build: release version 4.4.8-ba7opf.2.4 (549)

generatePost 的筛选从最近 24 小时改为当前过境窗口（aos..los），
与日志列表 recent 同一套过滤逻辑，不再混入其他过境的 QSO

README.md

@@ -4,6 +4,8 @@
 
 **BA7OPF 定制版** — 基于 [rt-bishop/Look4Sat](https://github.com/rt-bishop/Look4Sat) 的业余无线电卫星追踪器，增加了线性卫星频率计算器等功能。
 
+非官方修改版（fork），独立维护；首次发布 2026-09，持续修改中。
+
 ## 本仓库特色功能
 
 - **网格地图模式（Grid Mode）** — 地图页内置 VUCC 网格覆盖图：已通联网格绿色填充、漫游网格蓝色 45° 斜纹（疏朗半透明样式）、当前所在方格淡黄加粗框；点击已通联网格弹出该网格内通联明细弹窗；进入网格模式默认 VUCC 视图

THIRD_PARTY_NOTICES.md

@@ -0,0 +1,46 @@
+# Third-Party Notices
+
+Look4Sat-BA7OPF (this fork) bundles or adapts the following third-party
+components:
+
+## OrbitDeckiOS
+
+- Source: https://github.com/prstoetzer/OrbitDeckiOS
+- Copyright (c) 2025 Paul Stoetzer, N8HM
+- License: MIT
+- Used for: the Grid Finder feature — the VUCC grid line / grid point
+  geometry in `core/domain/.../utility/GridGeometry.kt` is ported from
+  OrbitDeckiOS' GridGeometry.
+
+### MIT License
+
+```
+MIT License
+
+Copyright (c) 2025 Paul Stoetzer, N8HM
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+```
+
+## Material Design Icons
+
+- Source: https://materialdesignicons.com (Pictogrammers)
+- License: Apache-2.0
+- Used for: `core/presentation/src/main/res/drawable/ic_grid_finder.xml`
+  (crosshairs-gps icon). Attribution is also noted in the icon file header.

app/src/main/AndroidManifest.xml

@@ -44,7 +44,7 @@
 
         <meta-data
             android:name="android.telephony.PROPERTY_SATELLITE_DATA_OPTIMIZED"
-            android:value="com.rtbishop.look4sat" />
+            android:value="cn.ba7opf.look4sat" />
 
         <provider
             android:name="androidx.core.content.FileProvider"

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

@@ -27,7 +27,9 @@ import android.view.View
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
+import androidx.compose.runtime.getValue
 import androidx.core.splashscreen.SplashScreen.Companion.installSplashScreen
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.lifecycle.lifecycleScope
 import com.rtbishop.look4sat.core.domain.repository.IContainerProvider
 import com.rtbishop.look4sat.core.presentation.MainTheme
@@ -47,9 +49,12 @@ class MainActivity : ComponentActivity() {
         installSplashScreen()
         enableEdgeToEdge()
         super.onCreate(savedInstanceState)
+        val settingsRepo = (applicationContext as IContainerProvider).getMainContainer().settingsRepo
         observeNightFilterState()
         setContent {
-            MainTheme(isDarkTheme = true) { NavRoot() }
+            val otherSettings by settingsRepo.otherSettings.collectAsStateWithLifecycle()
+            // Light theme is opt-in: the app stays dark until the user turns it on.
+            MainTheme(isDarkTheme = !otherSettings.stateOfLightTheme) { NavRoot() }
         }
     }
 

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

@@ -26,6 +26,7 @@ import com.rtbishop.look4sat.core.domain.repository.IContainerProvider
 import com.rtbishop.look4sat.core.domain.repository.IMainContainer
 import com.rtbishop.look4sat.core.domain.repository.LoTWSyncMode
 import com.rtbishop.look4sat.core.domain.repository.LoTWResult
+import com.rtbishop.look4sat.core.domain.logbook.toConfirmedRecord
 import com.rtbishop.look4sat.core.domain.repository.applyLoTWGridResult
 import com.rtbishop.look4sat.core.domain.repository.lotwCursorApi
 import com.rtbishop.look4sat.core.domain.repository.lotwSyncToday
@@ -50,6 +51,9 @@ class MainApplication : Application(), IContainerProvider {
         container.appScope.launch { checkAutoUpdate() }
         // automatic LoTW grid sync on every app start (gated, see checkLoTWAutoSync)
         container.appScope.launch { checkLoTWAutoSync() }
+        // repair logbooks split by the old name/band identity mismatch, independent of
+        // whether a sync is due (cheap read + in-memory match on every start)
+        container.appScope.launch { runCatching { container.qsoRepository.consolidateConfirmations() } }
         // load satellite data on every app start
         container.appScope.launch { container.satelliteRepo.initRepository() }
     }
@@ -116,6 +120,11 @@ class MainApplication : Application(), IContainerProvider {
         val result = container.lotwRepo.fetchConfirmedGridQsos(callsign, lotwSettings.password, since)
         if (result is LoTWResult.Success) {
             val count = applyLoTWGridResult(settingsRepo, result, mode, callsign, timeNow)
+            // Feed the logbook so confirmations appear and local uploads get matched.
+            runCatching {
+                val confirmed = result.qsos.values.flatten().map { it.toConfirmedRecord(callsign) }
+                container.qsoRepository.mergeLoTW(confirmed)
+            }
             println("Periodic LoTW grid sync finished: $count worked grids")
         } else {
             println("Periodic LoTW grid sync skipped (${result::class.simpleName})")

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

@@ -75,11 +75,14 @@ import com.rtbishop.look4sat.core.domain.repository.IContainerProvider
 import com.rtbishop.look4sat.core.domain.repository.MutualPassData
 import com.rtbishop.look4sat.core.presentation.DeeplinkResolver
 import com.rtbishop.look4sat.core.presentation.ElevationThresholds
+import com.rtbishop.look4sat.core.presentation.GridFinderDestination
 import com.rtbishop.look4sat.core.presentation.LocalElevationThresholds
+import com.rtbishop.look4sat.core.presentation.LoTWUploadDestination
 import com.rtbishop.look4sat.core.presentation.RadarDestination
 import com.rtbishop.look4sat.core.presentation.Screen
 import com.rtbishop.look4sat.core.presentation.hasEnoughHeight
 import com.rtbishop.look4sat.core.presentation.hasEnoughWidth
+import com.rtbishop.look4sat.feature.gridfinder.GridFinderDestination
 import com.rtbishop.look4sat.feature.map.MapDestination
 import com.rtbishop.look4sat.feature.map.MapFilterViewModel
 import com.rtbishop.look4sat.feature.mutual.MutualScreen
@@ -88,6 +91,7 @@ import com.rtbishop.look4sat.feature.passes.PassesDestination
 import com.rtbishop.look4sat.feature.radar.RadarDestination
 import com.rtbishop.look4sat.feature.satellites.SatellitesDestination
 import com.rtbishop.look4sat.feature.settings.SettingsDestination
+import com.rtbishop.look4sat.feature.settings.LoTWUploadDestination
 import com.rtbishop.look4sat.feature.status.SatStatusDestination
 
 @Composable
@@ -99,6 +103,8 @@ fun NavRoot(deeplink: String? = null) {
     }
     val navigateBack: () -> Unit = { rootBackStack.removeLastOrNull() }
     val navigateToRadar: () -> Unit = { rootBackStack.add(RadarDestination) }
+    val navigateToGridFinder: () -> Unit = { rootBackStack.add(GridFinderDestination) }
+    val navigateToLoTWStation: () -> Unit = { rootBackStack.add(LoTWUploadDestination) }
     // Incoming screen slides in from the right, outgoing drifts left at 1/3 speed (API35+ style)
     val pushTransition = slideInHorizontally(tween(300)) { it } togetherWith
         slideOutHorizontally(tween(300)) { -it / 3 }
@@ -132,7 +138,8 @@ fun NavRoot(deeplink: String? = null) {
             entryProvider = entryProvider {
                 entry<Screen.Passes> {
                     MainScreen(
-                        navigateToRadar = navigateToRadar
+                        navigateToRadar = navigateToRadar,
+                        navigateToGridFinder = navigateToGridFinder
                     )
                 }
                 entry<RadarDestination> {
@@ -143,6 +150,25 @@ fun NavRoot(deeplink: String? = null) {
                         RadarDestination(navigateUp = navigateBack)
                     }
                 }
+                entry<GridFinderDestination> {
+                    Surface(
+                        modifier = Modifier.fillMaxSize(),
+                        color = MaterialTheme.colorScheme.background
+                    ) {
+                        GridFinderDestination(
+                            navigateUp = navigateBack,
+                            onOpenLoTWStation = navigateToLoTWStation
+                        )
+                    }
+                }
+                entry<LoTWUploadDestination> {
+                    Surface(
+                        modifier = Modifier.fillMaxSize(),
+                        color = MaterialTheme.colorScheme.background
+                    ) {
+                        LoTWUploadDestination(navigateUp = navigateBack)
+                    }
+                }
             }
         )
     }
@@ -150,7 +176,8 @@ fun NavRoot(deeplink: String? = null) {
 
 @Composable
 fun MainScreen(
-    navigateToRadar: () -> Unit = {}
+    navigateToRadar: () -> Unit = {},
+    navigateToGridFinder: () -> Unit = {}
 ) {
     val backStack = rememberNavBackStack(Screen.Passes)
     val currentKey = backStack.lastOrNull()
@@ -291,7 +318,7 @@ fun MainScreen(
                         }
                         entry<Screen.AMSAT> { SatStatusDestination() }
                         entry<Screen.Settings> {
-                            SettingsDestination()
+                            SettingsDestination(onOpenGridFinder = navigateToGridFinder)
                         }
                     }
                 )

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

@@ -32,6 +32,7 @@ internal class ApplicationPlugin : Plugin<Project> {
             implementation(project(":core:domain"))
             implementation(project(":core:presentation"))
             implementation(project(":feature:map"))
+            implementation(project(":feature:gridfinder"))
             implementation(project(":feature:mutual"))
             implementation(project(":feature:passes"))
             implementation(project(":feature:radar"))

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

@@ -0,0 +1,50 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ */
+package com.rtbishop.look4sat.core.data.database
+
+import androidx.room.Dao
+import androidx.room.Insert
+import androidx.room.OnConflictStrategy
+import androidx.room.Query
+import androidx.room.Transaction
+import com.rtbishop.look4sat.core.data.database.entity.QsoEntity
+import kotlinx.coroutines.flow.Flow
+
+@Dao
+interface QsoDao {
+    @Query("SELECT * FROM qso_records ORDER BY startUtcMillis DESC, id DESC")
+    fun observeAll(): Flow<List<QsoEntity>>
+
+    @Query("SELECT * FROM qso_records WHERE id = :id LIMIT 1")
+    suspend fun find(id: Long): QsoEntity?
+
+    @Query("SELECT * FROM qso_records ORDER BY startUtcMillis DESC, id DESC")
+    suspend fun getAll(): List<QsoEntity>
+
+    @Query("SELECT dedupeKey FROM qso_records")
+    suspend fun getDedupeKeys(): List<String>
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun save(record: QsoEntity): Long
+
+    @Insert(onConflict = OnConflictStrategy.IGNORE)
+    suspend fun importRecords(records: List<QsoEntity>): List<Long>
+
+    @Transaction
+    suspend fun saveBatch(records: List<QsoEntity>) {
+        records.forEach { save(it) }
+    }
+
+    @Query("DELETE FROM qso_records WHERE id = :id")
+    suspend fun delete(id: Long)
+
+    @Query("UPDATE qso_records SET lotwUploaded = 1 WHERE id IN (:ids)")
+    suspend fun markUploaded(ids: List<Long>)
+}

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

@@ -0,0 +1,33 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ */
+package com.rtbishop.look4sat.core.data.database
+
+import androidx.room.Database
+import androidx.room.RoomDatabase
+import androidx.room.migration.Migration
+import androidx.sqlite.db.SupportSQLiteDatabase
+import com.rtbishop.look4sat.core.data.database.entity.QsoEntity
+
+/**
+ * Separate database for the logbook (QSO records, LoTW confirmations and
+ * upload receipts). Kept apart from [Look4SatDb] so existing installations
+ * never need a migration of the satellite database.
+ */
+@Database(entities = [QsoEntity::class], version = 2, exportSchema = false)
+abstract class QsoDatabase : RoomDatabase() {
+    abstract fun qsoDao(): QsoDao
+}
+
+/** v1 → v2: track whether a QSO was uploaded to LoTW (distinct from confirmed). */
+val MIGRATION_QSO_1_2 = object : Migration(1, 2) {
+    override fun migrate(db: SupportSQLiteDatabase) {
+        db.execSQL("ALTER TABLE qso_records ADD COLUMN lotwUploaded INTEGER NOT NULL DEFAULT 0")
+    }
+}

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

@@ -0,0 +1,55 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ */
+package com.rtbishop.look4sat.core.data.database.entity
+
+import androidx.room.ColumnInfo
+import androidx.room.Entity
+import androidx.room.Index
+import androidx.room.PrimaryKey
+
+@Entity(
+    tableName = "qso_records",
+    indices = [Index(value = ["dedupeKey"])]
+)
+data class QsoEntity(
+    @PrimaryKey(autoGenerate = true) val id: Long = 0L,
+    val startUtcMillis: Long,
+    val endUtcMillis: Long?,
+    val theirCallsign: String,
+    val myCallsign: String,
+    val theirGrid: String,
+    val myGrid: String,
+    val sentReport: String,
+    val receivedReport: String,
+    val txFrequencyHz: Long?,
+    val rxFrequencyHz: Long?,
+    val band: String,
+    val rxBand: String,
+    @ColumnInfo(defaultValue = "'MFSK'") val mode: String,
+    @ColumnInfo(defaultValue = "'FT4'") val submode: String,
+    val satelliteName: String,
+    val transponderName: String,
+    val satelliteMode: String,
+    val passAosUtcMillis: Long?,
+    val automatic: Boolean,
+    val status: String,
+    @ColumnInfo(defaultValue = "''") val dedupeKey: String,
+    @ColumnInfo(defaultValue = "''") val propagationMode: String = "",
+    @ColumnInfo(defaultValue = "0") val lotwConfirmed: Boolean = false,
+    @ColumnInfo(defaultValue = "0") val lotwUploaded: Boolean = false,
+    @ColumnInfo(defaultValue = "0") val lotwReceived: Boolean = false,
+    @ColumnInfo(defaultValue = "''") val lotwQslDate: String = "",
+    @ColumnInfo(defaultValue = "''") val vuccGrids: String = "",
+    val dxcc: Int? = null,
+    @ColumnInfo(defaultValue = "''") val country: String = "",
+    val cqZone: Int? = null,
+    @ColumnInfo(defaultValue = "''") val region: String = "",
+    @ColumnInfo(defaultValue = "''") val comment: String = ""
+)

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

@@ -330,12 +330,13 @@ object IcomCivProtocol {
 
     /**
      * Parse frequency + mode from a CMD_READ_FREQ reply payload.
-     * Payload layout after stripping command byte: [5 freq bytes] [mode byte] [filter byte]
+     * Payload layout after stripping command byte: [5 freq bytes]
+     * The IC-705 does not include a mode byte; if one is present it is parsed, otherwise mode is empty.
      */
     fun parseFreqModePayload(payload: ByteArray): Pair<Long, String>? {
-        if (payload.size < 6) return null
+        if (payload.size < 5) return null
         val freqHz = decodeFrequencyBcd(payload.copyOfRange(0, 5))
-        val mode   = BYTE_TO_MODE[payload[5]] ?: return null
+        val mode   = if (payload.size > 5) BYTE_TO_MODE[payload[5]] ?: return null else ""
         return freqHz to mode
     }
 

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

@@ -17,28 +17,36 @@
  */
 package com.rtbishop.look4sat.core.data.injection
 
+import android.Manifest
 import android.bluetooth.BluetoothManager
 import android.content.Context
+import android.content.pm.PackageManager
 import android.hardware.SensorManager
 import android.hardware.display.DisplayManager
 import android.location.LocationManager
+import androidx.core.content.ContextCompat
 import androidx.room.Room
 import com.rtbishop.look4sat.core.data.database.Look4SatDb
 import com.rtbishop.look4sat.core.data.database.MIGRATION_1_2
 import com.rtbishop.look4sat.core.data.database.MIGRATION_2_3
+import com.rtbishop.look4sat.core.data.database.MIGRATION_QSO_1_2
+import com.rtbishop.look4sat.core.data.database.QsoDatabase
 import com.rtbishop.look4sat.core.data.framework.BluetoothReporter
 import com.rtbishop.look4sat.core.data.framework.Ft817Controller
 import com.rtbishop.look4sat.core.data.framework.Ic705Controller
 import com.rtbishop.look4sat.core.data.framework.NetworkReporter
 import com.rtbishop.look4sat.core.data.framework.RadioTrackingService
+import com.rtbishop.look4sat.core.data.lotw.LoTWUploadRepository
 import com.rtbishop.look4sat.core.data.repository.AmSatRepository
 import com.rtbishop.look4sat.core.data.repository.DatabaseRepo
+import com.rtbishop.look4sat.core.data.repository.QsoRepository
 import com.rtbishop.look4sat.core.data.repository.SatelliteRepo
 import com.rtbishop.look4sat.core.data.repository.SelectionRepo
 import com.rtbishop.look4sat.core.data.repository.SensorsRepo
 import com.rtbishop.look4sat.core.data.repository.SettingsRepo
 import com.rtbishop.look4sat.core.data.repository.UpdateRepository
 import com.rtbishop.look4sat.core.data.repository.LoTWRepository
+import com.rtbishop.look4sat.core.data.repository.LocationRepo
 import com.rtbishop.look4sat.core.data.repository.WavelogRepository
 import com.rtbishop.look4sat.core.data.source.LocalSource
 import com.rtbishop.look4sat.core.data.source.RemoteSource
@@ -46,13 +54,16 @@ import com.rtbishop.look4sat.core.data.usecase.AddToCalendar
 import com.rtbishop.look4sat.core.data.usecase.AudioCapture
 import com.rtbishop.look4sat.core.data.usecase.SaveImage
 import com.rtbishop.look4sat.core.data.usecase.ShowToast
+import com.rtbishop.look4sat.core.domain.logbook.IQsoRepository
 import com.rtbishop.look4sat.core.domain.model.RadioControlSettings
 import com.rtbishop.look4sat.core.domain.repository.IDatabaseRepo
+import com.rtbishop.look4sat.core.domain.repository.ILoTWUploadRepository
 import com.rtbishop.look4sat.core.domain.repository.IMainContainer
 import com.rtbishop.look4sat.core.domain.repository.IRadioController
 import com.rtbishop.look4sat.core.domain.repository.IRadioTrackingService
 import com.rtbishop.look4sat.core.domain.repository.IReporter
 import com.rtbishop.look4sat.core.domain.repository.ILoTWRepository
+import com.rtbishop.look4sat.core.domain.repository.ILocationRepo
 import com.rtbishop.look4sat.core.domain.repository.ISatelliteRepo
 import com.rtbishop.look4sat.core.domain.repository.ISelectionRepo
 import com.rtbishop.look4sat.core.domain.repository.ISensorsRepo
@@ -90,17 +101,36 @@ class MainContainer(private val context: Context) : IMainContainer {
     override val updateRepo by lazy { UpdateRepository(remoteSource) }
     override val wavelogRepo: IWavelogRepository by lazy { WavelogRepository() }
     override val lotwRepo: ILoTWRepository by lazy { LoTWRepository() }
+    override val qsoRepository: IQsoRepository by lazy {
+        val database = Room.databaseBuilder(context, QsoDatabase::class.java, "Look4SatQsoDB")
+            .addMigrations(MIGRATION_QSO_1_2)
+            .build()
+        QsoRepository(database.qsoDao(), Dispatchers.IO)
+    }
+    override val lotwUploadRepository: ILoTWUploadRepository by lazy { LoTWUploadRepository(context) }
     override val radioTrackingService: IRadioTrackingService by lazy {
         val manager = context.getSystemService(Context.BLUETOOTH_SERVICE) as BluetoothManager
         RadioTrackingService(appScope, manager, satelliteRepo, settingsRepo)
     }
+    override val locationRepo: ILocationRepo by lazy {
+        val manager = context.getSystemService(Context.LOCATION_SERVICE) as LocationManager
+        LocationRepo(manager) {
+            ContextCompat.checkSelfPermission(context, Manifest.permission.ACCESS_FINE_LOCATION) ==
+                PackageManager.PERMISSION_GRANTED
+        }
+    }
 
     private val _mutualPassData = MutableStateFlow(MutualPassData())
     override val mutualPassData: StateFlow<MutualPassData> = _mutualPassData.asStateFlow()
+    private val _pendingLoTWStationGrid = MutableStateFlow<String?>(null)
+    override val pendingLoTWStationGrid: StateFlow<String?> = _pendingLoTWStationGrid.asStateFlow()
 
     override fun setMutualPassData(data: MutualPassData) {
         _mutualPassData.value = data
     }
+    override fun setPendingLoTWStationGrid(grid: String?) {
+        _pendingLoTWStationGrid.value = grid
+    }
 
     override fun provideAddToCalendar(): IAddToCalendar = AddToCalendar(context)
 

core/data/src/main/java/com/rtbishop/look4sat/core/data/lotw/LoTWConfig.kt

@@ -0,0 +1,195 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.data.lotw
+
+import com.rtbishop.look4sat.core.domain.logbook.QsoRecord
+import com.rtbishop.look4sat.core.domain.logbook.LoTWSatelliteAliases
+import com.rtbishop.look4sat.core.domain.logbook.displayMode
+import com.rtbishop.look4sat.core.domain.repository.LoTWProblem
+import com.rtbishop.look4sat.core.domain.repository.LoTWRegionField
+import com.rtbishop.look4sat.core.domain.repository.LoTWRegionOption
+import com.rtbishop.look4sat.core.domain.repository.LoTWStation
+import com.rtbishop.look4sat.core.domain.repository.LoTWStationMeta
+import com.rtbishop.look4sat.core.domain.repository.LoTWZonePair
+import org.w3c.dom.Element
+import org.xml.sax.InputSource
+import org.xml.sax.SAXException
+import java.io.InputStream
+import java.io.StringReader
+import java.util.Locale
+import java.util.zip.GZIPInputStream
+import javax.xml.parsers.DocumentBuilderFactory
+
+/** Bundled ARRL configuration 11.34 from https://lotw.arrl.org/lotw/config.tq6. */
+internal class LoTWConfig(input: InputStream) {
+    private val root = input.use { source -> GZIPInputStream(source).use { gzip ->
+        val xml = gzip.bufferedReader(Charsets.UTF_8).readText()
+        require(!xml.contains("<!DOCTYPE", true) && !xml.contains("<!ENTITY", true))
+        // Android's DOM provider does not support Xerces-specific setFeature flags.
+        DocumentBuilderFactory.newInstance().apply { isExpandEntityReferences = false }.newDocumentBuilder().apply {
+            setEntityResolver { _, _ -> throw SAXException("External entities are not permitted") }
+        }.parse(InputSource(StringReader(xml))).documentElement
+    } }
+    private val config = root.elements("tqslconfig").single()
+    val version = config.getAttribute("majorversion") + "." + config.getAttribute("minorversion")
+    private val spec = config.elements("sigspec").single { it.getAttribute("version") == "2.0" }
+    val stationOrder = spec.elements("tSTATION").single().childElements().map { it.tagName }
+    val contactOrder = spec.elements("tCONTACT").single().childElements().map { it.tagName }
+    private val primaryRegionFields = setOf("US_STATE", "CA_PROVINCE", "RU_OBLAST", "CN_PROVINCE", "AU_STATE", "JA_PREFECTURE", "FI_KUNTA")
+    private val secondaryRegionFields = setOf("US_COUNTY", "JA_CITY_GUN_KU")
+    private val bands = config.elements("bands").single().elements("band")
+    private val satellites = config.elements("satellite").associateBy { it.getAttribute("name").uppercase(Locale.US) }
+    private val modes = config.elements("modes").single().elements("mode").map { it.textContent }.toSet()
+
+    fun mode(record: QsoRecord): String {
+        val display = record.displayMode
+        if (display in modes) return display
+        val mapped = config.elements("adifmode").firstOrNull { it.textContent.equals(display, true) }?.getAttribute("mode")
+        return mapped ?: fail(LoTWProblem.MODE, display)
+    }
+
+    fun band(explicit: String, frequency: Long?, required: Boolean): String {
+        if (frequency != null && frequency <= 0) fail(LoTWProblem.BAND)
+        val frequencyBand = frequency?.let { hz -> bands.firstOrNull { band ->
+            val unit = if (band.getAttribute("spectrum") == "HF") 1_000.0 else 1_000_000.0
+            val mhz = hz / unit
+            mhz >= band.getAttribute("low").toDouble() && mhz <= band.getAttribute("high").toDouble()
+        }?.textContent }
+        val value = explicit.trim().uppercase(Locale.US).ifBlank { frequencyBand.orEmpty() }
+        if (value.isBlank() && !required && frequency == null) return ""
+        if (bands.none { it.textContent == value } || (frequency != null && frequencyBand != value)) fail(LoTWProblem.BAND, value)
+        return value
+    }
+
+    /** Every satellite name ARRL's config.tq6 knows, sorted: the only names LoTW accepts. */
+    fun satelliteNames(): List<String> = satellites.keys.sorted()
+
+    /**
+     * Resolve a tracker name to the ARRL name, or null when it is not an ARRL satellite.
+     * Exact official name first, then the alias table ("SAUDISAT 1C" -> "SO-50",
+     * "ISS (ZARYA)" -> "ARISS"), then an official name contained in the tracker name.
+     */
+    fun resolveSatellite(name: String): String? = LoTWSatelliteAliases.resolve(name, satellites.keys)
+
+    fun satellite(name: String, date: String): String {
+        val normalized = name.trim().uppercase(Locale.US)
+        // Tracker names differ from ARRL's: SatNOGS stores "SAUDISAT 1C" for "SO-50" and
+        // "ISS (ZARYA)" for "ARISS". resolveSatellite() checks the exact name, the alias
+        // table and finally substring containment; anything else is not uploadable.
+        val official = resolveSatellite(name) ?: fail(LoTWProblem.SATELLITE, normalized)
+        val sat = satellites.getValue(official)
+        val first = sat.getAttribute("startDate")
+        val last = sat.getAttribute("endDate")
+        if ((first.isNotBlank() && date < first) || (last.isNotBlank() && date > last)) fail(LoTWProblem.SATELLITE, normalized)
+        return sat.getAttribute("name").uppercase(Locale.US)
+    }
+
+    fun propagation(value: String): String {
+        val normalized = value.trim().uppercase(Locale.US)
+        if (normalized.isNotBlank() && config.elements("propmode").none { it.getAttribute("name") == normalized || it.textContent == normalized }) {
+            fail(LoTWProblem.INVALID_CONTACT, normalized)
+        }
+        return normalized
+    }
+
+    /** Region-field metadata and the national zonemap for one DXCC entity. */
+    fun stationMeta(dxcc: Int): LoTWStationMeta {
+        val pageFields = config.elements("page").filter { it.getAttribute("dependency") == dxcc.toString() }
+            .flatMap { it.elements("pageField") }.map { it.textContent }
+        val primary = pageFields.firstOrNull { it in primaryRegionFields }
+        val regionField = primary?.let { id ->
+            val field = config.elements("field").single { it.getAttribute("Id") == id }
+            val dependency = if (field.getAttribute("dependsOn") == "DXCC") dxcc.toString() else null
+            val options = field.elements("enums").filter {
+                it.getAttribute("dependency").isBlank() || it.getAttribute("dependency") == dependency
+            }.flatMap { it.elements("enum") }.map { enum ->
+                LoTWRegionOption(
+                    code = enum.getAttribute("value").uppercase(Locale.US),
+                    name = enum.textContent.trim().ifBlank { enum.getAttribute("value") },
+                    zones = parseZonemap(enum.getAttribute("zonemap"))
+                )
+            }
+            LoTWRegionField(id = id, label = field.getAttribute("label"), options = options)
+        }
+        val entity = config.elements("dxcc").flatMap { it.elements("entity") }
+            .firstOrNull { it.getAttribute("arrlId") == dxcc.toString() }
+        val countryZones = entity?.getAttribute("zonemap")?.let(::parseZonemap).orEmpty()
+        return LoTWStationMeta(regionField, countryZones)
+    }
+
+    private fun parseZonemap(zonemap: String): List<LoTWZonePair> = zonemap.split(',').mapNotNull { pair ->
+        val parts = pair.split(':')
+        if (parts.size != 2) return@mapNotNull null
+        val itu = parts[0].trim().toIntOrNull() ?: return@mapNotNull null
+        val cq = parts[1].trim().toIntOrNull() ?: return@mapNotNull null
+        LoTWZonePair(itu, cq)
+    }
+
+    fun stationFields(station: LoTWStation, dxcc: Int): Map<String, String> {
+        fun normalized(value: String) = value.trim().uppercase(Locale.US)
+        val grids = station.grid.split(',').map(::normalized).filter(String::isNotBlank).distinct()
+        if (grids.size !in 1..4 || grids.any { !it.matches(Regex("[A-R]{2}[0-9]{2}([A-X]{2}([0-9]{2})?)?")) }) {
+            fail(LoTWProblem.STATION_GRID)
+        }
+        // The primary grid goes into GRIDSQUARE (the field the config's tSTATION
+        // order signs); the full multi-grid set goes into MY_VUCC_GRIDS, an extra
+        // station field that TQSL stores but does not sign (same precedent as IOTA).
+        val fields = linkedMapOf("GRIDSQUARE" to grids.first())
+        if (grids.size > 1) fields["MY_VUCC_GRIDS"] = grids.joinToString(",")
+        fun zone(name: String, value: String, maximum: Int) {
+            if (value.isBlank()) return
+            val number = value.trim().toIntOrNull()?.takeIf { it in 1..maximum } ?: fail(LoTWProblem.STATION_ZONE)
+            fields[name] = number.toString()
+        }
+        zone("CQZ", station.cqZone, 40)
+        zone("ITUZ", station.ituZone, 90)
+        if (station.iota.isNotBlank()) {
+            val iota = normalized(station.iota)
+            if (!iota.matches(Regex("(AF|AN|AS|EU|NA|OC|SA)-[0-9]{3}"))) fail(LoTWProblem.STATION_IOTA)
+            fields["IOTA"] = iota
+        }
+        val pageFields = config.elements("page").filter { it.getAttribute("dependency") == dxcc.toString() }
+            .flatMap { it.elements("pageField") }.map { it.textContent }
+        val primary = pageFields.firstOrNull { it in primaryRegionFields }
+        val secondary = pageFields.firstOrNull { it in secondaryRegionFields }
+        fun region(name: String?, value: String) {
+            if (value.isBlank()) return
+            if (name == null) fail(LoTWProblem.STATION_REGION)
+            val field = config.elements("field").single { it.getAttribute("Id") == name }
+            val dependency = when (field.getAttribute("dependsOn")) {
+                "DXCC" -> dxcc.toString()
+                else -> fields[field.getAttribute("dependsOn")]
+            }
+            val options = field.elements("enums").filter {
+                it.getAttribute("dependency").isBlank() || it.getAttribute("dependency") == dependency
+            }.flatMap { it.elements("enum") }.map { it.getAttribute("value").uppercase(Locale.US) }
+            val code = normalized(value)
+            if (code !in options) fail(LoTWProblem.STATION_REGION, name)
+            fields[name] = code
+        }
+        region(primary, station.region)
+        region(secondary, station.county)
+        return fields
+    }
+}
+
+private fun Element.elements(tag: String): List<Element> = getElementsByTagName(tag).let { nodes ->
+    (0 until nodes.length).map { nodes.item(it) as Element }
+}
+private fun Element.childElements(): List<Element> = (0 until childNodes.length).mapNotNull { childNodes.item(it) as? Element }

core/data/src/main/java/com/rtbishop/look4sat/core/data/lotw/LoTWKeyMaterial.kt

@@ -0,0 +1,175 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.data.lotw
+
+import com.rtbishop.look4sat.core.domain.repository.LoTWCertificate
+import com.rtbishop.look4sat.core.domain.repository.LoTWOperationException
+import com.rtbishop.look4sat.core.domain.repository.LoTWProblem
+import java.security.KeyStore
+import java.security.PrivateKey
+import java.security.Signature
+import java.security.cert.X509Certificate
+import java.text.SimpleDateFormat
+import java.util.Collections
+import java.util.Date
+import java.util.Locale
+import java.util.TimeZone
+
+internal data class LoTWKeyMaterial(val key: PrivateKey, val certificate: X509Certificate, val info: LoTWCertificate) {
+    companion object {
+        fun read(bytes: ByteArray, password: CharArray, now: Long): LoTWKeyMaterial {
+            if (bytes.isEmpty() || bytes.size > MAX_CERTIFICATE_BYTES) fail(LoTWProblem.CERTIFICATE_INVALID)
+            val key: PrivateKey
+            val cert: X509Certificate
+            val store = try {
+                KeyStore.getInstance("PKCS12").apply { bytes.inputStream().use { load(it, password) } }
+            } catch (_: Exception) {
+                // Modern TQSL / OpenSSL 3 exports use PBES2+AES-CBC which Android's legacy
+                // Bouncy Castle parser cannot read. Fall back to our own PBES2 reader; if
+                // that fails too, report the real reason (format vs password).
+                if (isPbes2(bytes)) {
+                    try {
+                        val parsed = Pkcs12Reader.read(bytes, password)
+                        parsed.first to parsed.second
+                    } catch (e: Exception) {
+                        // Classify by exception type so the user sees the right message:
+                        //  - BadPadding (BAD_DECRYPT)          -> wrong password
+                        //  - IllegalStateException (error())    -> unsupported algorithm,
+                        //    message is the algorithm name
+                        //  - IllegalArgumentException (require()) -> structurally invalid file
+                        fail(
+                            when {
+                                e is javax.crypto.BadPaddingException -> LoTWProblem.CERTIFICATE_PASSWORD
+                                e is IllegalStateException && password.isNotEmpty() -> LoTWProblem.CERTIFICATE_FORMAT
+                                else -> LoTWProblem.CERTIFICATE_INVALID
+                            },
+                            if (e is IllegalStateException) (e.message ?: "") else ""
+                        )
+                    }
+                } else {
+                    fail(LoTWProblem.CERTIFICATE_PASSWORD)
+                }
+            }
+            if (store is Pair<*, *>) {
+                @Suppress("UNCHECKED_CAST")
+                key = store.first as PrivateKey
+                @Suppress("UNCHECKED_CAST")
+                cert = store.second as X509Certificate
+            } else {
+                val ks = store as KeyStore
+                val aliases = Collections.list(ks.aliases()).filter { ks.isKeyEntry(it) }
+                if (aliases.size != 1) fail(LoTWProblem.CERTIFICATE_INVALID)
+                val alias = aliases.single()
+                key = try { ks.getKey(alias, password) as? PrivateKey }
+                catch (_: Exception) { fail(LoTWProblem.CERTIFICATE_PASSWORD) }
+                    ?: fail(LoTWProblem.CERTIFICATE_INVALID)
+                cert = ks.getCertificate(alias) as? X509Certificate ?: fail(LoTWProblem.CERTIFICATE_INVALID)
+            }
+            if (key.algorithm != "RSA" || cert.publicKey.algorithm != "RSA") fail(LoTWProblem.CERTIFICATE_INVALID)
+            try { cert.checkValidity(Date(now)) } catch (_: Exception) { fail(LoTWProblem.CERTIFICATE_EXPIRED) }
+            val info = try { metadata(cert) } catch (_: Exception) { fail(LoTWProblem.CERTIFICATE_INVALID) }
+            // Use the platform's crypto implementation, including PKCS#1 padding. No custom cryptography.
+            val challenge = "Look4Sat LoTW certificate key check".toByteArray(Charsets.US_ASCII)
+            val signed = Signature.getInstance("SHA1withRSA").run { initSign(key); update(challenge); sign() }
+            val valid = Signature.getInstance("SHA1withRSA").run { initVerify(cert); update(challenge); verify(signed) }
+            if (!valid) fail(LoTWProblem.CERTIFICATE_INVALID)
+            return LoTWKeyMaterial(key, cert, info)
+        }
+
+        /** True when the PKCS12 uses PBES2 (OID 1.2.840.113549.1.5.13), the default
+         *  algorithm of OpenSSL 3 / modern TQSL. Android's legacy BC parser can't read it. */
+        private fun isPbes2(bytes: ByteArray): Boolean {
+            val oid = byteArrayOf(0x2a, 0x86.toByte(), 0x48, 0x86.toByte(), 0xf7.toByte(), 0x0d, 0x01, 0x05, 0x0d)
+            if (bytes.size < oid.size) return false
+            outer@ for (i in 0..bytes.size - oid.size) {
+                for (j in oid.indices) if (bytes[i + j] != oid[j]) continue@outer
+                return true
+            }
+            return false
+        }
+
+        private fun metadata(cert: X509Certificate): LoTWCertificate {
+            val oid = byteArrayOf(0x2b, 0x06, 0x01, 0x04, 0x01, 0xe0.toByte(), 0x3c, 0x01, 0x01)
+            val subject = DerValue.read(cert.subjectX500Principal.encoded).single()
+            require(subject.tag == 0x30)
+            val calls = subject.children().flatMap { it.children() }.mapNotNull { attribute ->
+                val pair = attribute.children()
+                if (pair.size == 2 && pair[0].tag == 6 && pair[0].data.contentEquals(oid)) pair[1].text() else null
+            }
+            val call = calls.single().trim().uppercase(Locale.US)
+            require(call.matches(Regex("[A-Z0-9]+(/[A-Z0-9]+)*")) && call.any(Char::isDigit) && call.any(Char::isLetter))
+            val first = extension(cert, "2")
+            val last = extension(cert, "3").takeUnless { it == "0000-00-00" }.orEmpty()
+            require(validDate(first) && (last.isBlank() || validDate(last)) && (last.isBlank() || last >= first))
+            val dxcc = extension(cert, "4").toInt()
+            require(dxcc > 0)
+            return LoTWCertificate(call, dxcc, cert.serialNumber.toString(16), utc(cert.notAfter.time, "yyyy-MM-dd"), first, last)
+        }
+
+        private fun extension(cert: X509Certificate, suffix: String): String {
+            val bytes = cert.getExtensionValue("1.3.6.1.4.1.12348.1.$suffix") ?: return ""
+            val outer = DerValue.read(bytes).single()
+            require(outer.tag == 4)
+            // TrustedQSL uses raw ASCII extension values. Also accept DER string-wrapped values.
+            return if (outer.data.all { it.toInt() in 32..126 || it.toInt() == 0 }) {
+                outer.data.toString(Charsets.US_ASCII).trim('\u0000', ' ')
+            } else DerValue.read(outer.data).single().text().trim()
+        }
+    }
+}
+
+internal const val MAX_CERTIFICATE_BYTES = 1024 * 1024
+internal fun fail(problem: LoTWProblem, detail: String = ""): Nothing = throw LoTWOperationException(problem, detail)
+internal fun utc(millis: Long, pattern: String): String = SimpleDateFormat(pattern, Locale.US).apply {
+    timeZone = TimeZone.getTimeZone("UTC")
+}.format(Date(millis))
+internal fun validDate(value: String): Boolean = value.matches(Regex("[0-9]{4}-[0-9]{2}-[0-9]{2}")) && runCatching {
+    SimpleDateFormat("yyyy-MM-dd", Locale.US).apply { isLenient = false }.parse(value) != null
+}.getOrDefault(false)
+
+/** Only bounded DER metadata decoding; cryptographic verification is delegated to JCA. */
+internal data class DerValue(val tag: Int, val data: ByteArray) {
+    fun children(): List<DerValue> = read(data)
+    fun text(): String = when (tag) {
+        12, 19, 20, 22, 23, 24 -> data.toString(Charsets.UTF_8)
+        30 -> data.toString(Charsets.UTF_16BE)
+        else -> error("Not an ASN.1 string")
+    }
+    companion object {
+        fun read(bytes: ByteArray): List<DerValue> {
+            val result = mutableListOf<DerValue>()
+            var offset = 0
+            while (offset < bytes.size) {
+                require(bytes.size - offset >= 2)
+                val tag = bytes[offset++].toInt() and 255
+                var length = bytes[offset++].toInt() and 255
+                if (length and 128 != 0) {
+                    val size = length and 127
+                    require(size in 1..3 && size <= bytes.size - offset)
+                    length = 0
+                    repeat(size) { length = (length shl 8) or (bytes[offset++].toInt() and 255) }
+                }
+                require(length <= bytes.size - offset)
+                result += DerValue(tag, bytes.copyOfRange(offset, offset + length))
+                offset += length
+            }
+            return result
+        }
+    }
+}

core/data/src/main/java/com/rtbishop/look4sat/core/data/lotw/LoTWSigner.kt

@@ -0,0 +1,98 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.data.lotw
+
+import com.rtbishop.look4sat.core.domain.logbook.QsoRecord
+import com.rtbishop.look4sat.core.domain.logbook.QsoStatus
+import com.rtbishop.look4sat.core.domain.logbook.isSatellite
+import com.rtbishop.look4sat.core.domain.repository.LoTWProblem
+import java.io.ByteArrayOutputStream
+import java.math.BigDecimal
+import java.security.MessageDigest
+import java.security.Signature
+import java.util.Locale
+import java.util.zip.GZIPOutputStream
+import kotlin.io.encoding.Base64
+
+internal data class LoTWContact(val record: QsoRecord, val fields: Map<String, String>, val signData: String, val fingerprint: String)
+
+internal class LoTWSigner(private val config: LoTWConfig) {
+    fun contact(record: QsoRecord, key: LoTWKeyMaterial, station: Map<String, String>, now: Long): LoTWContact {
+        val call = record.theirCallsign.trim().uppercase(Locale.US)
+        if (record.status != QsoStatus.COMPLETE || !call.matches(Regex("[A-Z0-9]+(/[A-Z0-9]+)*")) ||
+            !call.any(Char::isLetter) || !call.any(Char::isDigit)) fail(LoTWProblem.INVALID_CONTACT, call)
+        if (!record.myCallsign.trim().equals(key.info.callsign, true)) fail(LoTWProblem.CALLSIGN_MISMATCH, call)
+        val date = utc(record.startUtcMillis, "yyyy-MM-dd")
+        if (date < key.info.firstQsoDate || (key.info.lastQsoDate.isNotBlank() && date > key.info.lastQsoDate) || record.startUtcMillis > now) {
+            fail(LoTWProblem.QSO_DATE, call)
+        }
+        fun mhz(hz: Long?): String = hz?.let { BigDecimal.valueOf(it, 6).stripTrailingZeros().toPlainString() }.orEmpty()
+        val fields = linkedMapOf(
+            "BAND" to config.band(record.band, record.txFrequencyHz, true),
+            "BAND_RX" to config.band(record.rxBand, record.rxFrequencyHz, false),
+            "CALL" to call,
+            "FREQ" to mhz(record.txFrequencyHz),
+            "FREQ_RX" to mhz(record.rxFrequencyHz),
+            "MODE" to config.mode(record),
+            "PROP_MODE" to if (record.isSatellite) "SAT" else config.propagation(record.propagationMode),
+            "QSO_DATE" to date,
+            "QSO_TIME" to utc(record.startUtcMillis, "HH:mm:ss'Z'"),
+            "SAT_NAME" to if (record.isSatellite) config.satellite(record.satelliteName, date) else ""
+        ).filterValues { it.isNotBlank() }
+        val signData = (config.stationOrder.map { station[it].orEmpty() } + config.contactOrder.map { fields[it].orEmpty() }).joinToString("")
+        // Fingerprint identifies the CONTACT only (call, date/time, band, mode,
+        // satellite, frequency). Station fields (grid, zones, county, IOTA) are
+        // deliberately excluded: changing the station location must not change
+        // the fingerprint, otherwise previously-uploaded contacts would lose
+        // their ledger entry and be re-uploaded (and rejected as duplicates).
+        val identity = field("CALL", key.info.callsign) + field("DXCC", key.info.dxcc.toString()) +
+            fields.entries.joinToString("") { field(it.key, it.value) }
+        val hash = MessageDigest.getInstance("SHA-256").digest(identity.toByteArray(Charsets.UTF_8)).joinToString("") { "%02x".format(it) }
+        return LoTWContact(record, fields, signData, hash)
+    }
+
+    fun sign(contacts: List<LoTWContact>, key: LoTWKeyMaterial, station: Map<String, String>): ByteArray {
+        val text = buildString {
+            append(field("TQSL_IDENT", "Look4Sat LoTW Config: V${config.version} AllowDupes: false"))
+            append(field("REC_TYPE", "tCERT")); append(field("CERT_UID", "1"))
+            append(field("CERTIFICATE", Base64.Default.encode(key.certificate.encoded).chunked(64).joinToString("\n")))
+            append("<eor>\n")
+            append(field("REC_TYPE", "tSTATION")); append(field("STATION_UID", "1")); append(field("CERT_UID", "1"))
+            append(field("CALL", key.info.callsign)); append(field("DXCC", key.info.dxcc.toString()))
+            station.forEach { (name, value) -> append(field(name, value)) }
+            append("<eor>\n")
+            contacts.forEach { contact ->
+                append(field("REC_TYPE", "tCONTACT")); append(field("STATION_UID", "1"))
+                contact.fields.forEach { (name, value) -> append(field(name, value)) }
+                // SHA-1 is required by the LoTW V2.0 wire format, not chosen for general-purpose signing.
+                val signature = Signature.getInstance("SHA1withRSA").run {
+                    initSign(key.key); update(contact.signData.toByteArray(Charsets.UTF_8)); sign()
+                }
+                val encoded = Base64.Default.encode(signature).chunked(64).joinToString("\n")
+                append("<SIGN_LOTW_V2.0:${encoded.length}:6>$encoded\n")
+                append(field("SIGNDATA", contact.signData)); append("<eor>\n")
+            }
+        }
+        return ByteArrayOutputStream().also { output ->
+            GZIPOutputStream(output).use { it.write(text.toByteArray(Charsets.UTF_8)) }
+        }.toByteArray()
+    }
+}
+
+private fun field(name: String, value: String): String = "<$name:${value.toByteArray(Charsets.UTF_8).size}>$value\n"

core/data/src/main/java/com/rtbishop/look4sat/core/data/lotw/LoTWStorage.kt

@@ -0,0 +1,79 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.data.lotw
+
+import android.content.Context
+import android.security.keystore.KeyGenParameterSpec
+import android.security.keystore.KeyProperties
+import android.util.AtomicFile
+import java.io.File
+import java.security.KeyStore
+import javax.crypto.Cipher
+import javax.crypto.KeyGenerator
+import javax.crypto.SecretKey
+import javax.crypto.spec.GCMParameterSpec
+
+internal interface LoTWStorage {
+    fun read(name: String): ByteArray?
+    fun write(name: String, data: ByteArray)
+    fun delete(name: String)
+}
+
+/** P12 backups and their saved passwords are encrypted at rest and excluded from Android/cloud backup. */
+internal class AndroidLoTWStorage(context: Context) : LoTWStorage {
+    private val directory = File(context.noBackupFilesDir, "lotw")
+    private val store by lazy { KeyStore.getInstance("AndroidKeyStore").apply { load(null) } }
+    private fun file(name: String): AtomicFile {
+        require(name.matches(Regex("[a-z]+")))
+        check(directory.isDirectory || directory.mkdirs())
+        return AtomicFile(File(directory, name))
+    }
+    private fun key(): SecretKey = (store.getKey(ALIAS, null) as? SecretKey) ?: KeyGenerator.getInstance(
+        KeyProperties.KEY_ALGORITHM_AES, "AndroidKeyStore"
+    ).run {
+        init(KeyGenParameterSpec.Builder(ALIAS, KeyProperties.PURPOSE_ENCRYPT or KeyProperties.PURPOSE_DECRYPT)
+            .setBlockModes(KeyProperties.BLOCK_MODE_GCM).setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_NONE)
+            .setKeySize(256).build())
+        generateKey()
+    }
+    @Synchronized override fun read(name: String): ByteArray? {
+        val file = file(name)
+        if (!file.baseFile.exists() && !File(file.baseFile.path + ".bak").exists()) return null
+        val bytes = file.readFully()
+        require(bytes.size in 29..(16 * 1024 * 1024) && bytes[0] == 1.toByte())
+        return Cipher.getInstance("AES/GCM/NoPadding").run {
+            init(Cipher.DECRYPT_MODE, key(), GCMParameterSpec(128, bytes.copyOfRange(1, 13)))
+            updateAAD(name.toByteArray(Charsets.UTF_8))
+            doFinal(bytes, 13, bytes.size - 13)
+        }
+    }
+    @Synchronized override fun write(name: String, data: ByteArray) {
+        val cipher = Cipher.getInstance("AES/GCM/NoPadding").apply {
+            init(Cipher.ENCRYPT_MODE, key())
+            updateAAD(name.toByteArray(Charsets.UTF_8))
+        }
+        val bytes = byteArrayOf(1) + cipher.iv + cipher.doFinal(data)
+        val file = file(name)
+        val stream = file.startWrite()
+        try { stream.write(bytes); file.finishWrite(stream) }
+        catch (error: Exception) { file.failWrite(stream); throw error }
+    }
+    @Synchronized override fun delete(name: String) = file(name).delete()
+    private companion object { const val ALIAS = "look4sat.lotw.storage.v1" }
+}

core/data/src/main/java/com/rtbishop/look4sat/core/data/lotw/LoTWUploadRepository.kt

@@ -0,0 +1,459 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.data.lotw
+
+import android.content.Context
+import com.rtbishop.look4sat.core.domain.logbook.QsoRecord
+import com.rtbishop.look4sat.core.domain.logbook.satelliteIdentity
+import com.rtbishop.look4sat.core.domain.logbook.QsoStatus
+import com.rtbishop.look4sat.core.domain.repository.ILoTWUploadRepository
+import com.rtbishop.look4sat.core.domain.repository.LoTWCertificate
+import com.rtbishop.look4sat.core.domain.repository.LoTWOperationException
+import com.rtbishop.look4sat.core.domain.repository.LoTWProblem
+import com.rtbishop.look4sat.core.domain.repository.LoTWStation
+import com.rtbishop.look4sat.core.domain.repository.LoTWStationMeta
+import com.rtbishop.look4sat.core.domain.repository.LoTWUploadAudit
+import com.rtbishop.look4sat.core.domain.repository.LoTWUploadPreview
+import com.rtbishop.look4sat.core.domain.repository.LoTWUploadResult
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.ensureActive
+import kotlinx.coroutines.suspendCancellableCoroutine
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
+import kotlinx.coroutines.withContext
+import okhttp3.Call
+import okhttp3.Callback
+import okhttp3.MediaType.Companion.toMediaType
+import okhttp3.MultipartBody
+import okhttp3.OkHttpClient
+import okhttp3.Request
+import okhttp3.RequestBody.Companion.toRequestBody
+import okhttp3.Response
+import java.io.ByteArrayOutputStream
+import java.io.DataInputStream
+import java.io.DataOutputStream
+import java.io.IOException
+import java.nio.ByteBuffer
+import java.nio.CharBuffer
+import java.util.Locale
+import java.util.UUID
+import java.util.concurrent.TimeUnit
+import kotlin.coroutines.coroutineContext
+import kotlin.coroutines.resume
+
+private fun readBoundedBody(response: Response, limit: Int): String = response.body.charStream().use { reader ->
+    val result = StringBuilder()
+    val buffer = CharArray(8192)
+    while (true) {
+        val count = reader.read(buffer)
+        if (count < 0) break
+        require(result.length <= limit - count) { "Response exceeds size limit" }
+        result.append(buffer, 0, count)
+    }
+    result.toString()
+}
+
+class LoTWUploadRepository internal constructor(
+    private val storage: LoTWStorage,
+    private val config: () -> LoTWConfig,
+    client: OkHttpClient = OkHttpClient(),
+    private val now: () -> Long = System::currentTimeMillis
+) : ILoTWUploadRepository {
+    constructor(context: Context) : this(AndroidLoTWStorage(context), { LoTWConfig(context.assets.open("lotw/config.tq6")) })
+    private val client = client.newBuilder().connectTimeout(30, TimeUnit.SECONDS).readTimeout(120, TimeUnit.SECONDS)
+        .callTimeout(180, TimeUnit.SECONDS).retryOnConnectionFailure(false).followRedirects(false).followSslRedirects(false).build()
+    private val mutex = Mutex()
+    @Volatile private var pending: Pending? = null
+    private data class Pending(val preview: LoTWUploadPreview, val data: ByteArray, val hashes: List<String>, val created: Long)
+    private data class SigningContext(val key: LoTWKeyMaterial, val signer: LoTWSigner, val location: Map<String, String>)
+
+    override suspend fun certificate(): LoTWCertificate? = withContext(Dispatchers.IO) {
+        mutex.withLock {
+            val bytes = storage.read("certificate") ?: return@withLock null
+            try {
+                readBundle(bytes).let { bundle ->
+                    bundle.p12.fill(0)
+                    bundle.password?.fill(0)
+                    bundle.info.copy(passwordSaved = bundle.password != null)
+                }
+            } finally { bytes.fill(0) }
+        }
+    }
+
+    override suspend fun importCertificate(data: ByteArray, password: CharArray): LoTWCertificate = withContext(Dispatchers.IO) {
+        mutex.withLock {
+            val passwordBytes = encodePassword(password)
+            try {
+                if (passwordBytes.size > MAX_CERTIFICATE_PASSWORD_BYTES) fail(LoTWProblem.CERTIFICATE_PASSWORD)
+                val key = LoTWKeyMaterial.read(data, password, now())
+                val bytes = encodeBundle(key.info, data, passwordBytes)
+                try { storage.write("certificate", bytes) } finally { bytes.fill(0) }
+                discardPreview()
+                key.info.copy(passwordSaved = true)
+            } finally {
+                passwordBytes.fill(0)
+                password.fill('\u0000')
+                data.fill(0)
+            }
+        }
+    }
+
+    override suspend fun saveCertificatePassword(password: CharArray): LoTWCertificate = withContext(Dispatchers.IO) {
+        mutex.withLock {
+            val stored = storage.read("certificate") ?: fail(LoTWProblem.CERTIFICATE_MISSING)
+            val bundle = try { readBundle(stored) } finally { stored.fill(0) }
+            val passwordBytes = encodePassword(password)
+            try {
+                if (passwordBytes.size > MAX_CERTIFICATE_PASSWORD_BYTES) fail(LoTWProblem.CERTIFICATE_PASSWORD)
+                val key = LoTWKeyMaterial.read(bundle.p12, password, now())
+                val bytes = encodeBundle(key.info, bundle.p12, passwordBytes)
+                try { storage.write("certificate", bytes) } finally { bytes.fill(0) }
+                discardPreview()
+                key.info.copy(passwordSaved = true)
+            } finally {
+                bundle.p12.fill(0)
+                bundle.password?.fill(0)
+                passwordBytes.fill(0)
+                password.fill('\u0000')
+            }
+        }
+    }
+
+    override suspend fun station(): LoTWStation? = withContext(Dispatchers.IO) {
+        mutex.withLock { readStation() }
+    }
+
+    override suspend fun saveStation(station: LoTWStation): LoTWStation = withContext(Dispatchers.IO) {
+        mutex.withLock {
+            val stored = storage.read("certificate") ?: fail(LoTWProblem.CERTIFICATE_MISSING)
+            val bundle = try { readBundle(stored) } finally { stored.fill(0) }
+            val normalized = station.normalized()
+            try {
+                config().stationFields(normalized, bundle.info.dxcc)
+            } catch (e: LoTWOperationException) {
+                // A region saved under a different certificate no longer applies to
+                // this DXCC entity — drop it instead of failing the whole save.
+                if (e.reason != LoTWProblem.STATION_REGION) throw e
+                val cleaned = normalized.copy(region = "", county = "")
+                config().stationFields(cleaned, bundle.info.dxcc)
+                writeStation(cleaned)
+                discardPreview()
+                return@withLock cleaned
+            } finally {
+                bundle.p12.fill(0)
+                bundle.password?.fill(0)
+            }
+            writeStation(normalized)
+            discardPreview()
+            normalized
+        }
+    }
+
+    override suspend fun removeCertificate() = withContext(Dispatchers.IO) {
+        mutex.withLock { discardPreview(); storage.delete("certificate") }
+    }
+
+    override suspend fun stationMeta(dxcc: Int): LoTWStationMeta = withContext(Dispatchers.IO) {
+        config().stationMeta(dxcc)
+    }
+
+    /** The ARRL satellite catalogue is static for the lifetime of the bundled config.tq6. */
+    private val satelliteNames: List<String> by lazy { config().satelliteNames() }
+
+    override suspend fun satelliteCatalog(): List<String> = withContext(Dispatchers.IO) { satelliteNames }
+
+    /**
+     * What makes two records the same contact for batch de-duplication: the opposite station,
+     * the satellite (resolved to its ARRL identity, so the tracker spelling and the official
+     * name are one) and the minute the QSO started. Frequency and mode are deliberately not
+     * part of the key — the same contact logged twice with slightly different tuning (or with
+     * the frequency fields empty) must still be caught before LoTW rejects the duplicate.
+     */
+    private fun duplicateKey(record: QsoRecord): String = listOf(
+        record.theirCallsign.trim().uppercase(Locale.US),
+        satelliteIdentity(record.satelliteName),
+        (record.startUtcMillis / 60_000L).toString()
+    ).joinToString("|")
+
+    override suspend fun audit(records: List<QsoRecord>): LoTWUploadAudit = withContext(Dispatchers.IO) {
+        mutex.withLock {
+            val signing = signingContext()
+            val ledger = ledger()
+            val unique = hashSetOf<String>()
+            var pendingCount = 0
+            var uploaded = 0
+            var unknown = 0
+            var unavailable = 0
+            var duplicates = 0
+            var incomplete = 0
+            val reasons = mutableMapOf<LoTWProblem, Int>()
+            val details = mutableMapOf<LoTWProblem, String>()
+            records.sortedBy { it.startUtcMillis }.forEach { record ->
+                coroutineContext.ensureActive()
+                when {
+                    record.status != QsoStatus.COMPLETE -> {
+                        unavailable++
+                        incomplete++
+                    }
+
+                    record.lotwReceived || record.lotwUploaded -> uploaded++
+                    else -> {
+                        val contact = try {
+                            signing.signer.contact(record, signing.key, signing.location, now())
+                        } catch (e: LoTWOperationException) {
+                            unavailable++
+                            reasons[e.reason] = (reasons[e.reason] ?: 0) + 1
+                            if (e.detail.isNotBlank()) details.putIfAbsent(e.reason, e.detail)
+                            null
+                        }
+                        if (contact != null) when {
+                            !unique.add(duplicateKey(contact.record)) -> {
+                                unavailable++
+                                duplicates++
+                            }
+
+                            ledger[contact.fingerprint] == "accepted" -> uploaded++
+                            ledger[contact.fingerprint] == "unknown" -> unknown++
+                            else -> pendingCount++
+                        }
+                    }
+                }
+            }
+            LoTWUploadAudit(
+                records.size, pendingCount, uploaded, unknown, unavailable,
+                reasons, details, duplicates, incomplete
+            )
+        }
+    }
+
+    override suspend fun prepare(records: List<QsoRecord>, resubmit: Boolean): LoTWUploadPreview = withContext(Dispatchers.IO) {
+        mutex.withLock {
+            discardPreview()
+            if (records.size > 10_000) fail(LoTWProblem.TOO_MANY_CONTACTS)
+            val signing = signingContext()
+            val ledger = ledger()
+            var skipped = 0
+            var unknown = 0
+            var unavailable = 0
+            var duplicates = 0
+            val unique = hashSetOf<String>()
+            val reasons = mutableMapOf<LoTWProblem, Int>()
+            val contacts = records.sortedBy { it.startUtcMillis }.mapNotNull { record ->
+                coroutineContext.ensureActive()
+                if (record.status != QsoStatus.COMPLETE || ((record.lotwReceived || record.lotwUploaded) && !resubmit)) { skipped++; return@mapNotNull null }
+                val contact = try {
+                    signing.signer.contact(record, signing.key, signing.location, now())
+                } catch (e: LoTWOperationException) {
+                    // One un-signable record must not abort the whole batch:
+                    // skip it, count the real reason, and let the rest upload.
+                    unavailable++
+                    reasons[e.reason] = (reasons[e.reason] ?: 0) + 1
+                    return@mapNotNull null
+                }
+                val previous = ledger[contact.fingerprint]
+                when {
+                    (previous == "accepted" && !resubmit) -> { skipped++; null }
+                    !unique.add(duplicateKey(contact.record)) -> {
+                        skipped++
+                        duplicates++
+                        null
+                    }
+
+                    previous == "unknown" && !resubmit -> { skipped++; unknown++; null }
+                    else -> contact
+                }
+            }
+            val preview = LoTWUploadPreview(
+                UUID.randomUUID().toString(), signing.key.info.callsign, signing.key.info.dxcc, signing.location.getValue("GRIDSQUARE"),
+                contacts.size, skipped,
+                contacts.firstOrNull()?.record?.let { utc(it.startUtcMillis, "yyyy-MM-dd HH:mm:ss") }.orEmpty(),
+                contacts.lastOrNull()?.record?.let { utc(it.startUtcMillis, "yyyy-MM-dd HH:mm:ss") }.orEmpty(),
+                contacts.map { "${utc(it.record.startUtcMillis, "MM-dd HH:mm")} ${it.record.theirCallsign} ${it.fields["MODE"]} ${it.fields["SAT_NAME"].orEmpty()}" },
+                unknown,
+                unavailable,
+                reasons.toMap(),
+                duplicates,
+                contacts.map { it.record.id }
+            )
+            if (contacts.isNotEmpty()) pending = Pending(
+                preview,
+                signing.signer.sign(contacts, signing.key, signing.location),
+                contacts.map { it.fingerprint },
+                now()
+            )
+            preview
+        }
+    }
+
+    override suspend fun upload(previewId: String): LoTWUploadResult = withContext(Dispatchers.IO) {
+        mutex.withLock {
+            val payload = pending?.takeIf { it.preview.id == previewId && now() - it.created in 0..900_000 }
+                ?: return@withLock LoTWUploadResult.ExpiredPreview
+            pending = null // A preview is a one-shot authorization, including across failures.
+            val ledger = ledger()
+            payload.hashes.forEach { ledger[it] = "unknown" }
+            saveLedger(ledger) // Persist BEFORE the POST, so process death/cancellation cannot cause an automatic retry.
+            try {
+                val result = post(payload.data, payload.preview.count)
+                when (result) {
+                    is LoTWUploadResult.Accepted -> payload.hashes.forEach { ledger[it] = "accepted" }
+                    is LoTWUploadResult.Rejected -> payload.hashes.forEach { ledger.remove(it) }
+                    else -> Unit
+                }
+                saveLedger(ledger)
+                result
+            } finally { payload.data.fill(0) }
+        }
+    }
+
+    override fun discardPreview() { pending?.data?.fill(0); pending = null }
+
+    private fun signingContext(): SigningContext {
+        val stored = storage.read("certificate") ?: fail(LoTWProblem.CERTIFICATE_MISSING)
+        val bundle = try { readBundle(stored) } finally { stored.fill(0) }
+        val passwordBytes = bundle.password ?: run {
+            bundle.p12.fill(0)
+            fail(LoTWProblem.CERTIFICATE_PASSWORD)
+        }
+        val password = decodePassword(passwordBytes)
+        return try {
+            val key = LoTWKeyMaterial.read(bundle.p12, password, now())
+            val tqslConfig = config()
+            val signer = LoTWSigner(tqslConfig)
+            val station = readStation() ?: fail(LoTWProblem.STATION_GRID)
+            SigningContext(key, signer, tqslConfig.stationFields(station, key.info.dxcc))
+        } finally {
+            bundle.p12.fill(0)
+            passwordBytes.fill(0)
+            password.fill('\u0000')
+        }
+    }
+
+    private fun readStation(): LoTWStation? = storage.read("station")?.inputStream()?.let { stream ->
+        DataInputStream(stream).use { input ->
+            require(input.readInt() == 1)
+            LoTWStation(input.readUTF(), input.readUTF(), input.readUTF(), input.readUTF(), input.readUTF(), input.readUTF())
+        }
+    }
+
+    private fun writeStation(station: LoTWStation) {
+        val bytes = ByteArrayOutputStream().also { stream -> DataOutputStream(stream).use { output ->
+            output.writeInt(1)
+            listOf(station.grid, station.cqZone, station.ituZone, station.region, station.county, station.iota).forEach(output::writeUTF)
+        } }.toByteArray()
+        try { storage.write("station", bytes) } finally { bytes.fill(0) }
+    }
+
+    private suspend fun post(data: ByteArray, count: Int): LoTWUploadResult = suspendCancellableCoroutine { continuation ->
+        val body = MultipartBody.Builder().setType(MultipartBody.FORM)
+            .addFormDataPart("upfile", "look4sat-${UUID.randomUUID()}.tq8", data.toRequestBody("application/octet-stream".toMediaType())).build()
+        val call = client.newCall(Request.Builder().url("https://lotw.arrl.org/lotw/upload").post(body).build())
+        continuation.invokeOnCancellation { call.cancel() }
+        call.enqueue(object : Callback {
+            override fun onFailure(call: Call, e: IOException) {
+                if (continuation.isActive) continuation.resume(LoTWUploadResult.Unknown)
+            }
+            override fun onResponse(call: Call, response: Response) {
+                val result = try {
+                    response.use {
+                        if (!it.isSuccessful) LoTWUploadResult.Unknown else parseLoTWUploadResponse(readBoundedBody(it, 256 * 1024), count)
+                    }
+                } catch (_: Exception) { LoTWUploadResult.Unknown }
+                if (continuation.isActive) continuation.resume(result)
+            }
+        })
+    }
+
+    private fun ledger(): MutableMap<String, String> = storage.read("receipts")?.inputStream()?.let { stream ->
+        DataInputStream(stream).use { input ->
+            require(input.readInt() == 1)
+            val size = input.readInt().also { require(it in 0..200_000) }
+            val entries = linkedMapOf<String, String>()
+            repeat(size) { entries[input.readUTF()] = input.readUTF() }
+            entries
+        }
+    } ?: linkedMapOf()
+
+    private fun saveLedger(entries: Map<String, String>) {
+        val bytes = ByteArrayOutputStream().also { stream -> DataOutputStream(stream).use { output ->
+            output.writeInt(1); output.writeInt(entries.size)
+            entries.forEach { (hash, status) -> output.writeUTF(hash); output.writeUTF(status) }
+        } }.toByteArray()
+        storage.write("receipts", bytes)
+    }
+}
+
+internal fun parseLoTWUploadResponse(body: String, count: Int): LoTWUploadResult {
+    val markers = Regex("<!--\\s*\\.UPL\\.\\s*(accepted|rejected)\\s*-->", RegexOption.IGNORE_CASE)
+        .findAll(body).map { it.groupValues[1].lowercase() }.toList()
+    return when (markers.singleOrNull()) {
+        "accepted" -> LoTWUploadResult.Accepted(count)
+        "rejected" -> {
+            val message = Regex("<!--\\s*\\.UPLMESSAGE\\.\\s*(.*?)-->", setOf(RegexOption.IGNORE_CASE, RegexOption.DOT_MATCHES_ALL))
+                .find(body)?.groupValues?.get(1).orEmpty().replace(Regex("<[^>]*>"), " ")
+                .replace(Regex("[\\p{Cc}\\s]+"), " ").trim().take(500)
+            LoTWUploadResult.Rejected(message)
+        }
+        else -> LoTWUploadResult.Unknown
+    }
+}
+
+private data class StoredCertificate(val info: LoTWCertificate, val p12: ByteArray, val password: ByteArray?)
+
+private fun encodeBundle(info: LoTWCertificate, p12: ByteArray, password: ByteArray): ByteArray = ByteArrayOutputStream().also { stream ->
+    DataOutputStream(stream).use { output ->
+        output.writeInt(2)
+        output.writeUTF(info.callsign); output.writeInt(info.dxcc); output.writeUTF(info.serial)
+        output.writeUTF(info.expires); output.writeUTF(info.firstQsoDate); output.writeUTF(info.lastQsoDate)
+        output.writeInt(password.size); output.write(password)
+        output.writeInt(p12.size); output.write(p12)
+    }
+}.toByteArray()
+
+private fun readBundle(bytes: ByteArray): StoredCertificate = DataInputStream(bytes.inputStream()).use { input ->
+    val version = input.readInt().also { require(it in 1..2) }
+    val info = LoTWCertificate(input.readUTF(), input.readInt(), input.readUTF(), input.readUTF(), input.readUTF(), input.readUTF())
+    val password = if (version >= 2) {
+        val size = input.readInt().also { require(it in 0..MAX_CERTIFICATE_PASSWORD_BYTES) }
+        ByteArray(size).also { input.readFully(it) }
+    } else null
+    val p12Size = input.readInt().also { require(it in 1..MAX_CERTIFICATE_BYTES) }
+    StoredCertificate(info, ByteArray(p12Size).also { input.readFully(it) }, password)
+}
+
+private fun encodePassword(password: CharArray): ByteArray {
+    val buffer = Charsets.UTF_8.encode(CharBuffer.wrap(password))
+    return ByteArray(buffer.remaining()).also(buffer::get)
+}
+
+private fun decodePassword(password: ByteArray): CharArray {
+    val buffer = Charsets.UTF_8.decode(ByteBuffer.wrap(password))
+    return CharArray(buffer.remaining()).also(buffer::get)
+}
+
+private fun LoTWStation.normalized() = LoTWStation(
+    grid.trim().uppercase(Locale.US),
+    cqZone.trim(),
+    ituZone.trim(),
+    region.trim().uppercase(Locale.US),
+    county.trim().uppercase(Locale.US),
+    iota.trim().uppercase(Locale.US)
+)
+
+private const val MAX_CERTIFICATE_PASSWORD_BYTES = 16 * 1024

core/data/src/main/java/com/rtbishop/look4sat/core/data/lotw/Pkcs12Reader.kt

@@ -0,0 +1,301 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.rtbishop.look4sat.core.data.lotw
+
+import java.io.ByteArrayInputStream
+import java.security.KeyFactory
+import java.security.PrivateKey
+import java.security.cert.CertificateFactory
+import java.security.cert.X509Certificate
+import java.security.spec.PKCS8EncodedKeySpec
+import javax.crypto.Cipher
+import javax.crypto.SecretKeyFactory
+import javax.crypto.spec.IvParameterSpec
+import javax.crypto.spec.PBEKeySpec
+import javax.crypto.spec.SecretKeySpec
+
+/**
+ * Minimal PKCS#12 reader for the PBES2/AES-CBC format that OpenSSL 3 and modern
+ * TQSL produce by default. Android's legacy bundled Bouncy Castle PKCS12 parser
+ * cannot handle PBES2, so we parse the DER structure ourselves and decrypt with
+ * the platform JCE (PBKDF2WithHmacSHA1/256 + AES/CBC), which ships on Android.
+ *
+ * Handles both layouts:
+ *  - OpenSSL `-certpbe NONE`: plaintext certificate bags + a PBES2-shrouded key
+ *    inside a plaintext `data` ContentInfo.
+ *  - Modern TQSL: the certificate SafeContents wrapped in an `encryptedData`
+ *    ContentInfo (PBES2), plus the PBES2-shrouded key in a plaintext `data`
+ *    ContentInfo.
+ */
+internal object Pkcs12Reader {
+
+    private val OID_DATA = byteArrayOf(0x2a, 0x86.toByte(), 0x48, 0x86.toByte(), 0xf7.toByte(), 0x0d, 0x01, 0x07, 0x01)
+    private val OID_ENCRYPTED_DATA = byteArrayOf(0x2a, 0x86.toByte(), 0x48, 0x86.toByte(), 0xf7.toByte(), 0x0d, 0x01, 0x07, 0x06)
+    private val OID_PKCS8_SHROUDED_KEY_BAG = byteArrayOf(0x2a, 0x86.toByte(), 0x48, 0x86.toByte(), 0xf7.toByte(), 0x0d, 0x01, 0x0c, 0x0a, 0x01, 0x02)
+    private val OID_CERT_BAG = byteArrayOf(0x2a, 0x86.toByte(), 0x48, 0x86.toByte(), 0xf7.toByte(), 0x0d, 0x01, 0x0c, 0x0a, 0x01, 0x03)
+    private val OID_X509_CERT = byteArrayOf(0x2a, 0x86.toByte(), 0x48, 0x86.toByte(), 0xf7.toByte(), 0x0d, 0x01, 0x09, 0x16, 0x01)
+    private val OID_PBES2 = byteArrayOf(0x2a, 0x86.toByte(), 0x48, 0x86.toByte(), 0xf7.toByte(), 0x0d, 0x01, 0x05, 0x0d)
+    private val OID_PBKDF2 = byteArrayOf(0x2a, 0x86.toByte(), 0x48, 0x86.toByte(), 0xf7.toByte(), 0x0d, 0x01, 0x05, 0x0c)
+    private val OID_HMAC_SHA1 = byteArrayOf(0x2a, 0x86.toByte(), 0x48, 0x86.toByte(), 0xf7.toByte(), 0x0d, 0x02, 0x07)
+    private val OID_HMAC_SHA256 = byteArrayOf(0x2a, 0x86.toByte(), 0x48, 0x86.toByte(), 0xf7.toByte(), 0x0d, 0x02, 0x09)
+    private val OID_HMAC_SHA384 = byteArrayOf(0x2a, 0x86.toByte(), 0x48, 0x86.toByte(), 0xf7.toByte(), 0x0d, 0x02, 0x0a)
+    private val OID_HMAC_SHA512 = byteArrayOf(0x2a, 0x86.toByte(), 0x48, 0x86.toByte(), 0xf7.toByte(), 0x0d, 0x02, 0x0b)
+    private val OID_AES_256_CBC = byteArrayOf(0x60, 0x86.toByte(), 0x48, 0x01, 0x65, 0x03, 0x04, 0x01, 0x2a)
+    private val OID_AES_192_CBC = byteArrayOf(0x60, 0x86.toByte(), 0x48, 0x01, 0x65, 0x03, 0x04, 0x01, 0x16)
+    private val OID_AES_128_CBC = byteArrayOf(0x60, 0x86.toByte(), 0x48, 0x01, 0x65, 0x03, 0x04, 0x01, 0x02)
+    private val OID_DES_EDE3_CBC = byteArrayOf(0x2a, 0x86.toByte(), 0x48, 0x86.toByte(), 0xf7.toByte(), 0x0d, 0x03, 0x07)
+
+    fun read(bytes: ByteArray, password: CharArray): Pair<PrivateKey, X509Certificate> {
+        val pfx = DerReader.read(bytes)
+        require(pfx.tag == 0x30) { "not a PFX" }
+        val pfxChildren = DerReader.children(pfx.content)
+        require(pfxChildren.size >= 2) { "PFX too small" }
+        // authSafe ContentInfo
+        val authSafeCi = DerReader.children(pfxChildren[1].content)
+        require(authSafeCi.size >= 2) { "authSafe malformed" }
+        // content: [0] EXPLICIT OCTET STRING -> AuthenticatedSafe
+        val explicit = DerReader.children(authSafeCi[1].content).first()
+        val octet = DerReader.read(explicit.content)
+        // octet.content is the AuthenticatedSafe body: a sequence of ContentInfo.
+        var privateKey: PrivateKey? = null
+        val certs = mutableListOf<X509Certificate>()
+        for (info in DerReader.children(octet.content)) {
+            val parts = DerReader.children(info.content)
+            if (parts.isEmpty()) continue
+            when {
+                parts[0].content.contentEquals(OID_DATA) ->
+                    parseSafeContentsContent(parts, password, certs) { privateKey = it }
+                parts[0].content.contentEquals(OID_ENCRYPTED_DATA) ->
+                    parseEncryptedData(parts, password, certs)
+            }
+        }
+        val key = privateKey ?: error("no private key bag found")
+        require(certs.isNotEmpty()) { "no certificate bag found" }
+        return key to certs[0]
+    }
+
+    /** A plaintext ContentInfo: [0] EXPLICIT OCTET STRING -> full SafeContents DER. */
+    private fun parseSafeContentsContent(
+        parts: List<Der>,
+        password: CharArray,
+        certs: MutableList<X509Certificate>,
+        onKey: (PrivateKey) -> Unit
+    ) {
+        val explicit = DerReader.children(parts[1].content).first()
+        parseSafeBags(explicit.content, password, certs, onKey)
+    }
+
+    /** EncryptedData ContentInfo: version, EncryptedContentInfo{ oid, PBES2 alg, [0] IMPLICIT OCTET }. */
+    private fun parseEncryptedData(
+        parts: List<Der>,
+        password: CharArray,
+        certs: MutableList<X509Certificate>
+    ) {
+        // parts[0] = encryptedData OID; parts[1] = [0] EXPLICIT EncryptedData SEQ
+        val explicit = DerReader.children(parts[1].content).first()
+        val eciParts = DerReader.children(explicit.content)
+        // eciParts = [version INT, EncryptedContentInfo SEQ]
+        require(eciParts.size >= 2) { "EncryptedData malformed" }
+        val eci = DerReader.children(eciParts[1].content)
+        // eci = [contentType OID, contentEncryptionAlgorithm, [0] IMPLICIT OCTET STRING]
+        require(eci.size >= 3) { "EncryptedContentInfo malformed" }
+        val alg = eci[1]
+        val ciphertext = eci[2].content // [0] IMPLICIT OCTET STRING -> raw bytes
+        val safeContents = decryptPbes2(alg, ciphertext, password)
+        // The decrypted SafeContents holds certificate bags.
+        parseSafeBags(safeContents, password, certs) {}
+    }
+
+    /** Decrypt a PBES2-encrypted blob given its AlgorithmIdentifier. */
+    private fun decryptPbes2(algorithm: Der, encrypted: ByteArray, password: CharArray): ByteArray {
+        val algParts = DerReader.children(algorithm.content)
+        require(algParts.size >= 2 && algParts[0].content.contentEquals(OID_PBES2)) { "not PBES2" }
+        // PBES2-params ::= SEQUENCE { kdf AlgorithmIdentifier, enc AlgorithmIdentifier }
+        val pbes2 = DerReader.children(algParts[1].content)
+        val kdf = DerReader.children(pbes2[0].content)
+        // KDF must be PBKDF2 (OpenSSL 3 also supports scrypt — not available on the
+        // platform JCE, so report it by name instead of a generic failure).
+        if (kdf.isEmpty() || !kdf[0].content.contentEquals(OID_PBKDF2)) {
+            error(oidName(kdf.firstOrNull()?.content))
+        }
+        val kdfParams = DerReader.children(kdf[1].content)
+        val salt = kdfParams[0].content
+        val iterations = readInt(kdfParams[1].content)
+        require(iterations in 1..10_000_000) { "implausible PBKDF2 iteration count" }
+        // Optional PBKDF2-params elements: keyLength (INTEGER) and/or prf (SEQUENCE),
+        // in either order. Distinguish by DER tag — mistaking prf for keyLength yields
+        // an absurd key size and a PBKDF2 that runs for hours.
+        var keyBits = -1 // -1 = not written; defaulted below from the cipher
+        var prfName = "PBKDF2WithHmacSHA1"
+        for (i in 2 until kdfParams.size) {
+            val param = kdfParams[i]
+            when (param.tag) {
+                0x02 -> keyBits = readInt(param.content) * 8
+                0x30 -> {
+                    val prf = DerReader.children(param.content)
+                    prfName = when {
+                        prf.isEmpty() || prf[0].content.contentEquals(OID_HMAC_SHA1) -> "PBKDF2WithHmacSHA1"
+                        prf[0].content.contentEquals(OID_HMAC_SHA256) -> "PBKDF2WithHmacSHA256"
+                        prf[0].content.contentEquals(OID_HMAC_SHA384) -> "PBKDF2WithHmacSHA384"
+                        prf[0].content.contentEquals(OID_HMAC_SHA512) -> "PBKDF2WithHmacSHA512"
+                        else -> error(oidName(prf[0].content))
+                    }
+                }
+            }
+        }
+        val enc = DerReader.children(pbes2[1].content)
+        val encOid = enc[0].content
+        val iv = enc[1].content
+        val (cipherName, aesKeyBits) = when {
+            encOid.contentEquals(OID_AES_256_CBC) -> "AES/CBC/PKCS5Padding" to 256
+            encOid.contentEquals(OID_AES_192_CBC) -> "AES/CBC/PKCS5Padding" to 192
+            encOid.contentEquals(OID_AES_128_CBC) -> "AES/CBC/PKCS5Padding" to 128
+            encOid.contentEquals(OID_DES_EDE3_CBC) -> "DESede/CBC/PKCS5Padding" to 192
+            else -> error(oidName(encOid))
+        }
+        val finalKeyBits = if (keyBits > 0) keyBits else aesKeyBits
+        require(finalKeyBits in 128..512) { "implausible PBKDF2 key size" }
+
+        val spec = PBEKeySpec(password, salt, iterations, finalKeyBits)
+        val secretKey = try {
+            SecretKeyFactory.getInstance(prfName).generateSecret(spec)
+        } catch (e: java.security.NoSuchAlgorithmException) {
+            // e.g. PBKDF2WithHmacSHA512 needs API 26+; surface the real reason.
+            error(prfName.replace("PBKDF2WithHmac", "PBKDF2-HMAC-") + " (needs Android 8.0+)")
+        }
+        val cipher = Cipher.getInstance(cipherName)
+        cipher.init(
+            Cipher.DECRYPT_MODE,
+            if (cipherName == "AES/CBC/PKCS5Padding") SecretKeySpec(secretKey.encoded, "AES")
+            else SecretKeySpec(secretKey.encoded, "DESede"),
+            IvParameterSpec(iv)
+        )
+        return cipher.doFinal(encrypted)
+    }
+
+    /** Human-readable name for a known algorithm OID. */
+    private fun oidName(oid: ByteArray?): String = when {
+        oid == null -> "unknown algorithm"
+        oid.contentEquals(OID_PBKDF2) -> "PBKDF2"
+        oid.contentEquals(OID_HMAC_SHA1) -> "PBKDF2-HMAC-SHA1"
+        oid.contentEquals(OID_HMAC_SHA256) -> "PBKDF2-HMAC-SHA256"
+        oid.contentEquals(OID_HMAC_SHA384) -> "PBKDF2-HMAC-SHA384"
+        oid.contentEquals(OID_HMAC_SHA512) -> "PBKDF2-HMAC-SHA512"
+        oid.contentEquals(OID_AES_256_CBC) -> "AES-256-CBC"
+        oid.contentEquals(OID_AES_192_CBC) -> "AES-192-CBC"
+        oid.contentEquals(OID_AES_128_CBC) -> "AES-128-CBC"
+        oid.contentEquals(OID_DES_EDE3_CBC) -> "DES-EDE3-CBC"
+        else -> "unknown algorithm"
+    }
+
+    private fun parseSafeBags(
+        safeContentsDer: ByteArray,
+        password: CharArray,
+        certs: MutableList<X509Certificate>,
+        onKey: (PrivateKey) -> Unit
+    ) {
+        val safeContents = DerReader.read(safeContentsDer)
+        require(safeContents.tag == 0x30) { "SafeContents malformed" }
+        for (bag in DerReader.children(safeContents.content)) {
+            val bagParts = DerReader.children(bag.content)
+            if (bagParts.size < 2) continue
+            val bagOid = bagParts[0].content
+            val bagValue = DerReader.children(bagParts[1].content).first()
+            when {
+                bagOid.contentEquals(OID_PKCS8_SHROUDED_KEY_BAG) ->
+                    onKey(decryptShroudedKeyBag(bagValue, password))
+                bagOid.contentEquals(OID_CERT_BAG) -> parseCertBag(bagValue, certs)
+            }
+        }
+    }
+
+    private fun decryptShroudedKeyBag(bagValue: Der, password: CharArray): PrivateKey {
+        // bagValue = the SafeBag value SEQ (EncryptedPrivateKeyInfo): children are
+        // [AlgorithmIdentifier, encryptedData OCTET STRING].
+        val parts = DerReader.children(bagValue.content)
+        require(parts.size == 2) { "EncryptedPrivateKeyInfo malformed" }
+        val pkcs8 = decryptPbes2(parts[0], parts[1].content, password)
+        return KeyFactory.getInstance("RSA").generatePrivate(PKCS8EncodedKeySpec(pkcs8))
+    }
+
+    private fun parseCertBag(bagValue: Der, certs: MutableList<X509Certificate>) {
+        // bagValue = the SafeBag value SEQ (CertBag): children are
+        // [certType OID, [0] EXPLICIT OCTET STRING (full X.509 DER)].
+        val parts = DerReader.children(bagValue.content)
+        if (parts.size < 2) return
+        if (!parts[0].content.contentEquals(OID_X509_CERT)) return
+        // [0] EXPLICIT -> OCTET STRING -> full X.509 certificate DER.
+        val explicit = DerReader.children(parts[1].content).first()
+        val certDer = explicit.content
+        val factory = CertificateFactory.getInstance("X.509")
+        certs.add(factory.generateCertificate(ByteArrayInputStream(certDer)) as X509Certificate)
+    }
+
+    private fun readInt(bytes: ByteArray): Int {
+        var value = 0
+        var start = 0
+        if (bytes.size > 1 && bytes[0].toInt() == 0x00) start = 1 // strip leading zero for positive
+        for (i in start until bytes.size) value = (value shl 8) or (bytes[i].toInt() and 0xff)
+        return value
+    }
+
+    /** Minimal DER element parser. */
+    private data class Der(val tag: Int, val content: ByteArray)
+
+    private object DerReader {
+        fun read(der: ByteArray, offset: Int = 0): Der {
+            require(offset < der.size) { "DER truncated" }
+            val tag = der[offset].toInt() and 0xff
+            var i = offset + 1
+            var len = der[i].toInt() and 0xff
+            i++
+            if (len and 0x80 != 0) {
+                val numBytes = len and 0x7f
+                len = 0
+                repeat(numBytes) {
+                    len = (len shl 8) or (der[i].toInt() and 0xff)
+                    i++
+                }
+            }
+            require(i + len <= der.size) { "DER length overflow" }
+            return Der(tag, der.copyOfRange(i, i + len))
+        }
+
+        fun children(content: ByteArray): List<Der> {
+            val out = mutableListOf<Der>()
+            var off = 0
+            while (off < content.size) {
+                val d = read(content, off)
+                out.add(d)
+                val step = headerSize(content, off) + d.content.size
+                if (step <= 0) break // defensive: never spin on malformed input
+                off += step
+            }
+            return out
+        }
+
+        private fun headerSize(der: ByteArray, offset: Int): Int {
+            var i = offset + 1
+            var len = der[i].toInt() and 0xff
+            i++
+            if (len and 0x80 != 0) i += len and 0x7f
+            return i - offset
+        }
+    }
+}

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

@@ -1,3 +1,21 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
 package com.rtbishop.look4sat.core.data.repository
 
 import com.rtbishop.look4sat.core.domain.model.AmSatReportSubmission

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

@@ -322,9 +322,9 @@ class LoTWRepository : ILoTWRepository {
                 line.startsWith("<MODE:") ->
                     mode = adifValue(line)
                 line.startsWith("<BAND_RX:") ->
-                    bandUp = adifValue(line).uppercase()
-                line.startsWith("<BAND:") && !line.startsWith("<BAND_RX:") ->
                     bandDown = adifValue(line).uppercase()
+                line.startsWith("<BAND:") && !line.startsWith("<BAND_RX:") ->
+                    bandUp = adifValue(line).uppercase()
                 line.startsWith("<DXCC:") ->
                     dxcc = adifValue(line).toIntOrNull()
                 line.startsWith("<COUNTRY:") ->

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

@@ -0,0 +1,134 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.data.repository
+
+import android.location.Location
+import android.location.LocationListener
+import android.location.LocationManager
+import androidx.core.location.LocationManagerCompat
+import com.rtbishop.look4sat.core.domain.repository.ILocationRepo
+import com.rtbishop.look4sat.core.domain.repository.LocationFix
+import com.rtbishop.look4sat.core.domain.repository.LocationState
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+
+private const val UPDATE_INTERVAL_MS = 1_000L
+private const val UPDATE_MIN_DISTANCE_M = 0f
+
+/**
+ * Live-location adapter for the field tools. Deliberately independent of
+ * [SettingsRepo]'s station position: a walk around a grid corner must not
+ * rewrite the station that every pass prediction is built on.
+ *
+ * Unlike [SettingsRepo.setStationPosition], this class always calls
+ * [LocationManager.removeUpdates] in [stopUpdates], so the listener is only
+ * alive while a screen is actually collecting fixes.
+ */
+class LocationRepo(
+    private val locationManager: LocationManager,
+    private val permissionGranted: () -> Boolean
+) : ILocationRepo, LocationListener {
+
+    private val _state = MutableStateFlow(initialState())
+    override val state: StateFlow<LocationState> = _state.asStateFlow()
+
+    private var isRegistered = false
+
+    override fun hasPermission(): Boolean = permissionGranted()
+
+    override fun startUpdates() {
+        if (isRegistered) return
+        val request = describeProvider() ?: return
+        if (!request.permissionGranted || !request.providerEnabled) return
+        try {
+            // A last-known fix is better than an empty screen while GPS warms up.
+            locationManager.getLastKnownLocation(request.provider)?.let(::publish)
+            locationManager.requestLocationUpdates(
+                request.provider, UPDATE_INTERVAL_MS, UPDATE_MIN_DISTANCE_M, this
+            )
+            isRegistered = true
+        } catch (exception: SecurityException) {
+            println("LocationRepo: no permission - $exception")
+        } catch (exception: IllegalArgumentException) {
+            println("LocationRepo: provider unavailable - $exception")
+        }
+    }
+
+    override fun stopUpdates() {
+        if (!isRegistered) return
+        isRegistered = false
+        try {
+            locationManager.removeUpdates(this)
+        } catch (exception: SecurityException) {
+            println("LocationRepo: removing updates without permission - $exception")
+        }
+    }
+
+    override fun onLocationChanged(location: Location) = publish(location)
+
+    override fun onProviderDisabled(provider: String) = refreshWaitingState()
+
+    override fun onProviderEnabled(provider: String) = refreshWaitingState()
+
+    private fun publish(location: Location) {
+        _state.value = LocationState.Fix(
+            LocationFix(
+                latitude = location.latitude,
+                longitude = location.longitude,
+                altitudeMeters = location.altitude.takeIf { location.hasAltitude() } ?: 0.0,
+                // Providers that cannot report accuracy use -1; treat that as
+                // useless rather than perfect.
+                accuracyMeters = location.accuracy.takeIf { location.hasAccuracy() } ?: Float.MAX_VALUE,
+                epochMs = location.time.takeIf { it > 0L } ?: System.currentTimeMillis()
+            )
+        )
+    }
+
+    private fun initialState(): LocationState {
+        val request = describeProvider()
+        return LocationState.Waiting(
+            permissionGranted = request?.permissionGranted ?: false,
+            providerEnabled = request?.providerEnabled ?: false
+        )
+    }
+
+    private fun refreshWaitingState() {
+        if (_state.value is LocationState.Fix) return
+        _state.value = initialState()
+    }
+
+    private fun describeProvider(): ProviderRequest? {
+        if (!permissionGranted()) {
+            return ProviderRequest(LocationManager.GPS_PROVIDER, false, false)
+        }
+        val enabled = LocationManagerCompat.isLocationEnabled(locationManager)
+        val provider = when {
+            locationManager.allProviders.contains(LocationManager.GPS_PROVIDER) -> LocationManager.GPS_PROVIDER
+            locationManager.allProviders.contains(LocationManager.NETWORK_PROVIDER) -> LocationManager.NETWORK_PROVIDER
+            else -> null
+        } ?: return null
+        return ProviderRequest(provider, true, enabled)
+    }
+
+    private data class ProviderRequest(
+        val provider: String,
+        val permissionGranted: Boolean,
+        val providerEnabled: Boolean
+    )
+}

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

@@ -0,0 +1,346 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ */
+package com.rtbishop.look4sat.core.data.repository
+
+import com.rtbishop.look4sat.core.data.database.QsoDao
+import com.rtbishop.look4sat.core.data.database.entity.QsoEntity
+import com.rtbishop.look4sat.core.domain.logbook.AdifCodec
+import com.rtbishop.look4sat.core.domain.logbook.AdifImportResult
+import com.rtbishop.look4sat.core.domain.logbook.IQsoRepository
+import com.rtbishop.look4sat.core.domain.logbook.QsoRecord
+import com.rtbishop.look4sat.core.domain.logbook.QsoStatus
+import com.rtbishop.look4sat.core.domain.logbook.displayMode
+import com.rtbishop.look4sat.core.domain.logbook.sameConfirmedContact
+import com.rtbishop.look4sat.core.domain.logbook.satelliteIdentity
+import com.rtbishop.look4sat.core.domain.logbook.splitConfirmationPairs
+import com.rtbishop.look4sat.core.domain.logbook.withConfirmation
+import com.rtbishop.look4sat.core.domain.logbook.confirmationLookupKey
+import com.rtbishop.look4sat.core.domain.logbook.officialSatelliteName
+import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
+import kotlinx.coroutines.withContext
+import java.util.Locale
+
+class QsoRepository(
+    private val dao: QsoDao,
+    private val dispatcher: CoroutineDispatcher
+) : IQsoRepository {
+    private val importMutex = Mutex()
+
+    override val records: Flow<List<QsoRecord>> = dao.observeAll().map { records -> records.map(QsoEntity::toDomain) }
+
+    override suspend fun find(id: Long): QsoRecord? = withContext(dispatcher) { dao.find(id)?.toDomain() }
+
+    override suspend fun save(record: QsoRecord): Long = withContext(dispatcher) {
+        importMutex.withLock {
+            val previous = if (record.id != 0L) dao.find(record.id)?.toDomain() else null
+            // Editing a record that was already uploaded or confirmed must not rewrite it in
+            // place: that contact already exists on LoTW under the old values. The original row
+            // keeps its upload/confirmation state, and the edited content is saved as a NEW
+            // record (without any LoTW state, so it can be uploaded again).
+            if (previous != null && (previous.lotwUploaded || previous.lotwConfirmed) &&
+                !record.sameEditableContentAs(previous)
+            ) {
+                dao.save(record.copy(
+                    id = 0L,
+                    lotwUploaded = false, lotwConfirmed = false, lotwReceived = false,
+                    lotwQslDate = "", vuccGrids = emptyList(),
+                    dxcc = null, country = "", cqZone = null, region = ""
+                ).toEntity())
+            } else {
+                val saved = if (previous?.lotwConfirmed == true && sameConfirmedContact(record, previous)) {
+                    record.withConfirmation(previous)
+                } else if (previous?.lotwConfirmed == true) record.copy(
+                    lotwConfirmed = false, lotwQslDate = "", vuccGrids = emptyList(),
+                    dxcc = null, country = "", cqZone = null, region = ""
+                ) else record
+                val received = if (previous != null && (
+                    stableQsoKey(record) != stableQsoKey(previous) || record.myGrid != previous.myGrid ||
+                        record.rxFrequencyHz != previous.rxFrequencyHz || record.band != previous.band ||
+                        record.rxBand != previous.rxBand || record.propagationMode != previous.propagationMode
+                    )) false else saved.lotwReceived
+                dao.save(saved.copy(lotwReceived = received).toEntity())
+            }
+        }
+    }
+
+    override suspend fun delete(id: Long) = withContext(dispatcher) { importMutex.withLock { dao.delete(id) } }
+
+    override suspend fun markUploaded(ids: List<Long>) = withContext(dispatcher) {
+        if (ids.isEmpty()) return@withContext
+        dao.markUploaded(ids)
+    }
+
+    override suspend fun exportAdi(ids: Set<Long>?, includeIncomplete: Boolean): String = withContext(dispatcher) {
+        val records = dao.getAll()
+            .asSequence()
+            .filter { ids == null || it.id in ids }
+            .map(QsoEntity::toDomain)
+            .filter { includeIncomplete || it.status == QsoStatus.COMPLETE }
+            .toList()
+        AdifCodec.encode(records)
+    }
+
+    override suspend fun importAdi(content: String): AdifImportResult = withContext(dispatcher) {
+        importMutex.withLock {
+            mergeRecords(AdifCodec.decode(content))
+        }
+    }
+
+    override suspend fun mergeConfirmed(records: List<QsoRecord>): AdifImportResult = withContext(dispatcher) {
+        importMutex.withLock { mergeRecords(records.filter { it.lotwConfirmed }) }
+    }
+
+    override suspend fun mergeLoTW(records: List<QsoRecord>): AdifImportResult = withContext(dispatcher) {
+        importMutex.withLock { mergeRecords(records, fromLoTW = true) }
+    }
+
+    override suspend fun consolidateConfirmations(): Int = withContext(dispatcher) {
+        importMutex.withLock {
+            val working = dao.getAll().map(QsoEntity::toDomain).toMutableList()
+            val consolidation = consolidateSplitRows(working)
+            val renames = rewriteOfficialNames(working)
+            if (consolidation.merged.isEmpty() && consolidation.redundant.isEmpty() && renames.isEmpty()) {
+                return@withLock 0
+            }
+            val toSave = LinkedHashMap(consolidation.merged).apply { putAll(renames) }
+            dao.saveBatch(toSave.values.map(QsoRecord::toEntity))
+            consolidation.redundant.forEach { dao.delete(it.id) }
+            consolidation.redundant.size
+        }
+    }
+
+    private suspend fun mergeRecords(records: List<QsoRecord>, fromLoTW: Boolean = false): AdifImportResult {
+        val working = dao.getAll().map(QsoEntity::toDomain).toMutableList()
+        // Consolidate first: confirmations synced before the identity fix sit as their own
+        // rows (the tracker name and a mirrored band direction both failed the comparison),
+        // and left in place they would make the lookup below ambiguous between the operator's
+        // own row and the stale duplicate.
+        val consolidation = consolidateSplitRows(working)
+        // Rows imported under a tracking-source name join the ARRL name here, so what is stored
+        // is the identity both sides of a match resolve to (the lookup below is built on it).
+        val renames = rewriteOfficialNames(working)
+        val lookup = working.indices.groupBy { working[it].confirmationLookupKey() }
+            .mapValues { it.value.toMutableList() }.toMutableMap()
+        val keyIndex = working.indices.groupBy { stableQsoKey(working[it]) }
+            .mapValues { it.value.toMutableList() }.toMutableMap()
+        val knownKeys = keyIndex.keys.toMutableSet()
+        val changes = linkedMapOf<Int, QsoRecord>().apply {
+            putAll(consolidation.merged)
+            putAll(renames)
+        }
+        var imported = 0
+        var updated = consolidation.merged.size
+        var skipped = 0
+        records.forEach { remote ->
+            if (!fromLoTW && !remote.lotwConfirmed && stableQsoKey(remote) in knownKeys) { skipped++; return@forEach }
+            val candidates = if (fromLoTW || remote.lotwConfirmed) lookup[remote.confirmationLookupKey()].orEmpty()
+                .filter { sameConfirmedContact(working[it], remote) } else emptyList()
+            val exact = candidates.filter { working[it].startUtcMillis == remote.startUtcMillis }
+            val match = exact.singleOrNull() ?: candidates.singleOrNull()
+            if (match == null) {
+                // A confirmation downloaded by the pre-fix parser sits as its own row with the
+                // band direction read mirrored (the downlink was stored as the uplink). It has no
+                // local partner (so nothing folds it) and its dedupe key equals the fresh report,
+                // so it would otherwise be skipped forever, keeping the wrong band on display.
+                // When the bands are exactly mirrored, adopt the report's direction instead.
+                val stale = if (fromLoTW) keyIndex[stableQsoKey(remote)]?.firstOrNull()
+                    ?.takeIf { index -> working[index].lotwConfirmed &&
+                        working[index].band.equals(remote.rxBand, true) &&
+                        working[index].rxBand.equals(remote.band, true) } else null
+                if (stale != null) {
+                    val fixed = working[stale].copy(band = remote.band, rxBand = remote.rxBand)
+                    working[stale] = fixed
+                    changes[stale] = fixed
+                    updated++
+                    return@forEach
+                }
+                if (stableQsoKey(remote) in knownKeys) { skipped++; return@forEach }
+                val added = remote.copy(id = 0L, satelliteName = officialSatelliteName(remote.satelliteName))
+                changes[working.size] = added
+                lookup.getOrPut(added.confirmationLookupKey()) { mutableListOf() }.add(working.size)
+                keyIndex.getOrPut(stableQsoKey(added)) { mutableListOf() }.add(working.size)
+                knownKeys += stableQsoKey(added)
+                working += added
+                imported++
+            } else {
+                val previous = working[match]
+                val merged = previous.withConfirmation(remote)
+                if (merged == previous) skipped++ else {
+                    working[match] = merged
+                    changes[match] = merged
+                    updated++
+                }
+            }
+        }
+        dao.saveBatch(changes.values.map(QsoRecord::toEntity))
+        consolidation.redundant.forEach { dao.delete(it.id) }
+        return AdifImportResult(imported, skipped, updated)
+    }
+
+    /** Result of folding already-split rows back together. */
+    private data class Consolidation(
+        /** index in the stored list -> the record to save (local row + its confirmation). */
+        val merged: Map<Int, QsoRecord>,
+        /** imported confirmation rows that are now part of a local record. */
+        val redundant: List<QsoRecord>
+    )
+
+    /**
+     * Rewrites the names records were imported under into their ARRL names ("SAUDISAT 1C" ->
+     * "SO-50"), so the logbook, the ADIF export and the signed record all carry one name.
+     * Names the alias table does not know (recycled placeholders, satellites ARRL does not
+     * list) are kept exactly as they are. [working] is updated in place; the rewritten records
+     * are returned for the caller to save.
+     */
+    private fun rewriteOfficialNames(working: MutableList<QsoRecord>): Map<Int, QsoRecord> {
+        val renamed = mutableMapOf<Int, QsoRecord>()
+        working.indices.forEach { index ->
+            val record = working[index]
+            val official = officialSatelliteName(record.satelliteName)
+            if (official != record.satelliteName) {
+                val updated = record.copy(satelliteName = official)
+                working[index] = updated
+                renamed[index] = updated
+            }
+        }
+        return renamed
+    }
+
+    /**
+     * Folds confirmation rows that were imported as separate QSOs back into the local
+     * record they belong to (see [splitConfirmationPairs]). [working] is updated in
+     * place; the redundant rows are returned for the caller to delete.
+     */
+    private fun consolidateSplitRows(working: MutableList<QsoRecord>): Consolidation {
+        val merged = mutableMapOf<Int, QsoRecord>()
+        val redundant = mutableListOf<QsoRecord>()
+        // Snapshot the pairs first: the list is rewritten as pairs are applied.
+        splitConfirmationPairs(working.toList()).forEach { pair ->
+            val local = working[pair.localIndex]
+            val confirmation = working[pair.confirmationIndex]
+            val folded = local.withConfirmation(confirmation)
+            if (folded != local) {
+                working[pair.localIndex] = folded
+                merged[pair.localIndex] = folded
+            }
+            redundant += confirmation
+        }
+        return Consolidation(merged, redundant)
+    }
+}
+
+private fun QsoEntity.toDomain() = QsoRecord(
+    id = id,
+    startUtcMillis = startUtcMillis,
+    endUtcMillis = endUtcMillis,
+    theirCallsign = theirCallsign,
+    myCallsign = myCallsign,
+    theirGrid = theirGrid,
+    myGrid = myGrid,
+    sentReport = sentReport,
+    receivedReport = receivedReport,
+    txFrequencyHz = txFrequencyHz,
+    rxFrequencyHz = rxFrequencyHz,
+    band = band,
+    rxBand = rxBand,
+    mode = mode,
+    submode = submode,
+    satelliteName = satelliteName,
+    transponderName = transponderName,
+    satelliteMode = satelliteMode,
+    passAosUtcMillis = passAosUtcMillis,
+    automatic = automatic,
+    status = runCatching { QsoStatus.valueOf(status) }.getOrDefault(QsoStatus.DRAFT),
+    propagationMode = propagationMode,
+    lotwConfirmed = lotwConfirmed,
+    lotwUploaded = lotwUploaded,
+    lotwReceived = lotwReceived,
+    lotwQslDate = lotwQslDate,
+    vuccGrids = vuccGrids.split(',').filter(String::isNotBlank),
+    dxcc = dxcc,
+    country = country,
+    cqZone = cqZone,
+    region = region,
+    comment = comment
+)
+
+private fun QsoRecord.toEntity() = QsoEntity(
+    id = id,
+    startUtcMillis = startUtcMillis,
+    endUtcMillis = endUtcMillis,
+    theirCallsign = theirCallsign.trim().uppercase(Locale.US),
+    myCallsign = myCallsign.trim().uppercase(Locale.US),
+    theirGrid = theirGrid.trim().uppercase(Locale.US),
+    myGrid = myGrid.trim().uppercase(Locale.US),
+    sentReport = sentReport.trim(),
+    receivedReport = receivedReport.trim(),
+    txFrequencyHz = txFrequencyHz,
+    rxFrequencyHz = rxFrequencyHz,
+    band = band,
+    rxBand = rxBand,
+    mode = mode.trim(),
+    submode = submode.trim(),
+    satelliteName = satelliteName,
+    transponderName = transponderName,
+    satelliteMode = satelliteMode,
+    passAosUtcMillis = passAosUtcMillis,
+    automatic = automatic,
+    status = status.name,
+    dedupeKey = stableQsoKey(this),
+    propagationMode = propagationMode.ifBlank { if (satelliteName.isNotBlank()) "SAT" else "" },
+    lotwConfirmed = lotwConfirmed,
+    lotwUploaded = lotwUploaded,
+    lotwReceived = lotwReceived,
+    lotwQslDate = lotwQslDate,
+    vuccGrids = vuccGrids.joinToString(","),
+    dxcc = dxcc,
+    country = country,
+    cqZone = cqZone,
+    region = region,
+    comment = comment
+)
+
+internal fun stableQsoKey(record: QsoRecord): String = listOf(
+    record.startUtcMillis.toString(),
+    record.theirCallsign.trim().uppercase(Locale.US),
+    record.myCallsign.trim().uppercase(Locale.US),
+    record.txFrequencyHz?.toString().orEmpty(),
+    record.mode.trim().uppercase(Locale.US),
+    record.submode.trim().uppercase(Locale.US),
+    // The identity, not the spelling: a row stored as "SO-50" is the same QSO as one imported
+    // as "SAUDISAT 1C", so re-importing an older export does not duplicate it.
+    satelliteIdentity(record.satelliteName)
+).joinToString("|")
+
+/**
+ * Whether two rows carry the same operator-editable content.
+ *
+ * Minutes are the granularity for time: the edit dialog edits whole minutes (and rounds the
+ * stored seconds away when saving), so a seconds-only difference must not count as an edit.
+ * The satellite is compared by its ARRL identity, the mode by its display label — both sides
+ * of the same contact written differently (tracker vs official name, MFSK vs FT4) are the same
+ * content. Used to decide whether saving an already-uploaded/confirmed row should create a new
+ * record or leave the row alone.
+ */
+private fun QsoRecord.sameEditableContentAs(other: QsoRecord): Boolean =
+    theirCallsign.trim().equals(other.theirCallsign.trim(), true) &&
+        startUtcMillis / 60_000L == other.startUtcMillis / 60_000L &&
+        txFrequencyHz == other.txFrequencyHz &&
+        rxFrequencyHz == other.rxFrequencyHz &&
+        displayMode == other.displayMode &&
+        satelliteIdentity(satelliteName) == satelliteIdentity(other.satelliteName) &&
+        sentReport.trim() == other.sentReport.trim() &&
+        receivedReport.trim() == other.receivedReport.trim() &&
+        theirGrid.trim().uppercase(Locale.US) == other.theirGrid.trim().uppercase(Locale.US) &&
+        comment == other.comment

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

@@ -877,6 +877,31 @@ class SettingsRepo(
     }
     //endregion
 
+    //region # Per-satellite logbook mode preset settings
+    private val keySatelliteModes = "satelliteModes"
+
+    override fun getSatelliteMode(catnum: Int): String {
+        val json = preferences.getString(keySatelliteModes, "{}") ?: "{}"
+        return try {
+            JSONObject(json).optString(catnum.toString(), "")
+        } catch (_: Exception) {
+            ""
+        }
+    }
+
+    override fun setSatelliteMode(catnum: Int, mode: String) {
+        val json = preferences.getString(keySatelliteModes, "{}") ?: "{}"
+        val updated = try {
+            val obj = JSONObject(json)
+            if (mode.isBlank()) obj.remove(catnum.toString()) else obj.put(catnum.toString(), mode.uppercase())
+            obj.toString()
+        } catch (_: Exception) {
+            if (mode.isBlank()) "{}" else """{"$catnum": "${mode.uppercase()}"}"""
+        }
+        preferences.edit { putString(keySatelliteModes, updated) }
+    }
+    //endregion
+
     //region # AMSAT status report settings
     private val keyAmSatCallsign = "amSatCallsign"
 

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

@@ -1,3 +1,21 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
 package com.rtbishop.look4sat.core.data.repository
 
 import com.rtbishop.look4sat.core.domain.model.LatestRelease

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

@@ -29,7 +29,7 @@ class AddToCalendar(private val context: Context) : IAddToCalendar {
             addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
             setData(CalendarContract.Events.CONTENT_URI)
             putExtra(CalendarContract.Events.TITLE, name)
-            putExtra(CalendarContract.Events.DESCRIPTION, "Look4Sat Pass")
+            putExtra(CalendarContract.Events.DESCRIPTION, "Look4Sat-BA7OPF Pass")
             putExtra(CalendarContract.EXTRA_EVENT_BEGIN_TIME, aosTime)
             putExtra(CalendarContract.EXTRA_EVENT_END_TIME, losTime)
         }

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

@@ -1,3 +1,21 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
 package com.rtbishop.look4sat.core.data.framework
 
 import org.junit.Assert.assertArrayEquals

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

@@ -0,0 +1,51 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.data.framework
+
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNotNull
+import org.junit.Assert.assertNull
+import org.junit.Test
+
+class IcomCivProtocolTest {
+
+    private fun bytes(vararg values: Int) = ByteArray(values.size) { values[it].toByte() }
+
+    @Test
+    fun parseFreqModePayload_ic705ReadFreqReply() {
+        // Reply captured from an IC-705 to CMD 0x03: frequency only, no mode byte
+        val reply = bytes(0xFE, 0xFE, 0xE0, 0xA4, 0x03, 0x60, 0x74, 0x95, 0x45, 0x01, 0xFD)
+        val response = IcomCivProtocol.parseResponse(reply, IcomCivProtocol.CMD_READ_FREQ)
+        assertNotNull(response)
+        assertEquals(145957460L to "", IcomCivProtocol.parseFreqModePayload(response!!.payload))
+    }
+
+    @Test
+    fun parseFreqModePayload_withModeByte() {
+        assertEquals(
+            435611000L to "USB",
+            IcomCivProtocol.parseFreqModePayload(bytes(0x00, 0x10, 0x61, 0x35, 0x04, 0x01, 0x01))
+        )
+    }
+
+    @Test
+    fun parseFreqModePayload_tooShort() {
+        assertNull(IcomCivProtocol.parseFreqModePayload(bytes(0x60, 0x74, 0x95, 0x45)))
+    }
+}

core/data/src/test/java/com/rtbishop/look4sat/core/data/lotw/LoTWConfigTest.kt

@@ -0,0 +1,126 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ */
+package com.rtbishop.look4sat.core.data.lotw
+
+import com.rtbishop.look4sat.core.domain.logbook.LoTWSatelliteAliases
+import com.rtbishop.look4sat.core.domain.repository.LoTWOperationException
+import com.rtbishop.look4sat.core.domain.repository.LoTWZonePair
+import java.io.File
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+/** Parses the real bundled ARRL config.tq6 to verify region-field and zonemap extraction. */
+class LoTWConfigTest {
+
+    private val config = LoTWConfig(File("src/main/assets/lotw/config.tq6").inputStream())
+
+    @Test
+    fun `china exposes province field with all 31 options and zonemaps`() {
+        val meta = config.stationMeta(318)
+        assertEquals("CN_PROVINCE", meta.regionField?.id)
+        assertEquals("Province", meta.regionField?.label)
+        assertEquals(31, meta.regionField?.options?.size)
+        val gd = meta.regionField?.options?.first { it.code == "GD" }
+        assertEquals("Guangdong", gd?.name)
+        assertEquals(listOf(LoTWZonePair(44, 24)), gd?.zones)
+        val gx = meta.regionField?.options?.first { it.code == "GX" }
+        assertEquals(listOf(LoTWZonePair(43, 24), LoTWZonePair(44, 24)), gx?.zones)
+        // China spans 8 zone pairs — the UI must NOT prefill from the national map.
+        assertTrue(meta.countryZones.size > 1)
+    }
+
+    @Test
+    fun `usa exposes state field with 49 continental options`() {
+        val meta = config.stationMeta(291)
+        assertEquals("US_STATE", meta.regionField?.id)
+        assertEquals("State", meta.regionField?.label)
+        // AK and HI are separate DXCC entities (6 and 110) with their own 1-option blocks.
+        assertEquals(49, meta.regionField?.options?.size)
+        assertTrue(meta.regionField!!.options.none { it.code == "AK" || it.code == "HI" })
+        assertTrue(meta.countryZones.size > 1)
+    }
+
+    @Test
+    fun `alaska and hawaii each expose their own single-state block`() {
+        val ak = config.stationMeta(6)
+        assertEquals(listOf("AK"), ak.regionField?.options?.map { it.code })
+        val hi = config.stationMeta(110)
+        assertEquals(listOf("HI"), hi.regionField?.options?.map { it.code })
+    }
+
+    @Test
+    fun `germany has no region field and one national zone pair`() {
+        val meta = config.stationMeta(230)
+        assertNull(meta.regionField)
+        assertEquals(listOf(LoTWZonePair(28, 14)), meta.countryZones)
+    }
+
+    @Test
+    fun `india has no region field and one national zone pair`() {
+        val meta = config.stationMeta(324)
+        assertNull(meta.regionField)
+        assertEquals(listOf(LoTWZonePair(41, 22)), meta.countryZones)
+    }
+
+    @Test
+    fun `unknown entity yields empty meta`() {
+        val meta = config.stationMeta(999999)
+        assertNull(meta.regionField)
+        assertTrue(meta.countryZones.isEmpty())
+    }
+
+    @Test
+    fun `tracker catalogue names resolve to the ARRL satellite`() {
+        // The names the TLE sources store vs the single name ARRL knows for that satellite.
+        assertEquals("SO-50", config.resolveSatellite("SAUDISAT 1C"))
+        assertEquals("ARISS", config.resolveSatellite("ISS (ZARYA)"))
+        assertEquals("PO-101", config.resolveSatellite("DIWATA 2B"))
+        assertEquals("AO-91", config.resolveSatellite("FOX-1B"))
+        assertEquals("IO-86", config.resolveSatellite("LAPAN-A2"))
+        assertEquals("RS-44", config.resolveSatellite("DOSAAF-85"))
+        assertEquals("BO-102", config.resolveSatellite("CAS-7B"))
+        assertEquals("SO-50", config.resolveSatellite("SO-50"))
+    }
+
+    @Test
+    fun `satellite signing accepts tracker names and keeps ARRL spelling`() {
+        assertEquals("SO-50", config.satellite("SAUDISAT 1C", "2026-09-27"))
+        assertEquals("ARISS", config.satellite("ISS (ZARYA)", "2026-09-27"))
+        assertEquals("SO-50", config.satellite("SO-50 (SaudiOSCAR 50)", "2026-09-27"))
+    }
+
+    @Test
+    fun `satellite signing rejects names ARRL does not know`() {
+        // Placeholder designations are deliberately unmapped: signing them would name the
+        // wrong object, so the record must stay un-uploadable.
+        listOf("OBJECT AY", "MARINA", "NOT A SATELLITE").forEach { name ->
+            val error = runCatching { config.satellite(name, "2026-09-27") }.exceptionOrNull()
+            assertTrue("$name should be rejected", error is LoTWOperationException)
+        }
+    }
+
+    @Test
+    fun `satellite signing enforces the ARRL service dates`() {
+        // SO-50 is listed from 2002-12-20: a QSO before that cannot be signed.
+        val error = runCatching { config.satellite("SAUDISAT 1C", "2002-01-01") }.exceptionOrNull()
+        assertTrue(error is LoTWOperationException)
+        assertEquals("SO-50", config.satellite("SAUDISAT 1C", "2003-01-01"))
+    }
+
+    @Test
+    fun `every alias target is a real ARRL satellite name`() {
+        val catalogue = config.satelliteNames().toSet()
+        assertTrue("ARRL catalogue is unexpectedly small", catalogue.size > 100)
+        val unknown = LoTWSatelliteAliases.table.filterValues { it !in catalogue }
+        assertEquals("alias targets missing from config.tq6: $unknown", emptyMap<String, String>(), unknown)
+    }
+}

core/data/src/test/java/com/rtbishop/look4sat/core/data/lotw/Pkcs12ReaderTest.kt

@@ -0,0 +1,134 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.rtbishop.look4sat.core.data.lotw
+
+import java.security.Signature
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNotNull
+import org.junit.Assert.assertThrows
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+/**
+ * Verifies the PBES2/AES-256-CBC PKCS12 reader against a fixture generated with
+ * `openssl pkcs12 -export -certpbe NONE` — same layout as modern TQSL exports
+ * (plain certificate bags + PBES2-shrouded private key), which Android's legacy
+ * Bouncy Castle parser cannot read.
+ */
+class Pkcs12ReaderTest {
+
+    private fun fixture(): ByteArray =
+        javaClass.classLoader!!.getResourceAsStream("test_pbes2.p12")!!.use { it.readBytes() }
+
+    private fun fixture(name: String): ByteArray =
+        javaClass.classLoader!!.getResourceAsStream(name)!!.use { it.readBytes() }
+
+    @Test
+    fun readsAes192Variant() {
+        val (key, cert) = Pkcs12Reader.read(fixture("test_pbes2_aes192.p12"), "testpass123".toCharArray())
+        assertEquals("RSA", key.algorithm)
+        assertEquals("RSA", cert.publicKey.algorithm)
+        assertTrue("key/cert pair", keyMatches(key, cert))
+    }
+
+    @Test
+    fun readsDesEde3CbcVariant() {
+        val (key, cert) = Pkcs12Reader.read(fixture("test_pbes2_desede3.p12"), "testpass123".toCharArray())
+        assertEquals("RSA", key.algorithm)
+        assertEquals("RSA", cert.publicKey.algorithm)
+        assertTrue("key/cert pair", keyMatches(key, cert))
+    }
+
+    @Test
+    fun unsupportedCipherNamesTheAlgorithm() {
+        // A valid PBES2 file re-encrypted with an unsupported cipher must report the
+        // algorithm name (so the user can see exactly what to re-export with).
+        val fixtureBytes = fixture("test_pbes2.p12")
+        val e = assertThrows(IllegalStateException::class.java) {
+            // Simulate: patch the AES-256-CBC OID inside the file to an unknown OID.
+            val bogus = ByteArray(fixtureBytes.size) { fixtureBytes[it] }
+            // find AES-256-CBC OID bytes 0x60 86 48 01 65 03 04 01 2a
+            val oid = byteArrayOf(0x60, 0x86.toByte(), 0x48, 0x01, 0x65, 0x03, 0x04, 0x01, 0x2a)
+            var idx = -1
+            outer@ for (i in 0..bogus.size - oid.size) {
+                for (j in oid.indices) if (bogus[i + j] != oid[j]) continue@outer
+                idx = i; break
+            }
+            require(idx >= 0) { "AES-256-CBC OID not found in fixture" }
+            bogus[idx] = 0x7f.toByte() // corrupt the OID tag byte → unknown cipher
+            Pkcs12Reader.read(bogus, "testpass123".toCharArray())
+        }
+        assertTrue("mentions algorithm", e.message.orEmpty().contains("algorithm"))
+    }
+
+    private fun keyMatches(key: java.security.PrivateKey, cert: java.security.cert.X509Certificate): Boolean {
+        val challenge = "Look4Sat LoTW certificate key check".toByteArray(Charsets.US_ASCII)
+        val signed = Signature.getInstance("SHA1withRSA").run {
+            initSign(key); update(challenge); sign()
+        }
+        return Signature.getInstance("SHA1withRSA").run {
+            initVerify(cert); update(challenge); verify(signed)
+        }
+    }
+
+    @Test
+    fun wrongPasswordFailsWithBadPadding() {
+        // A wrong password must surface as a decryption failure (BadPadding), which
+        // LoTWKeyMaterial maps to CERTIFICATE_PASSWORD — not a format error.
+        val e = assertThrows(Exception::class.java) {
+            Pkcs12Reader.read(fixture(), "definitely-wrong-password".toCharArray())
+        }
+        assertTrue("BadPadding", e is javax.crypto.BadPaddingException)
+    }
+
+    @Test
+    fun readsPbes2KeyAndCertificate() {
+        val (key, cert) = Pkcs12Reader.read(fixture(), "testpass123".toCharArray())
+        assertEquals("RSA", key.algorithm)
+        assertEquals("RSA", cert.publicKey.algorithm)
+        assertNotNull(cert.subjectX500Principal)
+    }
+
+    @Test
+    fun keyPairsWithCertificate() {
+        val (key, cert) = Pkcs12Reader.read(fixture(), "testpass123".toCharArray())
+        val challenge = "Look4Sat LoTW certificate key check".toByteArray(Charsets.US_ASCII)
+        val signed = Signature.getInstance("SHA1withRSA").run {
+            initSign(key); update(challenge); sign()
+        }
+        val valid = Signature.getInstance("SHA1withRSA").run {
+            initVerify(cert); update(challenge); verify(signed)
+        }
+        assertTrue("private key must match certificate", valid)
+    }
+
+    @Test
+    fun wrongPasswordThrows() {
+        assertThrows(Exception::class.java) {
+            Pkcs12Reader.read(fixture(), "wrongpass".toCharArray())
+        }
+    }
+
+    @Test
+    fun garbageBytesThrows() {
+        assertThrows(Exception::class.java) {
+            Pkcs12Reader.read("not a p12 file at all".toByteArray(), "x".toCharArray())
+        }
+    }
+}

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

@@ -1,3 +1,21 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
 package com.rtbishop.look4sat.core.data.repository
 
 import com.rtbishop.look4sat.core.domain.model.SatStatus

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

@@ -298,6 +298,8 @@ private class FakeSettingsRepo(dataSources: DataSourcesSettings = defaultDataSou
     override fun updateRadioControlSettings(settings: RadioControlSettings) = Unit
 
     override fun getSatelliteOffset(catnum: Int): String = ""
+    override fun getSatelliteMode(catnum: Int): String = ""
+    override fun setSatelliteMode(catnum: Int, mode: String) {}
 
     override fun setSatelliteOffset(catnum: Int, offset: String) = Unit
 

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

@@ -1,3 +1,21 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
 package com.rtbishop.look4sat.core.data.repository
 
 import com.rtbishop.look4sat.core.domain.repository.LoTWResult
@@ -112,9 +130,12 @@ class LoTWRepositoryTest {
         assertEquals("A50QO", qso.call)
         assertEquals("FO-29", qso.satName)
         assertEquals("CW", qso.mode)
-        assertEquals("2M", qso.bandUp)
-        assertEquals("70CM", qso.bandDown)
-        assertEquals("V/U", qso.bandLabel)
+        // ADIF BAND is the transmitted (uplink) band, BAND_RX the received (downlink) one.
+        // Confirmed against the live report of the own uploads: SO-50 QSOs arrive as
+        // BAND=2M/FREQ=145.85000 + BAND_RX=70CM/FREQ_RX=436.80500, i.e. BAND=uplink.
+        assertEquals("70CM", qso.bandUp)
+        assertEquals("2M", qso.bandDown)
+        assertEquals("U/V", qso.bandLabel)
         assertEquals(2026, java.time.Instant.ofEpochMilli(qso.epochMs).atZone(java.time.ZoneOffset.UTC).year)
     }
 

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

@@ -0,0 +1,292 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ */
+package com.rtbishop.look4sat.core.data.repository
+
+import com.rtbishop.look4sat.core.data.database.QsoDao
+import com.rtbishop.look4sat.core.data.database.entity.QsoEntity
+import com.rtbishop.look4sat.core.domain.logbook.QsoRecord
+import com.rtbishop.look4sat.core.domain.logbook.QsoStatus
+import com.rtbishop.look4sat.core.domain.logbook.toConfirmedRecord
+import com.rtbishop.look4sat.core.domain.model.GridQso
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flowOf
+import kotlinx.coroutines.runBlocking
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertNotEquals
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+/**
+ * The logbook split reported 2026-09-28: a QSO uploaded from the app and the confirmation LoTW
+ * reported for it ended up as two rows, because the record keeps the tracking-source name
+ * ("SAUDISAT 1C") and the uplink band while the report carries the ARRL name ("SO-50") — and,
+ * before the direction fix, the mirrored band pair.
+ */
+class QsoRepositoryTest {
+
+    private val dao = FakeQsoDao()
+    private val repository = QsoRepository(dao, Dispatchers.Unconfined)
+
+    /** 2026-09-16 07:45Z, an SO-50 contact of the user's own report. */
+    private val qsoStart = 1_789_544_700_000L
+
+    @Test
+    fun mergeLoTW_confirmsTheUploadedRecordInsteadOfAddingASecondRow() = runBlocking {
+        val uploadedId = dao.save(loggedInApp("SAUDISAT 1C", lotwUploaded = true).toEntity()) // 145.850 -> 2M
+
+        repository.mergeLoTW(listOf(reportConfirmation(satName = "SO-50")))
+
+        val rows = dao.getAll()
+        assertEquals(1, rows.size)
+        assertEquals(uploadedId, rows.first().id)
+        assertTrue(rows.first().lotwConfirmed)
+        // The row is also renamed to the ARRL spelling while it is merged.
+        assertEquals("SO-50", rows.first().satelliteName)
+        assertEquals(145_850_000L, rows.first().txFrequencyHz)
+    }
+
+    @Test
+    fun mergeLoTW_foldsRowsSplitByTheOldNameAndBandMismatch() = runBlocking {
+        val uploadedId = dao.save(loggedInApp("SAUDISAT 1C", lotwUploaded = true).toEntity())
+        // Row imported before the fix: ARRL name and the mirrored band pair (BAND_RX read as
+        // the uplink), so it never folded into the local record.
+        dao.save(
+            reportConfirmation(satName = "SO-50").copy(band = "70CM", rxBand = "2M").toEntity()
+        )
+
+        repository.mergeLoTW(listOf(reportConfirmation(satName = "SO-50")))
+
+        val rows = dao.getAll()
+        assertEquals(1, rows.size)
+        assertEquals(uploadedId, rows.first().id)
+        assertTrue(rows.first().lotwConfirmed)
+        // The operator's own frequencies survive the consolidation.
+        assertEquals(145_850_000L, rows.first().txFrequencyHz)
+        assertEquals(436_795_000L, rows.first().rxFrequencyHz)
+    }
+
+    @Test
+    fun mergeLoTW_keepsAnotherContactOfTheSamePassApart() = runBlocking {
+        dao.save(loggedInApp("SAUDISAT 1C", lotwUploaded = true).toEntity())
+        val otherOperator = reportConfirmation(satName = "SO-50").copy(theirCallsign = "BG5JVM")
+
+        repository.mergeLoTW(listOf(reportConfirmation(satName = "SO-50"), otherOperator))
+
+        val rows = dao.getAll()
+        assertEquals(2, rows.size)
+        // The local row is confirmed by its own report entry; the second operator's contact
+        // is a separate QSO and stays a separate, separately confirmed row.
+        assertEquals(setOf("BG5JSB", "BG5JVM"), rows.map { it.theirCallsign }.toSet())
+        assertTrue(rows.all { it.lotwConfirmed })
+    }
+
+    @Test
+    fun consolidateConfirmations_repairsAnAlreadySplitLogbook() = runBlocking {
+        val uploadedId = dao.save(loggedInApp("SAUDISAT 1C", lotwUploaded = true).toEntity())
+        // Row imported before the fix: ARRL name + mirrored band pair.
+        dao.save(reportConfirmation(satName = "SO-50").copy(band = "70CM", rxBand = "2M").toEntity())
+
+        assertEquals(1, repository.consolidateConfirmations())
+
+        val rows = dao.getAll()
+        assertEquals(1, rows.size)
+        assertEquals(uploadedId, rows.first().id)
+        assertTrue(rows.first().lotwConfirmed)
+        // Nothing left to fold on a second pass.
+        assertEquals(0, repository.consolidateConfirmations())
+    }
+
+    @Test
+    fun consolidateConfirmations_renamesRowsImportedUnderATrackerName() = runBlocking {
+        // A record logged before names were normalised at write time.
+        val id = dao.save(loggedInApp("SAUDISAT 1C", lotwUploaded = true).toEntity())
+
+        repository.consolidateConfirmations()
+
+        val row = dao.getAll().single()
+        assertEquals(id, row.id)
+        assertEquals("SO-50", row.satelliteName)
+        // Upload state and the operator's own frequencies survive the rename.
+        assertTrue(row.lotwUploaded)
+        assertEquals(145_850_000L, row.txFrequencyHz)
+        // A satellite ARRL does not list keeps whatever the tracker published.
+        dao.save(loggedInApp("FOO-1", lotwUploaded = false).toEntity())
+        repository.consolidateConfirmations()
+        assertEquals(setOf("SO-50", "FOO-1"), dao.getAll().map { it.satelliteName }.toSet())
+    }
+
+    @Test
+    fun mergeLoTW_fixesBandDirectionOfAStaleConfirmationRow() = runBlocking {
+        // A confirmation downloaded by the pre-fix parser: ARRL name but the band direction
+        // mirrored (downlink stored as the uplink), and no local row to fold it into, so it
+        // sits as its own QSL row.
+        val staleId = dao.save(reportConfirmation(satName = "SO-50").copy(band = "70CM", rxBand = "2M").toEntity())
+
+        repository.mergeLoTW(listOf(reportConfirmation(satName = "SO-50")))
+
+        val rows = dao.getAll()
+        assertEquals(1, rows.size)
+        assertEquals(staleId, rows.first().id)
+        assertTrue(rows.first().lotwConfirmed)
+        // The stale row adopts the report's (uplink-first) direction instead of being skipped
+        // forever by the dedupe key.
+        assertEquals("2M", rows.first().band)
+        assertEquals("70CM", rows.first().rxBand)
+    }
+
+    @Test
+    fun save_editingAnUploadedRecordCreatesANewRecord() = runBlocking {
+        val originalId = repository.save(loggedInApp("SAUDISAT 1C", lotwUploaded = true))
+        val edited = loggedInApp("SAUDISAT 1C", lotwUploaded = true).copy(id = originalId, theirCallsign = "BG5JVM")
+
+        val newId = repository.save(edited)
+
+        assertNotEquals(originalId, newId)
+        val rows = dao.getAll()
+        assertEquals(2, rows.size)
+        // The original keeps its identity and upload state, untouched.
+        val original = rows.first { it.id == originalId }
+        assertEquals("BG5JSB", original.theirCallsign)
+        assertTrue(original.lotwUploaded)
+        // The edited content is a fresh, uploadable record.
+        val created = rows.first { it.id == newId }
+        assertEquals("BG5JVM", created.theirCallsign)
+        assertFalse(created.lotwUploaded)
+        assertFalse(created.lotwConfirmed)
+    }
+
+    @Test
+    fun save_editingAnUnuploadedRecordUpdatesInPlace() = runBlocking {
+        val id = repository.save(loggedInApp("SAUDISAT 1C", lotwUploaded = false))
+        repository.save(loggedInApp("SAUDISAT 1C", lotwUploaded = false).copy(id = id, theirCallsign = "BG5JVM"))
+
+        val rows = dao.getAll()
+        assertEquals(1, rows.size)
+        assertEquals("BG5JVM", rows.first().theirCallsign)
+    }
+
+    @Test
+    fun save_editingAnUploadedRecordWithoutChangesKeepsOneRow() = runBlocking {
+        val id = repository.save(loggedInApp("SAUDISAT 1C", lotwUploaded = true))
+        repository.save(loggedInApp("SAUDISAT 1C", lotwUploaded = true).copy(id = id))
+
+        assertEquals(1, dao.getAll().size)
+    }
+
+    @Test
+    fun save_editingAnUploadedRecordWithOnlySecondsChangedKeepsOneRow() = runBlocking {
+        val id = repository.save(loggedInApp("SAUDISAT 1C", lotwUploaded = true))
+        // The edit dialog edits whole minutes and rounds the seconds away on save, so a
+        // seconds-only difference must not be treated as an edit (no new record).
+        repository.save(loggedInApp("SAUDISAT 1C", lotwUploaded = true).copy(id = id, startUtcMillis = qsoStart + 10_000L))
+
+        assertEquals(1, dao.getAll().size)
+    }
+
+    /** A record as the log page creates it: tracker name, repeater pair, uplink band. */
+    private fun loggedInApp(satelliteName: String, lotwUploaded: Boolean) = QsoRecord(
+        startUtcMillis = qsoStart,
+        theirCallsign = "BG5JSB",
+        myCallsign = "BA7OPF",
+        txFrequencyHz = 145_850_000L,
+        rxFrequencyHz = 436_795_000L,
+        band = "2M",
+        rxBand = "70CM",
+        mode = "FM",
+        satelliteName = satelliteName,
+        propagationMode = "SAT",
+        status = QsoStatus.COMPLETE,
+        lotwUploaded = lotwUploaded
+    )
+
+    /** A confirmation as the report parser + [toConfirmedRecord] build it (BAND carries the uplink). */
+    private fun reportConfirmation(satName: String) = GridQso(
+        call = "BG5JSB",
+        epochMs = qsoStart,
+        satName = satName,
+        mode = "FM",
+        bandUp = "2M",
+        bandDown = "70CM",
+        dxcc = 318,
+        country = "China",
+        cqz = 24,
+        state = "GD",
+        myGrid = "OL62",
+        myGrids = setOf("OL62", "OL63")
+    ).toConfirmedRecord("BA7OPF")
+
+    private fun QsoRecord.toEntity() = QsoEntity(
+        id = id,
+        startUtcMillis = startUtcMillis,
+        endUtcMillis = endUtcMillis,
+        theirCallsign = theirCallsign,
+        myCallsign = myCallsign,
+        theirGrid = theirGrid,
+        myGrid = myGrid,
+        sentReport = sentReport,
+        receivedReport = receivedReport,
+        txFrequencyHz = txFrequencyHz,
+        rxFrequencyHz = rxFrequencyHz,
+        band = band,
+        rxBand = rxBand,
+        mode = mode,
+        submode = submode,
+        satelliteName = satelliteName,
+        transponderName = transponderName,
+        satelliteMode = satelliteMode,
+        passAosUtcMillis = passAosUtcMillis,
+        automatic = automatic,
+        status = status.name,
+        dedupeKey = listOf(startUtcMillis, theirCallsign, myCallsign, txFrequencyHz, mode, submode, satelliteName)
+            .joinToString("|"),
+        propagationMode = propagationMode,
+        lotwConfirmed = lotwConfirmed,
+        lotwUploaded = lotwUploaded,
+        lotwReceived = lotwReceived,
+        lotwQslDate = lotwQslDate,
+        vuccGrids = vuccGrids.joinToString(","),
+        dxcc = dxcc,
+        country = country,
+        cqZone = cqZone,
+        region = region,
+        comment = comment
+    )
+
+    private class FakeQsoDao : QsoDao {
+        private val rows = linkedMapOf<Long, QsoEntity>()
+        private var nextId = 1L
+
+        override fun observeAll(): Flow<List<QsoEntity>> = flowOf(rows.values.toList())
+
+        override suspend fun find(id: Long): QsoEntity? = rows[id]
+
+        override suspend fun getAll(): List<QsoEntity> = rows.values.toList()
+
+        override suspend fun getDedupeKeys(): List<String> = rows.values.map { it.dedupeKey }
+
+        override suspend fun save(record: QsoEntity): Long {
+            val id = if (record.id == 0L) nextId++ else record.id
+            rows[id] = record.copy(id = id)
+            return id
+        }
+
+        override suspend fun importRecords(records: List<QsoEntity>): List<Long> = records.map { save(it) }
+
+        override suspend fun delete(id: Long) {
+            rows.remove(id)
+        }
+
+        override suspend fun markUploaded(ids: List<Long>) {
+            ids.forEach { id -> rows[id]?.let { rows[id] = it.copy(lotwUploaded = true) } }
+        }
+    }
+}

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

@@ -343,6 +343,8 @@ private class FakeSettingsRepoForSearch : ISettingsRepo {
     override fun updateDataSourcesStatus(status: Map<String, Int>) = Unit
     override fun updateRadioControlSettings(settings: RadioControlSettings) = Unit
     override fun getSatelliteOffset(catnum: Int): String = ""
+    override fun getSatelliteMode(catnum: Int): String = ""
+    override fun setSatelliteMode(catnum: Int, mode: String) {}
     override fun setSatelliteOffset(catnum: Int, offset: String) = Unit
     override fun getAmSatCallsign(): String = ""
     override fun setAmSatCallsign(callsign: String) = Unit

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/logbook/AdifCodec.kt

@@ -0,0 +1,163 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ */
+package com.rtbishop.look4sat.core.domain.logbook
+
+import java.text.SimpleDateFormat
+import java.util.Date
+import java.util.Locale
+import java.util.TimeZone
+
+/** Small ADI codec for the logbook's actual field set (ADIF 3.1.7). */
+object AdifCodec {
+    private val utc = TimeZone.getTimeZone("UTC")
+
+    fun encode(records: List<QsoRecord>): String = buildString {
+        append(field("ADIF_VER", "3.1.7"))
+        append(field("PROGRAMID", "Look4Sat"))
+        append("<EOH>\r\n")
+        records.forEach { record ->
+            val startDate = format(record.startUtcMillis, "yyyyMMdd")
+            val startTime = format(record.startUtcMillis, "HHmmss")
+            append(field("QSO_DATE", startDate))
+            append(field("TIME_ON", startTime))
+            record.endUtcMillis?.let {
+                append(field("QSO_DATE_OFF", format(it, "yyyyMMdd")))
+                append(field("TIME_OFF", format(it, "HHmmss")))
+            }
+            append(field("CALL", record.theirCallsign))
+            append(field("STATION_CALLSIGN", record.myCallsign))
+            appendOptional("MODE", record.mode)
+            appendOptional("SUBMODE", record.submode)
+            appendOptional("GRIDSQUARE", record.theirGrid)
+            appendOptional("MY_GRIDSQUARE", record.myGrid)
+            appendOptional("RST_SENT", record.sentReport)
+            appendOptional("RST_RCVD", record.receivedReport)
+            record.txFrequencyHz?.let { append(field("FREQ", hzToMhz(it))) }
+            record.rxFrequencyHz?.let { append(field("FREQ_RX", hzToMhz(it))) }
+            appendOptional("BAND", record.band)
+            appendOptional("BAND_RX", record.rxBand)
+            appendOptional("PROP_MODE", record.propagationMode.ifBlank { if (record.satelliteName.isNotBlank()) "SAT" else "" })
+            appendOptional("SAT_NAME", record.satelliteName)
+            appendOptional("SAT_MODE", record.satelliteMode)
+            if (record.lotwConfirmed) append(field("LOTW_QSL_RCVD", "Y"))
+            if (record.lotwReceived) append(field("LOTW_QSL_SENT", "Y"))
+            appendOptional("LOTW_QSLRDATE", record.lotwQslDate)
+            appendOptional("VUCC_GRIDS", record.vuccGrids.joinToString(","))
+            record.dxcc?.let { append(field("DXCC", it.toString())) }
+            appendOptional("COUNTRY", record.country)
+            record.cqZone?.let { append(field("CQZ", it.toString())) }
+            appendOptional("STATE", record.region)
+            appendOptional("COMMENT", record.comment)
+            appendOptional("APP_LOOK4SAT_TRANSPONDER", record.transponderName)
+            record.passAosUtcMillis?.let { append(field("APP_LOOK4SAT_PASS_AOS", it.toString())) }
+            append(field("APP_LOOK4SAT_AUTOMATIC", if (record.automatic) "Y" else "N"))
+            append(field("APP_LOOK4SAT_STATUS", record.status.name))
+            append("<EOR>\r\n")
+        }
+    }
+
+    fun decode(content: String): List<QsoRecord> = decodeRecords(splitRecords(content))
+
+    fun decodeRecords(records: List<Map<String, String>>): List<QsoRecord> = records.mapNotNull { values ->
+        val call = values["CALL"].orEmpty().trim().uppercase(Locale.US)
+        val date = values["QSO_DATE"].orEmpty()
+        val time = values["TIME_ON"].orEmpty()
+        if (call.isBlank() || date.length != 8 || time.length !in setOf(4, 6)) return@mapNotNull null
+        val start = parse(date, time) ?: return@mapNotNull null
+        val end = values["QSO_DATE_OFF"]?.let { endDate ->
+            values["TIME_OFF"]?.let { endTime -> parse(endDate, endTime) }
+        }
+        QsoRecord(
+            startUtcMillis = start,
+            endUtcMillis = end,
+            theirCallsign = call,
+            myCallsign = values["STATION_CALLSIGN"].orEmpty().uppercase(Locale.US),
+            theirGrid = values["GRIDSQUARE"].orEmpty().uppercase(Locale.US),
+            myGrid = values["MY_GRIDSQUARE"].orEmpty().uppercase(Locale.US),
+            sentReport = values["RST_SENT"].orEmpty(),
+            receivedReport = values["RST_RCVD"].orEmpty(),
+            txFrequencyHz = mhzToHz(values["FREQ"]),
+            rxFrequencyHz = mhzToHz(values["FREQ_RX"]),
+            band = values["BAND"].orEmpty(),
+            rxBand = values["BAND_RX"].orEmpty(),
+            mode = values["MODE"].orEmpty(),
+            submode = values["SUBMODE"].orEmpty(),
+            satelliteName = values["SAT_NAME"].orEmpty(),
+            transponderName = values["APP_LOOK4SAT_TRANSPONDER"].orEmpty(),
+            satelliteMode = values["SAT_MODE"].orEmpty(),
+            passAosUtcMillis = values["APP_LOOK4SAT_PASS_AOS"]?.toLongOrNull(),
+            automatic = values["APP_LOOK4SAT_AUTOMATIC"].equals("Y", true),
+            status = values["APP_LOOK4SAT_STATUS"]?.let { runCatching { QsoStatus.valueOf(it) }.getOrNull() }
+                ?: QsoStatus.COMPLETE,
+            propagationMode = values["PROP_MODE"].orEmpty().trim().uppercase(Locale.US),
+            lotwConfirmed = values["LOTW_QSL_RCVD"].equals("Y", true),
+            lotwReceived = values["LOTW_QSL_SENT"].equals("Y", true),
+            lotwQslDate = values["LOTW_QSLRDATE"].orEmpty(),
+            vuccGrids = values["VUCC_GRIDS"].orEmpty().split(',').map { it.trim().uppercase(Locale.US) }
+                .filter { it.matches(Regex("[A-R]{2}[0-9]{2}([A-X]{2}([0-9]{2})?)?")) }.distinct(),
+            dxcc = values["DXCC"]?.toIntOrNull(),
+            country = values["COUNTRY"].orEmpty(),
+            cqZone = values["CQZ"]?.toIntOrNull()?.takeIf { it in 1..40 },
+            region = values["STATE"].orEmpty().substringBefore(" // ").trim().uppercase(Locale.US),
+            comment = values["COMMENT"].orEmpty()
+        )
+    }
+
+    private fun splitRecords(content: String): List<Map<String, String>> {
+        val records = mutableListOf<Map<String, String>>()
+        var values = linkedMapOf<String, String>()
+        var index = 0
+        while (index < content.length) {
+            val start = content.indexOf('<', index)
+            if (start < 0) break
+            val end = content.indexOf('>', start + 1)
+            if (end < 0) break
+            val descriptor = content.substring(start + 1, end)
+            val parts = descriptor.split(':')
+            val name = parts.first().trim().uppercase(Locale.US)
+            index = end + 1
+            when (name) {
+                "EOH" -> values.clear()
+                "EOR" -> {
+                    if (values.isNotEmpty()) records += values.toMap()
+                    values = linkedMapOf()
+                }
+                else -> {
+                    val length = parts.getOrNull(1)?.toIntOrNull() ?: continue
+                    if (length < 0 || index + length > content.length) continue
+                    values[name] = content.substring(index, index + length)
+                    index += length
+                }
+            }
+        }
+        return records
+    }
+
+    private fun StringBuilder.appendOptional(name: String, value: String) {
+        if (value.isNotBlank()) append(field(name, value))
+    }
+
+    private fun field(name: String, value: String): String = "<$name:${value.length}>$value"
+
+    private fun hzToMhz(value: Long): String = String.format(Locale.US, "%.6f", value / 1_000_000.0)
+
+    private fun mhzToHz(value: String?): Long? = value?.toDoubleOrNull()?.let { (it * 1_000_000.0).toLong() }
+
+    private fun format(value: Long, pattern: String): String =
+        SimpleDateFormat(pattern, Locale.US).apply { timeZone = utc }.format(Date(value))
+
+    private fun parse(date: String, time: String): Long? = runCatching {
+        val normalizedTime = if (time.length == 4) "${time}00" else time
+        SimpleDateFormat("yyyyMMddHHmmss", Locale.US).apply {
+            isLenient = false
+            timeZone = utc
+        }.parse(date + normalizedTime)?.time
+    }.getOrNull()
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/logbook/IQsoRepository.kt

@@ -0,0 +1,33 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ */
+package com.rtbishop.look4sat.core.domain.logbook
+
+import kotlinx.coroutines.flow.Flow
+
+interface IQsoRepository {
+    val records: Flow<List<QsoRecord>>
+
+    suspend fun find(id: Long): QsoRecord?
+    suspend fun save(record: QsoRecord): Long
+    suspend fun delete(id: Long)
+    suspend fun markUploaded(ids: List<Long>)
+    suspend fun exportAdi(ids: Set<Long>? = null, includeIncomplete: Boolean = false): String
+    suspend fun importAdi(content: String): AdifImportResult
+    suspend fun mergeConfirmed(records: List<QsoRecord>): AdifImportResult
+    suspend fun mergeLoTW(records: List<QsoRecord>): AdifImportResult
+
+    /**
+     * Folds LoTW confirmations that were imported as their own rows back into the local
+     * record they belong to (see [com.rtbishop.look4sat.core.domain.logbook.splitConfirmationPairs]).
+     * Confirmations merged before the tracker-name/band identity fix split every contact in
+     * two; this repairs the existing logbook. Returns the number of merged rows.
+     */
+    suspend fun consolidateConfirmations(): Int
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/logbook/LoTWReportBridge.kt

@@ -0,0 +1,46 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by 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.logbook
+
+import com.rtbishop.look4sat.core.domain.model.GridQso
+
+/** Bridge a LoTW report QSO (confirmed, download side) into a logbook record
+ *  so the logbook can show downloaded confirmations and mark local uploads
+ *  as confirmed (matched by [sameConfirmedContact]). */
+fun GridQso.toConfirmedRecord(accountCallsign: String): QsoRecord = QsoRecord(
+    startUtcMillis = epochMs,
+    theirCallsign = call,
+    myCallsign = accountCallsign.trim().uppercase(),
+    myGrid = (myGrids.firstOrNull() ?: myGrid).orEmpty(),
+    vuccGrids = myGrids.toList(),
+    band = bandUp,
+    rxBand = bandDown,
+    mode = mode,
+    // On satellites, MODE=MFSK means FT4 (ADIF pairing); keep the sub-mode so
+    // confirmations match local FT4 records (mode=MFSK, submode=FT4).
+    submode = if (mode.equals("MFSK", true)) "FT4" else "",
+    satelliteName = satName,
+    propagationMode = "SAT",
+    status = QsoStatus.COMPLETE,
+    lotwConfirmed = true,
+    dxcc = dxcc,
+    country = country.orEmpty(),
+    cqZone = cqz,
+    region = state.orEmpty()
+)

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/logbook/LoTWSatelliteAliases.kt

@@ -0,0 +1,148 @@
+/*
+ * 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.logbook
+
+import java.util.Locale
+
+/**
+ * Satellite names of the ARRL LoTW catalogue and the tracker names that map onto them.
+ *
+ * ARRL's config.tq6 knows every satellite by exactly ONE name ("SO-50", "ARISS", "PO-101",
+ * "BO-102"), while the TLE sources the tracker uses carry their own catalogue names: SatNOGS
+ * lists SO-50 as "SAUDISAT 1C", the ISS as "ISS (ZARYA)", PO-101 as "DIWATA 2B" and AO-123 as
+ * "OBJECT AY". Without this mapping a signed QSO on those satellites is rejected as an unknown
+ * satellite.
+ *
+ * Keys are tracker names normalised by [normalize] (upper case, A-Z0-9 only); values are the
+ * exact config.tq6 satellite names. Generated 2026-09-27 from:
+ *  - SatNOGS DB satellites (`name` + `names` alias list) joined to config.tq6 by exact alias,
+ *  - live SatNOGS 3LE names and Celestrak amateur names joined to the same NORAD id,
+ *  - designator tokens of the config.tq6 satellite descriptions (e.g. CAS-7B -> BO-102),
+ *  - the ISS family, which SatNOGS does not list under its ARRL name "ARISS".
+ * Placeholder names ("OBJECT AY" and friends) are deliberately NOT mapped: they are recycled
+ * between objects and would sign the wrong satellite. LoTWConfigTest asserts that every target
+ * here is a real config.tq6 name.
+ */
+object LoTWSatelliteAliases {
+
+    val table: Map<String, String> = mapOf(
+        "AMSATOSCAR7" to "AO-7", "AO123" to "AO-123", "AO16" to "AO-16",
+        "AO27" to "AO-27", "AO7" to "AO-7", "AO73" to "AO-73",
+        "AO85" to "AO-85", "AO91" to "AO-91", "AO92" to "AO-92",
+        "ARISSAT1" to "KEDR", "ASRTU1" to "AO-123", "ASRTUFRIENDSHIP" to "AO-123",
+        "BJ2CR" to "AO-123", "BREEZEKMRB" to "RS-44", "BRICSAT2" to "NO-103",
+        "BRICSATP" to "NO-83", "BY701" to "BY70-1", "CAMSAT" to "FO-118",
+        "CAS10" to "HO-119", "CAS2F" to "XW-2F", "CAS2T" to "CAS-2T",
+        "CAS3A" to "XW-2A", "CAS3B" to "XW-2B", "CAS3C" to "XW-2C",
+        "CAS3CBJ1SD" to "XW-2C", "CAS3D" to "XW-2D", "CAS3E" to "XW-2E",
+        "CAS3F" to "XW-2F", "CAS4A" to "CAS-4A", "CAS4B" to "CAS-4B",
+        "CAS5A" to "FO-118", "CAS6" to "TO-108", "CAS7B" to "BO-102",
+        "CAS9" to "HO-113", "CZ11RB" to "CAS-2T", "DELFIC3" to "DO-64",
+        "DIWATA2" to "PO-101", "DIWATA2B" to "PO-101", "DO64" to "DO-64",
+        "DOSAAF85" to "RS-44", "DRUZHBAATURK" to "AO-123", "EO79" to "EO-79",
+        "EO88" to "EO-88", "ESHAIL2" to "QO-100", "EUROPEANOSCAR79" to "EO-79",
+        "EYESAT1" to "AO-27", "EYESATA" to "AO-27", "FENGTAIOSCAR118" to "FO-118",
+        "FO118" to "FO-118", "FO29" to "FO-29", "FOX1" to "AO-85",
+        "FOX1A" to "AO-85", "FOX1B" to "AO-91", "FOX1D" to "AO-92",
+        "FRESCO" to "LO-87", "FUNCUBE1" to "AO-73", "FUNCUBE2" to "UKUBE1",
+        "FUNCUBE3" to "EO-79", "FUNCUBE5" to "EO-88", "GREENCUBE" to "IO-117",
+        "HADESD" to "SO-121", "HADESICM" to "SO-125", "HADESR" to "SO-124",
+        "HAIL2" to "QO-100", "HAMSAT" to "VO-52", "HO113" to "HO-113",
+        "HO119" to "HO-119", "HOPE4" to "HO-119", "HYDRA1" to "SO-121",
+        "INSPIRESAT7" to "INSPR7", "IO117" to "IO-117", "IO86" to "IO-86",
+        "ISS" to "ARISS", "ISSZARYA" to "ARISS", "JAS2" to "FO-29",
+        "JINNIUZUO1" to "TAURUS", "JO97" to "JO-97", "JORDANOSCAR97" to "JO-97",
+        "JY1SAT" to "JO-97", "LAPANA2" to "IO-86", "LILACSAT1" to "LO-90",
+        "LILACSAT2" to "CAS-3H", "LITUANICASAT1" to "LO-78", "LO19" to "LO-19",
+        "LO87" to "LO-87", "LUSAT" to "LO-19", "LUSEX" to "LO-87",
+        "MAYA3" to "MAYA-3", "MAYA4" to "MAYA-4", "MESAT1" to "MO-122",
+        "MESAT1OSCAR" to "MO-122", "MESAT1OSCAR122" to "MO-122", "MIRSAT1" to "MO-112",
+        "MO122" to "MO-122", "MTCUBE2" to "IO-117", "NA1SS" to "ARISS",
+        "NAYIF1" to "EO-88", "NEWSAT1" to "LO-87", "NO103" to "NO-103",
+        "NO104" to "NO-104", "NO44" to "NO-44", "NO83" to "NO-83",
+        "NO84" to "NO-84", "NUSAT1" to "LO-87", "ORARI" to "IO-86",
+        "OSCAR16PACSAT" to "AO-16", "OSCAR19LUSAT" to "LO-19", "OSCAR64" to "DO-64",
+        "OSCAR7" to "AO-7", "PACSAT" to "AO-16", "PARKINSONSAT" to "NO-84",
+        "PCSAT" to "NO-44", "PHILLIPINESOSCAR101" to "PO-101", "PO101" to "PO-101",
+        "PSAT" to "NO-84", "PSAT2" to "NO-104", "QB50P1" to "EO-79",
+        "QO100" to "QO-100", "RADFXSAT" to "AO-91", "RADIOROSTO" to "RS-15",
+        "RS0ISS" to "ARISS", "RS14" to "AO-21", "RS15" to "RS-15",
+        "RS44" to "RS-44", "RS64S" to "AO-123", "SAUDISAT1C" to "SO-50",
+        "SO121" to "SO-121", "SO124" to "SO-124", "SO125" to "SO-125",
+        "SO50" to "SO-50", "SOLUTUSNANOSATTELITE" to "SONATE", "SONATE2" to "SONATE",
+        "TAURUS1" to "TAURUS", "TEVEL21" to "TEV2-1", "TEVEL22" to "TEV2-2",
+        "TEVEL23" to "TEV2-3", "TEVEL24" to "TEV2-4", "TEVEL25" to "TEV2-5",
+        "TEVEL26" to "TEV2-6", "TEVEL27" to "TEV2-7", "TEVEL28" to "TEV2-8",
+        "TEVEL29" to "TEV2-9", "USAT1" to "LO-87", "USNAP1" to "NO-103",
+        "VO52" to "VO-52", "W3ADO" to "NO-44", "XW2A" to "XW-2A",
+        "XW2B" to "XW-2B", "XW2C" to "XW-2C", "XW2D" to "XW-2D",
+        "XW2E" to "XW-2E", "XW2F" to "XW-2F", "XW3" to "HO-113",
+        "XW3CAS9" to "HO-113", "XW4" to "HO-119", "YB0X" to "IO-86",
+        "ZARYA" to "ARISS",
+
+    )
+
+    /**
+     * Tracker name -> ARRL name. An exact table hit wins; otherwise the longest alias key
+     * contained in the name matches, so a name carrying an extra suffix ("SAUDISAT 1C
+     * (SO-50)") still resolves. Keys shorter than 5 characters never match loosely.
+     */
+    fun lookup(name: String): String? {
+        val normalized = normalize(name)
+        table[normalized]?.let { return it }
+        return table.entries
+            .filter { it.key.length >= 5 && normalized.contains(it.key) }
+            .maxByOrNull { it.key.length }
+            ?.value
+    }
+
+    /** Upper case, everything that is not A-Z0-9 removed ("ISS (ZARYA)" -> "ISSZARYA"). */
+    fun normalize(name: String): String = name.uppercase(Locale.US).filter { it.isLetterOrDigit() }
+
+    /**
+     * Resolve any tracker name against the ARRL catalogue: exact official name, then an alias
+     * from [table], then an official name contained in the tracker name. Returns the official
+     * name, or null when the tracker name is not an ARRL satellite at all.
+     */
+    fun resolve(name: String, officialNames: Collection<String>): String? {
+        val trimmed = name.trim()
+        if (trimmed.isEmpty()) return null
+        val normalized = trimmed.uppercase(Locale.US)
+        officialNames.firstOrNull { it.equals(trimmed, true) }?.let { return it }
+        lookup(trimmed)?.let { alias -> officialNames.firstOrNull { it.equals(alias, true) }?.let { return it } }
+        return officialNames.firstOrNull { it.length > 1 && normalized.contains(it) }
+    }
+
+    /**
+     * Catalogue candidates for a partly typed name. Alias keys are matched too, so the
+     * operator's own spelling ("diwata", "saudisat 1c", "ao9") reaches the ARRL name even
+     * when the two share no characters.
+     */
+    fun suggestions(query: String, officialNames: Collection<String>, limit: Int = 6): List<String> {
+        val normalized = normalize(query)
+        if (normalized.isEmpty()) return emptyList()
+        val fromAliases = table.entries
+            .filter { it.key.contains(normalized) || normalized.contains(it.key) }
+            .map { it.value }
+        val fromNames = officialNames.filter { normalize(it).contains(normalized) }
+        return (fromAliases + fromNames + listOfNotNull(lookup(query)))
+            .distinct()
+            .filter { candidate -> officialNames.any { it.equals(candidate, true) } }
+            .take(limit)
+    }
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/logbook/LoTWUploadMessages.kt

@@ -0,0 +1,70 @@
+/*
+ * 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.logbook
+
+import com.rtbishop.look4sat.core.domain.repository.LoTWProblem
+
+/**
+ * Wording for the reasons a QSO cannot be signed for LoTW.
+ *
+ * The logbook used to report every one of these as "invalid call/date", which sent the operator
+ * looking at the callsign and date even when the real cause was a missing frequency (no BAND) or
+ * a satellite name ARRL does not know.
+ */
+fun LoTWProblem.label(): String = when (this) {
+    LoTWProblem.BAND -> "missing frequency/band"
+    LoTWProblem.SATELLITE -> "satellite name not in ARRL's list"
+    LoTWProblem.MODE -> "mode not accepted by LoTW"
+    LoTWProblem.QSO_DATE -> "date outside the certificate"
+    LoTWProblem.CALLSIGN_MISMATCH -> "MY callsign does not match the certificate"
+    LoTWProblem.INVALID_CONTACT -> "invalid callsign/record"
+    LoTWProblem.STATION_GRID -> "station grid missing"
+    LoTWProblem.STATION_REGION -> "station region missing"
+    LoTWProblem.STATION_ZONE -> "station zones missing"
+    LoTWProblem.STATION_IOTA -> "station IOTA missing"
+    LoTWProblem.TOO_MANY_CONTACTS -> "too many contacts in one batch"
+    LoTWProblem.EMPTY_SELECTION -> "nothing selected"
+    else -> name.lowercase().replace('_', ' ')
+}
+
+/**
+ * One-line explanation of why records were left out of an upload, e.g.
+ * "3 QSO(s) can't be uploaded — 2× missing frequency/band, 1× satellite name not in ARRL's list (SAUDISAT 1C)".
+ * Returns an empty string when nothing was skipped.
+ */
+fun unavailableUploadSummary(
+    total: Int,
+    reasons: Map<LoTWProblem, Int> = emptyMap(),
+    details: Map<LoTWProblem, String> = emptyMap(),
+    duplicates: Int = 0,
+    incomplete: Int = 0
+): String {
+    if (total <= 0) return ""
+    val parts = reasons.entries
+        .sortedByDescending { it.value }
+        .map { (problem, count) ->
+            val detail = details[problem]?.takeIf { it.isNotBlank() }?.let { " ($it)" }.orEmpty()
+            "$count× ${problem.label()}$detail"
+        }
+        .toMutableList()
+    if (duplicates > 0) parts += "$duplicates× duplicate of another record in the batch"
+    if (incomplete > 0) parts += "$incomplete× record not completed"
+    val subject = if (total == 1) "1 QSO can't be uploaded" else "$total QSO(s) can't be uploaded"
+    val detail = parts.joinToString(", ").ifBlank { "check the logbook" }
+    return "$subject — $detail"
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/logbook/QsoConfirmationMerge.kt

@@ -0,0 +1,178 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by 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.logbook
+
+import java.util.Locale
+import kotlin.math.abs
+
+/** LoTW official name vs tracking-source name ("SO-50 (SaudiOSCAR 50)"): compare the
+ *  parenthetical-free prefix. Kept as the last-resort identity for names the alias
+ *  table does not know (see [satelliteIdentity]). */
+fun satMatchKey(name: String): String = name.substringBefore('(').trim().uppercase(Locale.US)
+
+/**
+ * The satellite identity both sides of a match resolve to.
+ *
+ * A local record keeps whatever the tracking source published ("SAUDISAT 1C",
+ * "ISS (ZARYA)", "DIWATA 2B", "JAS 2") while the LoTW report always carries the ARRL
+ * name ("SO-50", "ARISS", "PO-101", "FO-29"). Comparing the raw names made the two
+ * sides of the SAME contact unequal, so a downloaded confirmation was stored as a
+ * second, separate QSO instead of confirming the uploaded one.
+ *
+ * Both sides are therefore resolved through [LoTWSatelliteAliases], which maps the
+ * tracker names onto the ARRL names and every ARRL name onto itself. Names the table
+ * does not know (e.g. the recycled "OBJECT xx" placeholders) keep falling back to the
+ * parenthetical-free prefix, i.e. they simply never match anything else.
+ */
+fun satelliteIdentity(name: String): String {
+    val trimmed = name.trim()
+    if (trimmed.isEmpty()) return ""
+    val prefix = satMatchKey(trimmed)
+    return LoTWSatelliteAliases.lookup(trimmed)
+        ?: LoTWSatelliteAliases.lookup(prefix)
+        ?: prefix
+}
+
+/**
+ * The name a QSO is stored under: the ARRL name whenever the tracking source's name maps onto
+ * one, otherwise the name as published.
+ *
+ * Records used to keep the tracker's spelling ("SAUDISAT 1C", "ISS (ZARYA)", "OBJECT AY") while
+ * every signed ADIF carries the ARRL name, so the logbook showed a different satellite than the
+ * one LoTW knows and only the upload path resolved the two. Storing the ARRL name keeps one name
+ * for the logbook, the ADIF export and the signature. Names the alias table does not know are
+ * left exactly as they are: satellites ARRL does not list have no official name to store, and the
+ * recycled "OBJECT xx" placeholders must never be mapped onto a real satellite.
+ */
+fun officialSatelliteName(name: String, officialNames: Collection<String> = emptyList()): String {
+    val trimmed = name.trim()
+    if (trimmed.isEmpty()) return ""
+    LoTWSatelliteAliases.resolve(trimmed, officialNames)?.let { return it }
+    val prefix = satMatchKey(trimmed)
+    return LoTWSatelliteAliases.lookup(trimmed) ?: LoTWSatelliteAliases.lookup(prefix) ?: trimmed
+}
+
+/**
+ * Everything about a contact except its bands: the same opposite station, the same
+ * satellite, the same mode and less than a minute apart. LoTW reports the minute, so
+ * the time window is what makes a match unambiguous.
+ */
+fun sameContactIdentity(local: QsoRecord, remote: QsoRecord): Boolean {
+    val localSat = satelliteIdentity(local.satelliteName)
+    return localSat.isNotBlank() &&
+        localSat == satelliteIdentity(remote.satelliteName) &&
+        local.theirCallsign.trim().equals(remote.theirCallsign.trim(), true) &&
+        (local.myCallsign.isBlank() || remote.myCallsign.isBlank() || local.myCallsign.equals(remote.myCallsign, true)) &&
+        local.isSatellite == remote.isSatellite &&
+        local.displayMode == remote.displayMode &&
+        abs(local.startUtcMillis - remote.startUtcMillis) < 60_000L
+}
+
+/** Bands agree when both sides name one and they are the same; a missing band is not a mismatch. */
+private fun sameBandOrBlank(one: String, other: String): Boolean =
+    one.isBlank() || other.isBlank() || one.equals(other, true)
+
+/** LoTW omits frequency and may round time to a minute. Only merge an unambiguous contact. */
+fun sameConfirmedContact(local: QsoRecord, remote: QsoRecord): Boolean =
+    sameContactIdentity(local, remote) && sameBandOrBlank(local.band, remote.band)
+
+fun QsoRecord.confirmationLookupKey(): String = listOf(
+    theirCallsign.trim().uppercase(Locale.US), satelliteIdentity(satelliteName), displayMode
+).joinToString("|")
+
+/** A local row and the confirmation row that belongs to it, as indices into one list. */
+data class SplitConfirmationPair(val localIndex: Int, val confirmationIndex: Int)
+
+/**
+ * Rows that a confirmation should have been folded into but was not, so they can be
+ * consolidated back into one.
+ *
+ * Confirmations merged before the identity fix landed as their own rows: the tracker
+ * name vs ARRL name comparison failed, and the band direction of the report was read
+ * mirrored (BAND_RX was taken as the uplink), so even satellites with matching names
+ * were stored twice. The pair is only accepted when the contact identity matches and
+ * the bands are either identical or exactly mirrored — the signature of that second
+ * mismatch — which keeps unrelated QSOs of the same operator and minute apart.
+ */
+fun splitConfirmationPairs(records: List<QsoRecord>): List<SplitConfirmationPair> {
+    val pendingIndices = records.indices.filter { !records[it].lotwConfirmed }
+    val taken = mutableSetOf<Int>()
+    return records.indices.filter { records[it].lotwConfirmed }.mapNotNull { confirmationIndex ->
+        val confirmation = records[confirmationIndex]
+        val localIndex = pendingIndices.firstOrNull { index ->
+            index !in taken && sameContactIdentity(records[index], confirmation) &&
+                bandsMatchOrMirror(records[index], confirmation)
+        } ?: return@mapNotNull null
+        taken += localIndex
+        SplitConfirmationPair(localIndex, confirmationIndex)
+    }
+}
+
+/** Same band on both sides, or the mirrored pair the pre-fix parser produced. */
+private fun bandsMatchOrMirror(local: QsoRecord, confirmation: QsoRecord): Boolean =
+    (sameBandOrBlank(local.band, confirmation.band) && sameBandOrBlank(local.rxBand, confirmation.rxBand)) ||
+        (sameBandOrBlank(local.band, confirmation.rxBand) && sameBandOrBlank(local.rxBand, confirmation.band))
+
+fun QsoRecord.withConfirmation(confirmed: QsoRecord): QsoRecord = copy(
+    myCallsign = myCallsign.ifBlank { confirmed.myCallsign },
+    theirGrid = confirmed.theirGrid.ifBlank { theirGrid },
+    myGrid = myGrid.ifBlank { confirmed.myGrid },
+    sentReport = sentReport.ifBlank { confirmed.sentReport },
+    receivedReport = receivedReport.ifBlank { confirmed.receivedReport },
+    txFrequencyHz = txFrequencyHz ?: confirmed.txFrequencyHz,
+    rxFrequencyHz = rxFrequencyHz ?: confirmed.rxFrequencyHz,
+    band = band.ifBlank { confirmed.band },
+    rxBand = rxBand.ifBlank { confirmed.rxBand },
+    propagationMode = propagationMode.ifBlank { confirmed.propagationMode },
+    status = QsoStatus.COMPLETE,
+    lotwConfirmed = lotwConfirmed || confirmed.lotwConfirmed,
+    lotwReceived = lotwReceived || confirmed.lotwReceived || confirmed.lotwConfirmed,
+    lotwQslDate = confirmed.lotwQslDate.ifBlank { lotwQslDate },
+    vuccGrids = confirmed.vuccGrids.ifEmpty { vuccGrids },
+    dxcc = confirmed.dxcc ?: dxcc,
+    country = confirmed.country.ifBlank { country },
+    cqZone = confirmed.cqZone ?: cqZone,
+    region = confirmed.region.ifBlank { region }
+)
+
+val QsoRecord.displayMode: String
+    get() {
+        // Satellite FT4 is MODE=MFSK + SUBMODE=FT4; any other mode keeps its own
+        // label even when a stale submode default ("FT4") was persisted.
+        val label = if (mode.equals("MFSK", true) && submode.isNotBlank()) submode else mode
+        return label.trim().uppercase(Locale.US)
+    }
+
+val QsoRecord.isSatellite: Boolean
+    get() = propagationMode.equals("SAT", true) || (propagationMode.isBlank() && satelliteName.isNotBlank())
+
+fun frequencyBand(hz: Long?): String = when (hz) {
+    null -> ""
+    in 28_000_000L..29_700_000L -> "10M"
+    in 50_000_000L..54_000_000L -> "6M"
+    in 144_000_000L..148_000_000L -> "2M"
+    in 219_000_000L..225_000_000L -> "1.25M"
+    in 420_000_000L..450_000_000L -> "70CM"
+    in 902_000_000L..928_000_000L -> "33CM"
+    in 1_240_000_000L..1_300_000_000L -> "23CM"
+    in 2_300_000_000L..2_450_000_000L -> "13CM"
+    in 5_650_000_000L..5_925_000_000L -> "6CM"
+    in 10_000_000_000L..10_500_000_000L -> "3CM"
+    else -> ""
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/logbook/QsoModels.kt

@@ -0,0 +1,49 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ */
+package com.rtbishop.look4sat.core.domain.logbook
+
+enum class QsoStatus { DRAFT, COMPLETE, ABORTED }
+
+data class QsoRecord(
+    val id: Long = 0L,
+    val startUtcMillis: Long,
+    val endUtcMillis: Long? = null,
+    val theirCallsign: String,
+    val myCallsign: String,
+    val theirGrid: String = "",
+    val myGrid: String = "",
+    val sentReport: String = "",
+    val receivedReport: String = "",
+    val txFrequencyHz: Long? = null,
+    val rxFrequencyHz: Long? = null,
+    val band: String = "",
+    val rxBand: String = "",
+    val mode: String = "FM",
+    val submode: String = "",
+    val satelliteName: String = "",
+    val transponderName: String = "",
+    val satelliteMode: String = "",
+    val passAosUtcMillis: Long? = null,
+    val automatic: Boolean = false,
+    val status: QsoStatus = QsoStatus.DRAFT,
+    val propagationMode: String = if (satelliteName.isNotBlank()) "SAT" else "",
+    val lotwConfirmed: Boolean = false,
+    val lotwUploaded: Boolean = false,
+    val lotwReceived: Boolean = false,
+    val lotwQslDate: String = "",
+    val vuccGrids: List<String> = emptyList(),
+    val dxcc: Int? = null,
+    val country: String = "",
+    val cqZone: Int? = null,
+    val region: String = "",
+    val comment: String = ""
+)
+
+data class AdifImportResult(val imported: Int, val skipped: Int, val updated: Int = 0)

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

@@ -1,3 +1,21 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
 package com.rtbishop.look4sat.core.domain.model
 
 /** One public AMSAT satellite status report submission. */

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

@@ -26,9 +26,12 @@ package com.rtbishop.look4sat.core.domain.model
  * @param epochMs   QSO date+time in UTC milliseconds
  * @param satName   satellite name (e.g. "FO-29")
  * @param mode      ADIF mode (FM / CW / SSB ...)
- * @param bandUp    uplink band as reported by LoTW (BAND_RX: "70CM", "2M", "10M"...)
- * @param bandDown  downlink band (BAND: "2M", "70CM"...) — may be empty when
- *                  LoTW did not include it
+ * @param bandUp    uplink band, the band of the transmitted frequency (ADIF BAND:
+ *                  "2M", "70CM", "10M"...). Measured against the live report of the
+ *                  user's own uploads: SO-50 arrives as BAND=2M/FREQ=145.85 with
+ *                  BAND_RX=70CM/FREQ_RX=436.8, i.e. BAND carries the uplink.
+ * @param bandDown  downlink band (ADIF BAND_RX) — may be empty when LoTW did not
+ *                  include it
  * @param dxcc      ARRL DXCC entity code of the opposite station (from ADIF
  *                  <DXCC>), or null when LoTW omitted it
  * @param country   DXCC entity name (ADIF <COUNTRY>), or null

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

@@ -1,3 +1,21 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
 package com.rtbishop.look4sat.core.domain.model
 
 /** Latest release info fetched from the fork's GitHub releases API. */

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

@@ -1,3 +1,21 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
 package com.rtbishop.look4sat.core.domain.model
 
 /** One satellite status report (AMSAT site tooltip data) */

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

@@ -1,3 +1,21 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
 package com.rtbishop.look4sat.core.domain.repository
 
 import com.rtbishop.look4sat.core.domain.model.AmSatReportSubmission

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

@@ -0,0 +1,134 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.domain.repository
+
+import com.rtbishop.look4sat.core.domain.logbook.QsoRecord
+
+interface ILoTWUploadRepository {
+    suspend fun certificate(): LoTWCertificate?
+    suspend fun station(): LoTWStation?
+    suspend fun importCertificate(data: ByteArray, password: CharArray): LoTWCertificate
+    suspend fun saveCertificatePassword(password: CharArray): LoTWCertificate
+    suspend fun saveStation(station: LoTWStation): LoTWStation
+    suspend fun removeCertificate()
+    /** Region field (State/Province/Prefecture…) and national CQZ/ITUZ map for a DXCC entity. */
+    suspend fun stationMeta(dxcc: Int): LoTWStationMeta
+    /** Every satellite name ARRL accepts (config.tq6), sorted. Only these names may be
+     *  signed, so the logbook UI validates/picks satellite names from this list. */
+    suspend fun satelliteCatalog(): List<String>
+    suspend fun audit(records: List<QsoRecord>): LoTWUploadAudit
+    suspend fun prepare(records: List<QsoRecord>, resubmit: Boolean): LoTWUploadPreview
+    suspend fun upload(previewId: String): LoTWUploadResult
+    fun discardPreview()
+}
+
+data class LoTWCertificate(
+    val callsign: String,
+    val dxcc: Int,
+    val serial: String,
+    val expires: String,
+    val firstQsoDate: String,
+    val lastQsoDate: String,
+    val passwordSaved: Boolean = false
+)
+
+/** The location is explicitly confirmed for the selected contacts, not inferred from today's GPS. */
+data class LoTWStation(
+    val grid: String = "",
+    val cqZone: String = "",
+    val ituZone: String = "",
+    val region: String = "",
+    val county: String = "",
+    val iota: String = ""
+)
+
+/** One (ITU:CQ) pair from a LoTW zonemap, e.g. Guangdong is 44:24. */
+data class LoTWZonePair(val itu: Int, val cq: Int)
+
+/** One selectable region code with the zones it maps to (cross-zone regions carry several pairs). */
+data class LoTWRegionOption(val code: String, val name: String, val zones: List<LoTWZonePair>)
+
+/** Country-dependent region field (US_STATE, CN_PROVINCE, …) with its selectable options. */
+data class LoTWRegionField(val id: String, val label: String, val options: List<LoTWRegionOption>)
+
+/**
+ * Everything the station-location UI needs for one DXCC entity:
+ * the region field to show (null when the country has none) and the national
+ * zonemap (used to prefill CQZ/ITUZ when the country has a single zone pair).
+ */
+data class LoTWStationMeta(
+    val regionField: LoTWRegionField? = null,
+    val countryZones: List<LoTWZonePair> = emptyList()
+)
+
+data class LoTWUploadPreview(
+    val id: String,
+    val callsign: String,
+    val dxcc: Int,
+    val grid: String,
+    val count: Int,
+    val skipped: Int,
+    val firstUtc: String,
+    val lastUtc: String,
+    val contacts: List<String>,
+    val unknownSkipped: Int = 0,
+    /** Un-signable records (invalid call/date/…) skipped instead of aborting the batch. */
+    val unavailableSkipped: Int = 0,
+    /** Why those records were un-signable, so the operator sees the real cause. */
+    val unavailableReasons: Map<LoTWProblem, Int> = emptyMap(),
+    /** Records dropped because the same contact already appears earlier in the batch. */
+    val duplicateSkipped: Int = 0,
+    /** Ids of the records that actually made it into this TQ8 batch. Only these
+     *  may be marked "uploaded" after an accepted POST — never the full candidate list. */
+    val submittedIds: List<Long> = emptyList()
+)
+
+/** Why the un-uploadable records of a selection cannot be signed, and what was left out. */
+data class LoTWUploadAudit(
+    val total: Int,
+    val pending: Int,
+    val uploaded: Int,
+    val unknown: Int,
+    val unavailable: Int,
+    /** Signing failures counted per reason (see [com.rtbishop.look4sat.core.domain.logbook.label]). */
+    val reasons: Map<LoTWProblem, Int> = emptyMap(),
+    /** First offending value per reason, e.g. SATELLITE -> "SAUDISAT 1C". */
+    val details: Map<LoTWProblem, String> = emptyMap(),
+    /** Records dropped as duplicates of an earlier record in the same selection. */
+    val duplicates: Int = 0,
+    /** Records that are not marked complete, so they are not uploadable at all. */
+    val incomplete: Int = 0
+)
+
+sealed interface LoTWUploadResult {
+    data class Accepted(val count: Int) : LoTWUploadResult
+    data class Rejected(val message: String = "") : LoTWUploadResult
+    /** May have reached LoTW. Do not retry automatically. */
+    data object Unknown : LoTWUploadResult
+    data object ExpiredPreview : LoTWUploadResult
+}
+
+class LoTWOperationException(val reason: LoTWProblem, val detail: String = "") : Exception(reason.name)
+
+enum class LoTWProblem {
+    CERTIFICATE_PASSWORD, CERTIFICATE_INVALID, CERTIFICATE_EXPIRED, CERTIFICATE_MISSING,
+    CERTIFICATE_FORMAT, STORAGE, EMPTY_SELECTION, CALLSIGN_MISMATCH, QSO_DATE, STATION_GRID,
+    STATION_REGION, STATION_ZONE, STATION_IOTA, MODE, BAND, SATELLITE, INVALID_CONTACT,
+    LOCATION_MISMATCH, TOO_MANY_CONTACTS
+}

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

@@ -0,0 +1,65 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.domain.repository
+
+import kotlinx.coroutines.flow.StateFlow
+
+/**
+ * A single position fix from the device's location provider, with the
+ * horizontal accuracy reported by the platform.
+ */
+data class LocationFix(
+    val latitude: Double,
+    val longitude: Double,
+    val altitudeMeters: Double = 0.0,
+    val accuracyMeters: Float,
+    val epochMs: Long
+) {
+    /** ARRL VUCC work needs a fix good to the 20 ft (6.1 m) rule. */
+    fun isPreciseEnough(limitMeters: Float): Boolean = accuracyMeters in 0f..limitMeters
+}
+
+/** What the live-location source is currently able to give. */
+sealed interface LocationState {
+    /** No fix yet - either permission is missing or the provider is warming up. */
+    data class Waiting(val permissionGranted: Boolean, val providerEnabled: Boolean) : LocationState
+
+    data class Fix(val location: LocationFix) : LocationState
+}
+
+/**
+ * Live device position for field tools (currently the Grid Finder). Kept
+ * separate from [ISettingsRepo.stationPosition] on purpose: collecting fixes
+ * here must never move the user's station, which is what drives every pass
+ * prediction in the app.
+ *
+ * Callers register with [startUpdates] while their screen is alive and MUST
+ * call [stopUpdates] when it goes away.
+ */
+interface ILocationRepo {
+    val state: StateFlow<LocationState>
+
+    /** Whether the app currently holds the fine-location permission. */
+    fun hasPermission(): Boolean
+
+    /** Begins delivering fixes; no-op when permission is missing. */
+    fun startUpdates()
+
+    /** Stops delivering fixes and releases the platform listener. */
+    fun stopUpdates()
+}

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

@@ -16,6 +16,7 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 package com.rtbishop.look4sat.core.domain.repository
+import com.rtbishop.look4sat.core.domain.logbook.IQsoRepository
 import com.rtbishop.look4sat.core.domain.model.SatRadio
 import com.rtbishop.look4sat.core.domain.usecase.IAddToCalendar
 import com.rtbishop.look4sat.core.domain.usecase.IAudioCapture
@@ -34,9 +35,15 @@ interface IMainContainer {
     val updateRepo: IUpdateRepository
     val wavelogRepo: IWavelogRepository
     val lotwRepo: com.rtbishop.look4sat.core.domain.repository.ILoTWRepository
+    val qsoRepository: IQsoRepository
+    val lotwUploadRepository: ILoTWUploadRepository
     val radioTrackingService: IRadioTrackingService
+    val locationRepo: ILocationRepo
     val mutualPassData: StateFlow<MutualPassData>
+    /** Grid Finder → LoTW station page prefill, consumed once by that page. */
+    val pendingLoTWStationGrid: StateFlow<String?>
     fun setMutualPassData(data: MutualPassData)
+    fun setPendingLoTWStationGrid(grid: String?)
     fun provideAddToCalendar(): IAddToCalendar
     fun provideShowToast(): IShowToast
     fun provideBluetoothReporter(): IReporter

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

@@ -89,6 +89,12 @@ interface ISettingsRepo {
     fun setSatelliteOffset(catnum: Int, offset: String)
     //endregion
 
+    //region # Per-satellite logbook mode preset settings
+    /** Last selected logbook mode (CW/SSB/FT4) for a satellite; empty when unset. */
+    fun getSatelliteMode(catnum: Int): String
+    fun setSatelliteMode(catnum: Int, mode: String)
+    //endregion
+
     //region # AMSAT status report settings
     fun getAmSatCallsign(): String
     fun setAmSatCallsign(callsign: String)

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

@@ -1,3 +1,21 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
 package com.rtbishop.look4sat.core.domain.repository
 
 import com.rtbishop.look4sat.core.domain.model.LatestRelease

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

@@ -0,0 +1,193 @@
+/*
+ * 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/>.
+ *
+ * Contains code ported from OrbitDeckiOS (https://github.com/prstoetzer/OrbitDeckiOS),
+ * Copyright (c) 2025 Paul Stoetzer, N8HM, licensed under the MIT License.
+ * See THIRD_PARTY_NOTICES.md for the full MIT license text.
+ */
+package com.rtbishop.look4sat.core.domain.utility
+
+import kotlin.math.abs
+import kotlin.math.atan2
+import kotlin.math.cos
+import kotlin.math.hypot
+import kotlin.math.round
+
+/**
+ * Grid-line / grid-corner geometry for the 4-character Maidenhead squares that
+ * VUCC credits, used by the Grid Finder field tool.
+ *
+ * A 4-character square is 1 degree tall (boundaries at integer latitudes) and
+ * 2 degrees wide (boundaries at even offsets from the -180 degree antimeridian),
+ * so a station's distance to the nearest VUCC line and corner is a matter of
+ * simple planar geometry at the station's latitude.
+ *
+ * Geometry ported from OrbitDeck for iOS (MIT License, (c) 2026 Paul Stoetzer,
+ * N8HM) - `GridGeometry` in `Views/HomeView.swift` and `vuccGrids` in
+ * `Engine/FeatureEngine.swift`. Golden values are pinned by GridGeometryTest.
+ */
+
+/** ARRL VUCC "20 ft rule": a fix within this distance of a boundary counts as on it. */
+const val VUCC_BOUNDARY_TOLERANCE_METERS = 20.0 * 0.3048
+
+/** One degree of latitude in metres; 4-character squares are 1 degree tall. */
+private const val METERS_PER_DEGREE_LATITUDE = 111_320.0
+
+/** Nudge used to name the square on the far side of a boundary (display only). */
+private const val NEIGHBOUR_NUDGE_DEGREES = 0.0005
+
+/** Nudge used by [vuccClaimableGrids] so the neighbour lands squarely across. */
+private const val CLAIM_NEIGHBOUR_NUDGE_DEGREES = 0.001
+
+private const val DEG_TO_RAD = 0.017453292519943295
+private const val RAD_TO_DEG = 57.29577951308232
+
+/** Where the nearest 4-character boundary lies relative to the fix. */
+enum class GridBoundaryDirection { NORTH, SOUTH, EAST, WEST }
+
+/** ARRL VUCC standing of a fix, derived from how many squares it may claim. */
+enum class GridFixStatus { INSIDE_GRID, ON_GRID_LINE, ON_GRID_CORNER }
+
+/**
+ * Distance and bearing to the nearest 4-character grid corner and grid line,
+ * plus the locators of the squares that meet there. All distances are metres
+ * computed on a flat approximation local to the fix (the same approximation
+ * the source implementation uses; over the <=100 km distances involved the
+ * error is far below a GPS fix's own accuracy).
+ */
+data class GridGeometry(
+    val grid4: String,
+    val grid6: String,
+    val grid8: String,
+    val latLineMeters: Double,
+    val latLineDirection: GridBoundaryDirection,
+    val lonLineMeters: Double,
+    val lonLineDirection: GridBoundaryDirection,
+    val cornerMeters: Double,
+    val cornerBearingDegrees: Double,
+    val cornerGrids: List<String>,
+    val nearestLineMeters: Double,
+    val nearestLineBearingDegrees: Double,
+    val nearestLineIsLatitude: Boolean,
+    val nearestLineGrids: List<String>
+)
+
+/**
+ * The geometry of the VUCC (4-character) grid around a position, or null when
+ * the position is out of range.
+ */
+fun gridGeometry(latitude: Double, longitude: Double): GridGeometry? {
+    val grid4 = positionToGrid4(latitude, longitude) ?: return null
+    val grid6 = positionToQth(latitude, longitude) ?: return null
+    val grid8 = positionToGrid8(latitude, longitude) ?: return null
+
+    // 4-character boundaries: integer latitudes, even-degree longitudes.
+    val latBoundary = round(latitude)
+    val lonBoundary = round((longitude + 180.0) / 2.0) * 2.0 - 180.0
+
+    val metersPerDegreeLon = METERS_PER_DEGREE_LATITUDE * cos(latitude * DEG_TO_RAD)
+    val dNorth = (latBoundary - latitude) * METERS_PER_DEGREE_LATITUDE
+    val dEast = (lonBoundary - longitude) * metersPerDegreeLon
+
+    val otherLat = latBoundary - if (latitude >= latBoundary) NEIGHBOUR_NUDGE_DEGREES else -NEIGHBOUR_NUDGE_DEGREES
+    val otherLon = lonBoundary - if (longitude >= lonBoundary) NEIGHBOUR_NUDGE_DEGREES else -NEIGHBOUR_NUDGE_DEGREES
+
+    val cornerGrids = setOfNotNull(
+        positionToGrid4(latitude, longitude),
+        positionToGrid4(otherLat, longitude),
+        positionToGrid4(latitude, otherLon),
+        positionToGrid4(otherLat, otherLon)
+    ).sorted()
+
+    val onLatitude = abs(dNorth) <= abs(dEast)
+    val nearestLineGrids = if (onLatitude) {
+        setOfNotNull(grid4, positionToGrid4(otherLat, longitude)).sorted()
+    } else {
+        setOfNotNull(grid4, positionToGrid4(latitude, otherLon)).sorted()
+    }
+
+    return GridGeometry(
+        grid4 = grid4,
+        grid6 = grid6,
+        grid8 = grid8,
+        latLineMeters = abs(dNorth),
+        latLineDirection = if (dNorth >= 0) GridBoundaryDirection.NORTH else GridBoundaryDirection.SOUTH,
+        lonLineMeters = abs(dEast),
+        lonLineDirection = if (dEast >= 0) GridBoundaryDirection.EAST else GridBoundaryDirection.WEST,
+        cornerMeters = hypot(dNorth, dEast),
+        cornerBearingDegrees = bearingDegrees(dNorth, dEast),
+        cornerGrids = cornerGrids,
+        nearestLineMeters = if (onLatitude) abs(dNorth) else abs(dEast),
+        nearestLineBearingDegrees = if (onLatitude) {
+            if (dNorth >= 0) 0.0 else 180.0
+        } else {
+            if (dEast >= 0) 90.0 else 270.0
+        },
+        nearestLineIsLatitude = onLatitude,
+        nearestLineGrids = nearestLineGrids
+    )
+}
+
+/**
+ * The 4-character squares a station at this position may claim under ARRL VUCC
+ * rules: normally one, but two when the fix is on the line between two squares
+ * and four when it is on the corner where four squares meet. A fix within
+ * [toleranceMeters] of a boundary is considered to be on it (the 20 ft rule).
+ */
+fun vuccClaimableGrids(
+    latitude: Double,
+    longitude: Double,
+    toleranceMeters: Double = VUCC_BOUNDARY_TOLERANCE_METERS
+): List<String> {
+    val own = positionToGrid4(latitude, longitude) ?: return emptyList()
+    val grids = mutableSetOf(own)
+
+    val latBoundary = round(latitude)
+    val lonBoundary = round((longitude + 180.0) / 2.0) * 2.0 - 180.0
+    val metersPerDegreeLon = METERS_PER_DEGREE_LATITUDE * cos(latitude * DEG_TO_RAD)
+
+    val onLatitude = abs(latitude - latBoundary) * METERS_PER_DEGREE_LATITUDE <= toleranceMeters
+    val onLongitude = abs(longitude - lonBoundary) * metersPerDegreeLon <= toleranceMeters
+    if (!onLatitude && !onLongitude) return grids.sorted()
+
+    // Step just past the boundary so the neighbour's locator is unambiguous.
+    val otherLat = latBoundary - if (latitude >= latBoundary) CLAIM_NEIGHBOUR_NUDGE_DEGREES else -CLAIM_NEIGHBOUR_NUDGE_DEGREES
+    val otherLon = lonBoundary - if (longitude >= lonBoundary) CLAIM_NEIGHBOUR_NUDGE_DEGREES else -CLAIM_NEIGHBOUR_NUDGE_DEGREES
+
+    if (onLatitude) {
+        positionToGrid4(otherLat, longitude)?.let(grids::add)
+    }
+    if (onLongitude) {
+        positionToGrid4(latitude, otherLon)?.let(grids::add)
+    }
+    if (onLatitude && onLongitude) {
+        positionToGrid4(otherLat, otherLon)?.let(grids::add)
+    }
+    return grids.sorted()
+}
+
+/** VUCC standing implied by the number of squares a fix may claim. */
+fun gridFixStatus(claimableGrids: List<String>): GridFixStatus = when {
+    claimableGrids.size >= 4 -> GridFixStatus.ON_GRID_CORNER
+    claimableGrids.size >= 2 -> GridFixStatus.ON_GRID_LINE
+    else -> GridFixStatus.INSIDE_GRID
+}
+
+private fun bearingDegrees(dNorth: Double, dEast: Double): Double {
+    val bearing = atan2(dEast, dNorth) * RAD_TO_DEG
+    return if (bearing < 0.0) bearing + 360.0 else bearing
+}

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

@@ -69,6 +69,45 @@ fun positionToQth(latitude: Double, longitude: Double): String? {
     return "$lonFirst$latFirst$lonSecond$latSecond$lonThird$latThird"
 }
 
+/**
+ * Convert a position to its 4-char Maidenhead locator (field + square), the
+ * square VUCC credits, upper-cased. Returns null outside the Maidenhead grid
+ * (lat >= 90 is out of range: the top row is 80..90 N). The longitude is
+ * wrapped into [-180, 180) first, so fixes either side of the antimeridian
+ * resolve to the square they are actually in.
+ */
+fun positionToGrid4(latitude: Double, longitude: Double): String? {
+    if (latitude < -90.0 || latitude >= 90.0) return null
+    val normalizedLon = normalizeLongitude(longitude)
+    val fieldLat = ((latitude + 90.0) / 10.0).toInt().coerceIn(0, 17)
+    val fieldLon = ((normalizedLon + 180.0) / 20.0).toInt().coerceIn(0, 17)
+    val subLat = ((latitude + 90.0) % 10.0).toInt()
+    val subLon = ((normalizedLon + 180.0) % 20.0 / 2.0).toInt()
+    return "${'A' + fieldLon}${'A' + fieldLat}$subLon$subLat"
+}
+
+/**
+ * Convert a position to its 8-char Maidenhead locator: the 6-char locator plus
+ * the numeric extended-square pair (the Maidenhead maximum). Returns null for
+ * out-of-range positions.
+ */
+fun positionToGrid8(latitude: Double, longitude: Double): String? {
+    val normalizedLon = normalizeLongitude(longitude)
+    val base = positionToQth(latitude, normalizedLon) ?: return null
+    val latitudeOffset = latitude.coerceIn(-90.0, 89.999999) + 90.0
+    val longitudeOffset = normalizedLon.coerceIn(-180.0, 179.999999) + 180.0
+    val subLon = 2.0 / 24.0
+    val subLat = 1.0 / 24.0
+    val lonDigit = minOf(9, ((longitudeOffset % subLon) / subLon * 10).toInt())
+    val latDigit = minOf(9, ((latitudeOffset % subLat) / subLat * 10).toInt())
+    return "$base$lonDigit$latDigit"
+}
+
+/** Wrap any longitude into [-180, 180). */
+private fun normalizeLongitude(longitude: Double): Double {
+    return ((longitude + 180.0) % 360.0 + 360.0) % 360.0 - 180.0
+}
+
 private fun isValidPosition(lat: Double, lon: Double): Boolean {
     return (lat >= -90.0 && lat <= 90.0) && (lon >= -180.0 && lon <= 360.0)
 }

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

@@ -1,3 +1,21 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by 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.utility
 
 /**

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

@@ -0,0 +1,53 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.domain.utility
+
+import com.rtbishop.look4sat.core.domain.model.SatRadio
+import kotlin.math.abs
+
+/** Nominal uplink frequency: the middle of the passband when one is published. */
+fun SatRadio.uplinkHz(): Long? = uplinkLow?.let { low -> uplinkHigh?.let { high -> (low + high) / 2 } ?: low }
+
+/** Nominal downlink frequency: the middle of the passband when one is published. */
+fun SatRadio.downlinkHz(): Long? = downlinkLow?.let { low -> downlinkHigh?.let { high -> (low + high) / 2 } ?: low }
+
+/**
+ * The FM voice repeater of a satellite, if it has one.
+ *
+ * A voice repeater is the single-frequency FM transceiver the operator actually
+ * talks through (SatNOGS type "Transceiver", e.g. SO-50 "Mode V/U FM Voice
+ * CTCSS 67.0 Hz"). Beacons and telemetry carry no uplink, so requiring BOTH an
+ * uplink and a downlink already filters them out; the FM mode check removes
+ * AFSK/APRS and linear entries.
+ *
+ * Ranking when several FM duplex entries exist (ISS is the awkward case, it also
+ * lists crew V/V channels):
+ *  1. entries described as a repeater / voice channel,
+ *  2. amateur service entries,
+ *  3. cross-band pairs (a V/U repeater over a same-band V/V downlink).
+ */
+fun List<SatRadio>.voiceRepeater(): SatRadio? = asSequence()
+    .filter { it.isAlive }
+    .filter { it.uplinkHz() != null && it.downlinkHz() != null }
+    .filter { it.uplinkMode.equals("FM", true) || it.downlinkMode.equals("FM", true) }
+    .sortedWith(
+        compareByDescending<SatRadio> { it.info.contains("repeater", true) || it.info.contains("voice", true) }
+            .thenByDescending { it.service.equals("Amateur", true) }
+            .thenByDescending { abs((it.downlinkHz() ?: 0L) - (it.uplinkHz() ?: 0L)) }
+    )
+    .firstOrNull()

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

@@ -1,3 +1,21 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
 package com.rtbishop.look4sat.core.domain
 
 import com.rtbishop.look4sat.core.domain.model.SatRadio

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

@@ -0,0 +1,78 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.domain
+
+import com.rtbishop.look4sat.core.domain.logbook.LoTWSatelliteAliases
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+/** Alias table that maps tracker catalogue names onto the names ARRL's config.tq6 uses. */
+class LoTWSatelliteAliasesTest {
+
+    private val catalogue = listOf("SO-50", "ARISS", "PO-101", "BO-102", "AO-91", "RS-44", "IO-117")
+
+    @Test
+    fun `lookup maps SatNOGS catalogue names to ARRL names`() {
+        assertEquals("SO-50", LoTWSatelliteAliases.lookup("SAUDISAT 1C"))
+        assertEquals("ARISS", LoTWSatelliteAliases.lookup("ISS (ZARYA)"))
+        assertEquals("PO-101", LoTWSatelliteAliases.lookup("DIWATA 2B"))
+        assertEquals("AO-91", LoTWSatelliteAliases.lookup("FOX-1B"))
+        assertEquals("RS-44", LoTWSatelliteAliases.lookup("DOSAAF-85"))
+        assertEquals("IO-117", LoTWSatelliteAliases.lookup("GREENCUBE"))
+    }
+
+    @Test
+    fun `normalize strips separators and case`() {
+        assertEquals("ISSZARYA", LoTWSatelliteAliases.normalize("iss (zarya)"))
+        assertEquals("SAUDISAT1C", LoTWSatelliteAliases.normalize("SaudiSat-1C"))
+    }
+
+    @Test
+    fun `lookup ignores unknown and placeholder names`() {
+        assertNull(LoTWSatelliteAliases.lookup("NOT A SATELLITE"))
+        // Recycled temporary designations must never resolve: they would sign the wrong object.
+        assertNull(LoTWSatelliteAliases.lookup("OBJECT AY"))
+    }
+
+    @Test
+    fun `resolve accepts ARRL names, aliases and suffixed tracker names`() {
+        assertEquals("SO-50", LoTWSatelliteAliases.resolve("SO-50", catalogue))
+        assertEquals("SO-50", LoTWSatelliteAliases.resolve("saudisat 1c", catalogue))
+        assertEquals("SO-50", LoTWSatelliteAliases.resolve("SAUDISAT 1C (SO-50)", catalogue))
+        assertEquals("ARISS", LoTWSatelliteAliases.resolve("ISS (ZARYA)", catalogue))
+        assertEquals("AO-91", LoTWSatelliteAliases.resolve("AO-91 (RadFxSat)", catalogue))
+    }
+
+    @Test
+    fun `resolve rejects names that are not ARRL satellites`() {
+        assertNull(LoTWSatelliteAliases.resolve("", catalogue))
+        assertNull(LoTWSatelliteAliases.resolve("MARINA", catalogue))
+        assertNull(LoTWSatelliteAliases.resolve("OBJECT AY", catalogue))
+    }
+
+    @Test
+    fun `suggestions find the ARRL name from a tracker spelling`() {
+        assertEquals(listOf("SO-50"), LoTWSatelliteAliases.suggestions("saudisat 1c", catalogue))
+        assertTrue(LoTWSatelliteAliases.suggestions("ao9", catalogue).contains("AO-91"))
+        assertEquals(listOf("PO-101"), LoTWSatelliteAliases.suggestions("diwata", catalogue))
+        assertTrue(LoTWSatelliteAliases.suggestions("", catalogue).isEmpty())
+    }
+}

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

@@ -1,3 +1,21 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
 package com.rtbishop.look4sat.core.domain
 
 import com.rtbishop.look4sat.core.domain.utility.positionToQth

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

@@ -1,3 +1,21 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
 package com.rtbishop.look4sat.core.domain
 
 import com.rtbishop.look4sat.core.domain.model.SatRadio

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

@@ -1,3 +1,21 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
 package com.rtbishop.look4sat.core.domain
 
 import com.rtbishop.look4sat.core.domain.utility.VersionComparator

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

@@ -0,0 +1,140 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.domain
+
+import com.rtbishop.look4sat.core.domain.model.SatRadio
+import com.rtbishop.look4sat.core.domain.utility.downlinkHz
+import com.rtbishop.look4sat.core.domain.utility.uplinkHz
+import com.rtbishop.look4sat.core.domain.utility.voiceRepeater
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
+import org.junit.Test
+
+/** Fixtures are the real SatNOGS transceiver rows of the three hardcoded AMSAT Live FM
+ *  satellites (fetched 2026-09-27), so the selection rules are tested against live data. */
+class VoiceRepeaterTest {
+
+    private fun radio(
+        uuid: String,
+        info: String,
+        up: Long? = null,
+        upHigh: Long? = null,
+        down: Long? = null,
+        downHigh: Long? = null,
+        upMode: String? = null,
+        downMode: String? = null,
+        alive: Boolean = true,
+        service: String? = null,
+        catnum: Int = 12345
+    ) = SatRadio(
+        uuid = uuid, info = info, isAlive = alive,
+        downlinkLow = down, downlinkHigh = downHigh, downlinkMode = downMode,
+        uplinkLow = up, uplinkHigh = upHigh, uplinkMode = upMode,
+        isInverted = false, catnum = catnum, service = service
+    )
+
+    // SO-50 (27607)
+    private val so50Tlm = radio("so50-tlm", "Mode V TLM", down = 149_025_000L, downMode = "FM")
+    private val so50Voice = radio(
+        "so50-voice", "Mode V/U FM Voice CTCSS 67.0 Hz",
+        up = 145_850_000L, down = 436_795_000L, upMode = "FM", downMode = "FM", catnum = 27607
+    )
+
+    // ISS (25544): a voice repeater plus two crew V/V channels and an APRS transceiver
+    private val issCrew2 = radio(
+        "iss-crew2", "Mode V/V FM (crew R2+3)",
+        up = 144_490_000L, down = 145_800_000L, upMode = "FM", downMode = "FM", catnum = 25544
+    )
+    private val issCrew1 = radio(
+        "iss-crew1", "Mode V/V FM (crew R1)",
+        up = 145_200_000L, down = 145_800_000L, upMode = "FM", downMode = "FM", catnum = 25544
+    )
+    private val issVoice = radio(
+        "iss-voice", "Mode V/U FM - Voice Repeater CTCSS 67.0 Hz",
+        up = 145_990_000L, down = 437_800_000L, upMode = "FM", downMode = "FM",
+        service = "Amateur", catnum = 25544
+    )
+    private val issAprs = radio(
+        "iss-aprs", "Mode V APRS",
+        up = 145_825_000L, down = 145_825_000L, upMode = "AFSK", downMode = "AFSK", catnum = 25544
+    )
+
+    // AO-123 / ASRTU-1 (61781)
+    private val ao123Voice = radio(
+        "ao123-voice", "Mode V/U - FM Transceiver",
+        up = 145_850_000L, down = 435_400_000L, upMode = "FM", downMode = "FM",
+        service = "Amateur", catnum = 61781
+    )
+
+    @Test
+    fun voiceRepeater_picksSo50VoicePair() {
+        val repeater = listOf(so50Tlm, so50Voice).voiceRepeater()
+        assertEquals("so50-voice", repeater?.uuid)
+        assertEquals(145_850_000L, repeater?.uplinkHz())
+        assertEquals(436_795_000L, repeater?.downlinkHz())
+    }
+
+    @Test
+    fun voiceRepeater_prefersVoiceChannelOverCrewChannels() {
+        val transmitterList = listOf(issCrew2, issAprs, issVoice, issCrew1)
+        // Order must not matter - ranking decides.
+        assertEquals("iss-voice", transmitterList.voiceRepeater()?.uuid)
+        assertEquals("iss-voice", transmitterList.reversed().voiceRepeater()?.uuid)
+    }
+
+    @Test
+    fun voiceRepeater_picksAo123Transceiver() {
+        val repeater = listOf(ao123Voice).voiceRepeater()
+        assertEquals(145_850_000L, repeater?.uplinkHz())
+        assertEquals(435_400_000L, repeater?.downlinkHz())
+    }
+
+    @Test
+    fun voiceRepeater_ignoresBeaconsWithoutUplink() {
+        assertNull(listOf(so50Tlm).voiceRepeater())
+    }
+
+    @Test
+    fun voiceRepeater_ignoresDeadEntries() {
+        val dead = so50Voice.copy(uuid = "dead", isAlive = false)
+        assertNull(listOf(dead).voiceRepeater())
+    }
+
+    @Test
+    fun voiceRepeater_ignoresLinearTransponders() {
+        val linear = radio(
+            "lin", "Linear Transponder",
+            up = 145_900_000L, upHigh = 145_950_000L, down = 435_600_000L, downHigh = 435_650_000L,
+            upMode = "LSB", downMode = "USB"
+        )
+        assertNull(listOf(linear).voiceRepeater())
+    }
+
+    @Test
+    fun uplinkHz_usesPassbandMiddleWhenPresent() {
+        val wide = so50Voice.copy(uuid = "wide", uplinkLow = 145_840_000L, uplinkHigh = 145_860_000L)
+        assertEquals(145_850_000L, wide.uplinkHz())
+        assertEquals(145_850_000L, so50Voice.uplinkHz())
+    }
+
+    @Test
+    fun downlinkHz_isNullWhenNoDownlink() {
+        assertNull(so50Voice.copy(downlinkLow = null).downlinkHz())
+    }
+}

core/domain/src/test/java/com/rtbishop/look4sat/core/domain/logbook/AdifCodecTest.kt

@@ -0,0 +1,86 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ */
+package com.rtbishop.look4sat.core.domain.logbook
+
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+class AdifCodecTest {
+
+    @Test
+    fun encodeDecode_roundTrip() {
+        val record = QsoRecord(
+            startUtcMillis = 1_700_000_000_000L,
+            endUtcMillis = 1_700_000_000_100L,
+            theirCallsign = "BG5JVM",
+            myCallsign = "BA7OPF",
+            theirGrid = "OM60",
+            myGrid = "OL62TI",
+            sentReport = "59",
+            receivedReport = "59",
+            txFrequencyHz = 145_850_000L,
+            rxFrequencyHz = 436_805_000L,
+            band = "2M",
+            rxBand = "70CM",
+            mode = "FM",
+            satelliteName = "SO-50",
+            satelliteMode = "FM",
+            propagationMode = "SAT",
+            status = QsoStatus.COMPLETE,
+            lotwConfirmed = true,
+            lotwQslDate = "2026-09-20",
+            vuccGrids = listOf("OM60", "OM50")
+        )
+        val decoded = AdifCodec.decode(AdifCodec.encode(listOf(record))).single()
+        assertEquals(record.startUtcMillis, decoded.startUtcMillis)
+        assertEquals(record.theirCallsign, decoded.theirCallsign)
+        assertEquals(record.myCallsign, decoded.myCallsign)
+        assertEquals(record.satelliteName, decoded.satelliteName)
+        assertEquals("2M", decoded.band)
+        assertEquals("70CM", decoded.rxBand)
+        assertTrue(decoded.lotwConfirmed)
+        assertEquals(listOf("OM60", "OM50"), decoded.vuccGrids)
+    }
+
+    @Test
+    fun decode_lotwStyleReportFields() {
+        // LoTW report subset: lowercase eor, alphabetical fields, VUCC_GRIDS list.
+        val adi = """
+            <EOH>
+            <CALL:6>BH6RJD
+            <QSO_DATE:8>20260916
+            <TIME_ON:6>051300
+            <MODE:2>FM
+            <SAT_NAME:5>SO-50
+            <PROP_MODE:3>SAT
+            <BAND:3>2M
+            <BAND_RX:4>70CM
+            <GRIDSQUARE:4>OM60
+            <MY_GRIDSQUARE:8>OM60IL70
+            <VUCC_GRIDS:9>OM60,OM50
+            <STATION_CALLSIGN:6>BH6RJD
+            <DXCC:3>318
+            <COUNTRY:5>China
+            <LOTW_QSL_RCVD:1>Y
+            <eor>
+        """.trimIndent()
+        val records = AdifCodec.decode(adi)
+        assertEquals(1, records.size)
+        val record = records.single()
+        assertEquals("BH6RJD", record.theirCallsign)
+        assertEquals("SO-50", record.satelliteName)
+        assertEquals("FM", record.displayMode)
+        assertEquals("OM60IL70", record.myGrid)
+        assertEquals(listOf("OM60", "OM50"), record.vuccGrids)
+        assertTrue(record.lotwConfirmed)
+        assertTrue(record.isSatellite)
+    }
+}

core/domain/src/test/java/com/rtbishop/look4sat/core/domain/logbook/LogbookMergeTest.kt

@@ -0,0 +1,273 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ */
+package com.rtbishop.look4sat.core.domain.logbook
+
+import com.rtbishop.look4sat.core.domain.model.GridQso
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertNotEquals
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+class LogbookMergeTest {
+
+    private val local = QsoRecord(
+        startUtcMillis = 1_700_000_000_000L,
+        theirCallsign = "bg5jvm",
+        myCallsign = "ba7opf",
+        txFrequencyHz = 145_850_000L,
+        mode = "FM",
+        submode = "",
+        satelliteName = "SO-50 (SaudiOSCAR 50)",
+        propagationMode = "SAT",
+        status = QsoStatus.COMPLETE
+    )
+
+    private val confirmed = QsoRecord(
+        startUtcMillis = 1_700_000_000_000L,
+        theirCallsign = "BG5JVM",
+        myCallsign = "BA7OPF",
+        mode = "FM",
+        submode = "",
+        satelliteName = "SO-50",
+        propagationMode = "SAT",
+        status = QsoStatus.COMPLETE,
+        lotwConfirmed = true,
+        vuccGrids = listOf("OM60", "OM50")
+    )
+
+    @Test
+    fun satMatchKey_stripsParenthetical() {
+        assertEquals("SO-50", satMatchKey("SO-50 (SaudiOSCAR 50)"))
+        assertEquals("SO-50", satMatchKey("SO-50"))
+        assertEquals("AO-91", satMatchKey("AO-91 (FUNcube-1)"))
+        assertEquals("IO-86", satMatchKey("IO-86"))
+    }
+
+    @Test
+    fun sameConfirmedContact_matchesAcrossSatNOGSAndOfficialName() {
+        assertTrue(sameConfirmedContact(local, confirmed))
+    }
+
+    @Test
+    fun sameConfirmedContact_rejectsDifferentSatellite() {
+        val other = confirmed.copy(satelliteName = "AO-91")
+        assertFalse(sameConfirmedContact(local, other))
+    }
+
+    @Test
+    fun sameConfirmedContact_rejectsTimeSkew() {
+        val skewed = confirmed.copy(startUtcMillis = confirmed.startUtcMillis + 120_000L)
+        assertFalse(sameConfirmedContact(local, skewed))
+    }
+
+    @Test
+    fun confirmationLookupKey_usesNormalizedSatellite() {
+        assertEquals(local.confirmationLookupKey(), confirmed.confirmationLookupKey())
+    }
+
+    @Test
+    fun withConfirmation_marksConfirmedAndMergesVuccGrids() {
+        val merged = local.withConfirmation(confirmed)
+        assertTrue(merged.lotwConfirmed)
+        assertTrue(merged.lotwReceived)
+        assertEquals(listOf("OM60", "OM50"), merged.vuccGrids)
+        // Local myCallsign is kept when present; only blanks are backfilled.
+        assertEquals("ba7opf", merged.myCallsign)
+    }
+
+    @Test
+    fun toConfirmedRecord_mapsGridQso() {
+        val qso = GridQso(
+            call = "BH6RJD",
+            epochMs = 1_700_000_000_000L,
+            satName = "SO-50",
+            mode = "FM",
+            bandUp = "70CM",
+            bandDown = "2M",
+            dxcc = 318,
+            country = "China",
+            cqz = 24,
+            state = "GD",
+            myGrid = "OM60",
+            myGrids = setOf("OM60", "OM50")
+        )
+        val record = qso.toConfirmedRecord("ba7opf")
+        assertEquals("BH6RJD", record.theirCallsign)
+        assertEquals("BA7OPF", record.myCallsign)
+        assertEquals("OM60", record.myGrid)
+        assertEquals(listOf("OM60", "OM50"), record.vuccGrids)
+        assertTrue(record.lotwConfirmed)
+        assertTrue(record.isSatellite)
+        assertEquals("70CM", record.band)
+        assertEquals("2M", record.rxBand)
+    }
+
+    @Test
+    fun frequencyBand_edges() {
+        assertEquals("2M", frequencyBand(144_000_000L))
+        assertEquals("70CM", frequencyBand(450_000_000L))
+        assertEquals("10M", frequencyBand(29_000_000L))
+        assertEquals("", frequencyBand(null))
+    }
+
+    @Test
+    fun displayMode_prefersSubmode() {
+        val ft4 = QsoRecord(startUtcMillis = 0, theirCallsign = "x", myCallsign = "y", mode = "MFSK", submode = "FT4")
+        assertEquals("FT4", ft4.displayMode)
+        assertEquals("FM", local.displayMode)
+    }
+
+    @Test
+    fun displayMode_ignoresStaleSubmodeForOtherModes() {
+        // Regression: records persisted with the old default submode="FT4" must not
+        // show FT4 when the actual mode is FM/CW/SSB.
+        val staleFm = QsoRecord(startUtcMillis = 0, theirCallsign = "x", myCallsign = "y", mode = "FM", submode = "FT4")
+        val staleCw = QsoRecord(startUtcMillis = 0, theirCallsign = "x", myCallsign = "y", mode = "CW", submode = "FT4")
+        assertEquals("FM", staleFm.displayMode)
+        assertEquals("CW", staleCw.displayMode)
+    }
+
+    // region logbook split (tracker name / band direction, 2026-09-28)
+
+    @Test
+    fun satelliteIdentity_mapsTrackerNamesOntoArlNames() {
+        // Local records keep the tracking-source name, LoTW reports the ARRL name; both
+        // must land on one identity or every confirmation becomes a second row.
+        assertEquals("SO-50", satelliteIdentity("SAUDISAT 1C"))
+        assertEquals("SO-50", satelliteIdentity("SO-50"))
+        assertEquals("ARISS", satelliteIdentity("ISS (ZARYA)"))
+        assertEquals("ARISS", satelliteIdentity("ARISS"))
+        assertEquals("PO-101", satelliteIdentity("DIWATA 2B"))
+        assertEquals("FO-29", satelliteIdentity("JAS 2"))
+    }
+
+    @Test
+    fun satelliteIdentity_isSymmetricForEveryAliasEntry() {
+        // Guards the whole table: an entry whose target does not resolve back to the same
+        // identity would split that satellite's contacts again.
+        LoTWSatelliteAliases.table.forEach { (tracker, official) ->
+            assertEquals(official, satelliteIdentity(tracker), satelliteIdentity(official))
+        }
+    }
+
+    @Test
+    fun satelliteIdentity_keepsRecycledPlaceholdersUnmatched() {
+        // "OBJECT xx" names are reused between objects and deliberately unmapped, so they
+        // must never resolve onto a real ARRL satellite.
+        assertEquals("OBJECT AY", satelliteIdentity("OBJECT AY"))
+        assertNotEquals(satelliteIdentity("AO-123"), satelliteIdentity("OBJECT AY"))
+    }
+
+    @Test
+    fun sameConfirmedContact_matchesTrackerNameAgainstArlName() {
+        // The reported bug: SO-50 logged in the app (tracker name, 145.850 uplink) never
+        // picked up the confirmation LoTW reported for it.
+        val uploaded = loggedRecord("SAUDISAT 1C", uplinkHz = 145_850_000L, downlinkHz = 436_795_000L)
+        val reported = reportedRecord("SO-50", band = "2M", rxBand = "70CM")
+        assertTrue(sameConfirmedContact(uploaded, reported))
+    }
+
+    @Test
+    fun sameConfirmedContact_stillRejectsOtherContactOrMinute() {
+        val uploaded = loggedRecord("SAUDISAT 1C", uplinkHz = 145_850_000L, downlinkHz = 436_795_000L)
+        val otherOperator = reportedRecord("SO-50", band = "2M", rxBand = "70CM").copy(theirCallsign = "BG5JVM")
+        val anotherMinute = reportedRecord("SO-50", band = "2M", rxBand = "70CM")
+            .copy(startUtcMillis = uploaded.startUtcMillis + 90_000L)
+        assertFalse(sameConfirmedContact(uploaded, otherOperator))
+        assertFalse(sameConfirmedContact(uploaded, anotherMinute))
+    }
+
+    @Test
+    fun splitConfirmationPairs_foldsRowsSplitByTheOldMismatch() {
+        // Both pre-fix symptoms in one pair: the imported row keeps the ARRL name and the
+        // mirrored band direction the old parser produced (band=downlink).
+        val uploaded = loggedRecord("SAUDISAT 1C", 145_850_000L, 436_795_000L)
+            .copy(id = 1L, lotwUploaded = true)
+        val imported = reportedRecord("SO-50", band = "70CM", rxBand = "2M").copy(id = 2L)
+        val pairs = splitConfirmationPairs(listOf(uploaded, imported))
+        assertEquals(1, pairs.size)
+        assertEquals(0, pairs.first().localIndex)
+        assertEquals(1, pairs.first().confirmationIndex)
+    }
+
+    @Test
+    fun splitConfirmationPairs_keepsUnrelatedRowsApart() {
+        val uploaded = loggedRecord("SAUDISAT 1C", 145_850_000L, 436_795_000L)
+            .copy(id = 1L, lotwUploaded = true)
+        // Another operator on another satellite in the same minute must not be folded in.
+        val otherOperator = reportedRecord("SO-50", band = "70CM", rxBand = "2M")
+            .copy(id = 2L, theirCallsign = "BG5JVM")
+        // A contact on a satellite the local record does not name at all stays separate.
+        val otherSatellite = reportedRecord("AO-91", band = "70CM", rxBand = "2M").copy(id = 3L)
+        assertTrue(splitConfirmationPairs(listOf(uploaded, otherOperator, otherSatellite)).isEmpty())
+    }
+
+    /** A record as the log page creates it: tracker name, uplink/downlink bands, no flags. */
+    @Test
+    fun officialSatelliteName_storesTheArlName() {
+        assertEquals("SO-50", officialSatelliteName("SAUDISAT 1C"))
+        assertEquals("ARISS", officialSatelliteName("ISS (ZARYA)"))
+        assertEquals("PO-101", officialSatelliteName("DIWATA 2B"))
+        assertEquals("FO-29", officialSatelliteName("JAS 2"))
+        // Already-ARRL names are left alone (the rewrite is idempotent).
+        assertEquals("SO-50", officialSatelliteName("SO-50"))
+        assertEquals("AO-123", officialSatelliteName("AO-123"))
+        // Nothing to map onto: a satellite ARRL does not list, a recycled placeholder, a blank.
+        assertEquals("FOO-1", officialSatelliteName("FOO-1"))
+        assertEquals("OBJECT AY", officialSatelliteName("OBJECT AY"))
+        assertEquals("", officialSatelliteName("   "))
+    }
+
+    @Test
+    fun officialSatelliteName_usesTheCatalogueWhenItKnowsTheNameTheTrackerCarries() {
+        val catalogue = listOf("BO-102", "SO-50")
+        // "CAS-7B" resolves through the alias table, the description-only name through the catalogue.
+        assertEquals("BO-102", officialSatelliteName("CAS-7B", catalogue))
+        assertEquals("BO-102", officialSatelliteName("CAS-7B (BO-102)", catalogue))
+        assertEquals("SO-50", officialSatelliteName("SAUDISAT 1C", catalogue))
+    }
+
+    private fun loggedRecord(satelliteName: String, uplinkHz: Long, downlinkHz: Long) = QsoRecord(
+        startUtcMillis = REPORTED_START,
+        theirCallsign = "BG5JSB",
+        myCallsign = "BA7OPF",
+        txFrequencyHz = uplinkHz,
+        rxFrequencyHz = downlinkHz,
+        band = frequencyBand(uplinkHz),
+        rxBand = frequencyBand(downlinkHz),
+        mode = "FM",
+        satelliteName = satelliteName,
+        propagationMode = "SAT",
+        status = QsoStatus.COMPLETE,
+        lotwUploaded = true
+    )
+
+    /** A record as a LoTW confirmation carries it: ARRL name, report bands, confirmed. */
+    private fun reportedRecord(satelliteName: String, band: String, rxBand: String) = QsoRecord(
+        startUtcMillis = REPORTED_START,
+        theirCallsign = "BG5JSB",
+        myCallsign = "BA7OPF",
+        band = band,
+        rxBand = rxBand,
+        mode = "FM",
+        satelliteName = satelliteName,
+        propagationMode = "SAT",
+        status = QsoStatus.COMPLETE,
+        lotwConfirmed = true
+    )
+
+    private companion object {
+        /** 2026-09-16 07:45Z — an SO-50 pass of the user's real report. */
+        const val REPORTED_START = 1_789_544_700_000L
+    }
+
+    // endregion
+}

core/domain/src/test/java/com/rtbishop/look4sat/core/domain/repository/LoTWGridSyncTest.kt

@@ -285,6 +285,8 @@ class LoTWGridSyncTest {
         override fun updateDataSourcesStatus(status: Map<String, Int>) = TODO()
         override fun updateRadioControlSettings(settings: RadioControlSettings) = TODO()
         override fun getSatelliteOffset(catnum: Int): String = ""
+        override fun getSatelliteMode(catnum: Int): String = ""
+        override fun setSatelliteMode(catnum: Int, mode: String) {}
         override fun setSatelliteOffset(catnum: Int, offset: String) = TODO()
         override fun getAmSatCallsign(): String = ""
         override fun setAmSatCallsign(callsign: String) = TODO()

core/domain/src/test/java/com/rtbishop/look4sat/core/domain/utility/GridGeometryTest.kt

@@ -0,0 +1,171 @@
+/*
+ * 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.utility
+
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+/**
+ * Golden values were produced by a line-by-line port of the reference
+ * implementation (OrbitDeck for iOS, MIT) covering four hemispheres/quadrant
+ * cases plus the two awkward longitudes: the Greenwich meridian and the
+ * antimeridian.
+ */
+class GridGeometryTest {
+
+    private val meterDelta = 0.5
+    private val bearingDelta = 0.05
+
+    @Test
+    fun `station at home square reports both boundaries and the corner`() {
+        val geometry = requireNotNull(gridGeometry(22.3542, 113.6250))
+        assertEquals("OL62", geometry.grid4)
+        assertEquals("OL62TI", geometry.grid6)
+        assertEquals("OL62TI55", geometry.grid8)
+        assertEquals(39429.5, geometry.latLineMeters, meterDelta)
+        assertEquals(GridBoundaryDirection.SOUTH, geometry.latLineDirection)
+        assertEquals(38607.9, geometry.lonLineMeters, meterDelta)
+        assertEquals(GridBoundaryDirection.EAST, geometry.lonLineDirection)
+        assertEquals(55183.8, geometry.cornerMeters, meterDelta)
+        assertEquals(135.60, geometry.cornerBearingDegrees, bearingDelta)
+        assertEquals(listOf("OL61", "OL62", "OL71", "OL72"), geometry.cornerGrids)
+        assertEquals(38607.9, geometry.nearestLineMeters, meterDelta)
+        assertEquals(90.0, geometry.nearestLineBearingDegrees, bearingDelta)
+        assertEquals(false, geometry.nearestLineIsLatitude)
+        assertEquals(listOf("OL62", "OL72"), geometry.nearestLineGrids)
+    }
+
+    @Test
+    fun `fix on the 114 east line sits on the boundary itself`() {
+        val geometry = requireNotNull(gridGeometry(22.3542, 114.0000))
+        assertEquals("OL72", geometry.grid4)
+        assertEquals("OL72AI", geometry.grid6)
+        assertEquals("OL72AI05", geometry.grid8)
+        assertEquals(39429.5, geometry.latLineMeters, meterDelta)
+        assertEquals(0.0, geometry.lonLineMeters, meterDelta)
+        assertEquals(39429.5, geometry.cornerMeters, meterDelta)
+        assertEquals(180.00, geometry.cornerBearingDegrees, bearingDelta)
+        assertEquals(listOf("OL62", "OL72"), geometry.nearestLineGrids)
+    }
+
+    @Test
+    fun `fix on the 22 north 114 east corner names all four squares`() {
+        val geometry = requireNotNull(gridGeometry(22.00002, 114.00003))
+        assertEquals("OL72", geometry.grid4)
+        assertEquals(2.2, geometry.latLineMeters, meterDelta)
+        assertEquals(3.1, geometry.lonLineMeters, meterDelta)
+        assertEquals(3.8, geometry.cornerMeters, meterDelta)
+        assertEquals(234.28, geometry.cornerBearingDegrees, bearingDelta)
+        assertEquals(listOf("OL61", "OL62", "OL71", "OL72"), geometry.cornerGrids)
+        assertEquals("OL71", geometry.nearestLineGrids.first())
+    }
+
+    @Test
+    fun `greenwich meridian fix reports a zero distance latitude line to the north`() {
+        val geometry = requireNotNull(gridGeometry(45.0000, -0.0004))
+        assertEquals("IN95", geometry.grid4)
+        assertEquals("IN95XA", geometry.grid6)
+        assertEquals("IN95XA90", geometry.grid8)
+        assertEquals(0.0, geometry.latLineMeters, meterDelta)
+        assertEquals(GridBoundaryDirection.NORTH, geometry.latLineDirection)
+        assertEquals(31.5, geometry.lonLineMeters, meterDelta)
+        assertEquals(listOf("IN94", "IN95", "JN04", "JN05"), geometry.cornerGrids)
+        assertEquals(true, geometry.nearestLineIsLatitude)
+        assertEquals(listOf("IN94", "IN95"), geometry.nearestLineGrids)
+    }
+
+    @Test
+    fun `antimeridian fix wraps into the eastern square`() {
+        val geometry = requireNotNull(gridGeometry(0.05, 179.9998))
+        assertEquals("RJ90", geometry.grid4)
+        assertEquals("RJ90XB", geometry.grid6)
+        assertEquals("RJ90XB92", geometry.grid8)
+        assertEquals(22.3, geometry.lonLineMeters, meterDelta)
+        assertEquals(GridBoundaryDirection.EAST, geometry.lonLineDirection)
+        assertEquals(179.77, geometry.cornerBearingDegrees, bearingDelta)
+        // The corner's four squares straddle the antimeridian, so the western
+        // pair rolls over to the A-series fields.
+        assertEquals(listOf("AI09", "AJ00", "RI99", "RJ90"), geometry.cornerGrids)
+        assertEquals(listOf("AJ00", "RJ90"), geometry.nearestLineGrids)
+    }
+
+    @Test
+    fun `southern hemisphere fix keeps its bearings right way round`() {
+        val geometry = requireNotNull(gridGeometry(-33.86, 151.21))
+        assertEquals("QF56", geometry.grid4)
+        assertEquals("QF56OD", geometry.grid6)
+        assertEquals(15584.8, geometry.latLineMeters, meterDelta)
+        assertEquals(GridBoundaryDirection.SOUTH, geometry.latLineDirection)
+        assertEquals(73027.8, geometry.lonLineMeters, meterDelta)
+        assertEquals(GridBoundaryDirection.EAST, geometry.lonLineDirection)
+        assertEquals(102.05, geometry.cornerBearingDegrees, bearingDelta)
+        assertEquals(180.0, geometry.nearestLineBearingDegrees, bearingDelta)
+    }
+
+    @Test
+    fun `out of range positions yield no geometry`() {
+        assertNull(gridGeometry(90.0, 0.0))
+        assertNull(gridGeometry(-91.0, 0.0))
+    }
+
+    @Test
+    fun `vucc claims one square when the fix is inside`() {
+        assertEquals(listOf("OL62"), vuccClaimableGrids(22.3542, 113.6250))
+        assertEquals(GridFixStatus.INSIDE_GRID, gridFixStatus(vuccClaimableGrids(22.3542, 113.6250)))
+    }
+
+    @Test
+    fun `vucc claims both squares on a line`() {
+        val claimed = vuccClaimableGrids(22.3542, 114.0000)
+        assertEquals(listOf("OL62", "OL72"), claimed)
+        assertEquals(GridFixStatus.ON_GRID_LINE, gridFixStatus(claimed))
+    }
+
+    @Test
+    fun `vucc claims all four squares on a corner`() {
+        val claimed = vuccClaimableGrids(22.00002, 114.00003)
+        assertEquals(listOf("OL61", "OL62", "OL71", "OL72"), claimed)
+        assertEquals(GridFixStatus.ON_GRID_CORNER, gridFixStatus(claimed))
+    }
+
+    @Test
+    fun `vucc claims nothing extra just outside the 20 foot tolerance`() {
+        // Same corner, but ~38 m away: outside the 20 ft (6.096 m) rule.
+        val claimed = vuccClaimableGrids(22.0002, 114.0003)
+        assertEquals(listOf("OL72"), claimed)
+        assertEquals(GridFixStatus.INSIDE_GRID, gridFixStatus(claimed))
+    }
+
+    @Test
+    fun `vucc tolerance boundary is 20 feet`() {
+        assertEquals(6.096, VUCC_BOUNDARY_TOLERANCE_METERS, 0.0001)
+        // 5 m north of the 22 N line: inside the tolerance for a custom, tighter
+        // call, outside it when the caller demands sub-metre precision.
+        assertTrue(vuccClaimableGrids(22.00005, 113.62).size >= 2)
+        assertEquals(1, vuccClaimableGrids(22.00005, 113.62, toleranceMeters = 1.0).size)
+    }
+
+    @Test
+    fun `grid4 ignores longitudes beyond the antimeridian`() {
+        assertNull(positionToGrid4(91.0, 0.0))
+        // A longitude of 200 degrees is the same meridian as -160 degrees.
+        assertEquals(positionToGrid4(30.0, -160.0), positionToGrid4(30.0, 200.0))
+    }
+}

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

@@ -17,9 +17,15 @@
  */
 package com.rtbishop.look4sat.core.presentation
 
+import androidx.compose.animation.core.FastOutSlowInEasing
+import androidx.compose.animation.core.animate
+import androidx.compose.animation.core.tween
 import androidx.compose.foundation.MarqueeSpacing
+import androidx.compose.foundation.background
 import androidx.compose.foundation.basicMarquee
 import androidx.compose.foundation.clickable
+import androidx.compose.foundation.gestures.detectHorizontalDragGestures
+import androidx.compose.foundation.interaction.MutableInteractionSource
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
@@ -29,7 +35,9 @@ import androidx.compose.foundation.layout.RowScope
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.fillMaxHeight
 import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.offset
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.statusBarsPadding
@@ -49,16 +57,28 @@ import androidx.compose.material3.Text
 import androidx.compose.material3.rememberModalBottomSheetState
 import androidx.compose.material3.adaptive.currentWindowAdaptiveInfo
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.compositionLocalOf
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableFloatStateOf
+import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clipToBounds
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.drawscope.Stroke
+import androidx.compose.ui.hapticfeedback.HapticFeedbackType
 import androidx.compose.ui.input.nestedscroll.NestedScrollConnection
 import androidx.compose.ui.input.nestedscroll.NestedScrollSource
 import androidx.compose.ui.input.nestedscroll.nestedScroll
+import androidx.compose.ui.input.pointer.pointerInput
+import androidx.compose.ui.graphics.graphicsLayer
+import androidx.compose.ui.platform.LocalDensity
+import androidx.compose.ui.platform.LocalHapticFeedback
 import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.semantics.hideFromAccessibility
@@ -82,6 +102,8 @@ import com.rtbishop.look4sat.core.domain.predict.OrbitalData
 import com.rtbishop.look4sat.core.domain.predict.OrbitalPass
 import java.text.SimpleDateFormat
 import java.util.Date
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.launch
 import java.util.Locale
 import java.util.TimeZone
 
@@ -447,6 +469,134 @@ fun isVerticalLayout(): Boolean = !hasEnoughWidth()
 fun Modifier.infiniteMarquee(): Modifier =
     basicMarquee(iterations = Int.MAX_VALUE, spacing = MarqueeSpacing(16.dp))
 
+/** 共享的滑动行展开状态：同一列表内同时只允许一行展开（短信式联动）。 */
+class SwipeController {
+    var openKey by mutableStateOf<String?>(null)
+        private set
+    fun open(key: String) {
+        openKey = key
+    }
+    fun close() {
+        openKey = null
+    }
+}
+
+@Composable
+fun rememberSwipeController(): SwipeController = remember { SwipeController() }
+
+/** 短信式滑动行：右划露出 [revealButton]（默认红底垃圾桶+文字），点击按钮触发 [revealAction]。
+ *  通过 [controller] 联动：滑开新行时其他行自动收回；点按已展开的行内容也可收回（无涟漪）。 */
+@Composable
+fun SwipeRevealRow(
+    key: String,
+    controller: SwipeController,
+    modifier: Modifier = Modifier,
+    revealWidth: Dp = 64.dp,
+    revealAction: () -> Unit,
+    revealButton: @Composable () -> Unit = {
+        Box(
+            modifier = Modifier
+                .fillMaxSize()
+                .background(MaterialTheme.colorScheme.error),
+            contentAlignment = Alignment.Center
+        ) {
+            Icon(
+                painter = painterResource(R.drawable.ic_delete),
+                contentDescription = null,
+                tint = Color.White,
+                modifier = Modifier.size(24.dp)
+            )
+        }
+    },
+    content: @Composable () -> Unit
+) {
+    val density = LocalDensity.current
+    val revealPx = with(density) { revealWidth.toPx() }
+    var offsetX by remember { mutableFloatStateOf(0f) }
+    var settleJob by remember { mutableStateOf<Job?>(null) }
+    val scope = rememberCoroutineScope()
+    val haptics = LocalHapticFeedback.current
+    val isOpen = controller.openKey == key
+
+    fun settle(target: Float) {
+        settleJob?.cancel()
+        settleJob = scope.launch {
+            animate(offsetX, target, animationSpec = tween(durationMillis = 200, easing = FastOutSlowInEasing)) { value, _ ->
+                offsetX = value
+            }
+        }
+    }
+
+    // 另一行展开（或全部收回）时，本行随之收回。
+    LaunchedEffect(controller.openKey) {
+        if (!isOpen && offsetX < 0f) settle(0f)
+    }
+
+    Box(modifier.fillMaxWidth().clipToBounds()) {
+        // 背景删除按钮：初始位于内容右侧屏幕外，与内容同步平移（跟手滑入）。
+        // 父 Box clipToBounds 裁剪容器外部分——即便外层 item 带 padding、按钮
+        // 左缘落在容器外的屏幕内，也因裁剪而不可见、不可点。
+        Box(
+            modifier = Modifier
+                .align(Alignment.CenterEnd)
+                .fillMaxHeight()
+                .width(revealWidth)
+                .offset(x = revealWidth)
+                .graphicsLayer { translationX = offsetX }
+                .clickable {
+                    haptics.performHapticFeedback(HapticFeedbackType.LongPress)
+                    controller.close()
+                    settle(0f)
+                    revealAction()
+                }
+        ) { revealButton() }
+        // 前景内容：右划平移露出按钮
+        Box(
+            modifier = Modifier
+                .fillMaxWidth()
+                .graphicsLayer { translationX = offsetX }
+                .pointerInput(revealPx) {
+                    detectHorizontalDragGestures(
+                        onDragStart = { settleJob?.cancel() },
+                        onHorizontalDrag = { change, dragAmount ->
+                            change.consume()
+                            offsetX = (offsetX + dragAmount).coerceIn(-revealPx, 0f)
+                        },
+                        onDragEnd = {
+                            if (offsetX < -revealPx / 2) {
+                                controller.open(key)
+                                haptics.performHapticFeedback(HapticFeedbackType.SegmentTick)
+                                settle(-revealPx)
+                            } else {
+                                controller.close()
+                                settle(0f)
+                            }
+                        },
+                        onDragCancel = {
+                            if (offsetX < -revealPx / 2) {
+                                controller.open(key)
+                                settle(-revealPx)
+                            } else {
+                                controller.close()
+                                settle(0f)
+                            }
+                        }
+                    )
+                }
+                // 已展开的行，点按内容直接收回（无涟漪，避免整行出现点击反馈）
+                .clickable(
+                    interactionSource = remember { MutableInteractionSource() },
+                    indication = null
+                ) {
+                    if (isOpen) {
+                        controller.close()
+                        settle(0f)
+                    }
+                }
+        ) { content() }
+    }
+}
+
 @Composable
 fun Modifier.layoutPadding(): Modifier {
     val spacing = LocalSpacing.current.extraSmall

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

@@ -1,3 +1,21 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
 package com.rtbishop.look4sat.core.presentation
 
 import androidx.compose.foundation.Canvas

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

@@ -61,8 +61,9 @@ fun MainTheme(isDarkTheme: Boolean = isSystemInDarkTheme(), content: @Composable
             SideEffect {
                 val window = (view.context as ComponentActivity).window
                 val insetsController = WindowCompat.getInsetsController(window, view)
-                insetsController.isAppearanceLightStatusBars = false
-                insetsController.isAppearanceLightNavigationBars = false
+                // Light theme needs dark status/nav bar icons; the dark theme needs light ones.
+                insetsController.isAppearanceLightStatusBars = !isDarkTheme
+                insetsController.isAppearanceLightNavigationBars = !isDarkTheme
                 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
                     window.isNavigationBarContrastEnforced = false
                 }

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

@@ -45,6 +45,14 @@ sealed class Screen(val iconResId: Int, val titleResId: Int) : NavKey {
 @Serializable
 data object RadarDestination : NavKey
 
+/** Full-screen field tool: guides the operator onto a VUCC grid line or corner. */
+@Serializable
+data object GridFinderDestination : NavKey
+
+/** LoTW upload certificate + station location page, reached from the Grid Finder. */
+@Serializable
+data object LoTWUploadDestination : NavKey
+
 interface IDeeplinkMatcher {
     fun match(deeplink: String): NavKey?
 }

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

@@ -0,0 +1,82 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.presentation
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+
+/**
+ * The fork's Project Wiki: a short overview of what Look4Sat-BA7OPF adds over upstream
+ * and how to use those features. Shown in the What's-New card (first launch after an
+ * update) and behind the Settings → Project Wiki entry. Text lives in string resources,
+ * so it always renders even when the GitHub page is unreachable.
+ */
+@Composable
+fun ProjectWikiBody(modifier: Modifier = Modifier) {
+    Column(modifier = modifier, verticalArrangement = Arrangement.spacedBy(8.dp)) {
+        Text(
+            text = stringResource(R.string.project_wiki_intro),
+            fontSize = 13.sp
+        )
+        WikiSection(stringResource(R.string.project_wiki_section_logbook))
+        WikiEntry(stringResource(R.string.project_wiki_logbook_1))
+        WikiEntry(stringResource(R.string.project_wiki_logbook_2))
+        WikiEntry(stringResource(R.string.project_wiki_logbook_3))
+        WikiHow(stringResource(R.string.project_wiki_logbook_how))
+        WikiSection(stringResource(R.string.project_wiki_section_mutual))
+        WikiEntry(stringResource(R.string.project_wiki_mutual_1))
+        WikiHow(stringResource(R.string.project_wiki_mutual_how))
+        WikiSection(stringResource(R.string.project_wiki_section_grids))
+        WikiEntry(stringResource(R.string.project_wiki_grids_1))
+        WikiHow(stringResource(R.string.project_wiki_grids_how))
+    }
+}
+
+@Composable
+private fun WikiSection(text: String) {
+    Text(
+        text = text,
+        color = MaterialTheme.colorScheme.primary,
+        fontWeight = FontWeight.Medium,
+        fontSize = 13.sp
+    )
+}
+
+@Composable
+private fun WikiEntry(text: String) {
+    Text(text = text, fontSize = 12.sp)
+}
+
+@Composable
+private fun WikiHow(text: String) {
+    Text(
+        text = text,
+        fontSize = 12.sp,
+        color = MaterialTheme.colorScheme.onSurfaceVariant,
+        modifier = Modifier.padding(start = 8.dp)
+    )
+}

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

@@ -0,0 +1,386 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.presentation
+
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.heightIn
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.text.KeyboardOptions
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material3.AlertDialog
+import androidx.compose.material3.FilterChip
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.input.KeyboardCapitalization
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import com.rtbishop.look4sat.core.domain.logbook.LoTWSatelliteAliases
+import com.rtbishop.look4sat.core.domain.logbook.QsoRecord
+import com.rtbishop.look4sat.core.domain.logbook.displayMode
+import com.rtbishop.look4sat.core.domain.logbook.frequencyBand
+import java.math.BigDecimal
+import java.text.SimpleDateFormat
+import java.util.Date
+import java.util.Locale
+import java.util.TimeZone
+import kotlin.math.roundToLong
+
+private const val DATE_PATTERN = "yyyy-MM-dd"
+private const val TIME_PATTERN = "HH:mm:ss"
+
+/**
+ * Edit every field of a recorded QSO (the record list rows in the radar Log tab and
+ * the logbook dialog both open this). Frequencies are entered in MHz and the band is
+ * re-derived from them, because that derivation is what LoTW validates: a record with
+ * no uplink frequency has no BAND and cannot be signed.
+ *
+ * The satellite name is restricted to ARRL's catalogue ([satelliteCandidates], from
+ * config.tq6): typing shows fuzzy suggestions, the picker lists the whole catalogue, and
+ * a name that resolves to no ARRL satellite cannot be saved. A tracker name such as
+ * "SAUDISAT 1C" is accepted and stored as the ARRL name it resolves to ("SO-50").
+ */
+@Composable
+fun QsoEditDialog(
+    record: QsoRecord,
+    satelliteCandidates: List<String> = emptyList(),
+    onDismiss: () -> Unit,
+    onSave: (QsoRecord) -> Unit
+) {
+    val utc = remember { TimeZone.getTimeZone("UTC") }
+    fun formatDate(millis: Long) = SimpleDateFormat(DATE_PATTERN, Locale.US).apply { timeZone = utc }.format(Date(millis))
+    fun formatTime(millis: Long) = SimpleDateFormat(TIME_PATTERN, Locale.US).apply { timeZone = utc }.format(Date(millis))
+
+    var callsign by remember(record.id) { mutableStateOf(record.theirCallsign.trim()) }
+    var dateText by remember(record.id) { mutableStateOf(formatDate(record.startUtcMillis)) }
+    var timeText by remember(record.id) { mutableStateOf(formatTime(record.startUtcMillis)) }
+    var txText by remember(record.id) { mutableStateOf(formatMhz(record.txFrequencyHz)) }
+    var rxText by remember(record.id) { mutableStateOf(formatMhz(record.rxFrequencyHz)) }
+    var modeText by remember(record.id) { mutableStateOf(record.displayMode) }
+    var satelliteText by remember(record.id) { mutableStateOf(record.satelliteName) }
+    var pickerOpen by remember(record.id) { mutableStateOf(false) }
+    var sentText by remember(record.id) { mutableStateOf(record.sentReport) }
+    var receivedText by remember(record.id) { mutableStateOf(record.receivedReport) }
+    var gridText by remember(record.id) { mutableStateOf(record.theirGrid) }
+    var commentText by remember(record.id) { mutableStateOf(record.comment) }
+    var error by remember(record.id) { mutableStateOf("") }
+
+    // ARRL name the typed tracker name resolves to ("SAUDISAT 1C" -> "SO-50"), if any.
+    val officialSatellite = remember(satelliteText, satelliteCandidates) {
+        LoTWSatelliteAliases.resolve(satelliteText, satelliteCandidates)
+    }
+    val satelliteSuggestions = remember(satelliteText, satelliteCandidates) {
+        LoTWSatelliteAliases.suggestions(satelliteText, satelliteCandidates)
+    }
+
+    val txHz = parseMhz(txText)
+    val rxHz = parseMhz(rxText)
+    val bandText = listOf(frequencyBand(txHz), frequencyBand(rxHz)).filter { it.isNotBlank() }.distinct()
+        .joinToString(" / ")
+
+    val errCallsign = stringResource(R.string.qso_edit_err_callsign)
+    val errDateTime = stringResource(R.string.qso_edit_err_datetime)
+    val errFrequency = stringResource(R.string.qso_edit_err_frequency)
+    val errSatellite = stringResource(R.string.qso_edit_err_satellite)
+
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        shape = sheetDialogShape(),
+        containerColor = sheetDialogContainerColor(),
+        title = { SheetDialogTitle(stringResource(R.string.qso_edit_title)) },
+        text = {
+            Column(
+                modifier = Modifier.fillMaxWidth().heightIn(max = 460.dp).verticalScroll(rememberScrollState()),
+                verticalArrangement = Arrangement.spacedBy(6.dp)
+            ) {
+                if (record.lotwUploaded || record.lotwConfirmed) {
+                    Text(
+                        text = stringResource(R.string.qso_edit_uploaded_notice),
+                        fontSize = 12.sp,
+                        color = MaterialTheme.colorScheme.primary,
+                        style = MaterialTheme.typography.bodySmall
+                    )
+                }
+                EditField(stringResource(R.string.qso_edit_callsign), callsign, KeyboardCapitalization.Characters) {
+                    callsign = it.uppercase(Locale.US)
+                }
+                Row(horizontalArrangement = Arrangement.spacedBy(6.dp), modifier = Modifier.fillMaxWidth()) {
+                    EditField(stringResource(R.string.qso_edit_date), dateText, KeyboardCapitalization.None, Modifier.weight(1f)) {
+                        dateText = it
+                    }
+                    EditField(stringResource(R.string.qso_edit_time), timeText, KeyboardCapitalization.None, Modifier.weight(1f)) {
+                        timeText = it
+                    }
+                }
+                Row(horizontalArrangement = Arrangement.spacedBy(6.dp), modifier = Modifier.fillMaxWidth()) {
+                    EditField(stringResource(R.string.qso_edit_tx), txText, KeyboardCapitalization.None, Modifier.weight(1f)) {
+                        txText = it
+                    }
+                    EditField(stringResource(R.string.qso_edit_rx), rxText, KeyboardCapitalization.None, Modifier.weight(1f)) {
+                        rxText = it
+                    }
+                }
+                Text(
+                    text = stringResource(R.string.qso_edit_band, bandText.ifBlank { "—" }),
+                    fontSize = 12.sp,
+                    color = if (txHz == null) MaterialTheme.colorScheme.error else MaterialTheme.colorScheme.onSurfaceVariant
+                )
+                EditField(stringResource(R.string.qso_edit_mode), modeText, KeyboardCapitalization.Characters) {
+                    modeText = it.uppercase(Locale.US)
+                }
+                Row(verticalAlignment = Alignment.CenterVertically, modifier = Modifier.fillMaxWidth()) {
+                    EditField(
+                        label = stringResource(R.string.qso_edit_satellite),
+                        value = satelliteText,
+                        capitalization = KeyboardCapitalization.Characters,
+                        modifier = Modifier.weight(1f)
+                    ) { satelliteText = it.uppercase(Locale.US) }
+                    TextButton(
+                        onClick = { pickerOpen = true },
+                        enabled = satelliteCandidates.isNotEmpty()
+                    ) { Text(stringResource(R.string.qso_edit_satellite_pick), fontSize = 12.sp) }
+                }
+                when {
+                    // Resolves to an ARRL satellite under a different name: say so, the
+                    // ARRL name is what gets stored and signed.
+                    officialSatellite != null && !officialSatellite.equals(satelliteText.trim(), true) ->
+                        Text(
+                            text = stringResource(R.string.qso_edit_satellite_official, officialSatellite),
+                            fontSize = 11.sp,
+                            color = MaterialTheme.colorScheme.onSurfaceVariant
+                        )
+
+                    // Not an ARRL satellite at all: offer the closest catalogue names.
+                    satelliteText.isNotBlank() && officialSatellite == null -> {
+                        Text(
+                            text = stringResource(R.string.qso_edit_err_satellite),
+                            fontSize = 11.sp,
+                            color = MaterialTheme.colorScheme.error
+                        )
+                        if (satelliteSuggestions.isNotEmpty()) {
+                            Row(horizontalArrangement = Arrangement.spacedBy(4.dp)) {
+                                satelliteSuggestions.take(4).forEach { candidate ->
+                                    FilterChip(
+                                        selected = false,
+                                        onClick = { satelliteText = candidate },
+                                        label = { Text(candidate, fontSize = 11.sp) }
+                                    )
+                                }
+                            }
+                        }
+                    }
+
+                    else -> Text(
+                        text = stringResource(R.string.qso_edit_hint_satellite),
+                        fontSize = 11.sp,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant
+                    )
+                }
+                Row(horizontalArrangement = Arrangement.spacedBy(6.dp), modifier = Modifier.fillMaxWidth()) {
+                    EditField(stringResource(R.string.qso_edit_sent), sentText, KeyboardCapitalization.Characters, Modifier.weight(1f)) {
+                        sentText = it
+                    }
+                    EditField(stringResource(R.string.qso_edit_received), receivedText, KeyboardCapitalization.Characters, Modifier.weight(1f)) {
+                        receivedText = it
+                    }
+                }
+                Row(horizontalArrangement = Arrangement.spacedBy(6.dp), modifier = Modifier.fillMaxWidth()) {
+                    EditField(stringResource(R.string.qso_edit_grid), gridText, KeyboardCapitalization.Characters, Modifier.weight(1f)) {
+                        gridText = it.uppercase(Locale.US)
+                    }
+                    EditField(stringResource(R.string.qso_edit_comment), commentText, KeyboardCapitalization.None, Modifier.weight(1f)) {
+                        commentText = it
+                    }
+                }
+                if (txHz == null) {
+                    Text(
+                        text = stringResource(R.string.qso_edit_warn_no_freq),
+                        fontSize = 12.sp,
+                        color = MaterialTheme.colorScheme.error
+                    )
+                }
+                if (error.isNotBlank()) {
+                    Text(text = error, fontSize = 12.sp, color = MaterialTheme.colorScheme.error)
+                }
+            }
+        },
+        confirmButton = {
+            TextButton(onClick = {
+                val millis = parseUtc(dateText, timeText, utc)
+                val badFrequency = (txText.isNotBlank() && txHz == null) || (rxText.isNotBlank() && rxHz == null)
+                when {
+                    callsign.isBlank() -> error = errCallsign
+                    millis == null -> error = errDateTime
+                    badFrequency -> error = errFrequency
+                    // Only ARRL satellite names may be stored: a record that cannot be
+                    // resolved here would be rejected at upload time anyway.
+                    satelliteCandidates.isNotEmpty() && officialSatellite == null ->
+                        error = errSatellite
+
+                    else -> {
+                        val mode = modeText.trim().uppercase(Locale.US).ifBlank { "FM" }
+                        val satellite = officialSatellite ?: satelliteText.trim()
+                        onSave(
+                            record.copy(
+                                theirCallsign = callsign.trim().uppercase(Locale.US),
+                                startUtcMillis = millis,
+                                endUtcMillis = record.endUtcMillis?.let { millis },
+                                theirGrid = gridText.trim().uppercase(Locale.US),
+                                sentReport = sentText.trim(),
+                                receivedReport = receivedText.trim(),
+                                txFrequencyHz = txHz,
+                                rxFrequencyHz = rxHz,
+                                band = frequencyBand(txHz),
+                                rxBand = frequencyBand(rxHz),
+                                mode = if (mode == "FT4") "MFSK" else mode,
+                                submode = if (mode == "FT4") "FT4" else "",
+                                satelliteName = satellite,
+                                propagationMode = if (satellite.isBlank()) record.propagationMode else "SAT",
+                                comment = commentText.trim()
+                            )
+                        )
+                    }
+                }
+            }) { Text(stringResource(R.string.qso_edit_save)) }
+        },
+        dismissButton = {
+            TextButton(onClick = onDismiss) { Text(stringResource(R.string.qso_edit_cancel)) }
+        }
+    )
+
+    if (pickerOpen) {
+        SatellitePickerDialog(
+            candidates = satelliteCandidates,
+            onDismiss = { pickerOpen = false },
+            onPick = {
+                satelliteText = it
+                pickerOpen = false
+            }
+        )
+    }
+}
+
+/**
+ * Full ARRL satellite catalogue with a fuzzy filter: typing "saud" or "saudisat 1c" narrows the
+ * list down to "SO-50", so a tracker name can always be turned into the name LoTW accepts.
+ */
+@Composable
+private fun SatellitePickerDialog(
+    candidates: List<String>,
+    onDismiss: () -> Unit,
+    onPick: (String) -> Unit
+) {
+    var query by remember { mutableStateOf("") }
+    val matches = remember(query, candidates) { filteredCandidates(query, candidates) }
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        shape = sheetDialogShape(),
+        containerColor = sheetDialogContainerColor(),
+        title = { SheetDialogTitle(stringResource(R.string.qso_edit_satellite_pick_title)) },
+        text = {
+            Column(modifier = Modifier.fillMaxWidth(), verticalArrangement = Arrangement.spacedBy(6.dp)) {
+                OutlinedTextField(
+                    value = query,
+                    onValueChange = { query = it.uppercase(Locale.US) },
+                    label = { Text(stringResource(R.string.qso_edit_satellite_search), fontSize = 12.sp) },
+                    singleLine = true,
+                    textStyle = MaterialTheme.typography.bodyMedium,
+                    modifier = Modifier.fillMaxWidth()
+                )
+                LazyColumn(
+                    modifier = Modifier.fillMaxWidth().heightIn(max = 320.dp),
+                    verticalArrangement = Arrangement.spacedBy(2.dp)
+                ) {
+                    items(matches, key = { it }) { name ->
+                        Text(
+                            text = name,
+                            fontSize = 14.sp,
+                            modifier = Modifier
+                                .fillMaxWidth()
+                                .clickable { onPick(name) }
+                                .padding(horizontal = 4.dp, vertical = 8.dp)
+                        )
+                    }
+                }
+            }
+        },
+        confirmButton = {
+            TextButton(onClick = onDismiss) { Text(stringResource(R.string.qso_edit_cancel)) }
+        }
+    )
+}
+
+/** Catalogue filtered by the fuzzy query; the whole list when nothing matches or the query is blank. */
+internal fun filteredCandidates(query: String, candidates: List<String>): List<String> {
+    if (query.isBlank()) return candidates
+    val matches = LoTWSatelliteAliases.suggestions(query, candidates, limit = 500)
+    return matches.ifEmpty { candidates }
+}
+
+@Composable
+private fun EditField(
+    label: String,
+    value: String,
+    capitalization: KeyboardCapitalization,
+    modifier: Modifier = Modifier.fillMaxWidth(),
+    onValueChange: (String) -> Unit
+) {
+    OutlinedTextField(
+        value = value,
+        onValueChange = onValueChange,
+        label = { Text(label, fontSize = 12.sp) },
+        singleLine = true,
+        textStyle = MaterialTheme.typography.bodyMedium,
+        keyboardOptions = KeyboardOptions(capitalization = capitalization),
+        modifier = modifier.padding(vertical = 1.dp)
+    )
+}
+
+/** "436.795" (MHz) -> 436_795_000 Hz. Null when blank or unparsable. */
+internal fun parseMhz(text: String): Long? = text.trim()
+    .takeIf { it.isNotEmpty() }
+    ?.toDoubleOrNull()
+    ?.let { (it * 1_000_000.0).roundToLong() }
+
+/** Hz -> "436.795" (MHz), trailing zeros trimmed. */
+internal fun formatMhz(hz: Long?): String = hz
+    ?.let { BigDecimal.valueOf(it, 6).stripTrailingZeros().toPlainString() }
+    .orEmpty()
+
+internal fun parseUtc(date: String, time: String, zone: TimeZone): Long? = runCatching {
+    SimpleDateFormat("$DATE_PATTERN $TIME_PATTERN", Locale.US).apply {
+        timeZone = zone
+        isLenient = false
+    }.parse("${date.trim()} ${time.trim()}")?.time
+}.getOrNull()

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

@@ -0,0 +1,58 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.presentation
+
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.Shape
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.sp
+
+/**
+ * Styling of the app's sheet dialogs ([DialogShell] / [SharedDialog] / [InfoDialog], all built on
+ * ModalBottomSheet). AlertDialog-based dialogs (logbook, QSO editor, upload preview) use these so
+ * their container colour, corner radius and title look identical to the bottom sheets.
+ */
+
+/**
+ * Container colour of the app's bottom sheets. Equal to `BottomSheetDefaults.ContainerColor`
+ * (Material3 resolves that token to `ColorScheme.surfaceContainerLow`) — spelled out here so the
+ * dialogs don't have to opt into the experimental bottom-sheet API.
+ */
+@Composable
+fun sheetDialogContainerColor(): Color = MaterialTheme.colorScheme.surfaceContainerLow
+
+/** Corner radius of the app's bottom sheets (`MaterialTheme.shapes.medium`, 12 dp). */
+@Composable
+fun sheetDialogShape(): Shape = MaterialTheme.shapes.medium
+
+/** Title row of the app's sheet dialogs: 16 sp medium, primary colour, single line. */
+@Composable
+fun SheetDialogTitle(text: String) {
+    Text(
+        text = text,
+        fontSize = 16.sp,
+        fontWeight = FontWeight.Medium,
+        color = MaterialTheme.colorScheme.primary,
+        maxLines = 1,
+        overflow = TextOverflow.Ellipsis
+    )
+}

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

@@ -1,3 +1,21 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
 package com.rtbishop.look4sat.core.presentation
 
 import androidx.compose.animation.core.animateDpAsState

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

@@ -0,0 +1,13 @@
+<!--
+  Grid Finder icon: a GPS crosshair.
+  Ported from Material Design Icons (crosshairs-gps), Apache License 2.0.
+-->
+<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="M12,8A4,4 0 0,1 16,12A4,4 0 0,1 12,16A4,4 0 0,1 8,12A4,4 0 0,1 12,8M3.05,13H1V11H3.05C3.5,6.83 6.83,3.5 11,3.05V1H13V3.05C17.17,3.5 20.5,6.83 20.95,11H23V13H20.95C20.5,17.17 17.17,20.5 13,20.95V23H11V20.95C6.83,20.5 3.5,17.17 3.05,13M12,5A7,7 0 0,0 5,12A7,7 0 0,0 12,19A7,7 0 0,0 19,12A7,7 0 0,0 12,5Z" />
+</vector>

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

@@ -83,7 +83,6 @@
     <string name="map_visible">Visible</string>
 
     <!-- Settings screen -->
-    <string name="prefs_donate_title">Soporte</string>
     <string name="prefs_privacy_title">Política de privacidad</string>
 
     <string name="prefs_updated_title">Actualizado: %s</string>

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

@@ -82,7 +82,6 @@
     <string name="map_visible">Видимый</string>
 
     <!-- Settings screen -->
-    <string name="prefs_donate_title">Поддержать</string>
     <string name="prefs_privacy_title">Политика конфиденциальности</string>
 
     <string name="prefs_updated_title">Обновлено: %s</string>

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

@@ -83,7 +83,6 @@
     <string name="map_visible">දෘශ්‍ය</string>
 
     <!-- Settings screen -->
-    <string name="prefs_donate_title">දායකත්ව</string>
     <string name="prefs_privacy_title">රහස්යතා ප්රතිපත්තිය</string>
 
     <string name="prefs_updated_title">යාවත්කාලීන කරන ලදී: %s</string>

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

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
     <!-- Commmon -->
-    <string name="app_name" translatable="false">Look4Sat</string>
+    <string name="app_name" translatable="false">Look4Sat-BA7OPF</string>
     <string name="btn_accept">Kabul et</string>
     <string name="btn_cancel">İptal</string>
     <string name="empty_list_message">Gösterilecek veri bulunamadı</string>
@@ -104,18 +104,16 @@
     <string name="map_visible">Görünür</string>
 
     <!-- Settings screen -->
-    <string name="prefs_app_title" translatable="false">Look4Sat v%s</string>
-    <string name="prefs_app_url" translatable="false">https://play.google.com/store/apps/details?id=com.rtbishop.look4sat</string>
-    <string name="prefs_donate_title">Bağış yap</string>
-    <string name="prefs_donate_url" translatable="false">https://ko-fi.com/rt_bishop</string>
-    <string name="prefs_fdroid_title" translatable="false">F-Droid</string>
-    <string name="prefs_fdroid_url" translatable="false">https://f-droid.org/en/packages/com.rtbishop.look4sat/</string>
+    <string name="prefs_app_title" translatable="false">Look4Sat-BA7OPF v%s</string>
+    <string name="prefs_app_url" translatable="false">https://github.com/atsunatsu/Look4Sat/releases</string>
     <string name="prefs_github_title" translatable="false">GitHub</string>
-    <string name="prefs_github_url" translatable="false">https://github.com/rt-bishop/Look4Sat/</string>
+    <string name="prefs_github_url" translatable="false">https://github.com/atsunatsu/Look4Sat</string>
     <string name="prefs_license_title" translatable="false">GPLv3</string>
     <string name="prefs_license_url" translatable="false">https://www.gnu.org/licenses/gpl-3.0.html</string>
     <string name="prefs_privacy_title">Gizlilik Politikası</string>
     <string name="prefs_privacy_url" translatable="false">https://sites.google.com/view/look4sat-privacy-policy/home</string>
+    <string name="prefs_upstream_title" translatable="false">Upstream Project</string>
+    <string name="prefs_upstream_url" translatable="false">https://github.com/rt-bishop/Look4Sat</string>
 
     <string name="prefs_updated_title">Güncellendi: %s</string>
     <string name="prefs_updated_time">d MMM yyyy - HH:mm:ss</string>

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

@@ -83,7 +83,6 @@
     <string name="map_visible">Видимий</string>
 
     <!-- Settings screen -->
-    <string name="prefs_donate_title">Підтримати</string>
     <string name="prefs_privacy_title">Політика конфіденційності</string>
 
     <string name="prefs_updated_title">Оновлено: %s</string>

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

@@ -41,7 +41,6 @@
     <string name="pass_welcome_message">请务必在设置中通过GPS、经纬度或QTH定位您的位置\n建议至少每周更新一次数据库，以确保预测结果的准确性</string>
 
     <!-- AMSAT Status screen -->
-    <string name="pass_whatsnew_message">4.4.6 以来的全部更新（4.4.7 系列）：\n\n• 网格模式地图：LoTW 已确认网格绿色填充、漫游网格蓝色条纹、当前网格加粗框；右上角网格/卫星模式开关。\n\n• 首通呼号（VUCC 视图）：绿格显示该格最早通联的呼号，非绿格空白。\n\n• worked 网格可按操作网格筛选（含“全部”）；点击网格弹出 QSO 明细；每格 QSO 计数。\n\n• 各操作网格独立 VUCC 计数；极区网格标签；反经线修复；漫游条纹密度一致。\n\n• WAPC/WAJA 地图标签随系统语言。\n\n• 网格模式视口与筛选跨页保持。\n\n• LoTW 同步：账号直连、全量/增量模式、实时进度、可取消、启动自动同步（独立开关）、设置页显示上次同步时间。\n\n• 历史过境：过境筛选可回看过去数小时（历史过境时间）。\n\n• 指南针校准：8 字动作精度指示 + 手动航向偏置。\n\n• AMSAT 状态页：连续相同状态报告计数。\n\n• 过境/雷达：UTC 切换重算过境；日出日落与仰角颜色修复；卫星模糊搜索；相互过境页滚动保持、跟随 UTC、雷达快捷入口。\n\n• CW 解码器支持 32/64 位设备；Android 17 (API 37) 适配。</string>
 
 <string name="nav_amsat">AMSAT</string>
     <string name="amsat_title">AMSAT 卫星状态</string>
@@ -141,7 +140,6 @@
     <string name="map_visible">日照中</string>
 
     <!-- Settings screen -->
-    <string name="prefs_donate_title">支持</string>
     <string name="prefs_privacy_title">隐私政策</string>
 
     <string name="prefs_updated_title">更新：%s</string>
@@ -191,6 +189,36 @@
     <string name="lotw_sync_progress_qso">本次同步 %1$d 条 QSO，预计还需 %2$d 秒</string>
     <string name="prefs_locator_text">使用梅登黑德网格设置站点位置</string>
 
+    <string name="btn_delete">删除</string>
+    <string name="prefs_logbook_title">日志本</string>
+    <string name="prefs_logbook_count">%1$d 条记录 — 本地通联与 LoTW 确认</string>
+    <string name="prefs_logbook_empty">暂无记录 — 在雷达页 Log 标签记录通联</string>
+    <string name="prefs_logbook_close">关闭</string>
+    <string name="prefs_logbook_upload">上传</string>
+    <string name="prefs_logbook_upload_title">上传到 LoTW</string>
+    <string name="prefs_logbook_upload_confirm">确认上传</string>
+    <string name="prefs_lotw_upload_title">LoTW 上传证书</string>
+    <string name="prefs_lotw_upload_configured">证书已导入 · 台址网格 %1$s</string>
+    <string name="prefs_lotw_upload_not_configured">未配置 — 导入 TrustedQSL 证书后即可上传通联</string>
+    <string name="prefs_lotw_upload_busy">处理中…</string>
+    <string name="prefs_lotw_upload_cert_hint">导入你的 TrustedQSL .p12 证书（与 TQSL 同款）用于签名上传通联。密码仅加密保存在手机本地。</string>
+    <string name="prefs_lotw_upload_password">证书密码</string>
+    <string name="prefs_lotw_upload_import">选择 .p12 文件</string>
+    <string name="prefs_lotw_upload_import_confirm">导入</string>
+    <string name="prefs_lotw_upload_error_password">证书密码错误，请检查 TQSL 导出 .p12 时设置的密码</string>
+    <string name="prefs_lotw_upload_error_expired">证书已过期或尚未生效</string>
+    <string name="prefs_lotw_upload_error_invalid">不是有效的 LoTW 证书文件</string>
+    <string name="prefs_lotw_upload_error_format">不支持的 .p12 加密，请用 TQSL 默认加密重新导出后再试</string>
+    <string name="prefs_lotw_upload_error_format_alg">不支持的 .p12 加密（%1$s），请用 TQSL 默认加密重新导出后再试</string>
+    <string name="prefs_lotw_upload_error_unknown">导入失败，请重试</string>
+    <string name="prefs_lotw_upload_cert_info">%1$s · DXCC %2$d · 有效期至 %3$s</string>
+    <string name="prefs_lotw_upload_remove">移除证书</string>
+    <string name="prefs_lotw_upload_station_title">台址</string>
+    <string name="prefs_lotw_upload_region_hint">未选择</string>
+    <string name="prefs_lotw_upload_grid">网格（逗号分隔，可多格）</string>
+    <string name="prefs_lotw_upload_save">保存</string>
+    <string name="prefs_lotw_upload_close">关闭</string>
+
     <string name="prefs_data_title">卫星数据更新</string>
     <string name="prefs_data_entries">卫星：%s</string>
     <string name="prefs_data_radios">收发器：%s</string>
@@ -274,6 +302,7 @@
     <string name="prefs_compass_offset">手动航向偏置（°）</string>
     <string name="prefs_compass_offset_support">范围 −180° 至 +180°；正值为顺时针偏移。</string>
     <string name="prefs_compass_offset_reset">偏置归零</string>
+    <string name="prefs_other_switch_light_theme">浅色主题</string>
     <string name="prefs_other_switch_night_mode">启用红色夜间模式</string>
     <string name="prefs_other_switch_map_grid">地图显示 Maidenhead 网格</string>
 
@@ -282,7 +311,20 @@
     <string name="prefs_highlight_mid">中 %1$d-%2$d°</string>
     <string name="prefs_highlight_high">高 &gt; %1$d°</string>
 
-    <string name="prefs_outro_title">我要感谢：</string>
+    <string name="prefs_outro_title">致谢与声明</string>
+    <string name="prefs_project_wiki">Project Wiki</string>
+    <string name="project_wiki_intro">Look4Sat-BA7OPF 是基于 Look4Sat 的定制版，保留上游全部功能，并新增：</string>
+    <string name="project_wiki_section_logbook">卫星日志本与 LoTW</string>
+    <string name="project_wiki_logbook_1">卫星通联日志本——通联时一键记录呼号、时间、频率、模式、信号报告和网格。</string>
+    <string name="project_wiki_logbook_2">LoTW 直传——导入 ARRL 证书后，直接在 App 内把日志上传到 LoTW，无需电脑。</string>
+    <string name="project_wiki_logbook_3">确认同步——一键同步 LoTW 官方确认，日志自动标记“已上传 / 已确认”；修改已上传的记录会自动新建一条，原记录不受影响。</string>
+    <string name="project_wiki_logbook_how">用法：通联后点“记录”→ 日志页点“上传”→ 设置里“同步”查看确认。</string>
+    <string name="project_wiki_section_mutual">双站过境匹配</string>
+    <string name="project_wiki_mutual_1">友台共视匹配——输入你和友台的位置，找出双方同时可见的卫星过境，点一下直接进雷达图。</string>
+    <string name="project_wiki_mutual_how">用法：Match 页 → 设置两站位置 → 查询。</string>
+    <string name="project_wiki_section_grids">通联网格地图</string>
+    <string name="project_wiki_grids_1">已通联网格——LoTW/Wavelog 同步的网格在地图上标绿，支持奖状边界和首通呼号标签；点格子看该网格的通联记录，还能一键去匹配友台。</string>
+    <string name="project_wiki_grids_how">用法：地图页开启网格模式 → 设置里同步 LoTW/Wavelog。</string>
     <string name="prefs_outro_thanks" translatable="false">
         • Look4Sat 所有用户及贡献者!
         \n• David A. B. Johnson (predict4java)
@@ -292,8 +334,12 @@
         \n• Libre Space Foundation (SatNOGS)
         \n• xdsopl 和 Robot36 贡献者!
         \n• BG7NTA BG5JSU（CW解码功能）
-        \n• BH2VSQ BG5JSU（天地图渲染支持）</string>
-    <string name="prefs_outro_license">该应用程序不提供任何保修.</string>
+        \n• BH2VSQ BG5JSU（天地图渲染支持）
+        \n• BG5JSU（LoTW上传支持）
+    </string>
+    <string name="prefs_outro_notice">Look4Sat-BA7OPF 是基于 Look4Sat（GPL-3.0）的非官方修改版，由 BA7OPF 独立维护，与原项目无隶属关系，亦未获其背书。
+上游项目：https://github.com/rt-bishop/Look4Sat</string>
+<string name="prefs_outro_license">基于 GNU GPL v3 许可 · 本程序不提供任何保修</string>
 
     <!-- 匹配页 Mutual match page -->
     <string name="mutual_title">过境匹配</string>
@@ -342,4 +388,89 @@
     <string name="update_check_download_error">下载失败，请重试。</string>
     <string name="update_check_no_apk">该版本未附带 APK 安装包。</string>
 
+    <!-- QSO edit dialog -->
+    <string name="qso_edit_title">编辑通联记录</string>
+    <string name="qso_edit_uploaded_notice">该通联已上传或已确认。保存将保留原记录不变，并新建一条记录。</string>
+    <string name="qso_edit_callsign">呼号</string>
+    <string name="qso_edit_date">日期 (UTC)</string>
+    <string name="qso_edit_time">时间 (UTC)</string>
+    <string name="qso_edit_tx">上行频率 (MHz)</string>
+    <string name="qso_edit_rx">下行频率 (MHz)</string>
+    <string name="qso_edit_band">频段：%1$s</string>
+    <string name="qso_edit_mode">模式</string>
+    <string name="qso_edit_satellite">卫星</string>
+    <string name="qso_edit_hint_satellite">LoTW 只接受它的官方卫星名</string>
+    <string name="qso_edit_sent">发送报告</string>
+    <string name="qso_edit_received">接收报告</string>
+    <string name="qso_edit_grid">对方网格</string>
+    <string name="qso_edit_comment">备注</string>
+    <string name="qso_edit_save">保存</string>
+    <string name="qso_edit_cancel">取消</string>
+    <string name="qso_edit_err_callsign">呼号不能为空</string>
+    <string name="qso_edit_err_datetime">日期或时间格式不对 —— 应为 yyyy-MM-dd 与 HH:mm:ss（UTC）</string>
+    <string name="qso_edit_err_frequency">频率格式不对 —— 请输入 MHz，例如 145.850</string>
+    <string name="qso_edit_err_satellite">不是 LoTW 官方卫星名 —— 请从列表中选一个</string>
+    <string name="qso_edit_satellite_pick">选择</string>
+    <string name="qso_edit_satellite_pick_title">LoTW 官方卫星名</string>
+    <string name="qso_edit_satellite_search">搜索卫星名或数据源别名</string>
+    <string name="qso_edit_satellite_official">保存并签名时使用 %1$s</string>
+    <string name="qso_edit_warn_no_freq">没有上行频率：LoTW 要求 BAND，补上频率前这条无法上传</string>
+
+    <!-- 网格寻线（VUCC 网格线／网格角实地导航） -->
+    <string name="gridfinder_title">网格寻线</string>
+    <string name="gridfinder_status_corner">位于网格点上</string>
+    <string name="gridfinder_status_line">位于网格线上</string>
+    <string name="gridfinder_status_inside">在网格内部</string>
+    <string name="gridfinder_status_unknown">位置不可用</string>
+    <string name="gridfinder_status_waiting">正在获取定位…</string>
+    <string name="gridfinder_status_blocked">需要定位权限</string>
+    <string name="gridfinder_status_disabled">本机定位服务未开启</string>
+    <string name="gridfinder_status_confirmed">已由 %1$d 次连续满足 20 英尺规则的定位确认</string>
+    <string name="gridfinder_status_unconfirmed">尚未确认：精度达 6.1 m 的连续定位 %1$d/%2$d 次</string>
+    <string name="gridfinder_grant_permission">授予定位权限</string>
+    <string name="gridfinder_card_location">位置</string>
+    <string name="gridfinder_card_corner">最近网格点引导</string>
+    <string name="gridfinder_card_line">最近网格线引导</string>
+    <string name="gridfinder_card_lines">两条边界线</string>
+    <string name="gridfinder_card_map">近距离网格图</string>
+    <string name="gridfinder_card_fix">定位质量</string>
+    <string name="gridfinder_card_compass">罗盘</string>
+    <string name="gridfinder_label_claimable">此处可计分的网格</string>
+    <string name="gridfinder_label_grid4">网格 (4)</string>
+    <string name="gridfinder_label_grid6">网格 (6)</string>
+    <string name="gridfinder_label_grid8">网格 (8)</string>
+    <string name="gridfinder_label_latitude">纬度</string>
+    <string name="gridfinder_label_longitude">经度</string>
+    <string name="gridfinder_label_altitude">海拔</string>
+    <string name="gridfinder_label_accuracy">水平精度</string>
+    <string name="gridfinder_label_fix_age">定位时刻</string>
+    <string name="gridfinder_label_provider">定位来源</string>
+    <string name="gridfinder_value_provider_on">已开启</string>
+    <string name="gridfinder_value_provider_off">未开启</string>
+    <string name="gridfinder_label_distance">距离</string>
+    <string name="gridfinder_label_bearing">方位角</string>
+    <string name="gridfinder_label_direction">方向</string>
+    <string name="gridfinder_label_grids">网格</string>
+    <string name="gridfinder_label_lat_line">纬线</string>
+    <string name="gridfinder_label_lon_line">经线</string>
+    <string name="gridfinder_line_value">位于%2$s方向 %1$s</string>
+    <string name="gridfinder_line_latitude">这是纬度边界，东西走向</string>
+    <string name="gridfinder_line_longitude">这是经度边界，南北走向</string>
+    <string name="gridfinder_label_heading">朝向</string>
+    <string name="gridfinder_label_compass_accuracy">罗盘精度</string>
+    <string name="gridfinder_action_set_station">设为我的台址</string>
+    <string name="gridfinder_action_station_saved">台址已更新 —— 过境预报将使用这个位置</string>
+    <string name="gridfinder_action_calibrate">校准罗盘</string>
+    <string name="gridfinder_map_legend">中心点是你的位置，虚线是正北与正东，直线是两条网格边界，绿点是最近的网格点，圆环是最近网格线的垂足，红色指针是你的朝向</string>
+    <string name="gridfinder_compass_disabled_hint">设置里未开启罗盘，表盘按正北朝上显示。方位角数字仍可引导你</string>
+    <string name="gridfinder_compass_unavailable_hint">本机没有磁力传感器 —— 请按方位角数字导航</string>
+    <string name="gridfinder_compass_hint">请平持手机，箭头指向应走的方向</string>
+    <string name="gridfinder_vucc_rule_note">VUCC 20 英尺规则：%1$.1f m</string>
+    <string name="gridfinder_direction_north">北</string>
+    <string name="gridfinder_direction_south">南</string>
+    <string name="gridfinder_direction_east">东</string>
+    <string name="gridfinder_direction_west">西</string>
+    <string name="gridfinder_action_set_lotw_station">设为 LoTW 上传台址（%1$s）</string>
+    <string name="gridfinder_lotw_station_hint">预填上传台站网格：上传时 LoTW 按这些格记录（线上 2 格、角上 4 格）；证书呼号保持不变。</string>
+
 </resources>

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

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
     <!-- Commmon -->
-    <string name="app_name" translatable="false">Look4Sat</string>
+    <string name="app_name" translatable="false">Look4Sat-BA7OPF</string>
     <string name="btn_accept">Accept</string>
     <string name="btn_cancel">Cancel</string>
     <string name="empty_list_message">No data to show</string>
@@ -51,8 +51,6 @@
     <string name="pass_welcome_message">
         Make sure to set your position via GPS, Lat/Lon or QTH in Settings.
         \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">All changes since 4.4.6 (the 4.4.7 series):\n\n• Grid-mode map: LoTW confirmed grids in green, roamed grids with blue stripes, current grid highlighted; mode switch pill at the map\'s top-right.\n\n• First-call labels (VUCC view): show the first callsign worked in each green grid instead of the grid code; non-worked cells stay empty.\n\n• Worked grids filtered by operated grid (with an All option); tap a grid to see its QSO detail dialog; per-grid QSO counts.\n\n• Per-operated-grid VUCC counting; polar grid labels; antimeridian fixes; consistent roamed-stripe density.\n\n• WAPC/WAJA map labels follow the system language.\n\n• Grid-mode viewport and award filter survive page switches.\n\n• LoTW sync: direct login, full/incremental modes, live progress, cancel button, auto-sync on app start with its own toggle, last-sync time shown.\n\n• Pass history: filter can look back over past passes (Time before).\n\n• Compass calibration: figure-eight accuracy meter plus manual heading offset.\n\n• AMSAT status page: consecutive same-status report counts.\n\n• Passes/radar: UTC toggle recalculates passes; sunrise/sunset and elevation color fixes; satellite fuzzy search; mutual page keeps scroll, follows UTC, radar shortcut.\n\n• CW decoder for 32/64-bit devices; Android 17 (API 37) support.</string>
 
     <!-- AMSAT Status screen -->
     <string name="nav_amsat">AMSAT</string>
@@ -162,18 +160,16 @@
     <string name="map_visible">Visible</string>
 
     <!-- Settings screen -->
-    <string name="prefs_app_title" translatable="false">Look4Sat v%s</string>
-    <string name="prefs_app_url" translatable="false">https://play.google.com/store/apps/details?id=com.rtbishop.look4sat</string>
-    <string name="prefs_donate_title">Donate</string>
-    <string name="prefs_donate_url" translatable="false">https://ko-fi.com/rt_bishop</string>
-    <string name="prefs_fdroid_title" translatable="false">F-Droid</string>
-    <string name="prefs_fdroid_url" translatable="false">https://f-droid.org/en/packages/com.rtbishop.look4sat/</string>
+    <string name="prefs_app_title" translatable="false">Look4Sat-BA7OPF v%s</string>
+    <string name="prefs_app_url" translatable="false">https://github.com/atsunatsu/Look4Sat/releases</string>
     <string name="prefs_github_title" translatable="false">GitHub</string>
-    <string name="prefs_github_url" translatable="false">https://github.com/rt-bishop/Look4Sat/</string>
+    <string name="prefs_github_url" translatable="false">https://github.com/atsunatsu/Look4Sat</string>
     <string name="prefs_license_title" translatable="false">GPLv3</string>
     <string name="prefs_license_url" translatable="false">https://www.gnu.org/licenses/gpl-3.0.html</string>
     <string name="prefs_privacy_title">Privacy Policy</string>
     <string name="prefs_privacy_url" translatable="false">https://sites.google.com/view/look4sat-privacy-policy/home</string>
+    <string name="prefs_upstream_title" translatable="false">Upstream Project</string>
+    <string name="prefs_upstream_url" translatable="false">https://github.com/rt-bishop/Look4Sat</string>
 
     <string name="prefs_updated_title">Updated: %s</string>
     <string name="prefs_updated_time">d MMM yyyy - HH:mm:ss</string>
@@ -222,6 +218,36 @@
     <string name="lotw_sync_progress_qso">Syncing %1$d QSOs, ~%2$d s remaining</string>
     <string name="prefs_locator_text">Set station\'s position using locator</string>
 
+    <string name="btn_delete">Delete</string>
+    <string name="prefs_logbook_title">Logbook</string>
+    <string name="prefs_logbook_count">%1$d records — local QSOs and LoTW confirmations</string>
+    <string name="prefs_logbook_empty">No records yet — record QSOs from the Radar Log tab</string>
+    <string name="prefs_logbook_close">Close</string>
+    <string name="prefs_logbook_upload">Upload</string>
+    <string name="prefs_logbook_upload_title">Upload to LoTW</string>
+    <string name="prefs_logbook_upload_confirm">Upload</string>
+    <string name="prefs_lotw_upload_title">LoTW upload certificate</string>
+    <string name="prefs_lotw_upload_configured">Certificate imported · station grid %1$s</string>
+    <string name="prefs_lotw_upload_not_configured">Not configured — import your TrustedQSL certificate to upload QSOs</string>
+    <string name="prefs_lotw_upload_busy">Working…</string>
+    <string name="prefs_lotw_upload_cert_hint">Import your TrustedQSL .p12 certificate (same one you use in TQSL) to sign and upload QSOs. The password is stored encrypted on this device only.</string>
+    <string name="prefs_lotw_upload_password">Certificate password</string>
+    <string name="prefs_lotw_upload_import">Choose .p12 file</string>
+    <string name="prefs_lotw_upload_import_confirm">Import</string>
+    <string name="prefs_lotw_upload_error_password">Incorrect certificate password. Check the password you set when exporting the .p12 from TQSL.</string>
+    <string name="prefs_lotw_upload_error_expired">Certificate is expired or not yet valid.</string>
+    <string name="prefs_lotw_upload_error_invalid">Not a valid LoTW certificate file.</string>
+    <string name="prefs_lotw_upload_error_format">Unsupported .p12 encryption. Re-export from TQSL and try again.</string>
+    <string name="prefs_lotw_upload_error_format_alg">Unsupported .p12 encryption (%1$s). Re-export from TQSL and try again.</string>
+    <string name="prefs_lotw_upload_error_unknown">Import failed. Try again.</string>
+    <string name="prefs_lotw_upload_cert_info">%1$s · DXCC %2$d · expires %3$s</string>
+    <string name="prefs_lotw_upload_remove">Remove certificate</string>
+    <string name="prefs_lotw_upload_station_title">Station location</string>
+    <string name="prefs_lotw_upload_region_hint">Not selected</string>
+    <string name="prefs_lotw_upload_grid">Grid(s), comma-separated</string>
+    <string name="prefs_lotw_upload_save">Save</string>
+    <string name="prefs_lotw_upload_close">Close</string>
+
     <string name="prefs_data_title">Satellite data</string>
     <string name="prefs_data_entries">Satellites: %s</string>
     <string name="prefs_data_radios">Transceivers: %s</string>
@@ -304,6 +330,7 @@
     <string name="prefs_compass_offset">Manual heading offset (°)</string>
     <string name="prefs_compass_offset_support">Range −180° to +180°. Positive values rotate clockwise.</string>
     <string name="prefs_compass_offset_reset">Reset offset</string>
+    <string name="prefs_other_switch_light_theme">Light theme</string>
     <string name="prefs_other_switch_night_mode">Enable red night mode filter</string>
     <string name="prefs_other_switch_map_grid">Show Maidenhead grid on map</string>
 
@@ -312,7 +339,20 @@
     <string name="prefs_highlight_mid">Mid %1$d–%2$d°</string>
     <string name="prefs_highlight_high">High &gt; %1$d°</string>
 
-    <string name="prefs_outro_title">I would like to say thanks to</string>
+    <string name="prefs_outro_title">Credits &amp; Notices</string>
+    <string name="prefs_project_wiki">Project Wiki</string>
+    <string name="project_wiki_intro">Look4Sat-BA7OPF is a customized fork of Look4Sat. All upstream features, plus:</string>
+    <string name="project_wiki_section_logbook">Satellite Logbook &amp; LoTW</string>
+    <string name="project_wiki_logbook_1">Satellite logbook — one-tap logging of callsign, time, frequency, mode, report and grid.</string>
+    <string name="project_wiki_logbook_2">Direct LoTW upload — import your ARRL certificate and upload logs to LoTW right from the app, no PC needed.</string>
+    <string name="project_wiki_logbook_3">Confirmation sync — one-tap sync of LoTW confirmations, marked as uploaded/confirmed. Editing an uploaded entry creates a new one, leaving the original untouched.</string>
+    <string name="project_wiki_logbook_how">How: tap Record after a QSO → Upload on the log page → Sync in Settings.</string>
+    <string name="project_wiki_section_mutual">Mutual Pass Matching</string>
+    <string name="project_wiki_mutual_1">Enter your QTH and a friend\'s to find passes visible to both; tap a pass to open the radar.</string>
+    <string name="project_wiki_mutual_how">How: Match tab → set both stations → Query.</string>
+    <string name="project_wiki_section_grids">Worked-Grid Map</string>
+    <string name="project_wiki_grids_1">Grids synced from LoTW/Wavelog shown in green, with award boundaries and first-QSO callsign labels; tap a grid to see its QSOs and match a friend.</string>
+    <string name="project_wiki_grids_how">How: enable Grid mode on the map → sync LoTW/Wavelog in Settings.</string>
     <string name="prefs_outro_thanks" translatable="false">
         * Look4Sat users and contributors!
         \n* David A. B. Johnson (predict4java)
@@ -323,8 +363,11 @@
         \n* xdsopl and Robot36 contributors!
         \n* BG7NTA BG5JSU (CW decoding feature)
         \n* BH2VSQ BG5JSU (TianDiTu rendering support)
+        \n* BG5JSU (LoTW upload support)
     </string>
-    <string name="prefs_outro_license">The app comes with no warranty</string>
+    <string name="prefs_outro_notice">Look4Sat-BA7OPF is an unofficial modified build based on Look4Sat (GPL-3.0), independently maintained by BA7OPF. It is not affiliated with or endorsed by the original Look4Sat project.
+Upstream: https://github.com/rt-bishop/Look4Sat</string>
+<string name="prefs_outro_license">Licensed under the GNU General Public License v3 · The app comes with no warranty</string>
 
     <!-- Mutual match page -->
     <string name="mutual_title">Pass Match</string>
@@ -373,4 +416,89 @@
     <string name="update_check_download_error">Download failed. Try again.</string>
     <string name="update_check_no_apk">No APK attached to this release.</string>
 
+    <!-- QSO edit dialog -->
+    <string name="qso_edit_title">Edit QSO</string>
+    <string name="qso_edit_uploaded_notice">This QSO was already uploaded or confirmed. Saving keeps the original record unchanged and creates a new one.</string>
+    <string name="qso_edit_callsign">Callsign</string>
+    <string name="qso_edit_date">Date (UTC)</string>
+    <string name="qso_edit_time">Time (UTC)</string>
+    <string name="qso_edit_tx">Uplink (MHz)</string>
+    <string name="qso_edit_rx">Downlink (MHz)</string>
+    <string name="qso_edit_band">Band: %1$s</string>
+    <string name="qso_edit_mode">Mode</string>
+    <string name="qso_edit_satellite">Satellite</string>
+    <string name="qso_edit_hint_satellite">LoTW only accepts its official satellite name</string>
+    <string name="qso_edit_sent">Sent RST</string>
+    <string name="qso_edit_received">Received RST</string>
+    <string name="qso_edit_grid">Opposite grid</string>
+    <string name="qso_edit_comment">Comment</string>
+    <string name="qso_edit_save">Save</string>
+    <string name="qso_edit_cancel">Cancel</string>
+    <string name="qso_edit_err_callsign">Callsign is required</string>
+    <string name="qso_edit_err_datetime">Invalid date/time — use yyyy-MM-dd and HH:mm:ss (UTC)</string>
+    <string name="qso_edit_err_frequency">Invalid frequency — enter MHz, e.g. 145.850</string>
+    <string name="qso_edit_err_satellite">Not an ARRL satellite name — pick one from the list</string>
+    <string name="qso_edit_satellite_pick">Pick</string>
+    <string name="qso_edit_satellite_pick_title">ARRL satellite name</string>
+    <string name="qso_edit_satellite_search">Search name or catalogue alias</string>
+    <string name="qso_edit_satellite_official">Saved and signed as %1$s</string>
+    <string name="qso_edit_warn_no_freq">No uplink frequency: LoTW requires a band, so this QSO cannot be uploaded yet</string>
+
+    <!-- Grid Finder (VUCC grid line / corner field guide) -->
+    <string name="gridfinder_title">Grid Finder</string>
+    <string name="gridfinder_status_corner">ON GRID POINT</string>
+    <string name="gridfinder_status_line">ON GRID LINE</string>
+    <string name="gridfinder_status_inside">INSIDE GRID</string>
+    <string name="gridfinder_status_unknown">Position unavailable</string>
+    <string name="gridfinder_status_waiting">Waiting for a fix…</string>
+    <string name="gridfinder_status_blocked">Location permission required</string>
+    <string name="gridfinder_status_disabled">Location services are off on this device</string>
+    <string name="gridfinder_status_confirmed">Confirmed by %1$d consecutive fixes inside the 20 ft rule</string>
+    <string name="gridfinder_status_unconfirmed">Not confirmed yet: %1$d of %2$d consecutive fixes good to 6.1 m</string>
+    <string name="gridfinder_grant_permission">Grant location access</string>
+    <string name="gridfinder_card_location">Location</string>
+    <string name="gridfinder_card_corner">Guide to the nearest grid point</string>
+    <string name="gridfinder_card_line">Guide to the nearest grid line</string>
+    <string name="gridfinder_card_lines">Both boundary lines</string>
+    <string name="gridfinder_card_map">Close-up grid map</string>
+    <string name="gridfinder_card_fix">Fix quality</string>
+    <string name="gridfinder_card_compass">Compass</string>
+    <string name="gridfinder_label_claimable">VUCC grids here</string>
+    <string name="gridfinder_label_grid4">Grid (4)</string>
+    <string name="gridfinder_label_grid6">Grid (6)</string>
+    <string name="gridfinder_label_grid8">Grid (8)</string>
+    <string name="gridfinder_label_latitude">Latitude</string>
+    <string name="gridfinder_label_longitude">Longitude</string>
+    <string name="gridfinder_label_altitude">Altitude</string>
+    <string name="gridfinder_label_accuracy">Horizontal accuracy</string>
+    <string name="gridfinder_label_fix_age">Fix age</string>
+    <string name="gridfinder_label_provider">Location provider</string>
+    <string name="gridfinder_value_provider_on">On</string>
+    <string name="gridfinder_value_provider_off">Off</string>
+    <string name="gridfinder_label_distance">Distance</string>
+    <string name="gridfinder_label_bearing">Bearing</string>
+    <string name="gridfinder_label_direction">Direction</string>
+    <string name="gridfinder_label_grids">Grids</string>
+    <string name="gridfinder_label_lat_line">Latitude line</string>
+    <string name="gridfinder_label_lon_line">Longitude line</string>
+    <string name="gridfinder_line_value">%1$s to the %2$s</string>
+    <string name="gridfinder_line_latitude">This is the latitude boundary, which runs east to west</string>
+    <string name="gridfinder_line_longitude">This is the longitude boundary, which runs north to south</string>
+    <string name="gridfinder_label_heading">Heading</string>
+    <string name="gridfinder_label_compass_accuracy">Compass accuracy</string>
+    <string name="gridfinder_action_set_station">Set as my station</string>
+    <string name="gridfinder_action_station_saved">Station position updated — pass predictions now use this fix</string>
+    <string name="gridfinder_action_calibrate">Calibrate compass</string>
+    <string name="gridfinder_map_legend">The centre dot is you, dashed axes are north and east, the straight lines are the two grid boundaries, the green dot is the nearest grid point, the ring is the closest point of the nearest line and the red needle is your heading</string>
+    <string name="gridfinder_compass_disabled_hint">The compass is switched off in Settings, so the dials stay north-up. The bearing numbers still guide you</string>
+    <string name="gridfinder_compass_unavailable_hint">This device has no magnetic sensor — navigate with the bearing numbers</string>
+    <string name="gridfinder_compass_hint">Hold the phone flat; the arrow points the way to walk</string>
+    <string name="gridfinder_vucc_rule_note">VUCC 20 ft rule: %1$.1f m</string>
+    <string name="gridfinder_direction_north">north</string>
+    <string name="gridfinder_direction_south">south</string>
+    <string name="gridfinder_direction_east">east</string>
+    <string name="gridfinder_direction_west">west</string>
+    <string name="gridfinder_action_set_lotw_station">Set as LoTW station (%1$s)</string>
+    <string name="gridfinder_lotw_station_hint">Prefills the upload station grid — LoTW then records these squares (2 on a line, 4 on a corner). The certificate callsign stays unchanged.</string>
+
 </resources>

feature/cw/src/main/java/com/rtbishop/look4sat/feature/cw/CwDecodeScreen.kt

@@ -1,3 +1,21 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by 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/>.
+ */
 /*
  * CwDecodeScreen.kt — Look4Sat 的 CW 解码页面(Compose 外壳)。
  *

feature/gridfinder/build.gradle.kts

@@ -0,0 +1,23 @@
+plugins {
+    alias(libs.plugins.convention.featurePlugin)
+}
+
+android {
+    namespace = "com.rtbishop.look4sat.feature.gridfinder"
+    testOptions {
+        unitTests {
+            // Robolectric needs real Android resources for Compose UI tests.
+            isIncludeAndroidResources = true
+        }
+    }
+}
+
+dependencies {
+    testImplementation(libs.test.junit4)
+    testImplementation(libs.test.coroutines)
+    testImplementation(libs.robolectric)
+    testImplementation(libs.androidx.test.core)
+    testImplementation(libs.compose.ui.test.junit4)
+    testImplementation(libs.compose.navigation3)
+    debugImplementation(libs.compose.debug.manifest)
+}

feature/gridfinder/src/main/AndroidManifest.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest>
+
+</manifest>

feature/gridfinder/src/main/java/com/rtbishop/look4sat/feature/gridfinder/GridFinderCanvas.kt

@@ -0,0 +1,188 @@
+/*
+ * 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.gridfinder
+
+import androidx.compose.foundation.Canvas
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.geometry.Offset
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.PathEffect
+import androidx.compose.ui.graphics.StrokeCap
+import androidx.compose.ui.graphics.drawscope.Stroke
+import androidx.compose.ui.text.AnnotatedString
+import androidx.compose.ui.text.TextStyle
+import androidx.compose.ui.text.drawText
+import androidx.compose.ui.text.rememberTextMeasurer
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import com.rtbishop.look4sat.core.domain.utility.GridBoundaryDirection
+import com.rtbishop.look4sat.core.domain.utility.GridGeometry
+import kotlin.math.abs
+import kotlin.math.cos
+import kotlin.math.max
+import kotlin.math.sin
+
+/**
+ * Compass rose with a needle pointing along the true-north [bearingDegrees].
+ * When [headingDegrees] is available the rose turns with the device, so the
+ * needle is read against the top edge of the phone ("walk the way the arrow
+ * points"); without a magnetometer the rose stays north-up.
+ */
+@Composable
+fun GridCompassDial(
+    bearingDegrees: Double,
+    headingDegrees: Float?,
+    tint: Color,
+    modifier: Modifier = Modifier
+) {
+    val dialColor = MaterialTheme.colorScheme.outline
+    // North is a longer, brighter tick; red is reserved for the heading needle
+    // in the proximity map, so the legend stays unambiguous.
+    val northColor = MaterialTheme.colorScheme.onSurface
+    val labelColor = MaterialTheme.colorScheme.onSurfaceVariant
+    val measurer = rememberTextMeasurer()
+    Canvas(modifier = modifier) {
+        val center = Offset(size.width / 2f, size.height / 2f)
+        val radius = minOf(size.width, size.height) / 2f - 8.dp.toPx()
+        if (radius <= 0f) return@Canvas
+        val roseRotation = headingDegrees?.let { -it } ?: 0f
+
+        drawCircle(color = dialColor, radius = radius, center = center, style = Stroke(1.5.dp.toPx()))
+        drawCircle(
+            color = dialColor.copy(alpha = 0.35f),
+            radius = radius * 0.62f,
+            center = center,
+            style = Stroke(1.dp.toPx())
+        )
+
+        for (degrees in 0 until 360 step 30) {
+            val angle = Math.toRadians((degrees + roseRotation).toDouble())
+            val isNorth = degrees == 0
+            val innerRadius = radius * if (isNorth) 0.70f else 0.86f
+            val start = center.at(innerRadius, angle)
+            val end = center.at(radius, angle)
+            drawLine(
+                color = if (isNorth) northColor else dialColor,
+                start = start,
+                end = end,
+                strokeWidth = if (isNorth) 3.dp.toPx() else 1.dp.toPx(),
+                cap = StrokeCap.Round
+            )
+        }
+
+        listOf(0 to "N", 90 to "E", 180 to "S", 270 to "W").forEach { (degrees, label) ->
+            val angle = Math.toRadians((degrees + roseRotation).toDouble())
+            val position = center.at(radius * 0.50f, angle)
+            val layout = measurer.measure(
+                AnnotatedString(label),
+                TextStyle(fontSize = 12.sp, color = if (degrees == 0) northColor else labelColor)
+            )
+            drawText(
+                textLayoutResult = layout,
+                topLeft = Offset(
+                    position.x - layout.size.width / 2f,
+                    position.y - layout.size.height / 2f
+                )
+            )
+        }
+
+        val needleAngle = Math.toRadians(bearingDegrees - (headingDegrees ?: 0f))
+        val tip = center.at(radius * 0.88f, needleAngle)
+        drawLine(
+            color = tint,
+            start = center,
+            end = tip,
+            strokeWidth = 3.dp.toPx(),
+            cap = StrokeCap.Round
+        )
+        drawCircle(color = tint, radius = 4.dp.toPx(), center = tip)
+        drawCircle(color = tint, radius = 2.5.dp.toPx(), center = center)
+    }
+}
+
+/**
+ * North-up proximity sketch around the fix: dashed lines are the nearest grid
+ * boundaries, the green dot is the grid corner, the ring marks the closest
+ * point of the nearest line, and the amber needle is the device heading.
+ */
+@Composable
+fun GridProximityMap(
+    geometry: GridGeometry,
+    headingDegrees: Float?,
+    modifier: Modifier = Modifier
+) {
+    val outline = MaterialTheme.colorScheme.outline
+    val gridColor = MaterialTheme.colorScheme.primary
+    val lineColor = MaterialTheme.colorScheme.tertiary
+    val cornerColor = MaterialTheme.colorScheme.secondary
+    val headingColor = MaterialTheme.colorScheme.error
+    val youColor = MaterialTheme.colorScheme.onSurface
+    val dash = PathEffect.dashPathEffect(floatArrayOf(14f, 12f))
+    Canvas(modifier = modifier) {
+        val center = Offset(size.width / 2f, size.height / 2f)
+        val radius = minOf(size.width, size.height) / 2f - 8.dp.toPx()
+        if (radius <= 0f) return@Canvas
+        val dNorth = when (geometry.latLineDirection) {
+            GridBoundaryDirection.NORTH -> geometry.latLineMeters
+            else -> -geometry.latLineMeters
+        }
+        val dEast = when (geometry.lonLineDirection) {
+            GridBoundaryDirection.EAST -> geometry.lonLineMeters
+            else -> -geometry.lonLineMeters
+        }
+        val span = max(max(abs(dNorth), abs(dEast)), geometry.cornerMeters)
+        val scale = radius / max(span * 1.15, 15.0).toFloat()
+
+        drawCircle(color = outline.copy(alpha = 0.35f), radius = radius, center = center, style = Stroke(1.dp.toPx()))
+        drawLine(outline, Offset(center.x, center.y - radius), Offset(center.x, center.y + radius), 1.dp.toPx(), pathEffect = dash)
+        drawLine(outline, Offset(center.x - radius, center.y), Offset(center.x + radius, center.y), 1.dp.toPx(), pathEffect = dash)
+
+        val latY = center.y - (dNorth * scale).toFloat()
+        val lonX = center.x + (dEast * scale).toFloat()
+        drawLine(lineColor, Offset(center.x - radius, latY), Offset(center.x + radius, latY), 2.dp.toPx())
+        drawLine(lineColor, Offset(lonX, center.y - radius), Offset(lonX, center.y + radius), 2.dp.toPx())
+
+        val corner = Offset(lonX, latY)
+        drawCircle(color = cornerColor, radius = 5.dp.toPx(), center = corner)
+
+        val nearestPoint = if (geometry.nearestLineIsLatitude) {
+            Offset(center.x, latY)
+        } else {
+            Offset(lonX, center.y)
+        }
+        drawCircle(color = gridColor, radius = 5.dp.toPx(), center = nearestPoint, style = Stroke(2.dp.toPx()))
+
+        headingDegrees?.let { heading ->
+            val angle = Math.toRadians(heading.toDouble())
+            val tip = center.at(radius * 0.92f, angle)
+            drawLine(headingColor, center, tip, 2.dp.toPx(), cap = StrokeCap.Round)
+            drawCircle(headingColor, 3.dp.toPx(), tip)
+        }
+
+        drawCircle(color = youColor, radius = 3.dp.toPx(), center = center)
+    }
+}
+
+private fun Offset.at(radius: Float, angleRadians: Double): Offset {
+    return Offset(
+        x + (radius * sin(angleRadians)).toFloat(),
+        y - (radius * cos(angleRadians)).toFloat()
+    )
+}

feature/gridfinder/src/main/java/com/rtbishop/look4sat/feature/gridfinder/GridFinderScreen.kt

@@ -0,0 +1,676 @@
+/*
+ * 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.gridfinder
+
+import android.Manifest
+import androidx.activity.compose.rememberLauncherForActivityResult
+import androidx.activity.result.contract.ActivityResultContracts
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.ColumnScope
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.text.KeyboardOptions
+import androidx.compose.material3.Button
+import androidx.compose.material3.ElevatedCard
+import androidx.compose.material3.LinearProgressIndicator
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.DisposableEffect
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.saveable.rememberSaveable
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.input.KeyboardType
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import androidx.lifecycle.viewmodel.compose.viewModel
+import com.rtbishop.look4sat.core.domain.repository.CompassAccuracy
+import com.rtbishop.look4sat.core.domain.repository.IContainerProvider
+import com.rtbishop.look4sat.core.domain.utility.GridBoundaryDirection
+import com.rtbishop.look4sat.core.domain.utility.GridFixStatus
+import com.rtbishop.look4sat.core.domain.utility.GridGeometry
+import com.rtbishop.look4sat.core.domain.utility.VUCC_BOUNDARY_TOLERANCE_METERS
+import com.rtbishop.look4sat.core.presentation.ElevationHighColor
+import com.rtbishop.look4sat.core.presentation.ElevationLowColor
+import com.rtbishop.look4sat.core.presentation.IconCard
+import com.rtbishop.look4sat.core.presentation.R
+import com.rtbishop.look4sat.core.presentation.ScreenColumn
+import com.rtbishop.look4sat.core.presentation.SharedDialog
+import com.rtbishop.look4sat.core.presentation.TopBar
+import kotlin.math.abs
+
+/**
+ * Full-screen field tool: walks the operator onto a VUCC grid line or corner.
+ * Reached from the map's grid view and from Settings; the live fix it uses
+ * never moves the station unless the operator taps "Set as my station".
+ */
+@Composable
+fun GridFinderDestination(
+    navigateUp: () -> Unit,
+    onOpenLoTWStation: () -> Unit = {}
+) {
+    val context = LocalContext.current
+    val container = (context.applicationContext as IContainerProvider).getMainContainer()
+    val viewModel: GridFinderViewModel = viewModel(factory = GridFinderViewModel.factory(container))
+    val uiState by viewModel.uiState.collectAsStateWithLifecycle()
+
+    val permissionLauncher = rememberLauncherForActivityResult(
+        ActivityResultContracts.RequestPermission()
+    ) { granted -> viewModel.onAction(GridFinderAction.LocationPermissionResult(granted)) }
+    val requestLocationPermission = { permissionLauncher.launch(Manifest.permission.ACCESS_FINE_LOCATION) }
+    var hasAskedPermission by rememberSaveable { mutableStateOf(false) }
+    // "Set as LoTW station": hand the grids the operator currently stands on
+    // (1 inside, 2 on a line, 4 on a corner) to the upload station page.
+    val openLoTWStation: () -> Unit = {
+        val grids = uiState.claimableGrids
+        if (grids.isNotEmpty()) {
+            container.setPendingLoTWStationGrid(grids.joinToString(","))
+            onOpenLoTWStation()
+        }
+    }
+
+    DisposableEffect(viewModel) {
+        viewModel.onAction(GridFinderAction.StartUpdates)
+        onDispose { viewModel.onAction(GridFinderAction.StopUpdates) }
+    }
+    // Ask once automatically on the first visit; after a refusal the banner
+    // offers the request again, so returning to the screen is not a prompt loop.
+    LaunchedEffect(uiState.permissionGranted) {
+        if (!uiState.permissionGranted && !hasAskedPermission) {
+            hasAskedPermission = true
+            requestLocationPermission()
+        }
+    }
+
+    GridFinderScreen(
+        uiState = uiState,
+        onAction = viewModel::onAction,
+        navigateUp = navigateUp,
+        openLoTWStation = openLoTWStation,
+        requestLocationPermission = requestLocationPermission
+    )
+}
+
+@Composable
+private fun GridFinderScreen(
+    uiState: GridFinderState,
+    onAction: (GridFinderAction) -> Unit,
+    navigateUp: () -> Unit,
+    openLoTWStation: () -> Unit,
+    requestLocationPermission: () -> Unit
+) {
+    // Same top-bar → content rhythm as the settings page: ScreenColumn puts a
+    // small gap between the header row and the rounded surfaceContainer panel.
+    ScreenColumn(
+        topBar = {
+            TopBar {
+                IconCard(action = navigateUp, resId = R.drawable.ic_back)
+                Text(
+                    text = stringResource(R.string.gridfinder_title),
+                    fontSize = 20.sp,
+                    fontWeight = FontWeight.Medium,
+                    color = MaterialTheme.colorScheme.primary,
+                    modifier = Modifier.padding(start = 10.dp)
+                )
+            }
+        }
+    ) {
+        LazyColumn(
+            modifier = Modifier.fillMaxSize().clip(MaterialTheme.shapes.medium),
+            verticalArrangement = Arrangement.spacedBy(12.dp),
+            contentPadding = PaddingValues(top = 0.dp, bottom = 24.dp)
+        ) {
+                item { StandingCard(uiState, requestLocationPermission) }
+                uiState.geometry?.let { geometry ->
+                    item { LocationCard(uiState, onAction, openLoTWStation) }
+                    item {
+                        GuideCard(
+                            title = stringResource(R.string.gridfinder_card_corner),
+                            bearing = geometry.cornerBearingDegrees,
+                            distanceMeters = geometry.cornerMeters,
+                            direction = null,
+                            grids = geometry.cornerGrids,
+                            tint = ElevationHighColor,
+                            heading = uiState.headingDegrees
+                        )
+                    }
+                    item {
+                        GuideCard(
+                            title = stringResource(R.string.gridfinder_card_line),
+                            bearing = geometry.nearestLineBearingDegrees,
+                            distanceMeters = geometry.nearestLineMeters,
+                            direction = null,
+                            grids = geometry.nearestLineGrids,
+                            tint = MaterialTheme.colorScheme.primary,
+                            heading = uiState.headingDegrees,
+                            extra = stringResource(
+                                if (geometry.nearestLineIsLatitude) {
+                                    R.string.gridfinder_line_latitude
+                                } else {
+                                    R.string.gridfinder_line_longitude
+                                }
+                            )
+                        )
+                    }
+                    item { BoundaryLinesCard(geometry) }
+                    item { ProximityCard(geometry, uiState.headingDegrees) }
+                }
+                item { FixQualityCard(uiState) }
+                item { CompassCard(uiState, onAction) }
+            }
+        }
+}
+
+@Composable
+private fun StandingCard(uiState: GridFinderState, requestLocationPermission: () -> Unit) {
+    val grids = uiState.claimableGrids.joinToString(" · ")
+    val (headline, tint) = when {
+        !uiState.permissionGranted -> stringResource(R.string.gridfinder_status_blocked) to ElevationLowColor
+        !uiState.providerEnabled -> stringResource(R.string.gridfinder_status_disabled) to ElevationLowColor
+        uiState.fix == null -> stringResource(R.string.gridfinder_status_waiting) to MaterialTheme.colorScheme.onSurface
+        uiState.status == null -> stringResource(R.string.gridfinder_status_unknown) to ElevationLowColor
+        uiState.status == GridFixStatus.ON_GRID_CORNER -> stringResource(R.string.gridfinder_status_corner) to ElevationHighColor
+        uiState.status == GridFixStatus.ON_GRID_LINE -> stringResource(R.string.gridfinder_status_line) to ElevationHighColor
+        else -> stringResource(R.string.gridfinder_status_inside) to MaterialTheme.colorScheme.onSurface
+    }
+    GridCard(Modifier.fillMaxWidth()) {
+        Text(
+            text = headline,
+            fontSize = 22.sp,
+            fontWeight = FontWeight.Bold,
+            color = tint,
+            modifier = Modifier.fillMaxWidth()
+        )
+        if (grids.isNotEmpty()) {
+            GridMetricRow(
+                label = stringResource(R.string.gridfinder_label_claimable),
+                value = grids,
+                valueColor = when (uiState.status) {
+                    GridFixStatus.ON_GRID_CORNER, GridFixStatus.ON_GRID_LINE -> ElevationHighColor
+                    else -> null
+                }
+            )
+        }
+        when {
+            uiState.fix == null -> Unit
+            uiState.status == GridFixStatus.INSIDE_GRID -> Text(
+                text = stringResource(R.string.gridfinder_vucc_rule_note, VUCC_BOUNDARY_TOLERANCE_METERS),
+                fontSize = 12.sp,
+                color = MaterialTheme.colorScheme.onSurfaceVariant
+            )
+            uiState.isStandingConfirmed -> Text(
+                text = stringResource(R.string.gridfinder_status_confirmed, PRECISE_FIXES_REQUIRED),
+                fontSize = 12.sp,
+                color = ElevationHighColor
+            )
+            else -> Text(
+                text = stringResource(
+                    R.string.gridfinder_status_unconfirmed,
+                    uiState.preciseFixesInARow,
+                    PRECISE_FIXES_REQUIRED
+                ),
+                fontSize = 12.sp,
+                color = MaterialTheme.colorScheme.onSurfaceVariant
+            )
+        }
+        if (!uiState.permissionGranted) {
+            Button(onClick = requestLocationPermission) {
+                Text(text = stringResource(R.string.gridfinder_grant_permission))
+            }
+        }
+    }
+}
+
+@Composable
+private fun LocationCard(
+    uiState: GridFinderState,
+    onAction: (GridFinderAction) -> Unit,
+    openLoTWStation: () -> Unit
+) {
+    GridCard(Modifier.fillMaxWidth()) {
+        Text(
+            text = stringResource(R.string.gridfinder_card_location),
+            fontSize = 14.sp,
+            fontWeight = FontWeight.Medium,
+            color = MaterialTheme.colorScheme.primary
+        )
+        val geometry = uiState.geometry
+        val fix = uiState.fix
+        GridMetricRow(stringResource(R.string.gridfinder_label_grid4), geometry?.grid4 ?: "-")
+        GridMetricRow(stringResource(R.string.gridfinder_label_grid6), geometry?.grid6 ?: "-")
+        GridMetricRow(stringResource(R.string.gridfinder_label_grid8), geometry?.grid8 ?: "-")
+        GridMetricRow(
+            label = stringResource(R.string.gridfinder_label_latitude),
+            value = fix?.let { String.format("%+.5f°", it.latitude) } ?: "-"
+        )
+        GridMetricRow(
+            label = stringResource(R.string.gridfinder_label_longitude),
+            value = fix?.let { String.format("%+.5f°", it.longitude) } ?: "-"
+        )
+        GridMetricRow(
+            label = stringResource(R.string.gridfinder_label_altitude),
+            value = fix?.let { String.format("%.0f m", it.altitudeMeters) } ?: "-"
+        )
+        if (uiState.fix != null) {
+            Button(
+                onClick = { onAction(GridFinderAction.SetAsStation) },
+                modifier = Modifier.fillMaxWidth()
+            ) {
+                Text(text = stringResource(R.string.gridfinder_action_set_station))
+            }
+            if (uiState.isStationSaved) {
+                Text(
+                    text = stringResource(R.string.gridfinder_action_station_saved),
+                    fontSize = 12.sp,
+                    color = ElevationHighColor
+                )
+            }
+            val claimable = uiState.claimableGrids
+            if (claimable.isNotEmpty()) {
+                Spacer(modifier = Modifier.height(2.dp))
+                Button(
+                    onClick = openLoTWStation,
+                    modifier = Modifier.fillMaxWidth()
+                ) {
+                    Text(
+                        text = stringResource(
+                            R.string.gridfinder_action_set_lotw_station,
+                            claimable.joinToString(",")
+                        )
+                    )
+                }
+                Text(
+                    text = stringResource(R.string.gridfinder_lotw_station_hint),
+                    fontSize = 12.sp,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant
+                )
+            }
+        }
+    }
+}
+
+@Composable
+private fun GuideCard(
+    title: String,
+    bearing: Double,
+    distanceMeters: Double,
+    direction: GridBoundaryDirection?,
+    grids: List<String>,
+    tint: Color,
+    heading: Float?,
+    extra: String? = null
+) {
+    GridCard(Modifier.fillMaxWidth()) {
+        Text(
+            text = title,
+            fontSize = 14.sp,
+            fontWeight = FontWeight.Medium,
+            color = MaterialTheme.colorScheme.primary
+        )
+        Row(verticalAlignment = Alignment.CenterVertically, modifier = Modifier.fillMaxWidth()) {
+            GridCompassDial(
+                bearingDegrees = bearing,
+                headingDegrees = heading,
+                tint = tint,
+                modifier = Modifier.size(108.dp)
+            )
+            Spacer(modifier = Modifier.size(12.dp))
+            Column(verticalArrangement = Arrangement.spacedBy(4.dp)) {
+                GridMetricRow(
+                    label = stringResource(R.string.gridfinder_label_distance),
+                    value = formatDistance(distanceMeters),
+                    valueColor = tint
+                )
+                GridMetricRow(
+                    label = stringResource(R.string.gridfinder_label_bearing),
+                    value = String.format("%.0f° %s", bearing, cardinal(bearing))
+                )
+                if (direction != null) {
+                    GridMetricRow(stringResource(R.string.gridfinder_label_direction), directionLabel(direction))
+                }
+                if (grids.isNotEmpty()) {
+                    GridMetricRow(stringResource(R.string.gridfinder_label_grids), grids.joinToString(" / "))
+                }
+                extra?.let {
+                    Text(text = it, fontSize = 12.sp, color = MaterialTheme.colorScheme.onSurfaceVariant)
+                }
+            }
+        }
+    }
+}
+
+@Composable
+private fun BoundaryLinesCard(geometry: GridGeometry) {
+    GridCard(Modifier.fillMaxWidth()) {
+        Text(
+            text = stringResource(R.string.gridfinder_card_lines),
+            fontSize = 14.sp,
+            fontWeight = FontWeight.Medium,
+            color = MaterialTheme.colorScheme.primary
+        )
+        GridMetricRow(
+            label = stringResource(R.string.gridfinder_label_lat_line),
+            value = stringResource(
+                R.string.gridfinder_line_value,
+                formatDistance(geometry.latLineMeters),
+                directionLabel(geometry.latLineDirection)
+            )
+        )
+        GridMetricRow(
+            label = stringResource(R.string.gridfinder_label_lon_line),
+            value = stringResource(
+                R.string.gridfinder_line_value,
+                formatDistance(geometry.lonLineMeters),
+                directionLabel(geometry.lonLineDirection)
+            )
+        )
+        Text(
+            text = stringResource(R.string.gridfinder_vucc_rule_note, VUCC_BOUNDARY_TOLERANCE_METERS),
+            fontSize = 12.sp,
+            color = MaterialTheme.colorScheme.onSurfaceVariant
+        )
+    }
+}
+
+@Composable
+private fun ProximityCard(
+    geometry: GridGeometry,
+    heading: Float?
+) {
+    GridCard(Modifier.fillMaxWidth()) {
+        Text(
+            text = stringResource(R.string.gridfinder_card_map),
+            fontSize = 14.sp,
+            fontWeight = FontWeight.Medium,
+            color = MaterialTheme.colorScheme.primary
+        )
+        GridProximityMap(
+            geometry = geometry,
+            headingDegrees = heading,
+            modifier = Modifier
+                .fillMaxWidth()
+                .height(240.dp)
+        )
+        Text(
+            text = stringResource(R.string.gridfinder_map_legend),
+            fontSize = 12.sp,
+            color = MaterialTheme.colorScheme.onSurfaceVariant
+        )
+    }
+}
+
+@Composable
+private fun FixQualityCard(uiState: GridFinderState) {
+    val fix = uiState.fix
+    GridCard(Modifier.fillMaxWidth()) {
+        Text(
+            text = stringResource(R.string.gridfinder_card_fix),
+            fontSize = 14.sp,
+            fontWeight = FontWeight.Medium,
+            color = MaterialTheme.colorScheme.primary
+        )
+        GridMetricRow(
+            label = stringResource(R.string.gridfinder_label_accuracy),
+            value = fix?.let { String.format("± %.1f m", it.accuracyMeters) } ?: "-",
+            valueColor = fix?.let {
+                if (it.isPreciseEnough(VUCC_FIX_ACCURACY_LIMIT_METERS)) ElevationHighColor else ElevationLowColor
+            }
+        )
+        GridMetricRow(
+            label = stringResource(R.string.gridfinder_label_fix_age),
+            value = fix?.let { formatAge(it.epochMs) } ?: "-"
+        )
+        GridMetricRow(
+            label = stringResource(R.string.gridfinder_label_provider),
+            value = stringResource(
+                if (uiState.providerEnabled) {
+                    R.string.gridfinder_value_provider_on
+                } else {
+                    R.string.gridfinder_value_provider_off
+                }
+            )
+        )
+        LinearProgressIndicator(
+            progress = { uiState.preciseFixesInARow.toFloat() / PRECISE_FIXES_REQUIRED },
+            modifier = Modifier.fillMaxWidth()
+        )
+    }
+}
+
+@Composable
+private fun CompassCard(uiState: GridFinderState, onAction: (GridFinderAction) -> Unit) {
+    var showCalibration by rememberSaveable { mutableStateOf(false) }
+    GridCard(Modifier.fillMaxWidth()) {
+        Text(
+            text = stringResource(R.string.gridfinder_card_compass),
+            fontSize = 14.sp,
+            fontWeight = FontWeight.Medium,
+            color = MaterialTheme.colorScheme.primary
+        )
+        GridMetricRow(
+            label = stringResource(R.string.gridfinder_label_heading),
+            value = uiState.headingDegrees?.let { String.format("%.0f° %s", it, cardinal(it.toDouble())) } ?: "-"
+        )
+        GridMetricRow(
+            label = stringResource(R.string.gridfinder_label_compass_accuracy),
+            value = stringResource(compassAccuracyRes(uiState.compassAccuracy))
+        )
+        if (uiState.isCompassEnabled) {
+            Button(
+                onClick = { showCalibration = true },
+                enabled = uiState.compassAccuracy != CompassAccuracy.UNAVAILABLE,
+                modifier = Modifier.fillMaxWidth()
+            ) {
+                Text(text = stringResource(R.string.gridfinder_action_calibrate))
+            }
+        }
+        if (!uiState.isCompassEnabled) {
+            Text(
+                text = stringResource(R.string.gridfinder_compass_disabled_hint),
+                fontSize = 12.sp,
+                color = MaterialTheme.colorScheme.onSurfaceVariant
+            )
+        } else if (uiState.compassAccuracy == CompassAccuracy.UNAVAILABLE) {
+            Text(
+                text = stringResource(R.string.gridfinder_compass_unavailable_hint),
+                fontSize = 12.sp,
+                color = MaterialTheme.colorScheme.onSurfaceVariant
+            )
+        } else {
+            Text(
+                text = stringResource(R.string.gridfinder_compass_hint),
+                fontSize = 12.sp,
+                color = MaterialTheme.colorScheme.onSurfaceVariant
+            )
+        }
+    }
+    if (showCalibration) {
+        GridCompassCalibrationDialog(
+            accuracy = uiState.compassAccuracy,
+            heading = uiState.headingDegrees,
+            onSaveOffset = { offset -> onAction(GridFinderAction.SetCompassOffset(offset)) },
+            onDismiss = { showCalibration = false }
+        )
+    }
+}
+
+/**
+ * Compact figure-eight calibration dialog. It mirrors the settings screen's
+ * compass calibration but is self-contained in this module; the trim is saved
+ * through the same setting the radar page uses, so both stay in sync.
+ */
+@Composable
+private fun GridCompassCalibrationDialog(
+    accuracy: CompassAccuracy,
+    heading: Float?,
+    onSaveOffset: (Float) -> Unit,
+    onDismiss: () -> Unit
+) {
+    var offsetText by rememberSaveable { mutableStateOf("") }
+    val parsedOffset = offsetText.replace(',', '.').toFloatOrNull()?.takeIf { it in -180f..180f }
+    val progress = when (accuracy) {
+        CompassAccuracy.HIGH -> 1f
+        CompassAccuracy.MEDIUM -> 0.66f
+        CompassAccuracy.LOW -> 0.33f
+        else -> 0f
+    }
+    SharedDialog(
+        title = stringResource(R.string.prefs_compass_calibration_title),
+        onDismissRequest = onDismiss,
+        onCancel = onDismiss,
+        acceptEnabled = parsedOffset != null,
+        onAccept = {
+            parsedOffset?.let(onSaveOffset)
+            onDismiss()
+        }
+    ) { padding ->
+        Column(
+            horizontalAlignment = Alignment.CenterHorizontally,
+            verticalArrangement = Arrangement.spacedBy(8.dp),
+            modifier = Modifier.padding(horizontal = padding)
+        ) {
+            Text(
+                text = "∞",
+                fontSize = 84.sp,
+                color = MaterialTheme.colorScheme.primary,
+                lineHeight = 84.sp
+            )
+            Text(
+                text = stringResource(R.string.prefs_compass_calibration_instruction),
+                color = MaterialTheme.colorScheme.onSurface
+            )
+            Text(
+                text = stringResource(R.string.prefs_compass_accuracy, stringResource(compassAccuracyRes(accuracy))),
+                fontWeight = FontWeight.Medium,
+                color = MaterialTheme.colorScheme.onSurface
+            )
+            Text(
+                text = heading?.let { String.format("%.0f° %s", it, cardinal(it.toDouble())) } ?: "-",
+                fontSize = 28.sp,
+                fontWeight = FontWeight.Bold,
+                color = MaterialTheme.colorScheme.primary
+            )
+            LinearProgressIndicator(progress = { progress }, modifier = Modifier.fillMaxWidth())
+            Text(
+                text = stringResource(R.string.prefs_compass_offset_support),
+                fontSize = 12.sp,
+                color = MaterialTheme.colorScheme.onSurfaceVariant
+            )
+            OutlinedTextField(
+                value = offsetText,
+                onValueChange = { offsetText = it },
+                singleLine = true,
+                keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Number),
+                label = { Text(text = stringResource(R.string.prefs_compass_offset)) },
+                modifier = Modifier.fillMaxWidth()
+            )
+        }
+    }
+}
+
+@Composable
+private fun GridCard(modifier: Modifier = Modifier, content: @Composable ColumnScope.() -> Unit) {
+    ElevatedCard(modifier = modifier) {
+        Column(
+            verticalArrangement = Arrangement.spacedBy(6.dp),
+            modifier = Modifier.padding(12.dp),
+            content = content
+        )
+    }
+}
+
+@Composable
+private fun GridMetricRow(label: String, value: String, valueColor: Color? = null) {
+    Row(
+        modifier = Modifier.fillMaxWidth(),
+        horizontalArrangement = Arrangement.SpaceBetween,
+        verticalAlignment = Alignment.CenterVertically
+    ) {
+        Text(
+            text = label,
+            fontSize = 13.sp,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+            modifier = Modifier.weight(1f)
+        )
+        Text(
+            text = value,
+            fontSize = 13.sp,
+            fontWeight = FontWeight.Medium,
+            color = valueColor ?: MaterialTheme.colorScheme.onSurface
+        )
+    }
+}
+
+@Composable
+private fun directionLabel(direction: GridBoundaryDirection): String = stringResource(
+    when (direction) {
+        GridBoundaryDirection.NORTH -> R.string.gridfinder_direction_north
+        GridBoundaryDirection.SOUTH -> R.string.gridfinder_direction_south
+        GridBoundaryDirection.EAST -> R.string.gridfinder_direction_east
+        GridBoundaryDirection.WEST -> R.string.gridfinder_direction_west
+    }
+)
+
+@Composable
+private fun compassAccuracyRes(accuracy: CompassAccuracy): Int = when (accuracy) {
+    CompassAccuracy.HIGH -> R.string.prefs_compass_accuracy_high
+    CompassAccuracy.MEDIUM -> R.string.prefs_compass_accuracy_medium
+    CompassAccuracy.LOW -> R.string.prefs_compass_accuracy_low
+    CompassAccuracy.UNRELIABLE -> R.string.prefs_compass_accuracy_unreliable
+    CompassAccuracy.UNAVAILABLE -> R.string.prefs_compass_accuracy_unavailable
+}
+
+private fun formatDistance(meters: Double): String {
+    return if (abs(meters) < 1000.0) {
+        String.format("%.1f m", meters)
+    } else {
+        String.format("%.2f km", meters / 1000.0)
+    }
+}
+
+private fun formatAge(epochMs: Long): String {
+    val seconds = ((System.currentTimeMillis() - epochMs) / 1000L).coerceAtLeast(0L)
+    return if (seconds < 60L) "${seconds}s" else "${seconds / 60L}min"
+}
+
+private fun cardinal(bearingDegrees: Double): String {
+    val normalized = (bearingDegrees % 360.0 + 360.0) % 360.0
+    val names = listOf("N", "NE", "E", "SE", "S", "SW", "W", "NW", "N")
+    return names[((normalized + 22.5) / 45.0).toInt().coerceIn(0, 8)]
+}

feature/gridfinder/src/main/java/com/rtbishop/look4sat/feature/gridfinder/GridFinderState.kt

@@ -0,0 +1,92 @@
+/*
+ * 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.gridfinder
+
+import com.rtbishop.look4sat.core.domain.repository.CompassAccuracy
+import com.rtbishop.look4sat.core.domain.repository.LocationFix
+import com.rtbishop.look4sat.core.domain.utility.GridFixStatus
+import com.rtbishop.look4sat.core.domain.utility.GridGeometry
+
+/**
+ * How many consecutive precise fixes are required before a grid-line / corner
+ * claim is presented as confirmed. A single fix is not trustworthy enough to
+ * tell a walker that they are standing on a 6 m boundary.
+ */
+const val PRECISE_FIXES_REQUIRED = 3
+
+/** A fix must be at least this good before its grid line/corner claim counts. */
+const val VUCC_FIX_ACCURACY_LIMIT_METERS = 6.1f
+
+/** Outcome of pushing one fix through the 20 ft precision gate. */
+data class FixGateResult(val streak: Int, val isConfirmed: Boolean)
+
+/**
+ * Counts consecutive fixes that are both good to the 20 ft rule and inside a
+ * grid-square boundary. Any one bad fix resets the counter, so a claim is only
+ * confirmed once the walker has held it for several readings.
+ */
+fun nextFixGate(previousStreak: Int, fix: LocationFix): FixGateResult {
+    val streak = if (fix.isPreciseEnough(VUCC_FIX_ACCURACY_LIMIT_METERS)) {
+        (previousStreak + 1).coerceAtMost(PRECISE_FIXES_REQUIRED)
+    } else {
+        0
+    }
+    return FixGateResult(streak = streak, isConfirmed = streak >= PRECISE_FIXES_REQUIRED)
+}
+
+/**
+ * Grid Finder screen state. [status] and [claimableGrids] are always derived
+ * from the latest fix's distance to the boundary; [isStandingConfirmed] says
+ * whether that reading is backed by [PRECISE_FIXES_REQUIRED] consecutive fixes
+ * that are themselves good to the 20 ft rule.
+ */
+data class GridFinderState(
+    val permissionGranted: Boolean = false,
+    val providerEnabled: Boolean = true,
+    val providerReady: Boolean = true,
+    val fix: LocationFix? = null,
+    val geometry: GridGeometry? = null,
+    val claimableGrids: List<String> = emptyList(),
+    val status: GridFixStatus? = null,
+    val preciseFixesInARow: Int = 0,
+    val isStandingConfirmed: Boolean = false,
+    val headingDegrees: Float? = null,
+    val compassAccuracy: CompassAccuracy = CompassAccuracy.UNAVAILABLE,
+    val isCompassEnabled: Boolean = false,
+    val isStationSaved: Boolean = false
+) {
+    val isWaitingForFix: Boolean get() = fix == null
+}
+
+sealed interface GridFinderAction {
+    /** Called when the screen appears: starts location and (if enabled) compass updates. */
+    data object StartUpdates : GridFinderAction
+
+    /** Called when the screen goes away: releases both listeners. */
+    data object StopUpdates : GridFinderAction
+
+    data class LocationPermissionResult(val granted: Boolean) : GridFinderAction
+
+    /** Copies the current fix into the station position that drives pass predictions. */
+    data object SetAsStation : GridFinderAction
+
+    data object StationSavedShown : GridFinderAction
+
+    /** Saves the compass trim, shared with the radar page's calibration. */
+    data class SetCompassOffset(val offsetDegrees: Float) : GridFinderAction
+}

feature/gridfinder/src/main/java/com/rtbishop/look4sat/feature/gridfinder/GridFinderViewModel.kt

@@ -0,0 +1,214 @@
+/*
+ * 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.gridfinder
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import androidx.lifecycle.viewmodel.initializer
+import androidx.lifecycle.viewmodel.viewModelFactory
+import com.rtbishop.look4sat.core.domain.predict.GeoPos
+import com.rtbishop.look4sat.core.domain.repository.ILocationRepo
+import com.rtbishop.look4sat.core.domain.repository.IMainContainer
+import com.rtbishop.look4sat.core.domain.repository.ISensorsRepo
+import com.rtbishop.look4sat.core.domain.repository.ISettingsRepo
+import com.rtbishop.look4sat.core.domain.repository.LocationFix
+import com.rtbishop.look4sat.core.domain.repository.LocationState
+import com.rtbishop.look4sat.core.domain.utility.gridFixStatus
+import com.rtbishop.look4sat.core.domain.utility.gridGeometry
+import com.rtbishop.look4sat.core.domain.utility.vuccClaimableGrids
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.update
+import kotlinx.coroutines.launch
+import kotlin.math.abs
+
+/** Declination is only recomputed once the fix has moved this far (degrees). */
+private const val DECLINATION_REFRESH_DEGREES = 0.01
+
+/**
+ * Drives the Grid Finder: streams the live fix, turns it into grid-line /
+ * grid-corner geometry, and gates the VUCC claim on [PRECISE_FIXES_REQUIRED]
+ * consecutive fixes good to the 20 ft rule.
+ *
+ * The live fix never touches the station position - [GridFinderAction.SetAsStation]
+ * is the only thing that writes it, and only when the operator asks.
+ */
+class GridFinderViewModel(
+    private val settingsRepo: ISettingsRepo,
+    private val locationRepo: ILocationRepo,
+    private val sensorsRepo: ISensorsRepo
+) : ViewModel() {
+
+    private val _uiState = MutableStateFlow(GridFinderState())
+    val uiState: StateFlow<GridFinderState> = _uiState.asStateFlow()
+
+    private var locationJob: Job? = null
+    private var compassJob: Job? = null
+    private var accuracyJob: Job? = null
+    private var sensorsEnabledByUs = false
+    private var declinationCache: Pair<GeoPos, Float>? = null
+    private var lastSensorAzimuth: Float? = null
+
+    fun onAction(action: GridFinderAction) {
+        when (action) {
+            GridFinderAction.StartUpdates -> startUpdates()
+            GridFinderAction.StopUpdates -> stopUpdates()
+            is GridFinderAction.LocationPermissionResult -> startUpdates()
+            GridFinderAction.SetAsStation -> setAsStation()
+            GridFinderAction.StationSavedShown -> _uiState.update { it.copy(isStationSaved = false) }
+            is GridFinderAction.SetCompassOffset -> setCompassOffset(action.offsetDegrees)
+        }
+    }
+
+    /**
+     * Saves the compass trim shared with the radar page, then recomputes the
+     * heading from the last raw sensor sample so the dial reacts immediately.
+     */
+    private fun setCompassOffset(offsetDegrees: Float) {
+        settingsRepo.updateOtherSettings { it.copy(compassOffsetDegrees = offsetDegrees) }
+        lastSensorAzimuth?.let { azimuth ->
+            _uiState.update { it.copy(headingDegrees = correctedHeading(azimuth)) }
+        }
+    }
+
+    private fun startUpdates() {
+        val permissionGranted = locationRepo.hasPermission()
+        _uiState.update { it.copy(permissionGranted = permissionGranted) }
+        if (!permissionGranted) return
+        locationRepo.startUpdates()
+        collectLocation()
+        collectCompass()
+    }
+
+    private fun collectLocation() {
+        if (locationJob != null) return
+        locationJob = viewModelScope.launch {
+            locationRepo.state.collect { state ->
+                when (state) {
+                    is LocationState.Fix -> onFix(state.location)
+                    is LocationState.Waiting -> _uiState.update {
+                        it.copy(
+                            permissionGranted = state.permissionGranted,
+                            providerEnabled = state.providerEnabled
+                        )
+                    }
+                }
+            }
+        }
+    }
+
+    private fun collectCompass() {
+        val compassEnabled = settingsRepo.otherSettings.value.stateOfSensors
+        _uiState.update {
+            it.copy(isCompassEnabled = compassEnabled, compassAccuracy = sensorsRepo.compassAccuracy.value)
+        }
+        if (!compassEnabled || compassJob != null) return
+        sensorsRepo.enableSensor()
+        sensorsEnabledByUs = true
+        accuracyJob = viewModelScope.launch {
+            sensorsRepo.compassAccuracy.collect { accuracy ->
+                _uiState.update { it.copy(compassAccuracy = accuracy) }
+            }
+        }
+        compassJob = viewModelScope.launch {
+            sensorsRepo.sensorData.collect { data ->
+                lastSensorAzimuth = data.first
+                _uiState.update { it.copy(headingDegrees = correctedHeading(data.first)) }
+            }
+        }
+    }
+
+    /** Same convention as the radar page: sensor azimuth + magnetic declination + manual trim. */
+    private fun correctedHeading(sensorAzimuth: Float): Float {
+        val offset = settingsRepo.otherSettings.value.compassOffsetDegrees
+        val azimuth = sensorAzimuth + magDeclination() + offset
+        return (azimuth % 360f + 360f) % 360f
+    }
+
+    private fun magDeclination(): Float {
+        val position = _uiState.value.fix?.let { GeoPos(it.latitude, it.longitude, it.altitudeMeters) }
+            ?: settingsRepo.stationPosition.value
+        val cached = declinationCache
+        if (cached != null &&
+            abs(cached.first.latitude - position.latitude) < DECLINATION_REFRESH_DEGREES &&
+            abs(cached.first.longitude - position.longitude) < DECLINATION_REFRESH_DEGREES
+        ) {
+            return cached.second
+        }
+        val declination = sensorsRepo.getMagDeclination(position)
+        declinationCache = position to declination
+        return declination
+    }
+
+    private fun onFix(fix: LocationFix) {
+        val geometry = gridGeometry(fix.latitude, fix.longitude)
+        val claimable = vuccClaimableGrids(fix.latitude, fix.longitude)
+        val gate = nextFixGate(_uiState.value.preciseFixesInARow, fix)
+        _uiState.update {
+            it.copy(
+                permissionGranted = true,
+                providerReady = geometry != null,
+                fix = fix,
+                geometry = geometry,
+                claimableGrids = claimable,
+                status = if (claimable.isEmpty()) null else gridFixStatus(claimable),
+                preciseFixesInARow = gate.streak,
+                isStandingConfirmed = gate.isConfirmed
+            )
+        }
+    }
+
+    private fun setAsStation() {
+        val fix = _uiState.value.fix ?: return
+        val saved = settingsRepo.setStationPosition(fix.latitude, fix.longitude, fix.altitudeMeters)
+        if (saved) _uiState.update { it.copy(isStationSaved = true) }
+    }
+
+    private fun stopUpdates() {
+        locationRepo.stopUpdates()
+        locationJob?.cancel()
+        locationJob = null
+        compassJob?.cancel()
+        compassJob = null
+        accuracyJob?.cancel()
+        accuracyJob = null
+        if (sensorsEnabledByUs) {
+            sensorsRepo.disableSensor()
+            sensorsEnabledByUs = false
+        }
+    }
+
+    override fun onCleared() {
+        stopUpdates()
+        super.onCleared()
+    }
+
+    companion object {
+        fun factory(container: IMainContainer) = viewModelFactory {
+            initializer {
+                GridFinderViewModel(
+                    settingsRepo = container.settingsRepo,
+                    locationRepo = container.locationRepo,
+                    sensorsRepo = container.provideSensorsRepo()
+                )
+            }
+        }
+    }
+}

feature/gridfinder/src/test/java/com/rtbishop/look4sat/feature/gridfinder/GridFinderGateTest.kt

@@ -0,0 +1,74 @@
+/*
+ * 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.gridfinder
+
+import com.rtbishop.look4sat.core.domain.repository.LocationFix
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+class GridFinderGateTest {
+
+    @Test
+    fun `fix within the 20 ft rule is precise enough`() {
+        assertTrue(fix(accuracy = 6.0f).isPreciseEnough(VUCC_FIX_ACCURACY_LIMIT_METERS))
+    }
+
+    @Test
+    fun `fix worse than the 20 ft rule is not precise enough`() {
+        assertFalse(fix(accuracy = 12.0f).isPreciseEnough(VUCC_FIX_ACCURACY_LIMIT_METERS))
+    }
+
+    @Test
+    fun `streak grows on good fixes and confirms on the third`() {
+        val first = nextFixGate(0, fix(accuracy = 4.0f))
+        assertEquals(1, first.streak)
+        assertFalse(first.isConfirmed)
+
+        val second = nextFixGate(first.streak, fix(accuracy = 4.0f))
+        assertEquals(2, second.streak)
+        assertFalse(second.isConfirmed)
+
+        val third = nextFixGate(second.streak, fix(accuracy = 4.0f))
+        assertEquals(PRECISE_FIXES_REQUIRED, third.streak)
+        assertTrue(third.isConfirmed)
+    }
+
+    @Test
+    fun `streak stays capped once confirmed`() {
+        val capped = nextFixGate(PRECISE_FIXES_REQUIRED, fix(accuracy = 1.0f))
+        assertEquals(PRECISE_FIXES_REQUIRED, capped.streak)
+        assertTrue(capped.isConfirmed)
+    }
+
+    @Test
+    fun `one coarse fix resets a confirmed streak`() {
+        val reset = nextFixGate(PRECISE_FIXES_REQUIRED, fix(accuracy = 25.0f))
+        assertEquals(0, reset.streak)
+        assertFalse(reset.isConfirmed)
+    }
+
+    private fun fix(accuracy: Float) = LocationFix(
+        latitude = 22.0,
+        longitude = 114.0,
+        altitudeMeters = 30.0,
+        accuracyMeters = accuracy,
+        epochMs = 0L
+    )
+}

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

@@ -139,6 +139,18 @@ class AwardBoundaryOverlay : Overlay() {
         color = Color.argb(90, 76, 217, 100)
     }
 
+    /**
+     * Recolor the amber boundary/label paints for the active map theme (dark amber + white halo on
+     * the light map, light amber + black halo on the dark map). The worked fill reads on both.
+     */
+    fun applyTheme(isLightUi: Boolean) {
+        val line = if (isLightUi) Color.argb(200, 113, 92, 12) else Color.argb(160, 255, 224, 130)
+        val label = if (isLightUi) Color.argb(235, 30, 25, 5) else Color.argb(220, 255, 224, 130)
+        linePaint.color = line
+        labelPaint.color = label
+        labelPaint.setShadowLayer(3f, 2f, 2f, if (isLightUi) Color.WHITE else Color.BLACK)
+    }
+
     /** Boundary regions to render; assigning recomputes culling bounds. */
     var regions: List<AwardRegion> = emptyList()
         set(value) {

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

@@ -89,6 +89,24 @@ class MaidenheadGridOverlay : Overlay() {
         color = Color.argb(255, 76, 217, 100)
     }
 
+    /**
+     * Recolor the amber line/label paints for the active map theme: dark amber with a white halo
+     * on the light map, light amber with a black halo on the dark map. The worked / marked / roam /
+     * selected colors stay as they are — they read on both backgrounds.
+     */
+    fun applyTheme(isLightUi: Boolean) {
+        val line = if (isLightUi) Color.argb(200, 113, 92, 12) else Color.argb(160, 255, 224, 130)
+        val label = if (isLightUi) Color.argb(235, 30, 25, 5) else Color.argb(220, 255, 224, 130)
+        val halo = if (isLightUi) Color.WHITE else Color.BLACK
+        linePaint.color = line
+        // ownLine stays the same color as the normal grid lines (only thicker).
+        ownLinePaint.color = line
+        labelPaint.color = label
+        labelPaint.setShadowLayer(3f, 2f, 2f, halo)
+        firstCallPaint.color = label
+        firstCallPaint.setShadowLayer(3f, 2f, 2f, halo)
+    }
+
     /** Worked gridsquares (4-char, uppercase) to highlight, e.g. {"OL62", "PM95"}. */
     var workedGrids: Set<String> = emptySet()
 

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

@@ -1,3 +1,21 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by 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 androidx.compose.runtime.MutableState

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

@@ -116,8 +116,9 @@ class MapNightOverlay : Overlay() {
 
                 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) {
+                    val isNightAtTop = dotTop < 0
+                    val crossY = findCrossingY(proj, x, 0, h - 1, sinSunLat, cosSunLat, cosLonDiff, isNightAtTop)
+                    if (isNightAtTop) {
                         // Night at top, day at bottom
                         rect.set(x.toFloat(), 0f, (x + stepPx).toFloat(), crossY.toFloat())
                         canvas.drawRect(rect, nightPaint)
@@ -134,7 +135,11 @@ class MapNightOverlay : Overlay() {
 
     /**
      * 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).
+     *
+     * [isNightAtTop] states which side [yTop] is on. Both polarities occur: the pole nearest
+     * the sub-solar point is lit, so the terminator runs day-over-night while the sub-solar
+     * latitude is positive and night-over-day once it turns negative after the September
+     * equinox. Anchoring lo to the top pixel's side keeps the search valid either way.
      */
     private fun findCrossingY(
         proj: org.osmdroid.views.Projection,
@@ -143,7 +148,8 @@ class MapNightOverlay : Overlay() {
         yBot: Int,
         sinSunLat: Double,
         cosSunLat: Double,
-        cosLonDiff: Double
+        cosLonDiff: Double,
+        isNightAtTop: Boolean
     ): Int {
         var lo = yTop
         var hi = yBot
@@ -152,7 +158,8 @@ class MapNightOverlay : Overlay() {
             val geo = proj.fromPixels(x, mid, reusableGeoPoint) ?: 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
+            // Keep lo on the top pixel's side of the terminator and hi on the opposite side
+            if ((dot < 0) == isNightAtTop) lo = mid else hi = mid
         }
         return (lo + hi) / 2
     }

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

@@ -159,6 +159,71 @@ private val moonIconPaint = Paint(Paint.ANTI_ALIAS_FLAG).apply {
         android.graphics.PorterDuffColorFilter("#E0E0E0".toColorInt(), android.graphics.PorterDuff.Mode.SRC_IN)
 }
 
+/**
+ * Accent used for the station marker, footprint outline and map labels. It is recolored per
+ * theme (dark amber on light tiles, light amber on dark tiles) so every map element stays
+ * readable; [applyMapColors] keeps it in sync with the shared paints.
+ */
+private var mapAccentColor = "#FFE082".toColorInt()
+
+/** Grayscale + invert filter that turns the offline OSM map dark; unused (and off) in light theme. */
+private val darkTileFilter by lazy { createColorFilter() }
+
+/** Theme the shared map paints were last colored for; null = not applied yet this process. */
+private var mapIsLightUi: Boolean? = null
+
+/** Theme the tile filter / icon caches were last applied for (drives the per-frame theme check). */
+private var appliedLightUi: Boolean? = null
+
+/** True while the offline OSM source is active — satellite imagery (Tianditu) is never filtered. */
+private var offlineTilesActive = true
+
+/**
+ * Recolor the shared overlay paints and custom overlays for the current theme. Must run before the
+ * markers are (re)built each frame so freshly created icons use the new colors; [applyThemeToOverlays]
+ * and the icon-cache eviction in the update block handle the already created ones.
+ */
+private fun applyMapColors(isLightUi: Boolean) {
+    mapIsLightUi = isLightUi
+    if (isLightUi) {
+        // Dark amber (lightScheme primary) reads on light tiles; labels get a white halo.
+        mapAccentColor = "#715C0C".toColorInt()
+        footprintPaint.color = mapAccentColor
+        textPaint.color = "#1E1B13".toColorInt()
+        textPaint.setShadowLayer(3f, 3f, 3f, Color.WHITE)
+        sunIconPaint.colorFilter =
+            android.graphics.PorterDuffColorFilter(mapAccentColor, android.graphics.PorterDuff.Mode.SRC_IN)
+        moonIconPaint.colorFilter = android.graphics.PorterDuffColorFilter(
+            "#4C4639".toColorInt(), android.graphics.PorterDuff.Mode.SRC_IN
+        )
+    } else {
+        mapAccentColor = "#FFE082".toColorInt()
+        footprintPaint.color = mapAccentColor
+        textPaint.color = mapAccentColor
+        textPaint.setShadowLayer(3f, 3f, 3f, Color.BLACK)
+        sunIconPaint.colorFilter =
+            android.graphics.PorterDuffColorFilter(mapAccentColor, android.graphics.PorterDuff.Mode.SRC_IN)
+        moonIconPaint.colorFilter =
+            android.graphics.PorterDuffColorFilter("#E0E0E0".toColorInt(), android.graphics.PorterDuff.Mode.SRC_IN)
+    }
+    applyThemeToOverlays()
+}
+
+/** Push the current theme into the grid / award overlays, which own their own paints. */
+private fun applyThemeToOverlays() {
+    val isLight = mapIsLightUi == true
+    currentMapView?.overlays?.forEach { overlay ->
+        when (overlay) {
+            is MaidenheadGridOverlay -> overlay.applyTheme(isLight)
+            is AwardBoundaryOverlay -> overlay.applyTheme(isLight)
+            else -> Unit
+        }
+    }
+}
+
+/** The MapView currently attached to the map page; used to recolor overlays on a theme change. */
+private var currentMapView: MapView? = null
+
 @Composable
 fun MapDestination(
     mapFilterViewModel: MapFilterViewModel,
@@ -204,7 +269,14 @@ fun MapDestination(
             viewModel.onAction(MapAction.SetVisible(false))
         }
     }
-    MapScreen(uiState, viewModel::onAction, mapView, mapFilterViewModel, onMatchGrid, matchCalculating)
+    MapScreen(
+        uiState = uiState,
+        onAction = viewModel::onAction,
+        mapView = mapView,
+        mapFilterViewModel = mapFilterViewModel,
+        onMatchGrid = onMatchGrid,
+        matchCalculating = matchCalculating
+    )
 }
 
 @Composable
@@ -320,8 +392,8 @@ private fun MapScreen(
         val firstPos = uiState.track?.firstOrNull()?.firstOrNull() ?: return@LaunchedEffect
         mapView.controller.animateTo(GeoPoint(firstPos.latitude, firstPos.longitude))
     }
-    LaunchedEffect(uiState.mapSource, uiState.tiandituKey) {
-        configureTileSources(mapView, uiState.mapSource, uiState.tiandituKey)
+    LaunchedEffect(uiState.mapSource, uiState.tiandituKey, uiState.isLightUi) {
+        configureTileSources(mapView, uiState.mapSource, uiState.tiandituKey, uiState.isLightUi)
     }
     Column(modifier = Modifier.layoutPadding(), verticalArrangement = Arrangement.spacedBy(6.dp)) {
         val isVertical = isVerticalLayout()
@@ -359,6 +431,18 @@ private fun MapScreen(
                     mutableStateOf(restoredViewport && uiState.isGridMode)
                 }
                 AndroidView({ mapView }) { view ->
+                    // Theme change: recolor the paints/tile filter/overlays and drop the icon
+                    // caches, which baked the previous theme's colors into their bitmaps.
+                    if (appliedLightUi != uiState.isLightUi) {
+                        appliedLightUi = uiState.isLightUi
+                        applyMapColors(uiState.isLightUi)
+                        iconCache.evictAll()
+                        dotIcon = null
+                        view.overlayManager.tilesOverlay.setColorFilter(
+                            if (!uiState.isLightUi && offlineTilesActive) darkTileFilter else null
+                        )
+                        requestTileRefresh(view)
+                    }
                     // Award filter mode: show the selected award's regions with
                     // worked ones filled green; hide satellite layers like grid mode.
                     val awardMode = selectedAward?.takeIf { it != AwardType.VUCC }
@@ -393,13 +477,13 @@ private fun MapScreen(
                         }
                     }
                     if (!uiState.isGridMode) {
-                        uiState.stationPosition?.let { setStationPosition(it, view) }
+                        uiState.stationPosition?.let { setStationPosition(it, view, uiState.isLightUi) }
                         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)
+                        setSubSolarPoint(uiState.sunLatDeg, uiState.sunLonDeg, view, uiState.isLightUi)
+                        setMoonPosition(uiState.moonLatDeg, uiState.moonLonDeg, view, uiState.isLightUi)
                     }
                     view.invalidate()
                 }
@@ -634,7 +718,7 @@ private fun MarkedStationRow(
             text = marked.call,
             style = MaterialTheme.typography.titleMedium,
             fontFamily = androidx.compose.ui.text.font.FontFamily.Monospace,
-            color = ComposeColor(0xFFFFE082),
+            color = MaterialTheme.colorScheme.primary,
             maxLines = 1,
             overflow = androidx.compose.ui.text.style.TextOverflow.Ellipsis,
             modifier = Modifier.weight(1f)
@@ -651,7 +735,7 @@ private fun MarkedStationRow(
                 Icon(
                     painter = painterResource(R.drawable.ic_pin),
                     contentDescription = stringResource(R.string.grid_mark_pin),
-                    tint = if (isPinned) ComposeColor(0xFF9E9E9E) else ComposeColor(0xFFFFE082),
+                    tint = if (isPinned) ComposeColor(0xFF9E9E9E) else MaterialTheme.colorScheme.primary,
                     modifier = Modifier
                         .size(18.dp)
                         .clickable(onClick = onPinMark)
@@ -706,7 +790,7 @@ private fun WorkedGridCallRow(
                 text = call,
                 style = MaterialTheme.typography.titleMedium,
                 fontFamily = androidx.compose.ui.text.font.FontFamily.Monospace,
-                color = MaterialTheme.colorScheme.tertiary,
+                color = MaterialTheme.colorScheme.primary,
                 maxLines = 1,
                 overflow = androidx.compose.ui.text.style.TextOverflow.Ellipsis,
                 modifier = Modifier.weight(1f)
@@ -1092,22 +1176,29 @@ private fun FirstCallToggle(
 // region Tile sources
 private var configuredTileMapView: MapView? = null
 private var configuredTileSource: String? = null
+private var configuredTileIsLightUi: Boolean? = null
 
-private fun configureTileSources(mapView: MapView, mapSource: String, tiandituKey: String) {
+private fun configureTileSources(mapView: MapView, mapSource: String, tiandituKey: String, isLightUi: Boolean) {
     val key = tiandituKey.trim()
     val layers = tiandituLayers(mapSource)
-    val sourceKey = if (layers == null || key.isBlank()) MapSource.OSM else "${layers.base}:$key"
-    if (configuredTileMapView === mapView && configuredTileSource == sourceKey) return
+    val offlineSource = layers == null || key.isBlank()
+    offlineTilesActive = offlineSource
+    val sourceKey = if (offlineSource) MapSource.OSM else "${layers.base}:$key"
+    if (configuredTileMapView === mapView && configuredTileSource == sourceKey &&
+        configuredTileIsLightUi == isLightUi
+    ) return
 
     configuredTileMapView = mapView
     configuredTileSource = sourceKey
+    configuredTileIsLightUi = isLightUi
     (mapView.overlays.getOrNull(OVERLAY_TDT_LABELS) as? TilesOverlay)?.onDetach(mapView)
 
-    if (layers == null || key.isBlank()) {
+    if (offlineSource) {
         mapView.setUseDataConnection(false)
         mapView.setTileSource(offlineTileSource)
         mapView.maxZoomLevel = OFFLINE_MAX_ZOOM
-        mapView.overlayManager.tilesOverlay.applyTileOverlayDefaults(createColorFilter())
+        // The dark-map filter belongs to the dark theme only; the light theme shows plain tiles.
+        mapView.overlayManager.tilesOverlay.applyTileOverlayDefaults(if (isLightUi) null else darkTileFilter)
         mapView.overlays[OVERLAY_TDT_LABELS] = FolderOverlay()
         requestTileRefresh(mapView)
         return
@@ -1210,6 +1301,7 @@ private fun setAwardMode(award: AwardType, workedCodes: Set<String>, mapView: Ma
             isEnabled = true
             regions = AwardBoundaryData.load(mapView.context, asset)
             this.workedCodes = workedCodes
+            applyTheme(mapIsLightUi == true)
         }
     }
     for (index in OVERLAY_STATION..OVERLAY_MOON) {
@@ -1252,6 +1344,7 @@ private fun setGridMode(
                 this.firstCallsByGrid = firstCallsByGrid
                 this.markedGrids = markedGrids
                 this.ownGrid = ownGridOf(stationPosition)
+                applyTheme(mapIsLightUi == true)
             }
         }
         // Satellite-related layers are hidden in grid mode; the grid overlay
@@ -1306,17 +1399,28 @@ private fun gridOfPoint(latitude: Double, longitude: Double): String? {
     return "${'A' + fieldLon}${'A' + fieldLat}$subLon$subLat"
 }
 
-private fun setStationPosition(stationPos: GeoPos, mapView: MapView) {
+private fun setStationPosition(stationPos: GeoPos, mapView: MapView, isLightUi: Boolean) {
     try {
         val overlay = mapView.overlays[OVERLAY_STATION]
+        val stationPoint = GeoPoint(stationPos.latitude, stationPos.longitude)
         if (overlay is Marker) {
-            overlay.position = GeoPoint(stationPos.latitude, stationPos.longitude)
+            overlay.position = stationPoint
+            // Icon tint is baked into the drawable, so re-tint after a theme change.
+            if ((overlay.relatedObject as? Boolean) != isLightUi) {
+                overlay.icon = ContextCompat.getDrawable(mapView.context, R.drawable.ic_position)?.apply {
+                    setTint(mapAccentColor)
+                }
+                overlay.relatedObject = isLightUi
+            }
         } else {
             mapView.overlays[OVERLAY_STATION] = Marker(mapView).apply {
                 setInfoWindow(null)
                 setAnchor(Marker.ANCHOR_CENTER, Marker.ANCHOR_BOTTOM)
-                icon = ContextCompat.getDrawable(mapView.context, R.drawable.ic_position)
-                position = GeoPoint(stationPos.latitude, stationPos.longitude)
+                icon = ContextCompat.getDrawable(mapView.context, R.drawable.ic_position)?.apply {
+                    setTint(mapAccentColor)
+                }
+                position = stationPoint
+                relatedObject = isLightUi
             }
         }
     } catch (e: Exception) {
@@ -1539,26 +1643,37 @@ private fun setTerminator(sunLatDeg: Double, sunLonDeg: Double, mapView: MapView
     }
 }
 
+/** Build the 48dp sun/moon marker icon, tinted with the theme-dependent paint. */
+private fun buildMarkerIcon(mapView: MapView, resId: Int, paint: Paint): Drawable {
+    val iconSize = 48
+    val bmp = createBitmap(iconSize, iconSize)
+    ContextCompat.getDrawable(mapView.context, resId)?.apply {
+        setBounds(0, 0, iconSize, iconSize)
+        colorFilter = paint.colorFilter
+        draw(Canvas(bmp))
+    }
+    return bmp.toDrawable(mapView.context.resources)
+}
+
 /** Place an ic_sun icon marker at the sub-solar point. */
-private fun setSubSolarPoint(sunLatDeg: Double, sunLonDeg: Double, mapView: MapView) {
+private fun setSubSolarPoint(sunLatDeg: Double, sunLonDeg: Double, mapView: MapView, isLightUi: Boolean) {
     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))
+            // The icon bitmap bakes in the theme tint, so rebuild it after a theme change.
+            if ((overlay.relatedObject as? Boolean) != isLightUi) {
+                overlay.icon = buildMarkerIcon(mapView, R.drawable.ic_sun, sunIconPaint)
+                overlay.relatedObject = isLightUi
             }
+        } else {
             mapView.overlays[OVERLAY_SUN] = Marker(mapView).apply {
                 setInfoWindow(null)
                 setAnchor(Marker.ANCHOR_CENTER, Marker.ANCHOR_CENTER)
-                icon = bmp.toDrawable(mapView.context.resources)
+                icon = buildMarkerIcon(mapView, R.drawable.ic_sun, sunIconPaint)
                 position = sunPos
+                relatedObject = isLightUi
             }
         }
     } catch (e: Exception) {
@@ -1567,26 +1682,23 @@ private fun setSubSolarPoint(sunLatDeg: Double, sunLonDeg: Double, mapView: MapV
 }
 
 /** Place an ic_moon icon marker at the sub-lunar point. */
-private fun setMoonPosition(moonLatDeg: Double, moonLonDeg: Double, mapView: MapView) {
+private fun setMoonPosition(moonLatDeg: Double, moonLonDeg: Double, mapView: MapView, isLightUi: Boolean) {
     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)
+            if ((overlay.relatedObject as? Boolean) != isLightUi) {
+                overlay.icon = buildMarkerIcon(mapView, R.drawable.ic_moon, moonIconPaint)
+                overlay.relatedObject = isLightUi
             }
+        } else {
             mapView.overlays[OVERLAY_MOON] = Marker(mapView).apply {
                 setInfoWindow(null)
                 setAnchor(Marker.ANCHOR_CENTER, Marker.ANCHOR_CENTER)
-                icon = bmp.toDrawable(mapView.context.resources)
+                icon = buildMarkerIcon(mapView, R.drawable.ic_moon, moonIconPaint)
                 position = moonPos
+                relatedObject = isLightUi
             }
         }
     } catch (e: Exception) {
@@ -1631,10 +1743,12 @@ private fun rememberMapViewWithLifecycle(
             zoomController.setVisibility(CustomZoomButtonsController.Visibility.NEVER)
             overlayManager.tilesOverlay.loadingBackgroundColor = Color.TRANSPARENT
             overlayManager.tilesOverlay.loadingLineColor = Color.TRANSPARENT
-            overlayManager.tilesOverlay.setColorFilter(createColorFilter())
+            // The dark-map tile filter (or no filter in the light theme) is applied per theme from
+            // the AndroidView update block, so it also follows a theme switch at runtime.
             setScrollableAreaLimitLatitude(maxLat, minLat, 0)
             overlays.addAll(Array(OVERLAY_COUNT) { FolderOverlay() })
-            overlays[OVERLAY_GRID] = MaidenheadGridOverlay()
+            overlays[OVERLAY_GRID] = MaidenheadGridOverlay().apply { applyTheme(mapIsLightUi == true) }
+            currentMapView = this
         }
     }
     val lifecycleObserver = rememberMapViewLifecycleObserver(mapView)
@@ -1647,7 +1761,10 @@ private fun rememberMapViewWithLifecycle(
     // released with the MapView or they keep the Activity and its bitmaps alive after disposal.
     // (The viewport save lives in MapDestination, where the grid/satellite mode is known.)
     DisposableEffect(mapView) {
-        onDispose { clearMapCaches() }
+        onDispose {
+            clearMapCaches()
+            if (currentMapView === mapView) currentMapView = null
+        }
     }
     return mapView
 }

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

@@ -84,6 +84,7 @@ class MapViewModel(
                 _uiState.update {
                     it.copy(
                         isUtc = settings.stateOfUtc,
+                        isLightUi = settings.stateOfLightTheme,
                         mapSource = settings.mapSource,
                         tiandituKey = settings.tiandituKey,
                         isGridMode = settings.stateOfMapGrid,

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

@@ -1,3 +1,21 @@
+/*
+ * Look4Sat-BA7OPF. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2026 BA7OPF.
+ * Based on Look4Sat by 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.mutual
 
 import com.rtbishop.look4sat.core.domain.model.DataSourcesSettings
@@ -111,6 +129,8 @@ class FakeSettingsRepo(
     override fun updateRadioControlSettings(settings: RadioControlSettings) = TODO()
     override fun getSatelliteOffset(catnum: Int): String = ""
     override fun setSatelliteOffset(catnum: Int, offset: String) = TODO()
+    override fun getSatelliteMode(catnum: Int): String = ""
+    override fun setSatelliteMode(catnum: Int, mode: String) = TODO()
     override fun getAmSatCallsign(): String = ""
     override fun setAmSatCallsign(callsign: String) = TODO()
     override fun updateWavelogSettings(settings: WavelogSettings) = TODO()