fix: passband RX update now uses full Doppler round-trip instead of pure passband mapping

When adjusting RX in passband mode (via +/- buttons or slider), the old
code used TransponderMapper.mapDownlinkToUplink (pure passband mapping
without Doppler compensation), producing ~10kHz error at LEO velocities.

Fix: use DopplerFrequencyCalculator.computeUplinkFromDownlinkWithOffset
for the full TX-from-RX round-trip, matching the RX→PASSBAND button
onClick logic. Also fixed frame mismatch: position now uses txLow/txRange
(Doppler-shifted frame) consistently.

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

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

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

@@ -117,7 +117,8 @@ class MainContainer(private val context: Context) : IMainContainer {
             rc.rotatorAddress,
             rc.rotatorPort.toIntOrNull() ?: 0,
             rc.frequencyAddress,
-            rc.frequencyPort.toIntOrNull() ?: 0
+            rc.frequencyPort.toIntOrNull() ?: 0,
+            rc.frequencyOffsetHz
         )
     }
 

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

@@ -35,7 +35,10 @@ class AmSatRepository(private val remoteSource: IRemoteSource) : IAmSatRepositor
     override suspend fun fetchStatus(): SatStatusPage? = withContext(Dispatchers.IO) {
         val nowSec = System.currentTimeMillis() / 1000
         val catalogJson = remoteSource.getAmSatCatalog() ?: return@withContext null
-        val reportsJson = remoteSource.getAmSatReports(hours = 168, limit = 500) ?: return@withContext null
+        // 72h = 3 days; API hard cap is limit=500 regardless of what we send.
+        // 500 records across ~100 catalog satellites ≈ ~1-5 reports/satellite/day — enough for 3 days.
+        // Upgrade path: paginate or request AMSAT to raise the cap if catalog grows beyond ~200 sats.
+        val reportsJson = remoteSource.getAmSatReports(hours = 72, limit = 500) ?: return@withContext null
         
         val names = parseCatalog(catalogJson)
         val reports = parseReports(reportsJson)
@@ -52,7 +55,7 @@ class AmSatRepository(private val remoteSource: IRemoteSource) : IAmSatRepositor
         return try {
             val arr = JSONObject(json).getJSONArray("data")
             (0 until arr.length()).map { arr.getJSONObject(it).getString("name") }
-        } catch (e: Exception) {
+        } catch (_: Exception) {
             emptyList()
         }
     }
@@ -73,7 +76,7 @@ class AmSatRepository(private val remoteSource: IRemoteSource) : IAmSatRepositor
                     reportedTimeUtcSec = parseIsoUtcSec(iso)
                 )
             }
-        } catch (e: Exception) {
+        } catch (_: Exception) {
             emptyList()
         }
     }
@@ -82,22 +85,22 @@ class AmSatRepository(private val remoteSource: IRemoteSource) : IAmSatRepositor
     private fun parseIsoUtcSec(iso: String): Long {
         return try {
             (isoUtcFormat.parse(iso)?.time ?: 0L) / 1000
-        } catch (e: Exception) {
+        } catch (_: Exception) {
             0L
         }
     }
 
-    /** Build one SatStatus (6 days x 12 slots) per catalog satellite, slotting reports by age. */
+    /** Build one SatStatus (3 days x 12 slots) per catalog satellite, slotting reports by age. */
     private fun buildStatuses(names: List<String>, reports: List<ApiReport>, nowSec: Long): List<SatStatus> {
         val byName = reports.groupBy { it.name }
         val monthAbbr = arrayOf("Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec")
         val utc = Calendar.getInstance(TimeZone.getTimeZone("UTC"))
-        val labels = (0 until 6).map { d ->
+        val labels = (0 until 3).map { d ->
             utc.timeInMillis = (nowSec - d * 86400L) * 1000
             "${monthAbbr[utc.get(Calendar.MONTH)]} ${utc.get(Calendar.DAY_OF_MONTH)}"
         }
         return names.map { name ->
-            val slots = (0 until 72).map { slotIdx ->
+            val slots = (0 until 36).map { slotIdx ->
                 val slotStart = nowSec - (slotIdx + 1) * 7200L
                 val slotEnd = nowSec - slotIdx * 7200L
                 val inSlot = byName[name].orEmpty().filter { it.reportedTimeUtcSec in slotStart until slotEnd }
@@ -112,7 +115,7 @@ class AmSatRepository(private val remoteSource: IRemoteSource) : IAmSatRepositor
                     )
                 }
             }
-            val days = (0 until 6).map { d ->
+            val days = (0 until 3).map { d ->
                 SatDay(dateLabel = labels[d], slots = slots.subList(d * 12, (d + 1) * 12))
             }
             SatStatus(name = name, days = days)

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

@@ -66,25 +66,26 @@ class DatabaseRepo(
     }
 
     override suspend fun updateFromRemote() = withContext(dispatcher) {
-        val dataSourcesSettings = settingsRepo.dataSourcesSettings.value
-        val tleUrls = buildMap {
-            putAll(Sources.satelliteDataUrls)
-            if (dataSourcesSettings.useCustomTLE) put(customSourceType, dataSourcesSettings.tleUrl)
-        }.filterValues { it.isNotBlank() }
-        val radioUrls = buildMap {
-            putAll(Sources.transceiversDataUrls)
-            if (dataSourcesSettings.useCustomTransceivers) put(customSourceType, dataSourcesSettings.transceiversUrl)
-        }.filterValues { it.isNotBlank() }
+        val settings = settingsRepo.dataSourcesSettings.value
+        val tleUrls = settings.satelliteUrls.filter { it.isNotBlank() }.map(::normalizeUrl).distinct()
+        val radioUrls = settings.transceiversUrls.filter { it.isNotBlank() }.map(::normalizeUrl).distinct()
+        val builtinTypesByUrl = Sources.satelliteDataUrls
+            .filterValues { it.isNotBlank() }
+            .mapValues { normalizeUrl(it.value) }
+            .entries
+            .associate { (type, url) -> url to type }
+        val importedTypeIds = mutableMapOf<String, MutableList<Int>>()
         // launch all network requests concurrently
-        val tleJobs = tleUrls.values.map { url -> async { url to remoteSource.getNetworkStream(url) } }
-        val radioJobs = radioUrls.values.map { url -> async { url to remoteSource.getNetworkStream(url) } }
-        // parse fetched data concurrently and associate with types
+        val tleJobs = tleUrls.map { url -> async { url to remoteSource.getNetworkStream(url) } }
+        val radioJobs = radioUrls.map { url -> async { url to remoteSource.getNetworkStream(url) } }
+        // parse fetched data concurrently and associate known built-in URLs with existing type filters.
         val importedEntries = tleJobs.awaitAll().flatMap { (url, stream) ->
-            val type = tleUrls.entries.find { it.value == url }?.key ?: customSourceType
-            stream?.let { parseSatelliteStream(url, unwrapIfZipped(url, it)) }.orEmpty().also { entries ->
-                settingsRepo.setSatelliteTypeIds(type, entries.map { it.catnum })
-            }
+            val entries = stream?.let { parseSatelliteStream(url, unwrapIfZipped(url, it)) }.orEmpty()
+            val type = builtinTypesByUrl[url] ?: customSourceType
+            importedTypeIds.getOrPut(type) { mutableListOf() }.addAll(entries.map { it.catnum })
+            entries
         }
+        importedTypeIds.forEach { (type, ids) -> settingsRepo.setSatelliteTypeIds(type, ids.distinct()) }
         val importedRadios = radioJobs.awaitAll().flatMap { (url, stream) ->
             stream?.let { dataParser.parseJSONStream(unwrapIfZipped(url, it)) }.orEmpty()
         }
@@ -100,6 +101,9 @@ class DatabaseRepo(
         setUpdateSuccessful(0L)
     }
 
+    private fun normalizeUrl(url: String): String =
+        if (url.startsWith("http", ignoreCase = true)) url else "https://$url"
+
     private suspend fun parseSatelliteStream(url: String, stream: InputStream): List<OrbitalData> {
         val bufferedStream = stream.buffered()
         return when {

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

@@ -37,6 +37,8 @@ import com.rtbishop.look4sat.core.domain.utility.round
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.update
+import com.rtbishop.look4sat.core.domain.model.Constants
+import com.rtbishop.look4sat.core.domain.source.Sources
 
 class SettingsRepo(
     private val locationManager: LocationManager,
@@ -67,6 +69,7 @@ class SettingsRepo(
     private val keyFrequencyAddress = "frequencyAddress"
     private val keyFrequencyPort = "frequencyPort"
     private val keyFrequencyFormat = "frequencyFormat"
+    private val keyFrequencyOffsetHz = "frequencyOffsetHz"
     private val keySelectedIds = "selectedIds"
     private val keySelectedTypes = "selectedTypes"
     private val keySelectedModes = "selectedModes"
@@ -91,7 +94,10 @@ class SettingsRepo(
     private val keyUseCustomTransceivers = "useCustomTransceivers"
     private val keyTleUrl = "tleUrl"
     private val keyTransceiversUrl = "transceiversUrl"
+    private val keySatelliteUrls = "satelliteUrls"
+    private val keyTransceiversUrls = "transceiversUrls"
     private val separatorComma = ","
+    private val separatorUrl = "\n"
 
     //region # Satellites selection settings
     private val _satelliteSelection = MutableStateFlow(getSelectedIds())
@@ -298,6 +304,10 @@ class SettingsRepo(
     override val rcSettings: StateFlow<RCSettings> = _rcSettings
 
     override fun updateRCSettings(settings: RCSettings) {
+        val clampedFreqOffsetHz = settings.frequencyOffsetHz.coerceIn(
+            Constants.FREQ_OFFSET_MIN_HZ,
+            Constants.FREQ_OFFSET_MAX_HZ
+        )
         preferences.edit {
             putBoolean(keyRotatorState, settings.rotatorState)
             putString(keyRotatorAddress, settings.rotatorAddress)
@@ -307,6 +317,7 @@ class SettingsRepo(
             putString(keyFrequencyAddress, settings.frequencyAddress)
             putString(keyFrequencyPort, settings.frequencyPort)
             putString(keyFrequencyFormat, settings.frequencyFormat)
+            putLong(keyFrequencyOffsetHz, clampedFreqOffsetHz)
             putBoolean(keyBluetoothRotatorState, settings.bluetoothRotatorState)
             putString(keyBluetoothRotatorFormat, settings.bluetoothRotatorFormat)
             putString(keyBluetoothRotatorName, settings.bluetoothRotatorName)
@@ -315,7 +326,7 @@ class SettingsRepo(
             putString(keyBluetoothFrequencyFormat, settings.bluetoothFrequencyFormat)
             putString(keyBluetoothFrequencyAddress, settings.bluetoothFrequencyAddress)
         }
-        _rcSettings.value = settings
+        _rcSettings.value = settings.copy(frequencyOffsetHz = clampedFreqOffsetHz)
     }
 
     private fun getRCSettings(): RCSettings = RCSettings(
@@ -327,6 +338,8 @@ class SettingsRepo(
         frequencyAddress = preferences.getString(keyFrequencyAddress, null) ?: "127.0.0.1",
         frequencyPort = preferences.getString(keyFrequencyPort, null) ?: "4532",
         frequencyFormat = preferences.getString(keyFrequencyFormat, null) ?: $$"F $FREQ",
+        frequencyOffsetHz = preferences.getLong(keyFrequencyOffsetHz, 0L)
+            .coerceIn(Constants.FREQ_OFFSET_MIN_HZ, Constants.FREQ_OFFSET_MAX_HZ),
         bluetoothRotatorState = preferences.getBoolean(keyBluetoothRotatorState, false),
         bluetoothRotatorFormat = preferences.getString(keyBluetoothRotatorFormat, null) ?: $$"P $AZ $EL",
         bluetoothRotatorName = preferences.getString(keyBluetoothRotatorName, null) ?: "Default",
@@ -382,20 +395,45 @@ class SettingsRepo(
 
     override fun updateDataSourcesSettings(settings: DataSourcesSettings) {
         preferences.edit {
-            putBoolean(keyUseCustomTle, settings.useCustomTLE)
-            putBoolean(keyUseCustomTransceivers, settings.useCustomTransceivers)
-            putString(keyTleUrl, settings.tleUrl)
-            putString(keyTransceiversUrl, settings.transceiversUrl)
+            putString(keySatelliteUrls, settings.satelliteUrls.joinToString(separatorUrl))
+            putString(keyTransceiversUrls, settings.transceiversUrls.joinToString(separatorUrl))
         }
         _dataSourcesSettings.value = settings
     }
 
     private fun getDataSourcesSettings(): DataSourcesSettings = DataSourcesSettings(
-        useCustomTLE = preferences.getBoolean(keyUseCustomTle, false),
-        useCustomTransceivers = preferences.getBoolean(keyUseCustomTransceivers, false),
-        tleUrl = preferences.getString(keyTleUrl, "https://example.com/tle.txt") ?: "",
-        transceiversUrl = preferences.getString(keyTransceiversUrl, "https://example.com/radio.json") ?: ""
+        satelliteUrls = getDataSourceUrls(
+            key = keySatelliteUrls,
+            defaultUrls = Sources.satelliteDataUrls.values.filter { it.isNotBlank() },
+            legacyEnabledKey = keyUseCustomTle,
+            legacyUrlKey = keyTleUrl
+        ),
+        transceiversUrls = getDataSourceUrls(
+            key = keyTransceiversUrls,
+            defaultUrls = Sources.transceiversDataUrls.values.filter { it.isNotBlank() },
+            legacyEnabledKey = keyUseCustomTransceivers,
+            legacyUrlKey = keyTransceiversUrl
+        )
     )
+
+    private fun getDataSourceUrls(
+        key: String,
+        defaultUrls: List<String>,
+        legacyEnabledKey: String,
+        legacyUrlKey: String
+    ): List<String> {
+        val stored = preferences.getString(key, null)
+            ?.split(separatorUrl)
+            ?.map { it.trim() }
+            ?.filter { it.isNotBlank() }
+        if (stored != null) return stored
+        val legacyCustomUrl = preferences.getString(legacyUrlKey, null)?.trim().orEmpty()
+        return if (preferences.getBoolean(legacyEnabledKey, false) && legacyCustomUrl.isNotBlank()) {
+            (defaultUrls + legacyCustomUrl).distinct()
+        } else {
+            defaultUrls
+        }
+    }
     //endregion
 
     //region # Radio control settings

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

@@ -24,7 +24,6 @@ import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.withContext
 import okhttp3.OkHttpClient
 import okhttp3.Request
-import java.io.ByteArrayInputStream
 import java.io.InputStream
 
 class RemoteSource(
@@ -46,10 +45,14 @@ class RemoteSource(
     override suspend fun getNetworkStream(url: String): InputStream? = withContext(dispatcher) {
         try {
             val networkRequest = Request.Builder().url(url).build()
-            httpClient.newCall(networkRequest).execute().use { response ->
-                if (!response.isSuccessful) return@withContext null
-                ByteArrayInputStream(response.body.bytes())
+            val response = httpClient.newCall(networkRequest).execute()
+            if (!response.isSuccessful) {
+                response.close()
+                return@withContext null
             }
+            // Return the body stream directly as the caller is responsible for closing it.
+            // Closing the stream returns the connection to OkHttp's pool.
+            response.body.byteStream().buffered()
         } catch (exception: Exception) {
             println("RemoteSource network stream exception: $exception")
             null

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

@@ -91,10 +91,8 @@ class DatabaseRepoTest {
         }
         val settingsRepo = FakeSettingsRepo(
             dataSources = DataSourcesSettings(
-                useCustomTLE = true,
-                useCustomTransceivers = false,
-                tleUrl = customCsvUrl,
-                transceiversUrl = ""
+                satelliteUrls = listOf(customCsvUrl),
+                transceiversUrls = emptyList()
             )
         )
         val repository = DatabaseRepo(dispatcher, dataParser, localSource, remoteSource, settingsRepo)
@@ -124,6 +122,10 @@ private class FakeRemoteSource : IRemoteSource {
     override suspend fun getFileStream(uri: String): InputStream? = fileStreams[uri]?.invoke()
 
     override suspend fun getNetworkStream(url: String): InputStream? = networkStreams[url]?.invoke()
+
+    override suspend fun getAmSatCatalog(): String? = null
+
+    override suspend fun getAmSatReports(hours: Int, limit: Int): String? = null
 }
 
 private class FakeLocalSource : ILocalSource {
@@ -176,7 +178,7 @@ private class FakeSettingsRepo(dataSources: DataSourcesSettings = defaultDataSou
     override val databaseState: MutableStateFlow<DatabaseState> = MutableStateFlow(DatabaseState(0, 0, 0L))
 
     override val rcSettings: StateFlow<RCSettings> = MutableStateFlow(
-        RCSettings(false, "", "", "", false, "", "", "", false, "", "", "", false, "", "")
+        RCSettings(false, "", "", "", false, "", "", "", 0L, false, "", "", "", false, "", "")
     )
 
     override val otherSettings: StateFlow<OtherSettings> = MutableStateFlow(
@@ -226,9 +228,7 @@ private class FakeSettingsRepo(dataSources: DataSourcesSettings = defaultDataSou
 
 private fun defaultDataSourcesSettings(): DataSourcesSettings {
     return DataSourcesSettings(
-        useCustomTLE = false,
-        useCustomTransceivers = false,
-        tleUrl = "",
-        transceiversUrl = ""
+        satelliteUrls = emptyList(),
+        transceiversUrls = emptyList()
     )
 }

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

@@ -0,0 +1,23 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.domain.model
+
+object Constants {
+    const val FREQ_OFFSET_MIN_HZ = -50_000L
+    const val FREQ_OFFSET_MAX_HZ = 50_000L
+}

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

@@ -23,10 +23,10 @@ data class SatDay(
     val slots: List<SatSlot> // 12 槽(00-02 ... 22-24)
 )
 
-/** One satellite, 6 days of state */
+/** One satellite, 3 days of state */
 data class SatStatus(
     val name: String,        // "AO-123_[FM]"
-    val days: List<SatDay>   // 6 天(新→旧)
+    val days: List<SatDay>   // 3 days (newest first)
 )
 
 /** Overall page parse result */

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

@@ -42,6 +42,7 @@ data class RCSettings(
     val frequencyAddress: String,
     val frequencyPort: String,
     val frequencyFormat: String,
+    val frequencyOffsetHz: Long = 0L,
     val bluetoothRotatorState: Boolean,
     val bluetoothRotatorFormat: String,
     val bluetoothRotatorName: String,
@@ -66,10 +67,8 @@ data class OtherSettings(
 )
 
 data class DataSourcesSettings(
-    val useCustomTLE: Boolean,
-    val useCustomTransceivers: Boolean,
-    val tleUrl: String,
-    val transceiversUrl: String
+    val satelliteUrls: List<String>,
+    val transceiversUrls: List<String>
 )
 
 data class RadioControlSettings(

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

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

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

@@ -46,9 +46,11 @@ object Sources {
         "Classified" to "https://www.mmccants.org/tles/classfd.zip",
         "McCants" to "https://www.mmccants.org/tles/inttles.zip",
         "R4UAB" to "https://r4uab.ru/satonline.txt",
+        "ARISS" to "https://live.ariss.org/iss.txt",
         "Other" to "" // key for sats filter
     )
     val transceiversDataUrls = mapOf(
-        "SatNOGS" to "https://db.satnogs.org/api/transmitters/?format=json&status=active"
+        "SatNOGS" to "https://db.satnogs.org/api/transmitters/?format=json&status=active",
+        "R4UAB" to "https://r4uab.ru/transmitters.json"
     )
 }

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

@@ -280,6 +280,35 @@ fun getDefaultPass(): OrbitalPass = OrbitalPass(
     altitude = 0, maxElevation = 0.0, orbitalObject = NearEarthObject(defaultOrbitalData), progress = 0f
 )
 
+@Composable
+fun InfoDialog(
+    title: String,
+    onDismiss: () -> Unit,
+    onAccept: () -> Unit,
+    content: @Composable () -> Unit
+) {
+    DialogShell(onDismissRequest = onDismiss) { padding ->
+        Row(
+            verticalAlignment = Alignment.CenterVertically,
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(start = padding, top = padding, end = padding)
+        ) {
+            Text(
+                text = title,
+                fontSize = 16.sp,
+                fontWeight = FontWeight.Medium,
+                color = MaterialTheme.colorScheme.primary,
+                maxLines = 1,
+                overflow = TextOverflow.Ellipsis,
+                modifier = Modifier.weight(1f)
+            )
+            CardButton(onClick = onAccept, text = stringResource(R.string.btn_accept))
+        }
+        content()
+    }
+}
+
 @Composable
 fun SharedDialog(
     title: String, onCancel: () -> Unit, onAccept: () -> Unit, content: @Composable () -> Unit

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

@@ -29,9 +29,6 @@ sealed class Screen(val iconResId: Int, val titleResId: Int) : NavKey {
     @Serializable
     data object Passes : Screen(R.drawable.ic_passes, R.string.nav_pass)
 
-    @Serializable
-    data object Radar : Screen(R.drawable.ic_radar, R.string.nav_radar)
-
     @Serializable
     data object Map : Screen(R.drawable.ic_map, R.string.nav_map)
 

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

@@ -0,0 +1,3 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android" android:width="24dp" android:height="24dp" android:viewportWidth="24" android:viewportHeight="24">
+    <path android:fillColor="@android:color/white" android:pathData="M19,13H13V19H11V13H5V11H11V5H13V11H19V13Z" />
+</vector>

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

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

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

@@ -112,6 +112,13 @@
     <string name="prefs_data_update_success">Actualización completada con éxito</string>
 
     <string name="prefs_data_sources_title">Custom data sources</string>
+    <string name="prefs_data_import_satellites_error">No satellites imported. Select a valid TLE/3LE (.txt) or OMM (.csv) file.</string>
+    <string name="prefs_data_import_transceivers_error">No transceivers imported. Select a valid SatNOGS (.json) file.</string>
+    <string name="prefs_data_sources_url_title" translatable="false">URL</string>
+    <string name="prefs_data_sources_satellites_label" translatable="false">Satellites data</string>
+    <string name="prefs_data_sources_transceivers_label" translatable="false">Transceivers data</string>
+    <string name="prefs_net_frequency_offset_hint" translatable="false">Frequency offset (Hz)</string>
+    <string name="prefs_net_frequency_offset_help" translatable="false">Range: -50000 to 50000 Hz. Positive values increase reported frequency; negative values decrease it.</string>
     <string name="prefs_data_sources_tle_switch">Custom TLE URL</string>
     <string name="prefs_data_sources_transceivers_switch">Custom transceivers URL</string>
 

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

@@ -111,6 +111,13 @@
     <string name="prefs_data_update_success">Обновление прошло успешно</string>
 
     <string name="prefs_data_sources_title">Свои источники данных</string>
+    <string name="prefs_data_import_satellites_error">No satellites imported. Select a valid TLE/3LE (.txt) or OMM (.csv) file.</string>
+    <string name="prefs_data_import_transceivers_error">No transceivers imported. Select a valid SatNOGS (.json) file.</string>
+    <string name="prefs_data_sources_url_title" translatable="false">URL</string>
+    <string name="prefs_data_sources_satellites_label" translatable="false">Satellites data</string>
+    <string name="prefs_data_sources_transceivers_label" translatable="false">Transceivers data</string>
+    <string name="prefs_net_frequency_offset_hint" translatable="false">Frequency offset (Hz)</string>
+    <string name="prefs_net_frequency_offset_help" translatable="false">Range: -50000 to 50000 Hz. Positive values increase reported frequency; negative values decrease it.</string>
     <string name="prefs_data_sources_tle_switch">Custom TLE URL</string>
     <string name="prefs_data_sources_transceivers_switch">Custom Transceivers URL</string>
 

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

@@ -112,6 +112,13 @@
     <string name="prefs_data_update_success">යාවත්කාලීනය සම්පූර්ණ කිරීම සාර්ථකයි</string>
 
     <string name="prefs_data_sources_title">Custom data sources</string>
+    <string name="prefs_data_import_satellites_error">No satellites imported. Select a valid TLE/3LE (.txt) or OMM (.csv) file.</string>
+    <string name="prefs_data_import_transceivers_error">No transceivers imported. Select a valid SatNOGS (.json) file.</string>
+    <string name="prefs_data_sources_url_title" translatable="false">URL</string>
+    <string name="prefs_data_sources_satellites_label" translatable="false">Satellites data</string>
+    <string name="prefs_data_sources_transceivers_label" translatable="false">Transceivers data</string>
+    <string name="prefs_net_frequency_offset_hint" translatable="false">Frequency offset (Hz)</string>
+    <string name="prefs_net_frequency_offset_help" translatable="false">Range: -50000 to 50000 Hz. Positive values increase reported frequency; negative values decrease it.</string>
     <string name="prefs_data_sources_tle_switch">Custom TLE URL</string>
     <string name="prefs_data_sources_transceivers_switch">Custom transceivers URL</string>
 

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

@@ -143,6 +143,12 @@
     <string name="prefs_data_update_success">Güncelleme başarıyla tamamlandı</string>
 
     <string name="prefs_data_sources_title">Özel veri kaynakları</string>
+    <string name="prefs_data_import_satellites_error">No satellites imported. Select a valid TLE/3LE (.txt) or OMM (.csv) file.</string>
+    <string name="prefs_data_import_transceivers_error">No transceivers imported. Select a valid SatNOGS (.json) file.</string>
+    <string name="prefs_data_sources_satellites_label" translatable="false">Satellites data</string>
+    <string name="prefs_data_sources_transceivers_label" translatable="false">Transceivers data</string>
+    <string name="prefs_net_frequency_offset_hint" translatable="false">Frequency offset (Hz)</string>
+    <string name="prefs_net_frequency_offset_help" translatable="false">Range: -50000 to 50000 Hz. Positive values increase reported frequency; negative values decrease it.</string>
     <string name="prefs_data_sources_tle_switch">Özel TLE URL</string>
     <string name="prefs_data_sources_transceivers_switch">Özel transceiver URL</string>
     <string name="prefs_data_sources_url_title" translatable="false">URL (HTTPS)</string>

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

@@ -112,6 +112,13 @@
     <string name="prefs_data_update_success">Оновлення успішне</string>
 
     <string name="prefs_data_sources_title">Custom data sources</string>
+    <string name="prefs_data_import_satellites_error">No satellites imported. Select a valid TLE/3LE (.txt) or OMM (.csv) file.</string>
+    <string name="prefs_data_import_transceivers_error">No transceivers imported. Select a valid SatNOGS (.json) file.</string>
+    <string name="prefs_data_sources_url_title" translatable="false">URL</string>
+    <string name="prefs_data_sources_satellites_label" translatable="false">Satellites data</string>
+    <string name="prefs_data_sources_transceivers_label" translatable="false">Transceivers data</string>
+    <string name="prefs_net_frequency_offset_hint" translatable="false">Frequency offset (Hz)</string>
+    <string name="prefs_net_frequency_offset_help" translatable="false">Range: -50000 to 50000 Hz. Positive values increase reported frequency; negative values decrease it.</string>
     <string name="prefs_data_sources_tle_switch">Custom TLE URL</string>
     <string name="prefs_data_sources_transceivers_switch">Custom transceivers URL</string>
 

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

@@ -136,6 +136,9 @@
     <string name="prefs_data_sources_title">自定义数据源</string>
     <string name="prefs_data_sources_tle_switch">自定义TLE URL</string>
     <string name="prefs_data_sources_transceivers_switch">自定义收发器URL</string>
+    <string name="prefs_data_sources_url_title" translatable="false">URL</string>
+    <string name="prefs_data_sources_satellites_label">卫星数据</string>
+    <string name="prefs_data_sources_transceivers_label">收发器数据</string>
 
     <string name="prefs_data_output_title">数据输出</string>
     <string name="prefs_net_output">网络</string>
@@ -149,6 +152,8 @@
     <string name="prefs_net_frequency_switch">启用多普勒频率输出</string>
     <string name="prefs_net_frequency_address_hint">IP:端口</string>
     <string name="prefs_net_frequency_format_hint">数据格式</string>
+    <string name="prefs_net_frequency_offset_hint" translatable="false">频率偏移 (Hz)</string>
+    <string name="prefs_net_frequency_offset_help" translatable="false">范围：-50000 到 50000 Hz。正值提高上报频率，负值降低上报频率。</string>
 
     <string name="prefs_bt_title">蓝牙数据输出</string>
     <string name="prefs_bt_rotator_switch">启用方位俯仰角输出</string>

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

@@ -171,6 +171,8 @@
     <string name="prefs_data_sources_tle_switch">Custom TLE URL</string>
     <string name="prefs_data_sources_transceivers_switch">Custom transceivers URL</string>
     <string name="prefs_data_sources_url_title" translatable="false">URL (HTTPS)</string>
+    <string name="prefs_data_sources_satellites_label">Satellites data</string>
+    <string name="prefs_data_sources_transceivers_label">Transceivers data</string>
 
     <string name="prefs_data_output_title">Data output</string>
     <string name="prefs_net_output">Network</string>
@@ -194,6 +196,8 @@
     <string name="prefs_net_frequency_switch">Enable frequency output</string>
     <string name="prefs_net_frequency_address_hint">IP:Port</string>
     <string name="prefs_net_frequency_format_hint">Format</string>
+    <string name="prefs_net_frequency_offset_hint" translatable="false">Frequency offset (Hz)</string>
+    <string name="prefs_net_frequency_offset_help" translatable="false">Range: -50000 to 50000 Hz. Positive values increase reported frequency; negative values decrease it.</string>
 
     <string name="prefs_bt_title">Bluetooth data output</string>
     <string name="prefs_bt_rotator_switch">Enable rotation output</string>