feat: /cesium

src/pages/cesium/cesium-helper/demo_02_Track.ts

@@ -51,11 +51,7 @@ export async function demo_02_Track(viewer: Viewer) {
   const totalSeconds = 60 * 60 * 2; // 2小时的轨迹
   const timeStepInSeconds = 30; // 每30秒一个点
   const startTime = Cesium.JulianDate.fromDate(new Date());
-  const endTime = Cesium.JulianDate.addSeconds(
+  const endTime = Cesium.JulianDate.addSeconds(startTime, totalSeconds, new Cesium.JulianDate());
-    startTime,
-    totalSeconds,
-    new Cesium.JulianDate(),
-  );
 
   // 设置时钟范围
   viewer.clock.startTime = startTime.clone();
@@ -73,13 +69,12 @@ export async function demo_02_Track(viewer: Viewer) {
   // 用于存储轨道点的数组（用于显示完整轨道）
   const orbitPositions: Cesium.Cartesian3[] = [];
 
+  // 保存卫星高度数据，用于覆盖范围计算
+  // const satelliteAltitude = 550_000; // 默认高度为550公里
+
   // 计算轨道上的点
   for (let i = 0; i <= totalSeconds; i += timeStepInSeconds) {
-    const time = Cesium.JulianDate.addSeconds(
+    const time = Cesium.JulianDate.addSeconds(startTime, i, new Cesium.JulianDate());
-      startTime,
-      i,
-      new Cesium.JulianDate(),
-    );
     const jsDate = Cesium.JulianDate.toDate(time);
 
     // 计算卫星位置
@@ -91,11 +86,11 @@ export async function demo_02_Track(viewer: Viewer) {
       const position = eciToEcf(positionAndVelocity.position, gmst);
 
       // 转换为Cesium坐标（单位：米）
-      const cesiumPosition = new Cesium.Cartesian3(
+      const cesiumPosition = new Cesium.Cartesian3(position.x * 1000, position.y * 1000, position.z * 1000);
-        position.x * 1000,
+
-        position.y * 1000,
+      // 计算卫星高度
-        position.z * 1000,
+      // const cartographic = Cesium.Cartographic.fromCartesian(cesiumPosition);
-      );
+      // satelliteAltitude = cartographic.height;
 
       // 保存位置用于绘制完整轨道
       orbitPositions.push(cesiumPosition);
@@ -122,16 +117,52 @@ export async function demo_02_Track(viewer: Viewer) {
 
   // 设置卫星的位置
   satelliteEntity.position = positionProperty;
-  satelliteEntity.orientation = new Cesium.VelocityOrientationProperty(
+  satelliteEntity.orientation = new Cesium.VelocityOrientationProperty(positionProperty);
-    positionProperty,
-  );
 
   // 添加卫星覆盖范围
   // Starlink 卫星通常覆盖范围以锥形方式向地面投射
   // 创建一个椭球体来表示卫星的覆盖范围
   const coverageAngle = 45; // 覆盖角度（度）
 
+  // satelliteAltitude * Math.tan(Cesium.Math.toRadians(coverageAngle));
+
   // 创建覆盖范围实体
+  viewer.entities.add({
+    ellipsoid: {
+      material: Cesium.Color.BLUE.withAlpha(0.2),
+      outline: true,
+      outlineColor: Cesium.Color.BLUE.withAlpha(0.8),
+      radii: new Cesium.CallbackProperty(() => {
+        const position = satelliteEntity.position?.getValue(viewer.clock.currentTime);
+        if (!position) return new Cesium.Cartesian3(10_000, 10_000, 10_000);
+
+        // 获取当前卫星高度
+        const cartographic = Cesium.Cartographic.fromCartesian(position);
+        const height = cartographic.height;
+
+        // 计算覆盖范围半径 (基于锥角)
+        const coverageRadius = height * Math.tan(Cesium.Math.toRadians(coverageAngle));
+
+        // 椭球体形状: xy平面为圆形基底，z轴方向为高度
+        return new Cesium.Cartesian3(coverageRadius, coverageRadius, height / 2);
+      }, false),
+      slicePartitions: 24,
+      stackPartitions: 16,
+    },
+    id: 'STARLINK-11371-coverage',
+    name: 'STARLINK-11371 Coverage',
+    orientation: new Cesium.CallbackProperty(() => {
+      // 确保椭球体始终指向地球中心
+      const position = satelliteEntity.position?.getValue(viewer.clock.currentTime);
+      if (!position) return Cesium.Transforms.eastNorthUpToFixedFrame(new Cesium.Cartesian3());
+
+      // 计算从卫星到地球中心的方向
+      Cesium.Cartesian3.normalize(Cesium.Cartesian3.negate(position, new Cesium.Cartesian3()), new Cesium.Cartesian3());
+
+      return Cesium.Transforms.headingPitchRollQuaternion(position, new Cesium.HeadingPitchRoll(0, Math.PI, 0));
+    }, false),
+    position: positionProperty,
+  });
 
   // 添加地面覆盖范围投影
   viewer.entities.add({
@@ -143,51 +174,39 @@ export async function demo_02_Track(viewer: Viewer) {
       outlineColor: Cesium.Color.BLUE.withAlpha(0.8),
       outlineWidth: 2,
       semiMajorAxis: new Cesium.CallbackProperty(() => {
-        const satPosition = satelliteEntity.position?.getValue(
+        const satPosition = satelliteEntity.position?.getValue(viewer.clock.currentTime);
-          viewer.clock.currentTime,
-        );
         if (!satPosition) return 10_000;
 
         // 计算卫星高度
         const cartographic = Cesium.Cartographic.fromCartesian(satPosition);
         // 根据高度和覆盖角度计算地面覆盖半径
-        return (
+        return cartographic.height * Math.tan(Cesium.Math.toRadians(coverageAngle));
-          cartographic.height * Math.tan(Cesium.Math.toRadians(coverageAngle))
-        );
       }, false),
       semiMinorAxis: new Cesium.CallbackProperty(() => {
-        const satPosition = satelliteEntity.position?.getValue(
+        const satPosition = satelliteEntity.position?.getValue(viewer.clock.currentTime);
-          viewer.clock.currentTime,
-        );
         if (!satPosition) return 10_000;
 
         // 计算卫星高度
         const cartographic = Cesium.Cartographic.fromCartesian(satPosition);
         // 根据高度和覆盖角度计算地面覆盖半径
-        return (
+        return cartographic.height * Math.tan(Cesium.Math.toRadians(coverageAngle));
-          cartographic.height * Math.tan(Cesium.Math.toRadians(coverageAngle))
-        );
       }, false),
     },
     id: 'STARLINK-11371-ground-coverage',
     name: 'STARLINK-11371 Ground Coverage',
     position: new Cesium.CallbackPositionProperty(() => {
-      const satPosition = satelliteEntity.position?.getValue(
+      const satPosition = satelliteEntity.position?.getValue(viewer.clock.currentTime);
-        viewer.clock.currentTime,
-      );
       if (!satPosition) return new Cesium.Cartesian3();
 
       // 计算卫星在地表的投影点
       const cartographic = Cesium.Cartographic.fromCartesian(satPosition);
-      return Cesium.Cartesian3.fromRadians(
+      return Cesium.Cartesian3.fromRadians(cartographic.longitude, cartographic.latitude, 0);
-        cartographic.longitude,
-        cartographic.latitude,
-        0,
-      );
     }, false),
   });
 
-  // https://github.com/CesiumGS/cesium/issues/8350
+  // - https://community.cesium.com/t/entity-viewfrom-property-example/2299/3
+  // - https://github.com/CesiumGS/cesium/issues/8900#issuecomment-638114149
+  //   - which is normal from a bird's eye view. But after setting it as the trackedEntity, it behaves abnormally.
   // 设置相机自动跟踪卫星
   viewer.trackedEntity = satelliteEntity;