestialComputer.findSunRiseSet(stationPos, pass.aosTime)
+            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
+        }
+        return result
+    }
+
     /** Computes live progress for each pass, filtering out expired ones. */
     private fun computePassProgress(passList: List<OrbitalPass>, time: Long): List<OrbitalPass> {
         val result = ArrayList<OrbitalPass>(passList.size)
@@ -169,11 +199,12 @@ class PassesViewModel(
     }
 
     companion object {
-        val Factory: ViewModelProvider.Factory = viewModelFactory {
-            val applicationKey = ViewModelProvider.AndroidViewModelFactory.APPLICATION_KEY
+        fun factory(container: IMainContainer) = viewModelFactory {
             initializer {
-                val container = (this[applicationKey] as IContainerProvider).getMainContainer()
-                PassesViewModel(container.satelliteRepo, container.settingsRepo)
+                PassesViewModel(
+                    satelliteRepo = container.satelliteRepo,
+                    settingsRepo = container.settingsRepo
+                )
             }
         }
     }

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

@@ -42,11 +42,13 @@ import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.rotate
 import androidx.compose.ui.keepScreenOn
+import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.semantics.contentDescription
@@ -58,18 +60,15 @@ import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.lifecycle.viewmodel.compose.viewModel
-import androidx.navigation.NavGraphBuilder
-import androidx.navigation.compose.composable
-import androidx.navigation.navArgument
 import com.rtbishop.look4sat.core.domain.model.SatRadio
 import com.rtbishop.look4sat.core.domain.predict.OrbitalPos
+import com.rtbishop.look4sat.core.domain.repository.IContainerProvider
 import com.rtbishop.look4sat.core.domain.utility.toDegrees
 import com.rtbishop.look4sat.core.presentation.EmptyListCard
 import com.rtbishop.look4sat.core.presentation.IconCard
 import com.rtbishop.look4sat.core.presentation.MainTheme
 import com.rtbishop.look4sat.core.presentation.NextPassRow
 import com.rtbishop.look4sat.core.presentation.R
-import com.rtbishop.look4sat.core.presentation.Screen
 import com.rtbishop.look4sat.core.presentation.TimerRow
 import com.rtbishop.look4sat.core.presentation.TopBar
 import com.rtbishop.look4sat.core.presentation.getDefaultPass
@@ -77,20 +76,22 @@ import com.rtbishop.look4sat.core.presentation.infiniteMarquee
 import com.rtbishop.look4sat.core.presentation.isVerticalLayout
 import com.rtbishop.look4sat.core.presentation.layoutPadding
 
-fun NavGraphBuilder.radarDestination(
+@Composable
+fun RadarDestination(
+    catNum: Int = 0,
+    aosTime: Long = 0L,
     navigateUp: () -> Unit,
     navigateToRadioControl: (Int, Long) -> Unit = { _, _ -> }
 ) {
-    val radarRoute = "${Screen.Radar.route}?catNum={catNum}&aosTime={aosTime}"
-    val radarArgs = listOf(
-        navArgument("catNum") { defaultValue = 0 },
-        navArgument("aosTime") { defaultValue = 0L }
+    val context = LocalContext.current
+    val container = (context.applicationContext as IContainerProvider).getMainContainer()
+    val viewModel = viewModel(
+        modelClass = RadarViewModel::class.java,
+        key = "$catNum-$aosTime",
+        factory = RadarViewModel.factory(catNum, aosTime, container)
     )
-    composable(radarRoute, radarArgs) {
-        val viewModel = viewModel(RadarViewModel::class.java, factory = RadarViewModel.Factory)
-        val uiState by viewModel.uiState.collectAsStateWithLifecycle()
-        RadarScreen(uiState, viewModel::onAction, navigateUp, navigateToRadioControl)
-    }
+    val uiState by viewModel.uiState.collectAsStateWithLifecycle()
+    RadarScreen(uiState, viewModel::onAction, navigateUp, navigateToRadioControl)
 }
 
 @Composable
@@ -101,7 +102,7 @@ private fun RadarScreen(
     navigateToRadioControl: (Int, Long) -> Unit
 ) {
     val upcomingPass = uiState.currentPass ?: getDefaultPass()
-    if (upcomingPass.losTime < System.currentTimeMillis()) navigateUp()
+    LaunchedEffect(uiState.isLos) { if (uiState.isLos) navigateUp() }
 
     val addToCalendar: () -> Unit = {
         uiState.currentPass?.let { pass ->
@@ -123,14 +124,14 @@ private fun RadarScreen(
         if (isVertical) {
             TopBar {
                 IconCard(action = addToCalendar, resId = R.drawable.ic_calendar)
-                TimerRow(timeString = uiState.currentTime, isTimeAos = uiState.isCurrentTimeAos)
+                TimerRow(timeString = uiState.currentTime, isTimeAos = uiState.isTimeAos)
                 IconCard(action = openRadioControl, resId = R.drawable.ic_radios)
             }
             TopBar { NextPassRow(pass = upcomingPass, isUtc = uiState.isUtc) }
         } else {
             TopBar {
                 IconCard(action = addToCalendar, resId = R.drawable.ic_calendar)
-                TimerRow(timeString = uiState.currentTime, isTimeAos = uiState.isCurrentTimeAos)
+                TimerRow(timeString = uiState.currentTime, isTimeAos = uiState.isTimeAos)
                 NextPassRow(pass = upcomingPass, modifier = Modifier.weight(1f), isUtc = uiState.isUtc)
                 IconCard(action = openRadioControl, resId = R.drawable.ic_radios)
             }
@@ -149,8 +150,8 @@ private fun RadarScreen(
 
 @Composable
 private fun RadarCard(uiState: RadarState, modifier: Modifier = Modifier) {
-    val isEclipsed = uiState.orbitalPos?.eclipsed == true
-    val borderModifier = if (isEclipsed) {
+    val satellitePos = uiState.orbitalPos
+    val borderModifier = if (satellitePos?.aboveHorizon == true && satellitePos.eclipsed) {
         val infiniteTransition = rememberInfiniteTransition(label = "eclipsedBorder")
         val borderAlpha by infiniteTransition.animateFloat(
             initialValue = 1.0f,
@@ -183,7 +184,9 @@ private fun RadarCard(uiState: RadarState, modifier: Modifier = Modifier) {
                     azimElev = uiState.orientationValues,
                     shouldShowSweep = uiState.shouldShowSweep,
                     shouldUseCompass = uiState.shouldUseCompass,
-                    modifier = Modifier.align(Alignment.Center)
+                    modifier = Modifier.align(Alignment.Center),
+                    sunPosition = uiState.sunPosition,
+                    moonPosition = uiState.moonPosition,
                 )
                 PositionOverlay(position)
             }

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

@@ -18,19 +18,23 @@
 package com.rtbishop.look4sat.feature.radar
 
 import com.rtbishop.look4sat.core.domain.model.SatRadio
+import com.rtbishop.look4sat.core.domain.predict.CelestialComputer
 import com.rtbishop.look4sat.core.domain.predict.OrbitalPass
 import com.rtbishop.look4sat.core.domain.predict.OrbitalPos
 
 data class RadarState(
     val currentPass: OrbitalPass? = null,
     val currentTime: String = "00:00:00",
-    val isCurrentTimeAos: Boolean = true,
+    val isTimeAos: Boolean = true,
+    val isLos: Boolean = false,
     val isUtc: Boolean = false,
     val orientationValues: Pair<Float, Float> = 0f to 0f,
     val orbitalPos: OrbitalPos? = null,
     val satTrack: List<OrbitalPos> = emptyList(),
     val shouldShowSweep: Boolean = false,
     val shouldUseCompass: Boolean = false,
+    val sunPosition: CelestialComputer.SunPosition? = null,
+    val moonPosition: CelestialComputer.MoonPosition? = null,
     val transmitters: List<SatRadio> = emptyList(),
     val selectedTransmitterUuid: String? = null,
     val selectedFrequency: Long? = null

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

@@ -32,6 +32,7 @@ import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.geometry.Offset
+import androidx.compose.ui.geometry.Size
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.Path
 import androidx.compose.ui.graphics.PathEffect
@@ -44,14 +45,19 @@ import androidx.compose.ui.graphics.drawscope.Fill
 import androidx.compose.ui.graphics.drawscope.Stroke
 import androidx.compose.ui.graphics.drawscope.rotate
 import androidx.compose.ui.graphics.drawscope.translate
+import androidx.compose.ui.graphics.drawscope.withTransform
+import androidx.compose.ui.graphics.painter.Painter
+import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.text.TextMeasurer
 import androidx.compose.ui.text.TextStyle
 import androidx.compose.ui.text.drawText
 import androidx.compose.ui.text.rememberTextMeasurer
 import androidx.compose.ui.unit.sp
+import com.rtbishop.look4sat.core.domain.predict.CelestialComputer
 import com.rtbishop.look4sat.core.domain.predict.OrbitalPos
 import com.rtbishop.look4sat.core.domain.predict.PI_2
 import com.rtbishop.look4sat.core.domain.utility.toRadians
+import com.rtbishop.look4sat.core.presentation.R
 import kotlin.math.cos
 import kotlin.math.sin
 
@@ -66,11 +72,14 @@ fun RadarViewCompose(
     azimElev: Pair<Float, Float>,
     shouldShowSweep: Boolean,
     shouldUseCompass: Boolean,
-    modifier: Modifier = Modifier
+    modifier: Modifier = Modifier,
+    sunPosition: CelestialComputer.SunPosition? = null,
+    moonPosition: CelestialComputer.MoonPosition? = null,
 ) {
-    val radarColor = MaterialTheme.colorScheme.secondary
-    val trackColor = MaterialTheme.colorScheme.primary
     val aimColor = MaterialTheme.colorScheme.error
+    val primaryColor = MaterialTheme.colorScheme.primary
+    val radarColor = MaterialTheme.colorScheme.secondary
+    val sunColor = MaterialTheme.colorScheme.primary
     val animTransition = rememberInfiniteTransition(label = "animScale")
     val animScale by animTransition.animateFloat(
         initialValue = 16f,
@@ -79,6 +88,8 @@ fun RadarViewCompose(
         label = "animScale"
     )
     val measurer = rememberTextMeasurer()
+    val sunPainter = painterResource(R.drawable.ic_sun)
+    val moonPainter = painterResource(R.drawable.ic_moon)
     var sweepDegrees by remember { mutableFloatStateOf(0f) }
     var cachedRadius by remember { mutableFloatStateOf(0f) }
     var trackPath by remember { mutableStateOf(Path()) }
@@ -92,13 +103,26 @@ fun RadarViewCompose(
             cachedRadius = radius
         }
         rotate(if (shouldUseCompass) -azimElev.first else 0f) {
-            if (shouldShowSweep) drawSweep(center, sweepDegrees, radius, trackColor)
+            if (shouldShowSweep) drawSweep(center, sweepDegrees, radius, primaryColor)
             drawRadar(radius, radarColor)
-            drawElevationLabels(radius, trackColor, measurer)
+            drawElevationLabels(radius, primaryColor, measurer)
             translate(center.x, center.y) {
-                drawTrack(trackPath, trackEffect, aimColor, trackColor)
+                drawTrack(trackPath, trackEffect, aimColor, primaryColor)
                 if (item.elevation > 0) {
-                    drawPosition(item, radius, animScale, trackColor)
+                    drawPosition(item, radius, animScale, primaryColor)
+                }
+                sunPosition?.let { sun ->
+                    if (sun.elevation > 0) drawBodyIcon(sun.azimuth, sun.elevation, radius, sunColor, sunPainter, 52f)
+                }
+                moonPosition?.let { moon ->
+                    if (moon.elevation > 0) drawBodyIcon(
+                        moon.azimuth,
+                        moon.elevation,
+                        radius,
+                        radarColor,
+                        moonPainter,
+                        52f
+                    )
                 }
                 if (shouldUseCompass) drawAim(azimElev.first, azimElev.second, radius, aimColor)
             }
@@ -180,6 +204,27 @@ private fun createTrackEffect(trackPath: Path): PathEffect {
     return PathEffect.stampedPathEffect(shape, trackLength / 2f, trackLength / 4f, StampedPathEffectStyle.Rotate)
 }
 
+private fun DrawScope.drawBodyIcon(
+    azimDeg: Double,
+    elevDeg: Double,
+    radius: Float,
+    color: Color,
+    painter: Painter,
+    iconSize: Float
+) {
+    val azimRad = azimDeg.toRadians()
+    val elevRad = elevDeg.toRadians()
+    val pos = sph2Cart(azimRad, elevRad, radius.toDouble())
+    val half = iconSize / 2f
+    withTransform({
+        translate(pos.x - half, pos.y - half)
+    }) {
+        with(painter) {
+            draw(Size(iconSize, iconSize), colorFilter = androidx.compose.ui.graphics.ColorFilter.tint(color))
+        }
+    }
+}
+
 private fun sph2Cart(azim: Double, elev: Double, r: Double): Offset {
     val radius = r * (PI_2 - elev) / PI_2
     return Offset(

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

@@ -17,17 +17,15 @@
  */
 package com.rtbishop.look4sat.feature.radar
 
-import androidx.lifecycle.SavedStateHandle
 import androidx.lifecycle.ViewModel
-import androidx.lifecycle.ViewModelProvider
-import androidx.lifecycle.createSavedStateHandle
 import androidx.lifecycle.viewModelScope
 import androidx.lifecycle.viewmodel.initializer
 import androidx.lifecycle.viewmodel.viewModelFactory
 import com.rtbishop.look4sat.core.domain.model.SatRadio
+import com.rtbishop.look4sat.core.domain.predict.CelestialComputer
 import com.rtbishop.look4sat.core.domain.predict.OrbitalObject
 import com.rtbishop.look4sat.core.domain.predict.OrbitalPos
-import com.rtbishop.look4sat.core.domain.repository.IContainerProvider
+import com.rtbishop.look4sat.core.domain.repository.IMainContainer
 import com.rtbishop.look4sat.core.domain.repository.IReporter
 import com.rtbishop.look4sat.core.domain.repository.ISatelliteRepo
 import com.rtbishop.look4sat.core.domain.repository.ISensorsRepo
@@ -45,7 +43,8 @@ import kotlinx.coroutines.isActive
 import kotlinx.coroutines.launch
 
 class RadarViewModel(
-    private val savedStateHandle: SavedStateHandle,
+    private val catNum: Int,
+    private val aosTime: Long,
     private val bluetoothReporter: IReporter,
     private val networkReporter: IReporter,
     private val satelliteRepo: ISatelliteRepo,
@@ -85,8 +84,6 @@ class RadarViewModel(
         }
         // Resolve which pass we're tracking and start the tick loop
         viewModelScope.launch {
-            val catNum = savedStateHandle.get<Int>("catNum") ?: 0
-            val aosTime = savedStateHandle.get<Long>("aosTime") ?: 0L
             val passes = satelliteRepo.passes.value
             val currentPass = passes.find { it.catNum == catNum && it.aosTime == aosTime }
                 ?: passes.firstOrNull()
@@ -104,8 +101,20 @@ class RadarViewModel(
                 while (isActive) {
                     val timeNow = System.currentTimeMillis()
                     val pos = satelliteRepo.getPosition(satPass.orbitalObject, stationPos, timeNow)
+                    val sunPos = CelestialComputer.getSunPosition(stationPos, timeNow)
+                    val moonPos = CelestialComputer.getMoonPosition(stationPos, timeNow)
                     val (time, isAos) = computeTimer(satPass.isDeepSpace, satPass.aosTime, satPass.losTime, timeNow)
-                    _uiState.update { it.copy(currentTime = time, isCurrentTimeAos = isAos, orbitalPos = pos) }
+                    val isLos = !satPass.isDeepSpace && timeNow > satPass.losTime
+                    _uiState.update {
+                        it.copy(
+                            currentTime = time,
+                            isTimeAos = isAos,
+                            isLos = isLos,
+                            orbitalPos = pos,
+                            sunPosition = sunPos,
+                            moonPosition = moonPos
+                        )
+                    }
                     processRadios(transmitters, satPass.orbitalObject, timeNow)
                     sendPassData(pos)
                     delay(1000)
@@ -204,18 +213,17 @@ class RadarViewModel(
     }
 
     companion object {
-        val Factory: ViewModelProvider.Factory = viewModelFactory {
-            val applicationKey = ViewModelProvider.AndroidViewModelFactory.APPLICATION_KEY
+        fun factory(catNum: Int, aosTime: Long, container: IMainContainer) = viewModelFactory {
             initializer {
-                val container = (this[applicationKey] as IContainerProvider).getMainContainer()
                 RadarViewModel(
-                    createSavedStateHandle(),
-                    container.provideBluetoothReporter(),
-                    container.provideNetworkReporter(),
-                    container.satelliteRepo,
-                    container.settingsRepo,
-                    container.provideSensorsRepo(),
-                    container.provideAddToCalendar()
+                    catNum = catNum,
+                    aosTime = aosTime,
+                    bluetoothReporter = container.provideBluetoothReporter(),
+                    networkReporter = container.provideNetworkReporter(),
+                    satelliteRepo = container.satelliteRepo,
+                    settingsRepo = container.settingsRepo,
+                    sensorsRepo = container.provideSensorsRepo(),
+                    addToCalendar = container.provideAddToCalendar()
                 )
             }
         }

feature/radiocontrol/src/main/java/com/rtbishop/look4sat/feature/radiocontrol/RadioControlScreen.kt

@@ -45,21 +45,19 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.keepScreenOn
+import androidx.compose.ui.platform.LocalContext
 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.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.lifecycle.viewmodel.compose.viewModel
-import androidx.navigation.NavGraphBuilder
-import androidx.navigation.compose.composable
-import androidx.navigation.navArgument
 import com.rtbishop.look4sat.core.domain.model.SatRadio
+import com.rtbishop.look4sat.core.domain.repository.IContainerProvider
 import com.rtbishop.look4sat.core.presentation.CardButton
 import com.rtbishop.look4sat.core.presentation.IconCard
 import com.rtbishop.look4sat.core.presentation.NextPassRow
 import com.rtbishop.look4sat.core.presentation.R
-import com.rtbishop.look4sat.core.presentation.Screen
 import com.rtbishop.look4sat.core.presentation.TimerRow
 import com.rtbishop.look4sat.core.presentation.TopBar
 import com.rtbishop.look4sat.core.presentation.getDefaultPass
@@ -67,17 +65,17 @@ import com.rtbishop.look4sat.core.presentation.isVerticalLayout
 import com.rtbishop.look4sat.core.presentation.layoutPadding
 import java.util.Locale
 
-fun NavGraphBuilder.radioControlDestination(navigateUp: () -> Unit) {
-    val route = "${Screen.RadioControl.route}?catNum={catNum}&aosTime={aosTime}"
-    val args = listOf(
-        navArgument("catNum") { defaultValue = 0 },
-        navArgument("aosTime") { defaultValue = 0L }
+@Composable
+fun RadioControlDestination(catNum: Int = 0, aosTime: Long = 0L, navigateUp: () -> Unit) {
+    val context = LocalContext.current
+    val container = (context.applicationContext as IContainerProvider).getMainContainer()
+    val viewModel = viewModel(
+        modelClass = RadioControlViewModel::class.java,
+        key = "$catNum-$aosTime",
+        factory = RadioControlViewModel.factory(catNum, aosTime, container)
     )
-    composable(route, args) {
-        val viewModel = viewModel(RadioControlViewModel::class.java, factory = RadioControlViewModel.Factory)
-        val uiState by viewModel.uiState.collectAsStateWithLifecycle()
-        RadioControlScreen(uiState, viewModel::onAction, navigateUp)
-    }
+    val uiState by viewModel.uiState.collectAsStateWithLifecycle()
+    RadioControlScreen(uiState, viewModel::onAction, navigateUp)
 }
 
 @Composable

feature/radiocontrol/src/main/java/com/rtbishop/look4sat/feature/radiocontrol/RadioControlViewModel.kt

@@ -17,16 +17,13 @@
  */
 package com.rtbishop.look4sat.feature.radiocontrol
 
-import androidx.lifecycle.SavedStateHandle
 import androidx.lifecycle.ViewModel
-import androidx.lifecycle.ViewModelProvider
-import androidx.lifecycle.createSavedStateHandle
 import androidx.lifecycle.viewModelScope
 import androidx.lifecycle.viewmodel.initializer
 import androidx.lifecycle.viewmodel.viewModelFactory
 import com.rtbishop.look4sat.core.domain.model.SatRadio
 import com.rtbishop.look4sat.core.domain.predict.OrbitalPass
-import com.rtbishop.look4sat.core.domain.repository.IContainerProvider
+import com.rtbishop.look4sat.core.domain.repository.IMainContainer
 import com.rtbishop.look4sat.core.domain.repository.IRadioTrackingService
 import com.rtbishop.look4sat.core.domain.repository.ISatelliteRepo
 import com.rtbishop.look4sat.core.domain.repository.ISettingsRepo
@@ -41,7 +38,8 @@ import kotlinx.coroutines.launch
 import java.util.Locale
 
 class RadioControlViewModel(
-    savedStateHandle: SavedStateHandle,
+    private val catNum: Int,
+    private val aosTime: Long,
     private val trackingService: IRadioTrackingService,
     private val satelliteRepo: ISatelliteRepo,
     settingsRepo: ISettingsRepo
@@ -72,9 +70,6 @@ class RadioControlViewModel(
     val uiState: StateFlow<RadioControlState> = _uiState
 
     init {
-        val catNum = savedStateHandle.get<Int>("catNum") ?: 0
-        val aosTime = savedStateHandle.get<Long>("aosTime") ?: 0L
-
         // Resolve pass and load transponders
         viewModelScope.launch {
             val passes = satelliteRepo.passes.value
@@ -177,10 +172,12 @@ class RadioControlViewModel(
 
     companion object {
 
-        val CTCSS_TONES = listOf(67.0, 69.3, 71.9, 74.4, 77.0, 79.7, 82.5, 85.4, 88.5, 91.5,
+        val CTCSS_TONES = listOf(
+            67.0, 69.3, 71.9, 74.4, 77.0, 79.7, 82.5, 85.4, 88.5, 91.5,
             94.8, 97.4, 100.0, 103.5, 107.2, 110.9, 114.8, 118.8, 123.0, 127.3, 131.8, 136.5,
             141.3, 146.2, 151.4, 156.7, 162.2, 167.9, 173.8, 179.9, 186.2, 192.8, 203.5, 210.7,
-            218.1, 225.7, 233.6, 241.8, 250.3)
+            218.1, 225.7, 233.6, 241.8, 250.3
+        )
 
         fun formatFrequency(frequencyHz: Long): String {
             if (frequencyHz <= 0) return "---"
@@ -190,15 +187,14 @@ class RadioControlViewModel(
             return String.format(Locale.ENGLISH, "%d.%03d.%03d", mhz, khz, hz)
         }
 
-        val Factory: ViewModelProvider.Factory = viewModelFactory {
-            val applicationKey = ViewModelProvider.AndroidViewModelFactory.APPLICATION_KEY
+        fun factory(catNum: Int, aosTime: Long, container: IMainContainer) = viewModelFactory {
             initializer {
-                val container = (this[applicationKey] as IContainerProvider).getMainContainer()
                 RadioControlViewModel(
-                    createSavedStateHandle(),
-                    container.radioTrackingService,
-                    container.satelliteRepo,
-                    container.settingsRepo
+                    catNum = catNum,
+                    aosTime = aosTime,
+                    trackingService = container.radioTrackingService,
+                    satelliteRepo = container.satelliteRepo,
+                    settingsRepo = container.settingsRepo
                 )
             }
         }

feature/satellites/src/main/java/com/rtbishop/look4sat/feature/satellites/SatellitesScreen.kt

@@ -44,6 +44,7 @@ import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.SolidColor
+import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.semantics.contentDescription
@@ -56,9 +57,8 @@ import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.lifecycle.viewmodel.compose.viewModel
-import androidx.navigation.NavGraphBuilder
-import androidx.navigation.compose.composable
 import com.rtbishop.look4sat.core.domain.model.SatItem
+import com.rtbishop.look4sat.core.domain.repository.IContainerProvider
 import com.rtbishop.look4sat.core.presentation.CardLoadingIndicator
 import com.rtbishop.look4sat.core.presentation.EmptyListCard
 import com.rtbishop.look4sat.core.presentation.IconCard
@@ -66,20 +66,21 @@ import com.rtbishop.look4sat.core.presentation.InfoDialog
 import com.rtbishop.look4sat.core.presentation.MainTheme
 import com.rtbishop.look4sat.core.presentation.PrimaryIconCard
 import com.rtbishop.look4sat.core.presentation.R
-import com.rtbishop.look4sat.core.presentation.Screen
 import com.rtbishop.look4sat.core.presentation.TopBar
 import com.rtbishop.look4sat.core.presentation.infiniteMarquee
 import com.rtbishop.look4sat.core.presentation.isVerticalLayout
 import com.rtbishop.look4sat.core.presentation.layoutPadding
 
-fun NavGraphBuilder.satellitesDestination(navigateUp: () -> Unit) {
-    composable(Screen.Satellites.route) {
-        val viewModel = viewModel(
-            modelClass = SatellitesViewModel::class.java, factory = SatellitesViewModel.Factory
-        )
-        val uiState = viewModel.uiState.collectAsStateWithLifecycle().value
-        SatellitesScreen(uiState, viewModel::onAction, navigateUp)
-    }
+@Composable
+fun SatellitesDestination(navigateUp: () -> Unit) {
+    val context = LocalContext.current
+    val container = (context.applicationContext as IContainerProvider).getMainContainer()
+    val viewModel = viewModel(
+        modelClass = SatellitesViewModel::class.java,
+        factory = SatellitesViewModel.factory(container)
+    )
+    val uiState = viewModel.uiState.collectAsStateWithLifecycle().value
+    SatellitesScreen(uiState, viewModel::onAction, navigateUp)
 }
 
 @Composable

feature/satellites/src/main/java/com/rtbishop/look4sat/feature/satellites/SatellitesViewModel.kt

@@ -18,11 +18,10 @@
 package com.rtbishop.look4sat.feature.satellites
 
 import androidx.lifecycle.ViewModel
-import androidx.lifecycle.ViewModelProvider
 import androidx.lifecycle.viewModelScope
 import androidx.lifecycle.viewmodel.initializer
 import androidx.lifecycle.viewmodel.viewModelFactory
-import com.rtbishop.look4sat.core.domain.repository.IContainerProvider
+import com.rtbishop.look4sat.core.domain.repository.IMainContainer
 import com.rtbishop.look4sat.core.domain.repository.ISelectionRepo
 import com.rtbishop.look4sat.core.domain.repository.ISettingsRepo
 import kotlinx.coroutines.flow.MutableStateFlow
@@ -97,11 +96,12 @@ class SatellitesViewModel(
     }
 
     companion object {
-        val Factory: ViewModelProvider.Factory = viewModelFactory {
-            val applicationKey = ViewModelProvider.AndroidViewModelFactory.APPLICATION_KEY
+        fun factory(container: IMainContainer) = viewModelFactory {
             initializer {
-                val container = (this[applicationKey] as IContainerProvider).getMainContainer()
-                SatellitesViewModel(container.selectionRepo, container.settingsRepo)
+                SatellitesViewModel(
+                    selectionRepo = container.selectionRepo,
+                    settingsRepo = container.settingsRepo
+                )
             }
         }
     }

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

@@ -51,6 +51,7 @@ 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.platform.LocalContext
 import androidx.compose.ui.platform.LocalUriHandler
 import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
@@ -60,16 +61,14 @@ import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.lifecycle.viewmodel.compose.viewModel
-import androidx.navigation.NavGraphBuilder
-import androidx.navigation.compose.composable
 import com.rtbishop.look4sat.core.domain.model.OtherSettings
 import com.rtbishop.look4sat.core.domain.predict.GeoPos
+import com.rtbishop.look4sat.core.domain.repository.IContainerProvider
 import com.rtbishop.look4sat.core.presentation.CardButton
 import com.rtbishop.look4sat.core.presentation.IconCard
 import com.rtbishop.look4sat.core.presentation.MainTheme
 import com.rtbishop.look4sat.core.presentation.PrimaryIconCard
 import com.rtbishop.look4sat.core.presentation.R
-import com.rtbishop.look4sat.core.presentation.Screen
 import com.rtbishop.look4sat.core.presentation.ScreenColumn
 import com.rtbishop.look4sat.core.presentation.TopBar
 import com.rtbishop.look4sat.core.presentation.infiniteMarquee
@@ -78,15 +77,16 @@ import java.text.SimpleDateFormat
 import java.util.Date
 import java.util.Locale
 
-fun NavGraphBuilder.settingsDestination() {
-    composable(Screen.Settings.route) {
-        val viewModel = viewModel(
-            modelClass = SettingsViewModel::class.java,
-            factory = SettingsViewModel.Factory
-        )
-        val uiState by viewModel.uiState.collectAsStateWithLifecycle()
-        SettingsScreen(uiState, viewModel::onAction)
-    }
+@Composable
+fun SettingsDestination() {
+    val context = LocalContext.current
+    val container = (context.applicationContext as IContainerProvider).getMainContainer()
+    val viewModel = viewModel(
+        modelClass = SettingsViewModel::class.java,
+        factory = SettingsViewModel.factory(container)
+    )
+    val uiState by viewModel.uiState.collectAsStateWithLifecycle()
+    SettingsScreen(uiState, viewModel::onAction)
 }
 
 @Composable
@@ -426,6 +426,7 @@ private fun OtherCardPreview() = MainTheme {
         stateOfSweep = true,
         stateOfUtc = false,
         stateOfLightTheme = false,
+        stateOfNightMode = false,
         shouldSeeWarning = false,
         shouldSeeWhatsNew = false
     )
@@ -437,7 +438,7 @@ private fun OtherCard(settings: OtherSettings, onAction: (SettingsAction) -> Uni
     ElevatedCard(
         modifier = Modifier
             .fillMaxWidth()
-            .height(220.dp)
+            .height(268.dp)
     ) {
         Column(modifier = Modifier.padding(horizontal = 8.dp, vertical = 4.dp)) {
             Text(
@@ -456,6 +457,9 @@ private fun OtherCard(settings: OtherSettings, onAction: (SettingsAction) -> Uni
             SwitchRow(R.string.prefs_other_switch_sensors, settings.stateOfSensors) {
                 onAction(SettingsAction.ToggleSensor(it))
             }
+            SwitchRow(R.string.prefs_other_switch_night_mode, settings.stateOfNightMode) {
+                onAction(SettingsAction.ToggleNightMode(it))
+            }
         }
     }
 }
@@ -506,7 +510,7 @@ private fun CardCredits(modifier: Modifier = Modifier) {
     ElevatedCard(
         modifier = modifier
             .fillMaxWidth()
-            .height(220.dp)
+            .height(268.dp)
     ) {
         Column(
             verticalArrangement = Arrangement.SpaceBetween,

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

@@ -60,6 +60,7 @@ sealed interface SettingsAction {
     data class ToggleSweep(val value: Boolean) : SettingsAction
     data class ToggleSensor(val value: Boolean) : SettingsAction
     data class ToggleLightTheme(val value: Boolean) : SettingsAction
+    data class ToggleNightMode(val value: Boolean) : SettingsAction
 
     // Remote control
     data class UpdateRC(val settings: RCSettings) : SettingsAction

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

@@ -18,12 +18,11 @@
 package com.rtbishop.look4sat.feature.settings
 
 import androidx.lifecycle.ViewModel
-import androidx.lifecycle.ViewModelProvider
 import androidx.lifecycle.viewModelScope
 import androidx.lifecycle.viewmodel.initializer
 import androidx.lifecycle.viewmodel.viewModelFactory
-import com.rtbishop.look4sat.core.domain.repository.IContainerProvider
 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.usecase.IShowToast
 import com.rtbishop.look4sat.core.presentation.R
@@ -121,6 +120,7 @@ class SettingsViewModel(
             is SettingsAction.ToggleSweep -> settingsRepo.updateOtherSettings { it.copy(stateOfSweep = action.value) }
             is SettingsAction.ToggleSensor -> settingsRepo.updateOtherSettings { it.copy(stateOfSensors = action.value) }
             is SettingsAction.ToggleLightTheme -> settingsRepo.updateOtherSettings { it.copy(stateOfLightTheme = action.value) }
+            is SettingsAction.ToggleNightMode -> settingsRepo.updateOtherSettings { it.copy(stateOfNightMode = action.value) }
             // Remote control & data sources
             is SettingsAction.UpdateRC -> settingsRepo.updateRCSettings(action.settings)
             is SettingsAction.UpdateRadioControl -> settingsRepo.updateRadioControlSettings(action.settings)
@@ -187,14 +187,12 @@ class SettingsViewModel(
     // endregion
 
     companion object {
-        val Factory: ViewModelProvider.Factory = viewModelFactory {
-            val applicationKey = ViewModelProvider.AndroidViewModelFactory.APPLICATION_KEY
+        fun factory(container: IMainContainer) = viewModelFactory {
             initializer {
-                val container = (this[applicationKey] as IContainerProvider).getMainContainer()
                 SettingsViewModel(
-                    container.databaseRepo,
-                    container.settingsRepo,
-                    container.provideShowToast()
+                    databaseRepo = container.databaseRepo,
+                    settingsRepo = container.settingsRepo,
+                    showToast = container.provideShowToast()
                 )
             }
         }

gradle/libs.versions.toml

@@ -1,8 +1,8 @@
 [versions]
 #noinspection UnusedVersionCatalogEntry
-appVersionCode = "421"
+appVersionCode = "430"
 #noinspection UnusedVersionCatalogEntry
-appVersionName = "4.2.1"
+appVersionName = "4.3.0"
 #noinspection GradleDependency,UnusedVersionCatalogEntry
 compileSdk = "36"
 #noinspection UnusedVersionCatalogEntry
@@ -12,21 +12,23 @@ jdkVersion = "17"
 #noinspection UnusedVersionCatalogEntry
 packageName = "com.rtbishop.look4sat"
 
-android-gradle-plugin = "9.1.1"
-google-ksp = "2.3.6"
-kotlin = "2.3.20"
+android-gradle-plugin = "9.2.0"
 
 androidx-core-ktx = "1.18.0"
 androidx-core-splashscreen = "1.2.0"
 androidx-room = "2.8.4"
 
-compose-bom = "2026.03.01"
+compose-bom = "2026.04.01"
 compose-activity = "1.13.0"
 compose-lifecycle = "2.10.0"
-compose-navigation = "2.9.7"
+compose-navigation3 = "1.1.1"
+
+google-ksp = "2.3.6"
+
+kotlin = "2.3.21"
+kotlin-coroutines = "1.10.2"
+kotlin-serialization = "1.11.0"
 
-other-coroutines = "1.10.2"
-other-json = "20251224"
 other-okhttp = "5.3.2"
 other-osmdroid = "6.1.20"
 
@@ -50,32 +52,32 @@ androidx-room-runtime = { module = "androidx.room:room-runtime", version.ref = "
 
 #noinspection UnusedVersionCatalogEntry
 compose-bom = { group = "androidx.compose", name = "compose-bom", version.ref = "compose-bom" }
-compose-animation = { group = "androidx.compose.animation", name = "animation" }
 compose-material3 = { group = "androidx.compose.material3", name = "material3" }
-compose-material3-navigation = { group = "androidx.compose.material3", name = "material3-adaptive-navigation-suite" }
+#noinspection UnusedVersionCatalogEntry
+compose-material3-adaptive = { group = "androidx.compose.material3", name = "material3-adaptive-navigation-suite" }
 compose-runtime = { group = "androidx.compose.runtime", name = "runtime" }
 compose-tooling = { group = "androidx.compose.ui", name = "ui-tooling-preview" }
 
 compose-activity = { module = "androidx.activity:activity-compose", version.ref = "compose-activity" }
-compose-lifecycle = { module = "androidx.lifecycle:lifecycle-runtime-compose", version.ref = "compose-lifecycle" }
-compose-navigation = { module = "androidx.navigation:navigation-compose", version.ref = "compose-navigation" }
-compose-viewmodel = { module = "androidx.lifecycle:lifecycle-viewmodel-compose", version.ref = "compose-lifecycle" }
+#noinspection UnusedVersionCatalogEntry
+compose-navigation3 = { module = "androidx.navigation3:navigation3-ui", version.ref = "compose-navigation3" }
+compose-viewmodel = { module = "androidx.lifecycle:lifecycle-viewmodel-navigation3", version.ref = "compose-lifecycle" }
 
 compose-debug-manifest = { group = "androidx.compose.ui", name = "ui-test-manifest" }
 compose-debug-tooling = { group = "androidx.compose.ui", name = "ui-tooling" }
 
-kotlin-gradlePlugin = { group = "org.jetbrains.kotlin", name = "kotlin-gradle-plugin", version.ref = "kotlin" }
+#noinspection UnusedVersionCatalogEntry
+kotlin-coroutines = { module = "org.jetbrains.kotlinx:kotlinx-coroutines-core", version.ref = "kotlin-coroutines" }
+kotlin-gradlePlugin = { module = "org.jetbrains.kotlin:kotlin-gradle-plugin", version.ref = "kotlin" }
+#noinspection UnusedVersionCatalogEntry
+kotlin-serialization = { module = "org.jetbrains.kotlinx:kotlinx-serialization-json", version.ref = "kotlin-serialization" }
 
-#noinspection UnusedVersionCatalogEntry
-other-coroutines = { module = "org.jetbrains.kotlinx:kotlinx-coroutines-core", version.ref = "other-coroutines" }
-#noinspection UnusedVersionCatalogEntry
-other-json = { module = "org.json:json", version.ref = "other-json" }
 #noinspection UnusedVersionCatalogEntry
 other-okhttp = { module = "com.squareup.okhttp3:okhttp", version.ref = "other-okhttp" }
 #noinspection UnusedVersionCatalogEntry
 other-osmdroid = { module = "org.osmdroid:osmdroid-android", version.ref = "other-osmdroid" }
 
-test-coroutines = { module = "org.jetbrains.kotlinx:kotlinx-coroutines-test", version.ref = "other-coroutines" }
+test-coroutines = { module = "org.jetbrains.kotlinx:kotlinx-coroutines-test", version.ref = "kotlin-coroutines" }
 test-junit4 = { module = "junit:junit", version.ref = "test-junit4" }
 
 androidTest-junit = { module = "androidx.test.ext:junit", version.ref = "androidTest-junit" }
@@ -87,6 +89,7 @@ android-library = { id = "com.android.library", version.ref = "android-gradle-pl
 compose-compiler = { id = "org.jetbrains.kotlin.plugin.compose", version.ref = "kotlin" }
 google-ksp = { id = "com.google.devtools.ksp", version.ref = "google-ksp" }
 kotlin-jvm = { id = "org.jetbrains.kotlin.jvm", version.ref = "kotlin" }
+kotlin-serialization = { id = "org.jetbrains.kotlin.plugin.serialization", version.ref = "kotlin" }
 # plugins defined by this project
 convention-applicationPlugin = { id = "com.rtbishop.look4sat.convention.applicationPlugin" }
 convention-coreDataPlugin = { id = "com.rtbishop.look4sat.convention.coreDataPlugin" }
@@ -96,11 +99,7 @@ convention-featurePlugin = { id = "com.rtbishop.look4sat.convention.featurePlugi
 
 [bundles]
 #noinspection UnusedVersionCatalogEntry
-composeAll = [
-    "compose-animation", "compose-runtime", "compose-tooling",
-    "compose-activity", "compose-lifecycle", "compose-material3",
-    "compose-material3-navigation", "compose-navigation", "compose-viewmodel"
-]
+composeAll = ["compose-runtime", "compose-tooling", "compose-activity", "compose-material3", "compose-viewmodel"]
 #noinspection UnusedVersionCatalogEntry
 composeDebug = ["compose-debug-manifest", "compose-debug-tooling"]
 #noinspection UnusedVersionCatalogEntry

gradle/wrapper/gradle-wrapper.properties

@@ -1,7 +1,7 @@
-#Sun Mar 22 10:09:53 GMT 2026
+#Tue Apr 28 15:46:23 BST 2026
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-9.4.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.5.0-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME