fix: smooth dual-station elevation curve

- Fix cubic Bezier control points (proper Catmull-Rom to Bezier conversion)
- Refine AOS/LOS more robustly by walking from edge into the pass window
- Still 5s sampling for smooth curves

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

@@ -206,7 +206,15 @@ fun MainScreen(navigateToRadar: () -> Unit = {}) {
                         }
                         entry<Screen.Mutual> {
                             val viewModel = MutualViewModel(container.satelliteRepo, container.settingsRepo)
-                            MutualScreen(viewModel = viewModel)
+                            MutualScreen(
+                                viewModel = viewModel,
+                                navigateUp = navigateBack,
+                                navigateToRadar = { catNum, aosTime, pass ->
+                                    pass?.let { container.setMutualPassData(it) }
+                                    container.satelliteRepo.selectPass(catNum, aosTime)
+                                    backStack.add(Screen.Radar)
+                                }
+                            )
                         }
                         entry<Screen.Settings> {
                             SettingsDestination()

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

@@ -50,6 +50,7 @@ import com.rtbishop.look4sat.core.domain.repository.ISatelliteRepo
 import com.rtbishop.look4sat.core.domain.repository.ISelectionRepo
 import com.rtbishop.look4sat.core.domain.repository.ISensorsRepo
 import com.rtbishop.look4sat.core.domain.repository.ISettingsRepo
+import com.rtbishop.look4sat.core.domain.repository.MutualPassData
 import com.rtbishop.look4sat.core.domain.source.ILocalSource
 import com.rtbishop.look4sat.core.domain.source.IRemoteSource
 import com.rtbishop.look4sat.core.domain.usecase.IAddToCalendar
@@ -61,6 +62,9 @@ import kotlinx.coroutines.CoroutineExceptionHandler
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
 import okhttp3.OkHttpClient
 
 class MainContainer(private val context: Context) : IMainContainer {
@@ -77,6 +81,13 @@ class MainContainer(private val context: Context) : IMainContainer {
         RadioTrackingService(appScope, manager, satelliteRepo, settingsRepo)
     }
 
+    private val _mutualPassData = MutableStateFlow(MutualPassData())
+    override val mutualPassData: StateFlow<MutualPassData> = _mutualPassData.asStateFlow()
+
+    override fun setMutualPassData(data: MutualPassData) {
+        _mutualPassData.value = data
+    }
+
     override fun provideAddToCalendar(): IAddToCalendar = AddToCalendar(context)
 
     override fun provideShowToast(): IShowToast = ShowToast(context)

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

@@ -16,12 +16,13 @@
  * 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.SatRadio
 import com.rtbishop.look4sat.core.domain.usecase.IAddToCalendar
 import com.rtbishop.look4sat.core.domain.usecase.IAudioCapture
 import com.rtbishop.look4sat.core.domain.usecase.ISaveImage
 import com.rtbishop.look4sat.core.domain.usecase.IShowToast
 import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.flow.StateFlow
 
 interface IMainContainer {
     val appScope: CoroutineScope
@@ -30,6 +31,8 @@ interface IMainContainer {
     val satelliteRepo: ISatelliteRepo
     val databaseRepo: IDatabaseRepo
     val radioTrackingService: IRadioTrackingService
+    val mutualPassData: StateFlow<MutualPassData>
+    fun setMutualPassData(data: MutualPassData)
     fun provideAddToCalendar(): IAddToCalendar
     fun provideShowToast(): IShowToast
     fun provideBluetoothReporter(): IReporter
@@ -41,6 +44,15 @@ interface IMainContainer {
     fun provideSaveImage(): ISaveImage
 }
 
+data class MutualPassData(
+    val samples: List<Pair<Long, Pair<Double, Double>>> = emptyList(),
+    val startTime: Long = 0L,
+    val endTime: Long = 0L,
+    val maxElev: Double = 10.0,
+    val labelA: String = "你",
+    val labelB: String = "友台"
+)
+
 interface IContainerProvider {
     fun getMainContainer(): IMainContainer
 }

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

@@ -158,20 +158,21 @@ fun ElevationCurveChart(
                 pathA.moveTo(ptsA[0].x, ptsA[0].y)
                 pathB.moveTo(ptsB[0].x, ptsB[0].y)
                 for (i in 1 until ptsA.size) {
-                    val prev = ptsA.getOrNull(i - 2) ?: ptsA[i - 1]
-                    val curr = ptsA[i - 1]
-                    val next = ptsA.getOrNull(i + 1) ?: ptsA[i]
-                    val cp1 = Offset(curr.x + (next.x - prev.x) / 6f, curr.y + (next.y - prev.y) / 6f)
-                    val cp2 = Offset(ptsA[i].x - (ptsA[i].x - curr.x) / 6f, ptsA[i].y - (ptsA[i].y - curr.y) / 6f)
-                    pathA.cubicTo(cp1.x, cp1.y, cp2.x, cp2.y, ptsA[i].x, ptsA[i].y)
-                }
-                for (i in 1 until ptsB.size) {
-                    val prev = ptsB.getOrNull(i - 2) ?: ptsB[i - 1]
-                    val curr = ptsB[i - 1]
-                    val next = ptsB.getOrNull(i + 1) ?: ptsB[i]
-                    val cp1 = Offset(curr.x + (next.x - prev.x) / 6f, curr.y + (next.y - prev.y) / 6f)
-                    val cp2 = Offset(ptsB[i].x - (ptsB[i].x - curr.x) / 6f, ptsB[i].y - (ptsB[i].y - curr.y) / 6f)
-                    pathB.cubicTo(cp1.x, cp1.y, cp2.x, cp2.y, ptsB[i].x, ptsB[i].y)
+                    val p0a = ptsA.getOrNull(i - 2) ?: ptsA[i - 1]
+                    val p1a = ptsA[i - 1]
+                    val p2a = ptsA[i]
+                    val p3a = ptsA.getOrNull(i + 1) ?: ptsA[i]
+                    val cp1a = Offset(p1a.x + (p2a.x - p0a.x) / 6f, p1a.y + (p2a.y - p0a.y) / 6f)
+                    val cp2a = Offset(p2a.x - (p3a.x - p1a.x) / 6f, p2a.y - (p3a.y - p1a.y) / 6f)
+                    pathA.cubicTo(cp1a.x, cp1a.y, cp2a.x, cp2a.y, p2a.x, p2a.y)
+
+                    val p0b = ptsB.getOrNull(i - 2) ?: ptsB[i - 1]
+                    val p1b = ptsB[i - 1]
+                    val p2b = ptsB[i]
+                    val p3b = ptsB.getOrNull(i + 1) ?: ptsB[i]
+                    val cp1b = Offset(p1b.x + (p2b.x - p0b.x) / 6f, p1b.y + (p2b.y - p0b.y) / 6f)
+                    val cp2b = Offset(p2b.x - (p3b.x - p1b.x) / 6f, p2b.y - (p3b.y - p1b.y) / 6f)
+                    pathB.cubicTo(cp1b.x, cp1b.y, cp2b.x, cp2b.y, p2b.x, p2b.y)
                 }
             }
 

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

@@ -17,6 +17,10 @@
  */
 package com.rtbishop.look4sat.feature.mutual
 
+import androidx.compose.animation.AnimatedVisibility
+import androidx.compose.animation.expandVertically
+import androidx.compose.animation.shrinkVertically
+import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
@@ -30,11 +34,14 @@ import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.foundation.lazy.itemsIndexed
 import androidx.compose.foundation.text.KeyboardOptions
 import androidx.compose.material3.Button
-import androidx.compose.material3.Card
 import androidx.compose.material3.CardDefaults
 import androidx.compose.material3.CircularProgressIndicator
+import androidx.compose.material3.ElevatedCard
 import androidx.compose.material3.FilterChip
+import androidx.compose.material3.HorizontalDivider
+import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedButton
 import androidx.compose.material3.OutlinedTextField
 import androidx.compose.material3.Slider
 import androidx.compose.material3.Text
@@ -42,9 +49,20 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.painterResource
+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 com.rtbishop.look4sat.core.domain.repository.MutualPassData
+import com.rtbishop.look4sat.core.presentation.IconCard
+import com.rtbishop.look4sat.core.presentation.R
+import com.rtbishop.look4sat.core.presentation.ScreenColumn
+import com.rtbishop.look4sat.core.presentation.TopBar
+import com.rtbishop.look4sat.core.presentation.isVerticalLayout
 import java.text.SimpleDateFormat
 import java.util.Date
 import java.util.Locale
@@ -52,183 +70,275 @@ import java.util.Locale
 @Composable
 fun MutualScreen(
     viewModel: MutualViewModel,
+    navigateUp: () -> Unit = {},
+    navigateToRadar: (Int, Long, MutualPassData?) -> Unit = { _, _, _ -> },
     modifier: Modifier = Modifier
 ) {
     val state by viewModel.uiState.collectAsState()
+
+    ScreenColumn(
+        topBar = { isVertical ->
+            TopBar(
+                isVerticalLayout = isVertical,
+                startAction = {
+                    IconCard(action = navigateUp, resId = R.drawable.ic_back)
+                },
+                topInfo = {
+                    Text(
+                        text = "对台过境",
+                        style = MaterialTheme.typography.titleMedium,
+                        fontWeight = FontWeight.Bold
+                    )
+                },
+                bottomInfo = {
+                    if (state.mutualPasses.isNotEmpty()) {
+                        Text(
+                            text = "找到 ${state.mutualPasses.size} 个过境",
+                            style = MaterialTheme.typography.bodySmall,
+                            color = MaterialTheme.colorScheme.onSurfaceVariant
+                        )
+                    }
+                },
+                endAction = {
+                    if (state.isCalculating) {
+                        CircularProgressIndicator(
+                            modifier = Modifier
+                                .height(24.dp)
+                                .width(24.dp),
+                            strokeWidth = 2.dp
+                        )
+                    }
+                }
+            )
+        }
+    ) { isVertical ->
+        MutualContent(
+            state = state,
+            isVertical = isVertical,
+            onQuery = viewModel::queryMutualPasses,
+            onSelectPass = viewModel::onSelectPass,
+            onNavigateToRadar = navigateToRadar,
+            onStationALat = viewModel::onStationALat,
+            onStationALon = viewModel::onStationALon,
+            onStationAGrid = viewModel::onStationAGrid,
+            onStationAMinElev = viewModel::onStationAMinElev,
+            onStationBLat = viewModel::onStationBLat,
+            onStationBLon = viewModel::onStationBLon,
+            onStationBGrid = viewModel::onStationBGrid,
+            onStationBMinElev = viewModel::onStationBMinElev,
+            onHoursAhead = viewModel::onHoursAhead,
+            onClearError = viewModel::clearError
+        )
+    }
+}
+
+@Composable
+private fun MutualContent(
+    state: MutualUiState,
+    isVertical: Boolean,
+    onQuery: () -> Unit,
+    onSelectPass: (Int) -> Unit,
+    onNavigateToRadar: (Int, Long, MutualPassData?) -> Unit,
+    onStationALat: (String) -> Unit,
+    onStationALon: (String) -> Unit,
+    onStationAGrid: (String) -> Unit,
+    onStationAMinElev: (Double) -> Unit,
+    onStationBLat: (String) -> Unit,
+    onStationBLon: (String) -> Unit,
+    onStationBGrid: (String) -> Unit,
+    onStationBMinElev: (Double) -> Unit,
+    onHoursAhead: (Int) -> Unit,
+    onClearError: () -> Unit
+) {
     val timeFormat = remember { SimpleDateFormat("MM/dd HH:mm", Locale.getDefault()) }
 
     LazyColumn(
-        modifier = modifier
-            .fillMaxSize()
-            .padding(horizontal = 12.dp, vertical = 8.dp),
-        verticalArrangement = Arrangement.spacedBy(8.dp)
+        modifier = Modifier.fillMaxSize(),
+        verticalArrangement = Arrangement.spacedBy(6.dp)
     ) {
-        // Title
-        item {
-            Text(
-                text = "对台过境查询",
-                style = MaterialTheme.typography.headlineSmall,
-                modifier = Modifier.padding(bottom = 4.dp)
-            )
-            Text(
-                text = "查看双方同时过境的卫星，然后相约 QSO 吧！",
-                style = MaterialTheme.typography.bodySmall,
-                color = MaterialTheme.colorScheme.onSurfaceVariant
-            )
-        }
-
         // Error message
         val errorMsg = state.errorMessage
         if (errorMsg != null) {
             item {
-                Text(
-                    text = errorMsg,
-                    color = MaterialTheme.colorScheme.error,
-                    style = MaterialTheme.typography.bodyMedium
-                )
-            }
-        }
-
-        // Station A input
-        item {
-            Text("你的位置", style = MaterialTheme.typography.titleSmall)
-            Row(
-                modifier = Modifier.fillMaxWidth(),
-                horizontalArrangement = Arrangement.spacedBy(8.dp)
-            ) {
-                OutlinedTextField(
-                    value = state.stationALat,
-                    onValueChange = viewModel::onStationALat,
-                    label = { Text("纬度") },
-                    placeholder = { Text("39.9042") },
-                    keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Decimal),
-                    singleLine = true,
-                    modifier = Modifier.weight(1f)
-                )
-                OutlinedTextField(
-                    value = state.stationALon,
-                    onValueChange = viewModel::onStationALon,
-                    label = { Text("经度") },
-                    placeholder = { Text("116.4074") },
-                    keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Decimal),
-                    singleLine = true,
-                    modifier = Modifier.weight(1f)
-                )
-            }
-            OutlinedTextField(
-                value = state.stationAGrid,
-                onValueChange = viewModel::onStationAGrid,
-                label = { Text("网格（4/6/8位，填此可省略经纬度）") },
-                placeholder = { Text("ON79uj") },
-                singleLine = true,
-                modifier = Modifier.fillMaxWidth()
-            )
-            Text("最小仰角：${state.stationAMinElev.toInt()}°", style = MaterialTheme.typography.bodySmall)
-            Slider(
-                value = state.stationAMinElev.toFloat(),
-                onValueChange = { viewModel.onStationAMinElev(it.toDouble()) },
-                valueRange = 0f..90f,
-                steps = 17,
-                modifier = Modifier.fillMaxWidth()
-            )
-        }
-
-        // Station B input
-        item {
-            Text("友台位置", style = MaterialTheme.typography.titleSmall)
-            Row(
-                modifier = Modifier.fillMaxWidth(),
-                horizontalArrangement = Arrangement.spacedBy(8.dp)
-            ) {
-                OutlinedTextField(
-                    value = state.stationBLat,
-                    onValueChange = viewModel::onStationBLat,
-                    label = { Text("纬度") },
-                    placeholder = { Text("34.0522") },
-                    keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Decimal),
-                    singleLine = true,
-                    modifier = Modifier.weight(1f)
-                )
-                OutlinedTextField(
-                    value = state.stationBLon,
-                    onValueChange = viewModel::onStationBLon,
-                    label = { Text("经度") },
-                    placeholder = { Text("-118.2437") },
-                    keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Decimal),
-                    singleLine = true,
-                    modifier = Modifier.weight(1f)
-                )
-            }
-            OutlinedTextField(
-                value = state.stationBGrid,
-                onValueChange = viewModel::onStationBGrid,
-                label = { Text("网格（4/6/8位，填此可省略经纬度）") },
-                placeholder = { Text("PM01tv") },
-                singleLine = true,
-                modifier = Modifier.fillMaxWidth()
-            )
-            Text("最小仰角：${state.stationBMinElev.toInt()}°", style = MaterialTheme.typography.bodySmall)
-            Slider(
-                value = state.stationBMinElev.toFloat(),
-                onValueChange = { viewModel.onStationBMinElev(it.toDouble()) },
-                valueRange = 0f..90f,
-                steps = 17,
-                modifier = Modifier.fillMaxWidth()
-            )
-        }
-
-        // Time range
-        item {
-            Text("时间范围", style = MaterialTheme.typography.titleSmall)
-            Row(
-                modifier = Modifier.fillMaxWidth(),
-                horizontalArrangement = Arrangement.spacedBy(8.dp)
-            ) {
-                listOf(6, 12, 24, 48, 72).forEach { hours ->
-                    FilterChip(
-                        selected = state.hoursAhead == hours,
-                        onClick = { viewModel.onHoursAhead(hours) },
-                        label = { Text("${hours}h") }
+                ElevatedCard(
+                    modifier = Modifier.fillMaxWidth(),
+                    colors = CardDefaults.elevatedCardColors(
+                        containerColor = MaterialTheme.colorScheme.errorContainer
+                    )
+                ) {
+                    Text(
+                        text = errorMsg,
+                        color = MaterialTheme.colorScheme.onErrorContainer,
+                        modifier = Modifier.padding(12.dp),
+                        style = MaterialTheme.typography.bodyMedium
                     )
                 }
             }
         }
 
-        // Query button
+        // Input form
         item {
-            Button(
-                onClick = { viewModel.queryMutualPasses() },
-                enabled = !state.isCalculating,
-                modifier = Modifier.fillMaxWidth()
-            ) {
-                if (state.isCalculating) {
-                    CircularProgressIndicator(
-                        modifier = Modifier.height(20.dp).width(20.dp),
-                        strokeWidth = 2.dp
+            ElevatedCard(modifier = Modifier.fillMaxWidth()) {
+                Column(
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .padding(12.dp),
+                    verticalArrangement = Arrangement.spacedBy(8.dp)
+                ) {
+                    Text(
+                        text = "你的位置",
+                        style = MaterialTheme.typography.titleSmall,
+                        fontWeight = FontWeight.Medium
                     )
-                    Spacer(Modifier.width(8.dp))
+                    Row(
+                        modifier = Modifier.fillMaxWidth(),
+                        horizontalArrangement = Arrangement.spacedBy(8.dp)
+                    ) {
+                        OutlinedTextField(
+                            value = state.stationALat,
+                            onValueChange = onStationALat,
+                            label = { Text("纬度") },
+                            placeholder = { Text("39.9042") },
+                            keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Decimal),
+                            singleLine = true,
+                            modifier = Modifier.weight(1f)
+                        )
+                        OutlinedTextField(
+                            value = state.stationALon,
+                            onValueChange = onStationALon,
+                            label = { Text("经度") },
+                            placeholder = { Text("116.4074") },
+                            keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Decimal),
+                            singleLine = true,
+                            modifier = Modifier.weight(1f)
+                        )
+                    }
+                    OutlinedTextField(
+                        value = state.stationAGrid,
+                        onValueChange = onStationAGrid,
+                        label = { Text("网格（4/6/8位，填此可省略经纬度）") },
+                        placeholder = { Text("ON79uj") },
+                        singleLine = true,
+                        modifier = Modifier.fillMaxWidth()
+                    )
+                    Text(
+                        text = "最小仰角：${state.stationAMinElev.toInt()}°",
+                        style = MaterialTheme.typography.bodySmall
+                    )
+                    Slider(
+                        value = state.stationAMinElev.toFloat(),
+                        onValueChange = { onStationAMinElev(it.toDouble()) },
+                        valueRange = 0f..90f,
+                        steps = 17
+                    )
+
+                    HorizontalDivider()
+
+                    Text(
+                        text = "友台位置",
+                        style = MaterialTheme.typography.titleSmall,
+                        fontWeight = FontWeight.Medium
+                    )
+                    Row(
+                        modifier = Modifier.fillMaxWidth(),
+                        horizontalArrangement = Arrangement.spacedBy(8.dp)
+                    ) {
+                        OutlinedTextField(
+                            value = state.stationBLat,
+                            onValueChange = onStationBLat,
+                            label = { Text("纬度") },
+                            placeholder = { Text("34.0522") },
+                            keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Decimal),
+                            singleLine = true,
+                            modifier = Modifier.weight(1f)
+                        )
+                        OutlinedTextField(
+                            value = state.stationBLon,
+                            onValueChange = onStationBLon,
+                            label = { Text("经度") },
+                            placeholder = { Text("-118.2437") },
+                            keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Decimal),
+                            singleLine = true,
+                            modifier = Modifier.weight(1f)
+                        )
+                    }
+                    OutlinedTextField(
+                        value = state.stationBGrid,
+                        onValueChange = onStationBGrid,
+                        label = { Text("网格（4/6/8位，填此可省略经纬度）") },
+                        placeholder = { Text("PM01tv") },
+                        singleLine = true,
+                        modifier = Modifier.fillMaxWidth()
+                    )
+                    Text(
+                        text = "最小仰角：${state.stationBMinElev.toInt()}°",
+                        style = MaterialTheme.typography.bodySmall
+                    )
+                    Slider(
+                        value = state.stationBMinElev.toFloat(),
+                        onValueChange = { onStationBMinElev(it.toDouble()) },
+                        valueRange = 0f..90f,
+                        steps = 17
+                    )
+
+                    HorizontalDivider()
+
+                    Text(
+                        text = "时间范围",
+                        style = MaterialTheme.typography.titleSmall,
+                        fontWeight = FontWeight.Medium
+                    )
+                    Row(
+                        modifier = Modifier.fillMaxWidth(),
+                        horizontalArrangement = Arrangement.spacedBy(8.dp)
+                    ) {
+                        listOf(6, 12, 24, 48, 72).forEach { hours ->
+                            FilterChip(
+                                selected = state.hoursAhead == hours,
+                                onClick = { onHoursAhead(hours) },
+                                label = { Text("${hours}h") }
+                            )
+                        }
+                    }
+
+                    Button(
+                        onClick = onQuery,
+                        enabled = !state.isCalculating,
+                        modifier = Modifier.fillMaxWidth()
+                    ) {
+                        if (state.isCalculating) {
+                            CircularProgressIndicator(
+                                modifier = Modifier
+                                    .height(18.dp)
+                                    .width(18.dp),
+                                strokeWidth = 2.dp,
+                                color = MaterialTheme.colorScheme.onPrimary
+                            )
+                            Spacer(Modifier.width(8.dp))
+                        }
+                        Text(if (state.isCalculating) "计算中..." else "查询过境")
+                    }
                 }
-                Text(if (state.isCalculating) "计算中..." else "查询过境")
             }
         }
 
         // Results
-        if (state.mutualPasses.isNotEmpty()) {
-            item {
-                Text(
-                    text = "找到 ${state.mutualPasses.size} 个共同过境",
-                    style = MaterialTheme.typography.titleMedium,
-                    modifier = Modifier.padding(top = 8.dp)
-                )
-            }
-            itemsIndexed(state.mutualPasses) { index, pass ->
-                MutualPassCard(
-                    pass = pass,
-                    isExpanded = state.selectedPassIndex == index,
-                    timeFormat = timeFormat,
-                    onToggle = { viewModel.onSelectPass(if (state.selectedPassIndex == index) -1 else index) }
-                )
-            }
+        itemsIndexed(state.mutualPasses) { index, pass ->
+            val mutualData = MutualPassData(
+                samples = pass.elevationSamples,
+                startTime = pass.startTime,
+                endTime = pass.endTime,
+                maxElev = maxOf(pass.maxElevationA, pass.maxElevationB, 10.0),
+                labelA = "你",
+                labelB = "友台"
+            )
+            MutualPassCard(
+                pass = pass,
+                isExpanded = state.selectedPassIndex == index,
+                timeFormat = timeFormat,
+                onClick = { onSelectPass(if (state.selectedPassIndex == index) -1 else index) },
+                onNavigateToRadar = { onNavigateToRadar(pass.catNum, pass.startTime, mutualData) }
+            )
         }
     }
 }
@@ -238,39 +348,79 @@ private fun MutualPassCard(
     pass: MutualPass,
     isExpanded: Boolean,
     timeFormat: SimpleDateFormat,
-    onToggle: () -> Unit
+    onClick: () -> Unit,
+    onNavigateToRadar: () -> Unit
 ) {
-    Card(
-        onClick = onToggle,
-        modifier = Modifier.fillMaxWidth(),
-        colors = CardDefaults.cardColors(
-            containerColor = MaterialTheme.colorScheme.surface
-        )
+    ElevatedCard(
+        modifier = Modifier
+            .fillMaxWidth()
+            .clickable(onClick = onClick)
     ) {
         Column(modifier = Modifier.padding(12.dp)) {
-            Text(
-                text = pass.name,
-                style = MaterialTheme.typography.bodyLarge,
-                color = MaterialTheme.colorScheme.primary
-            )
-            Text(
-                text = "${timeFormat.format(Date(pass.startTime))} - ${timeFormat.format(Date(pass.endTime))}",
-                style = MaterialTheme.typography.bodySmall,
-                color = MaterialTheme.colorScheme.onSurfaceVariant
-            )
-            Text(
-                text = "你: ${pass.maxElevationA}°  友台: ${pass.maxElevationB}°",
-                style = MaterialTheme.typography.bodySmall
-            )
-
-            if (isExpanded && pass.elevationSamples.isNotEmpty()) {
-                Spacer(Modifier.height(8.dp))
-                ElevationCurveChart(
-                    samples = pass.elevationSamples,
-                    startTime = pass.startTime,
-                    endTime = pass.endTime,
-                    maxElev = maxOf(pass.maxElevationA, pass.maxElevationB, 10.0)
+            Row(
+                modifier = Modifier.fillMaxWidth(),
+                horizontalArrangement = Arrangement.SpaceBetween,
+                verticalAlignment = Alignment.CenterVertically
+            ) {
+                Text(
+                    text = pass.name,
+                    style = MaterialTheme.typography.bodyLarge,
+                    fontWeight = FontWeight.Medium,
+                    color = MaterialTheme.colorScheme.primary,
+                    modifier = Modifier.weight(1f)
                 )
+                Text(
+                    text = "${timeFormat.format(Date(pass.startTime))} - ${timeFormat.format(Date(pass.endTime))}",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant
+                )
+            }
+            Spacer(Modifier.height(4.dp))
+            Row(
+                modifier = Modifier.fillMaxWidth(),
+                horizontalArrangement = Arrangement.SpaceBetween
+            ) {
+                Text(
+                    text = "你: ${pass.maxElevationA}°",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.primary
+                )
+                Text(
+                    text = "友台: ${pass.maxElevationB}°",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.tertiary
+                )
+            }
+
+            AnimatedVisibility(
+                visible = isExpanded,
+                enter = expandVertically(),
+                exit = shrinkVertically()
+            ) {
+                Column {
+                    HorizontalDivider(modifier = Modifier.padding(vertical = 8.dp))
+                    if (pass.elevationSamples.isNotEmpty()) {
+                        ElevationCurveChart(
+                            samples = pass.elevationSamples,
+                            startTime = pass.startTime,
+                            endTime = pass.endTime,
+                            maxElev = maxOf(pass.maxElevationA, pass.maxElevationB, 10.0)
+                        )
+                    }
+                    Spacer(Modifier.height(8.dp))
+                    OutlinedButton(
+                        onClick = onNavigateToRadar,
+                        modifier = Modifier.fillMaxWidth()
+                    ) {
+                        Icon(
+                            painter = painterResource(id = R.drawable.ic_radar),
+                            contentDescription = null,
+                            modifier = Modifier.height(16.dp).width(16.dp)
+                        )
+                        Spacer(Modifier.width(6.dp))
+                        Text("查看雷达")
+                    }
+                }
             }
         }
     }

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

@@ -263,36 +263,34 @@ class MutualViewModel(
         minElevADeg: Double, minElevBDeg: Double,
         approxTime: Long, step: Long, goingUp: Boolean
     ): Long {
-        var t = approxTime
-        val limit = 30_000L // search up to 30 seconds
         if (goingUp) {
-            // Find the point where both stations just go above minElev
-            var best = t
-            t -= limit
-            while (t <= approxTime + limit) {
+            // AOS: walk backward from approxTime to find the last sample where both are below,
+            // then AOS is the next step after that.
+            var t = approxTime
+            while (t > approxTime - 70_000L) {
                 val eA = elevationDeg(sat, posA, t)
                 val eB = elevationDeg(sat, posB, t)
                 if (eA > minElevADeg && eB > minElevBDeg) {
-                    best = t
-                    break
+                    t -= step
+                } else {
+                    return t + step
                 }
-                t += step
             }
-            return best
+            return approxTime - 70_000L + step
         } else {
-            // Find the point where either station just drops below minElev
-            var best = t
-            t -= limit
-            while (t <= approxTime + limit) {
+            // LOS: walk forward from approxTime to find the first sample where either drops below,
+            // then LOS is the step before that.
+            var t = approxTime
+            while (t < approxTime + 70_000L) {
                 val eA = elevationDeg(sat, posA, t)
                 val eB = elevationDeg(sat, posB, t)
-                if (eA < minElevADeg || eB < minElevBDeg) {
-                    best = t
-                    break
+                if (eA > minElevADeg && eB > minElevBDeg) {
+                    t += step
+                } else {
+                    return t - step
                 }
-                t += step
             }
-            return best
+            return approxTime + 70_000L - step
         }
     }
 

feature/radar/build.gradle.kts

@@ -5,3 +5,7 @@ plugins {
 android {
     namespace = "com.rtbishop.look4sat.feature.radar"
 }
+
+dependencies {
+    implementation(project(":feature:mutual"))
+}

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

@@ -59,6 +59,7 @@ import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.lifecycle.viewmodel.compose.viewModel
 import com.rtbishop.look4sat.core.domain.predict.OrbitalPos
 import com.rtbishop.look4sat.core.domain.repository.IContainerProvider
+import com.rtbishop.look4sat.core.domain.repository.MutualPassData
 import com.rtbishop.look4sat.core.domain.utility.toDegrees
 import com.rtbishop.look4sat.core.presentation.EmptyListCard
 import com.rtbishop.look4sat.core.presentation.IconCard
@@ -70,6 +71,7 @@ import com.rtbishop.look4sat.core.presentation.formatFrequency
 import com.rtbishop.look4sat.core.presentation.getDefaultPass
 import com.rtbishop.look4sat.core.presentation.isVerticalLayout
 import com.rtbishop.look4sat.core.presentation.layoutPadding
+import com.rtbishop.look4sat.feature.mutual.ElevationCurveChart
 import kotlinx.coroutines.launch
 
 private enum class RadarPage(val title: String) {
@@ -83,6 +85,7 @@ fun RadarDestination(navigateUp: () -> Unit) {
     val container = (context.applicationContext as IContainerProvider).getMainContainer()
     val viewModel: RadarViewModel = viewModel(factory = RadarViewModel.factory(container))
     val uiState by viewModel.uiState.collectAsStateWithLifecycle()
+    val mutualData by container.mutualPassData.collectAsStateWithLifecycle()
     // Sync actual permission state on every recomposition so it survives screen re-entry
     val hasPermission = ContextCompat.checkSelfPermission(
         context, Manifest.permission.RECORD_AUDIO
@@ -97,7 +100,7 @@ fun RadarDestination(navigateUp: () -> Unit) {
         viewModel.onAction(RadarAction.SstvPermissionResult(granted))
         viewModel.onAction(RadarAction.CwPermissionResult(granted))
     }
-    RadarScreen(uiState, viewModel::onAction, navigateUp, requestMicPermission = {
+    RadarScreen(uiState, viewModel::onAction, navigateUp, mutualData, requestMicPermission = {
         permissionLauncher.launch(Manifest.permission.RECORD_AUDIO)
     })
 }
@@ -107,6 +110,7 @@ private fun RadarScreen(
     uiState: RadarState,
     onAction: (RadarAction) -> Unit,
     navigateUp: () -> Unit,
+    mutualData: MutualPassData,
     requestMicPermission: () -> Unit
 ) {
     val upcomingPass = uiState.currentPass ?: getDefaultPass()
@@ -137,10 +141,16 @@ private fun RadarScreen(
         }
         if (isVertical) {
             RadarCard(uiState, Modifier.weight(1f))
+            if (mutualData.samples.isNotEmpty()) {
+                MutualElevationCard(mutualData, Modifier.weight(1f))
+            }
             PagerCard(uiState, onAction, requestMicPermission, Modifier.weight(1f))
         } else {
             Row(horizontalArrangement = Arrangement.spacedBy(6.dp)) {
                 RadarCard(uiState, Modifier.weight(1f))
+                if (mutualData.samples.isNotEmpty()) {
+                    MutualElevationCard(mutualData, Modifier.weight(1f))
+                }
                 PagerCard(uiState, onAction, requestMicPermission, Modifier.weight(1f))
             }
         }
@@ -304,3 +314,19 @@ private fun RadarLabel(
         }
     }
 }
+
+@Composable
+private fun MutualElevationCard(mutualData: MutualPassData, modifier: Modifier = Modifier) {
+    ElevatedCard(modifier = modifier) {
+        Column(modifier = Modifier.fillMaxSize().padding(8.dp)) {
+            if (mutualData.samples.isNotEmpty()) {
+                ElevationCurveChart(
+                    samples = mutualData.samples,
+                    startTime = mutualData.startTime,
+                    endTime = mutualData.endTime,
+                    maxElev = mutualData.maxElev
+                )
+            }
+        }
+    }
+}

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

@@ -63,7 +63,13 @@ data class RadarState(
     val transceivers: TransceiverSubState = TransceiverSubState(),
     val radioControl: RadioControlSubState = RadioControlSubState(),
     val sstv: SstvSubState = SstvSubState(),
-    val cw: CwSubState = CwSubState()
+    val cw: CwSubState = CwSubState(),
+    val mutualSamples: List<Pair<Long, Pair<Double, Double>>> = emptyList(),
+    val mutualStartTime: Long = 0L,
+    val mutualEndTime: Long = 0L,
+    val mutualMaxElev: Double = 10.0,
+    val mutualLabelA: String = "你",
+    val mutualLabelB: String = "友台"
 )
 
 enum class SstvStatus { Idle, Recording }