feat: mutual pass FM/Linear transponder filters (AMSAT Live source)

Mutual match page gains FM/Linear transponder-type filters. The
authoritative source is AMSAT's human-maintained Live FM/Linear
Satellites pages, fetched during data sync and stored as catnum sets;
filters resolve to those sets (falling back to DB mode filter when
empty), and unchecking both shows a prompt instead of querying.

- DataParser.parseAmSatLivePage: table rows to satellite names,
  TEVEL2-1 thru TEVEL2-9 range expansion, bracket-alias matching
- SettingsRepo: AMSAT FM/Linear catnum sets persisted in prefs
- DatabaseRepo: fetch AMSAT pages in updateFromRemote, best-effort
  (failure keeps previous list, never blocks the update)
- getIdsWithModes: AND isAlive = 1
- MutualScreen: FilterChip row inside MatchSearchCard
- Tests: parser (4) + viewmodel (3) + repo fakes

core/data/src/main/java/com/rtbishop/look4sat/core/data/database/Look4SatDao.kt

@@ -45,7 +45,7 @@ interface Look4SatDao {
     @Query("DELETE FROM entries")
     suspend fun deleteEntries()
 
-    @Query("SELECT catnum FROM radios WHERE downlinkMode IN (:modes)")
+    @Query("SELECT catnum FROM radios WHERE downlinkMode IN (:modes) AND isAlive = 1")
     suspend fun getIdsWithModes(modes: List<String>): List<Int>
 
     @Query("SELECT COUNT(*) FROM radios")

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

@@ -115,12 +115,48 @@ class DatabaseRepo(
             localSource.insertRadios(importedRadios)
         }
         if (importedEntries.isNotEmpty()) localSource.insertEntries(importedEntries)
+        updateAmSatLiveLists()
         setUpdateSuccessful(System.currentTimeMillis())
     }
 
+    /**
+     * Refresh the AMSAT Live FM/Linear satellite lists (transponders currently
+     * on the air). Best effort: any failure keeps the previous lists and never
+     * blocks the rest of the data update, so the mutual-match filter simply
+     * falls back to the last successful snapshot.
+     */
+    private suspend fun updateAmSatLiveLists() = withContext(dispatcher) {
+        runCatching {
+            val entries = localSource.getEntriesList() // catnum -> name
+            val jobs = Sources.amSatLiveUrls.map { (type, url) ->
+                async { type to remoteSource.getNetworkStream(url) }
+            }
+            val results = jobs.awaitAll()
+            val fmNames = results.firstOrNull { it.first == "FM" }?.second?.stream
+                ?.let { dataParser.parseAmSatLivePage(it) }.orEmpty()
+            val linearNames = results.firstOrNull { it.first == "Linear" }?.second?.stream
+                ?.let { dataParser.parseAmSatLivePage(it) }.orEmpty()
+            val nameToCatnum = entries.associate { it.name.uppercase() to it.catnum }
+            fun resolve(names: List<String>): Set<Int> = names.mapNotNull { name ->
+                val keys = dataParser.normalizeAmSatName(name)
+                nameToCatnum.entries.firstOrNull { (localName, _) ->
+                    keys.any { key -> localName.contains(key) }
+                }?.value
+            }.toSet()
+            val fmCatnums = resolve(fmNames)
+            val linearCatnums = resolve(linearNames)
+            settingsRepo.setAmSatCatnums(fmCatnums, linearCatnums)
+            println("AMSAT live lists updated: FM=${fmCatnums.size}, Linear=${linearCatnums.size}")
+        }.onFailure {
+            // Keep the previous lists; the mutual filter stays on the last good snapshot.
+            println("AMSAT live lists update failed: $it")
+        }
+    }
+
     override suspend fun clearAllData() = withContext(dispatcher) {
         localSource.deleteEntries()
         localSource.deleteRadios()
+        settingsRepo.setAmSatCatnums(emptySet(), emptySet())
         setUpdateSuccessful(0L)
     }
 

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

@@ -65,6 +65,8 @@ class SatelliteRepo(
 
     override suspend fun getRadiosWithId(id: Int) = localStorage.getRadiosWithId(id)
 
+    override suspend fun getSatelliteIdsWithModes(modes: List<String>) = localStorage.getIdsWithModes(modes)
+
     override suspend fun initRepository() = withContext(dispatcher) {
         combine(
             settingsRepo.selectedIds,

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

@@ -107,6 +107,8 @@ class SettingsRepo(
     private val keySatelliteEnabled = "satelliteEnabled"
     private val keyTransceiversEnabled = "transceiversEnabled"
     private val keySatnogsTleSourceMigration = "satnogsTleSourceMigration"
+    private val keyAmSatFmCatnums = "amSatFmCatnums"
+    private val keyAmSatLinearCatnums = "amSatLinearCatnums"
     private val separatorComma = ","
     private val separatorUrl = "\n"
     private val legacyCelestrakSatnogsUrl =
@@ -745,6 +747,25 @@ class SettingsRepo(
     }
     //endregion
 
+    //region # AMSAT live-transponder lists
+    override fun getAmSatFmCatnums(): Set<Int> {
+        val raw = preferences.getString(keyAmSatFmCatnums, null) ?: return emptySet()
+        return raw.split(separatorComma).mapNotNull { it.toIntOrNull() }.toSet()
+    }
+
+    override fun getAmSatLinearCatnums(): Set<Int> {
+        val raw = preferences.getString(keyAmSatLinearCatnums, null) ?: return emptySet()
+        return raw.split(separatorComma).mapNotNull { it.toIntOrNull() }.toSet()
+    }
+
+    override fun setAmSatCatnums(fmCatnums: Set<Int>, linearCatnums: Set<Int>) {
+        preferences.edit {
+            putString(keyAmSatFmCatnums, fmCatnums.sorted().joinToString(separatorComma))
+            putString(keyAmSatLinearCatnums, linearCatnums.sorted().joinToString(separatorComma))
+        }
+    }
+    //endregion
+
     //region # Radio control settings
     private val keyRadioControlEnabled = "radioControlEnabled"
     private val keyRadioModel = "radioModel"

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

@@ -269,6 +269,10 @@ private class FakeSettingsRepo(dataSources: DataSourcesSettings = defaultDataSou
         (dataSourcesStatus as? MutableStateFlow)?.value = status
     }
 
+    override fun getAmSatFmCatnums(): Set<Int> = emptySet()
+    override fun getAmSatLinearCatnums(): Set<Int> = emptySet()
+    override fun setAmSatCatnums(fmCatnums: Set<Int>, linearCatnums: Set<Int>) = Unit
+
     override fun updateRadioControlSettings(settings: RadioControlSettings) = Unit
 
     override fun getSatelliteOffset(catnum: Int): String = ""

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

@@ -65,4 +65,9 @@ interface ISatelliteRepo {
 
     /** Fetch radio transceivers for a satellite by its catalog number. */
     suspend fun getRadiosWithId(id: Int): List<SatRadio>
+
+    /** Satellite catnums whose radios carry any of the given downlink modes.
+     *  Empty modes -> empty result; used to filter the mutual-match satellite
+     *  set to transponder satellites (FM voice / linear). */
+    suspend fun getSatelliteIdsWithModes(modes: List<String>): List<Int>
 }

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

@@ -79,6 +79,14 @@ interface ISettingsRepo {
     fun updateDataSourcesStatus(status: Map<String, Int>)
     //endregion
 
+    //region # AMSAT live-transponder lists
+    /** Catalog numbers of satellites listed on AMSAT's "Live FM Satellites" page. */
+    fun getAmSatFmCatnums(): Set<Int>
+    /** Catalog numbers of satellites listed on AMSAT's "Live Linear Satellites" page. */
+    fun getAmSatLinearCatnums(): Set<Int>
+    fun setAmSatCatnums(fmCatnums: Set<Int>, linearCatnums: Set<Int>)
+    //endregion
+
     //region # Radio control settings
     val radioControlSettings: StateFlow<RadioControlSettings>
     fun updateRadioControlSettings(settings: RadioControlSettings)

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

@@ -55,4 +55,11 @@ object Sources {
         "SatNOGS" to "https://db.satnogs.org/api/transmitters/?format=json&status=active",
         "R4UAB" to "https://r4uab.ru/transmitters.json"
     )
+    /** AMSAT "Live FM/Linear Satellites" pages: human-maintained lists of
+     *  transponders currently on the air. Parsed into the mutual-match filter
+     *  (satellites that actually carry a working FM-voice / linear repeater). */
+    val amSatLiveUrls = mapOf(
+        "FM" to "https://www.amsat.org/live-fm-satellites/",
+        "Linear" to "https://www.amsat.org/live-linear-satellites/"
+    )
 }

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

@@ -58,6 +58,82 @@ class DataParser(private val dispatcher: CoroutineDispatcher) {
         }.getOrDefault(emptyList())
     }
 
+    /**
+     * Parse an AMSAT "Live FM/Linear Satellites" page into satellite names.
+     * The page is an HTML table whose first column is the satellite name,
+     * sometimes written as an alias list ("AO-91(RadFxSat / Fox-1B)") or a
+     * range ("TEVEL2-1 thru TEVEL2-9"). Returns the distinct expanded names.
+     */
+    suspend fun parseAmSatLivePage(stream: InputStream): List<String> = withContext(dispatcher) {
+        runCatching {
+            val html = stream.bufferedReader().readText()
+            // Grab table rows, take the first cell of each row, keep rows that
+            // look like satellite names (start with letters/digits, not a header).
+            val rows = Regex("<tr[^>]*>(.*?)</tr>", RegexOption.IGNORE_CASE)
+                .findAll(html)
+                .mapNotNull { match ->
+                    val cells = Regex("<t[dh][^>]*>(.*?)</t[dh]>", RegexOption.IGNORE_CASE)
+                        .findAll(match.groupValues[1])
+                        .map { cell -> stripHtml(cell.groupValues[1]).trim() }
+                        .toList()
+                    cells.firstOrNull()?.takeIf { it.isNotBlank() && !it.equals("Satellite", ignoreCase = true) }
+                }
+                .toList()
+            rows.flatMap { expandNameRange(it) }.distinct()
+        }.getOrDefault(emptyList())
+    }
+
+    private fun stripHtml(raw: String): String =
+        raw.replace(Regex("<[^>]+>"), " ").replace(Regex("\\s+"), " ").trim()
+
+    /** Expand "NAME1 thru NAME9" ranges (e.g. TEVEL2-1 thru TEVEL2-9). */
+    private fun expandNameRange(name: String): List<String> {
+        val m = Regex("^(.*?)(\\d+)\\s+thru\\s+(.*?)(\\d+)$", RegexOption.IGNORE_CASE).find(name)
+        if (m == null) return listOf(name)
+        val prefix1 = m.groupValues[1].trim()
+        val startNum = m.groupValues[2].toIntOrNull() ?: return listOf(name)
+        val endNum = m.groupValues[4].toIntOrNull() ?: return listOf(name)
+        val prefix2 = m.groupValues[3].trim()
+        if (startNum > endNum) return listOf(name)
+        // Suffix after the end number, if any (e.g. "TEVEL2-1 thru TEVEL2-9 ").
+        val suffix = name.substringAfterLast(m.groupValues[4]).trim()
+        return (startNum..endNum).map { "$prefix1$it$suffix" }
+    }
+
+    /**
+     * Normalize a satellite name from the AMSAT live pages into lookup keys
+     * used to match against the local entries table:
+     *  - primary key: the leading designator ("AO-91" from "AO-91 (RadFxSat / Fox-1B)")
+     *  - alias keys: every bracketed alias, uppercased, digits preserved
+     * The local entry names are normalized the same way in [matchesAmSatName].
+     */
+    fun normalizeAmSatName(name: String): List<String> {
+        val keys = mutableListOf<String>()
+        // Primary: everything before the first '(' (or '['), then the first token.
+        val primary = name.substringBefore('(').substringBefore('[').trim()
+        primary.split(Regex("\\s+")).firstOrNull()?.takeIf { it.isNotBlank() }?.let {
+            keys += it.uppercase()
+        }
+        // Aliases inside parentheses / brackets: "RadFxSat / Fox-1B" -> two keys.
+        Regex("\\(([^)]*)\\)").findAll(name).forEach { m ->
+            m.groupValues[1].split('/', '|').forEach { alias ->
+                alias.trim().takeIf { it.isNotBlank() }?.let { keys += it.uppercase() }
+            }
+        }
+        Regex("\\[([^]]*)]").findAll(name).forEach { m ->
+            m.groupValues[1].split('/', '|').forEach { alias ->
+                alias.trim().takeIf { it.isNotBlank() }?.let { keys += it.uppercase() }
+            }
+        }
+        return keys.distinct()
+    }
+
+    /** True if a local entry name matches any of the AMSAT normalized keys. */
+    fun matchesAmSatName(localName: String, amSatKeys: List<String>): Boolean {
+        val localUpper = localName.uppercase()
+        return amSatKeys.any { key -> localUpper.contains(key) }
+    }
+
     private fun parseCSV(values: List<String>): OrbitalData? = runCatching {
         val name = values[0]
         val timestamp = values[2]

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

@@ -239,4 +239,51 @@ class DataParserTest {
         // Matches the CSV test data epoch: 2021-11-16 → day 320
         assert(dataParser.getDayOfYear(2021, 11, 16) == 320)
     }
+
+    @Test
+    fun `AMSAT FM page parses satellite names and expands thru ranges`() = runTest(testDispatcher) {
+        val html = """
+            <html><body><table>
+            <tr><th>Satellite</th><th>Uplink</th><th>Downlink</th><th>Comment</th></tr>
+            <tr><td>AO-91(RadFxSat / Fox-1B)</td><td>435.250</td><td>145.960</td></tr>
+            <tr><td>SO-50(SaudiSat-1C)</td><td>145.850</td><td>436.795</td></tr>
+            <tr><td>TEVEL2-1 thru TEVEL2-9</td><td>145.970</td><td>436.400</td></tr>
+            </table></body></html>
+        """.trimIndent().byteInputStream()
+        val names = dataParser.parseAmSatLivePage(html)
+        assert(names.contains("AO-91(RadFxSat / Fox-1B)"))
+        assert(names.contains("SO-50(SaudiSat-1C)"))
+        assert(names.contains("TEVEL2-1"))
+        assert(names.contains("TEVEL2-9"))
+        assert(names.size == 11) // 2 singles + 9 expanded TEVEL2
+    }
+
+    @Test
+    fun `AMSAT linear page keeps mode-suffixed names`() = runTest(testDispatcher) {
+        val html = """
+            <table>
+            <tr><th>Satellite</th><th>Frequencies</th><th>Comment</th></tr>
+            <tr><td>AO-7 Mode B U/v Inverting Analog</td><td>Uplink LSB</td></tr>
+            <tr><td>FO-29 (JAS-2)V/u Inverting Analog</td><td>Uplink LSB</td></tr>
+            </table>
+        """.trimIndent().byteInputStream()
+        val names = dataParser.parseAmSatLivePage(html)
+        assert(names.contains("AO-7 Mode B U/v Inverting Analog"))
+        assert(names.contains("FO-29 (JAS-2)V/u Inverting Analog"))
+    }
+
+    @Test
+    fun `AMSAT name normalization produces primary and alias keys`() {
+        assert(dataParser.normalizeAmSatName("AO-91(RadFxSat / Fox-1B)") == listOf("AO-91", "RADFXSAT", "FOX-1B"))
+        assert(dataParser.normalizeAmSatName("QO-100 (Es'hail-2/P4A) S/x") == listOf("QO-100", "ES'HAIL-2", "P4A"))
+        assert(dataParser.normalizeAmSatName("ISS") == listOf("ISS"))
+        assert(dataParser.matchesAmSatName("AO-91 (RADFXSAT)", listOf("AO-91", "RADFXSAT")))
+        assert(!dataParser.matchesAmSatName("SO-50", listOf("AO-91")))
+    }
+
+    @Test
+    fun `AMSAT live page with no table returns empty`() = runTest(testDispatcher) {
+        val html = "<html><body>No data</body></html>".byteInputStream()
+        assert(dataParser.parseAmSatLivePage(html).isEmpty())
+    }
 }

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

@@ -283,6 +283,9 @@ class LoTWGridSyncTest {
         override fun updateOtherSettings(transform: (OtherSettings) -> OtherSettings) = TODO()
         override fun updateDataSourcesSettings(settings: DataSourcesSettings) = TODO()
         override fun updateDataSourcesStatus(status: Map<String, Int>) = TODO()
+        override fun getAmSatFmCatnums(): Set<Int> = emptySet()
+        override fun getAmSatLinearCatnums(): Set<Int> = emptySet()
+        override fun setAmSatCatnums(fmCatnums: Set<Int>, linearCatnums: Set<Int>) = Unit
         override fun updateRadioControlSettings(settings: RadioControlSettings) = TODO()
         override fun getSatelliteOffset(catnum: Int): String = ""
         override fun setSatelliteOffset(catnum: Int, offset: String) = TODO()

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

@@ -308,6 +308,9 @@
     <string name="mutual_grid_hint">支持 4/6/8 位 Maidenhead 网格；也可直接输入经纬度</string>
     <string name="mutual_min_elevation">最小仰角：%d°</string>
     <string name="mutual_time_range">时间范围</string>
+    <string name="mutual_filter_transponder">转发器</string>
+    <string name="mutual_filter_fm">FM</string>
+    <string name="mutual_filter_linear">线性</string>
     <string name="mutual_calculating">计算中…</string>
     <string name="mutual_query">查询匹配</string>
     <string name="mutual_elevation_you">你：%d°</string>

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

@@ -338,6 +338,9 @@
     <string name="mutual_grid_hint">Supports 4/6/8-char Maidenhead grid; or enter lat/lon directly</string>
     <string name="mutual_min_elevation">Min elevation: %d°</string>
     <string name="mutual_time_range">Time range</string>
+    <string name="mutual_filter_transponder">Transponders</string>
+    <string name="mutual_filter_fm">FM</string>
+    <string name="mutual_filter_linear">Linear</string>
     <string name="mutual_calculating">Calculating…</string>
     <string name="mutual_query">Query Match</string>
     <string name="mutual_elevation_you">You: %d°</string>

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

@@ -174,6 +174,8 @@ fun MutualScreen(
             onStationBMinElev = viewModel::onStationBMinElev,
             onUseCurrentPosition = viewModel::onUseCurrentPosition,
             onHoursAhead = viewModel::onHoursAhead,
+            onFilterFM = viewModel::onFilterFM,
+            onFilterLinear = viewModel::onFilterLinear,
             onClearError = viewModel::clearError
         )
     }
@@ -197,6 +199,8 @@ private fun MutualContent(
     onStationBMinElev: (Double) -> Unit,
     onUseCurrentPosition: () -> Unit,
     onHoursAhead: (Int) -> Unit,
+    onFilterFM: (Boolean) -> Unit,
+    onFilterLinear: (Boolean) -> Unit,
     onClearError: () -> Unit
 ) {
     val timeFormat = remember(state.isUtc) {
@@ -353,6 +357,10 @@ private fun MutualContent(
             MatchSearchCard(
                 hoursAhead = state.hoursAhead,
                 isCalculating = state.isCalculating,
+                filterFM = state.filterFM,
+                filterLinear = state.filterLinear,
+                onFilterFM = onFilterFM,
+                onFilterLinear = onFilterLinear,
                 onHoursAhead = onHoursAhead,
                 onQuery = onQuery
             )
@@ -570,6 +578,10 @@ private fun StationInputCard(
 private fun MatchSearchCard(
     hoursAhead: Int,
     isCalculating: Boolean,
+    filterFM: Boolean,
+    filterLinear: Boolean,
+    onFilterFM: (Boolean) -> Unit,
+    onFilterLinear: (Boolean) -> Unit,
     onHoursAhead: (Int) -> Unit,
     onQuery: () -> Unit,
     modifier: Modifier = Modifier
@@ -596,6 +608,28 @@ private fun MatchSearchCard(
                     )
                 }
             }
+            // 转发器类型筛选: 只匹配 AMSAT Live 清单里的 FM 话音 / 线性转发器卫星,
+            // 防止选入大量无转发器卫星占用匹配页.
+            Row(
+                modifier = Modifier.fillMaxWidth(),
+                horizontalArrangement = Arrangement.spacedBy(8.dp),
+                verticalAlignment = Alignment.CenterVertically
+            ) {
+                Text(
+                    text = stringResource(R.string.mutual_filter_transponder),
+                    style = MaterialTheme.typography.labelLarge
+                )
+                FilterChip(
+                    selected = filterFM,
+                    onClick = { onFilterFM(!filterFM) },
+                    label = { Text(stringResource(R.string.mutual_filter_fm)) }
+                )
+                FilterChip(
+                    selected = filterLinear,
+                    onClick = { onFilterLinear(!filterLinear) },
+                    label = { Text(stringResource(R.string.mutual_filter_linear)) }
+                )
+            }
             Button(
                 onClick = onQuery,
                 enabled = !isCalculating,

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

@@ -55,6 +55,10 @@ data class MutualUiState(
     /** 历史过境回看窗口(小时), 跟随主页面 Passes 设置; 匹配查询从
      *  now-hoursBefore 开始, 使设置过历史回看时匹配页也包含历史过境. */
     val hoursBefore: Int = 0,
+    /** 转发器类型筛选: 只匹配搭载 FM 话音转发器的卫星. 默认开启. */
+    val filterFM: Boolean = true,
+    /** 转发器类型筛选: 只匹配搭载线性(USB/LSB/CW/SSB)转发器的卫星. 默认开启. */
+    val filterLinear: Boolean = true,
     val mutualPasses: List<MutualPass> = emptyList(),
     val isCalculating: Boolean = false,
     val hasSearched: Boolean = false,
@@ -201,6 +205,8 @@ class MutualViewModel(
         ) }
     }
     fun onHoursAhead(value: Int) = _uiState.update { it.copy(hoursAhead = value) }
+    fun onFilterFM(value: Boolean) = _uiState.update { it.copy(filterFM = value) }
+    fun onFilterLinear(value: Boolean) = _uiState.update { it.copy(filterLinear = value) }
     fun onSelectPass(index: Int) = _uiState.update { it.copy(selectedPassIndex = index) }
 
     /**
@@ -264,6 +270,17 @@ class MutualViewModel(
             return
         }
 
+        // 转发器类型筛选: 至少勾选一种(默认 FM + Linear 都开), 否则提示不查询.
+        // 防止用户选入大量无转发器卫星占用匹配页.
+        if (!state.filterFM && !state.filterLinear) {
+            _uiState.update { it.copy(errorMessage = "Select at least one transponder type (FM / Linear) to run the match.") }
+            return
+        }
+        // AMSAT Live 清单(同步自 AMSAT "Live FM/Linear Satellites" 页面)是本过滤的
+        // 权威来源: 只匹配当前在轨且话音/线性转发器实际工作的卫星. 清单为空
+        // (从未成功同步过)时回退到数据库 downlinkMode 过滤, 避免首启匹配页空结果.
+        // 过滤本身在下面的协程里执行 (getSatelliteIdsWithModes 是 suspend).
+
         _uiState.update {
             it.copy(
                 isCalculating = true,
@@ -286,6 +303,24 @@ class MutualViewModel(
 
         viewModelScope.launch {
             val now = System.currentTimeMillis()
+            // 转发器类型过滤(协程上下文): AMSAT Live 清单优先, 为空时回退数据库.
+            val amSatFm = settingsRepo.getAmSatFmCatnums()
+            val amSatLinear = settingsRepo.getAmSatLinearCatnums()
+            val filteredSatellites = if (amSatFm.isEmpty() && amSatLinear.isEmpty()) {
+                val filterModes = buildList {
+                    if (state.filterFM) add("FM")
+                    if (state.filterLinear) addAll(listOf("USB", "LSB", "CW", "SSB"))
+                }
+                val idsWithModes = satelliteRepo.getSatelliteIdsWithModes(filterModes)
+                if (idsWithModes.isEmpty()) satellites
+                else satellites.filter { it.data.catnum in idsWithModes }
+            } else {
+                val allowed = buildSet {
+                    if (state.filterFM) addAll(amSatFm)
+                    if (state.filterLinear) addAll(amSatLinear)
+                }
+                satellites.filter { it.data.catnum in allowed }
+            }
             // 历史回看: 查询窗口起点 = now - hoursBefore (跟随主页面 Passes 设置),
             // 终点 = now + hoursAhead 不变.
             val time = now - state.hoursBefore * 60L * 60L * 1000L
@@ -295,7 +330,7 @@ class MutualViewModel(
 
             val results = try {
                 withContext(computeDispatcher) {
-                    findMutualPasses(satellites, posA, posB, minElevA, minElevB, time, hours, state.hoursBefore)
+                    findMutualPasses(filteredSatellites, posA, posB, minElevA, minElevB, time, hours, state.hoursBefore)
                 }
             } catch (t: Throwable) {
                 // Never leave the query stuck in "calculating" (which would also
@@ -350,7 +385,10 @@ class MutualViewModel(
         // Use the main page's pass list for AOS/LOS times, then sample the curves
         // using the actual positions. The passes list is already computed by getLeoPass
         // and its AOS/LOS times match the Passes page exactly.
-        val existingPasses = satelliteRepo.passes.value
+        // The satellites argument may be a subset (transponder-type filter), so
+        // only passes belonging to the filtered satellites are reused.
+        val allowedCatnums = satellites.map { it.data.catnum }.toSet()
+        val existingPasses = satelliteRepo.passes.value.filter { it.catNum in allowedCatnums }
         val results = findMutualPassesFromList(existingPasses, satellites, posA, posB,
             minElevADeg, minElevBDeg, time, endTime, sampleInterval)
         if (results.isNotEmpty()) return results

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

@@ -44,13 +44,18 @@ class FakeSatelliteRepo(
     override suspend fun getTrack(sat: OrbitalObject, pos: GeoPos, start: Long, end: Long): List<OrbitalPos> = TODO()
     override suspend fun getRadios(sat: OrbitalObject, pos: GeoPos, radios: List<SatRadio>, time: Long): List<SatRadio> = TODO()
     override suspend fun getRadiosWithId(id: Int): List<SatRadio> = TODO()
+    override suspend fun getSatelliteIdsWithModes(modes: List<String>): List<Int> = emptyList()
 }
 
 /**
  * Test fake for ISettingsRepo. Only [stationPosition] is backed by mutable
  * state; everything else the ViewModel never touches fails loudly.
  */
-class FakeSettingsRepo(initialPosition: GeoPos = GeoPos(23.13, 113.26)) : ISettingsRepo {
+class FakeSettingsRepo(
+    initialPosition: GeoPos = GeoPos(23.13, 113.26),
+    val amSatFm: Set<Int> = emptySet(),
+    val amSatLinear: Set<Int> = emptySet()
+) : ISettingsRepo {
 
     override val stationPosition = MutableStateFlow(initialPosition)
 
@@ -103,6 +108,10 @@ class FakeSettingsRepo(initialPosition: GeoPos = GeoPos(23.13, 113.26)) : ISetti
 
     override fun updateDataSourcesStatus(status: Map<String, Int>) = TODO()
 
+    override fun getAmSatFmCatnums(): Set<Int> = amSatFm
+    override fun getAmSatLinearCatnums(): Set<Int> = amSatLinear
+    override fun setAmSatCatnums(fmCatnums: Set<Int>, linearCatnums: Set<Int>) = TODO()
+
     override fun updateRadioControlSettings(settings: RadioControlSettings) = TODO()
     override fun getSatelliteOffset(catnum: Int): String = ""
     override fun setSatelliteOffset(catnum: Int, offset: String) = TODO()

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

@@ -31,10 +31,12 @@ class MutualViewModelTest {
     private fun TestScope.createVm(
         satellites: List<OrbitalObject> = emptyList(),
         passes: List<OrbitalPass> = emptyList(),
-        position: GeoPos = TestOrbits.GUANGZHOU
+        position: GeoPos = TestOrbits.GUANGZHOU,
+        amSatFm: Set<Int> = emptySet(),
+        amSatLinear: Set<Int> = emptySet()
     ): MutualViewModel = MutualViewModel(
         satelliteRepo = FakeSatelliteRepo(satellites, passes),
-        settingsRepo = FakeSettingsRepo(position),
+        settingsRepo = FakeSettingsRepo(position, amSatFm, amSatLinear),
         computeDispatcher = StandardTestDispatcher(mainDispatcherRule.dispatcher.scheduler)
     )
 
@@ -320,4 +322,67 @@ class MutualViewModelTest {
         assertEquals(4, vm.listScrollIndex)
         assertEquals(137, vm.listScrollOffset)
     }
+
+    // --------------------------------------------- transponder filters (AMSAT)
+
+    @Test
+    fun `both filters off sets an error and does not search`() = runTest(mainDispatcherRule.dispatcher.scheduler) {
+        val windows = TestOrbits.findPassWindows()
+        val vm = createVm(satellites = listOf(TestOrbits.ISS), passes = windows)
+        vm.onStationBGrid("OL62")
+        vm.onFilterFM(false)
+        vm.onFilterLinear(false)
+
+        queryAndSettle(vm)
+
+        assertEquals(
+            "Select at least one transponder type (FM / Linear) to run the match.",
+            vm.uiState.value.errorMessage
+        )
+        assertFalse(vm.uiState.value.hasSearched)
+    }
+
+    @Test
+    fun `AMSAT filter restricts results to listed catnums`() = runTest(mainDispatcherRule.dispatcher.scheduler) {
+        val windows = TestOrbits.findPassWindows(hoursAhead = 24) +
+            TestOrbits.findPassWindows(sat = TestOrbits.ISS_VARIANT, hoursAhead = 24)
+        assertTrue("fixture must produce windows", windows.isNotEmpty())
+        // Only ISS (25544) is on the AMSAT live FM list; ISS_VARIANT (25545) is not.
+        val vm = createVm(
+            satellites = listOf(TestOrbits.ISS, TestOrbits.ISS_VARIANT),
+            passes = windows,
+            amSatFm = setOf(25544)
+        )
+        vm.onStationBGrid("OL62")
+        vm.onHoursAhead(24)
+
+        queryAndSettle(vm)
+
+        val state = vm.uiState.value
+        assertNull(state.errorMessage)
+        assertTrue(state.mutualPasses.isNotEmpty())
+        assertTrue("only AMSAT-listed satellites should appear", state.mutualPasses.all { it.catNum == 25544 })
+    }
+
+    @Test
+    fun `AMSAT filter off for one type excludes its satellites`() = runTest(mainDispatcherRule.dispatcher.scheduler) {
+        val windows = TestOrbits.findPassWindows(hoursAhead = 24) +
+            TestOrbits.findPassWindows(sat = TestOrbits.ISS_VARIANT, hoursAhead = 24)
+        // FM filter off, Linear on: neither sat is linear-listed -> nothing matches.
+        val vm = createVm(
+            satellites = listOf(TestOrbits.ISS, TestOrbits.ISS_VARIANT),
+            passes = windows,
+            amSatFm = setOf(25544),
+            amSatLinear = setOf(25545)
+        )
+        vm.onStationBGrid("OL62")
+        vm.onHoursAhead(24)
+        vm.onFilterFM(false)
+
+        queryAndSettle(vm)
+
+        val state = vm.uiState.value
+        assertNull(state.errorMessage)
+        assertTrue("only linear-listed satellites should appear", state.mutualPasses.all { it.catNum == 25545 })
+    }
 }