Cesium 卫星轨迹、卫星通信、卫星过境，模拟数据传输。

起因：看了cesium官网卫星通信示例发现只有cmzl版本的，决定自己动手写一个。欢迎大家一起探讨，评论留言。

效果

全部代码在最后

起步

寻找卫星轨迹数据，在网站space-track上找的，自己注册账号QQ邮箱即可。

1. 卫星轨道类型 轨道高度 卫星用途
2. LEO (低地球轨道) 500-2000km 对地观测、测地、通信、导航等
3. MEO (中地球轨道) 2000-35786km 导航
4. GEO(地球静止轨道) 35786km 通信 导航、气象观测等
5. SSO (太阳同步轨道) <6000km 观测等
6. IGSO(倾斜地球同步轨道) 35786km 导航
   
   点击TLE就可以得到卫星的两个轨道数据
   
   当然这个数据需要相对应的插件satellite.js转换成我们熟悉的经纬高；
   拔下来的数据存入json文件中:
   
   最后构造卫星轨迹对象

import {twoline2satrec, gstime, eciToGeodetic,PositionAndVelocity, propagate, EciVec3,degreesLong
} from 'satellite.js';fetch("data/points.json").then(res => res.json()).then(data => {for (const key in data) {if (Object.prototype.hasOwnProperty.call(data, key)) {const element = data[key];const satrec = twoline2satrec(element.data[0], element.data[1]);const positionAndVelocity: PositionAndVelocity = propagate(satrec, time);const positionEci = positionAndVelocity.position as EciVec3<number>;obj[key] = {country: element.country,times: [],positions: []};let lon, lat, alt;//一年365天 一天为间隔for (let index = min; index <= nowTime; index = index + 86400000) {const gmst = gstime(new Date(index));const positionGd = eciToGeodetic(positionEci, gmst)lon = positionGd.longitude,lat = positionGd.latitude,alt = positionGd.height;obj[key].times.push(index)obj[key].positions.push([degreesLong(lon), degreesLong(lat), alt])}}}})

加载卫星和轨迹线

//用数据集方便管理
const satellites = new Cesium.CustomDataSource("satellite");
const polylines = new Cesium.CustomDataSource("statelliteLine");
function computeCirclularFlight(arr: Obj, hasLine: boolean = true) {for (const key in arr) {if (Object.prototype.hasOwnProperty.call(arr, key)) {const element = arr[key];const property = new Cesium.SampledPositionProperty();const length = element.positions.lengthconst positions: number[] = []let p, tfor (let index = 0; index < length; index++) {p = element.positions[index]t = element.times[index]property.addSample(Cesium.JulianDate.addHours(Cesium.JulianDate.fromDate(new Date(t)), 8, new Cesium.JulianDate()), Cesium.Cartesian3.fromDegrees(p[0], p[1], p[2]));positions.push(...element.positions[index])}satellites.entities.add({id: key,model: {uri: element.country === 'US' ? 'models/satellite/satellite1/Satellite.gltf': element.country === 'PRC' ? 'models/satellite/satellite2/10477_Satellite_v1_L3.gltf' : 'models/satellite/satellite3/satellite.gltf',minimumPixelSize: 32},position: property,});if (hasLine)polylines.entities.add({id: key,polyline: {width: 1,material: Cesium.Color.BLUE.withAlpha(.5),positions: Cesium.Cartesian3.fromDegreesArrayHeights(positions)}})}}viewer.dataSources.add(satellites);viewer.dataSources.add(polylines);
}

加载卫星和轨迹的效果

加载地面雷达

const radars = new Cesium.CustomDataSource("radar");
const radarpoints: {id: string;lon: number;lat: number;radius: number
}[] = [{ id: 'radar1', lon: 104, lat: 34, radius: 300000 },{ id: 'radar2', lon: -100, lat: 55, radius: 300000 },{ id: 'radar3', lon: 109.70841, lat: 19.365791, radius: 300000 },]//添加雷达radarpoints.forEach(i => {createRadar(i.id, i.lon, i.lat, i.radius)})function createRadar(id: string, lon: number, lat: number, radius: number) {radars.entities.add({id: id,model: {uri: 'models/antenna_07.glb',minimumPixelSize: 32,},position: Cesium.Cartesian3.fromDegrees(lon, lat),})viewer.dataSources.add(radars)new LCesiumApi.RadarPrimitive({radius: radius,stackPartitions: 10,slicePartitions: 10,stackDegrees: {x: 0,y: 90,},sliceDegrees: {x: 0,y: 360,},color: Cesium.Color.GREEN.withAlpha(0.2),lineColor: Cesium.Color.RED,scanColor: Cesium.Color.YELLOW.withAlpha(0.2),scanLineColor: Cesium.Color.RED,scene: viewer.scene,center: Cesium.Cartesian3.fromDegrees(lon, lat),scanSpeed: 5000,show: true,scan: true,});
}

关于雷达效果在我之前文章里面有

卫星与地面雷达通信

• 暂时只做了m(雷达)-n(卫星)，m*n;没有做卫星之间的通信判断，不过原理都是一样的.
• 网上搜索了一下通信距离一般是3,580km
• 计算此时卫星距雷达的距离,其实就是计算带高度的经纬度之间的距离

Cartesian3.distance(point1: Cartesian3, point2: Cartesian3)

当卫星和地面卫星通信时，创建连线，离开设置为隐藏。

function computeRange() {satellites.entities.values.forEach(i => {radars.entities.values.forEach(j => {const po1 = i.position?.getValue(viewer.clock.currentTime)const po2 = j.position?.getValue(viewer.clock.currentTime)if (po1 && po2) {const len = LCesiumApi.Tool.getDistanceFromCartesian3(po1, po2)if (len <= communicationRange) {if (showFlyObject[`${i.id}-${j.id}`]) {showFlyObject[`${i.id}-${j.id}`].show = trueshowFlyObject[`${i.id}-${j.id}`].po1 = LCesiumApi.Tramsform.degreesFromCartesian(po1)showFlyObject[`${i.id}-${j.id}`].po2 = LCesiumApi.Tramsform.degreesFromCartesian(po2)}else {showFlyObject[`${i.id}-${j.id}`] = {entity: null,show: true,po1: LCesiumApi.Tramsform.degreesFromCartesian(po1),po2: LCesiumApi.Tramsform.degreesFromCartesian(po2)}}} else {if (showFlyObject[`${i.id}-${j.id}`]) showFlyObject[`${i.id}-${j.id}`].show = false}}})})setLine()
}
function setLine() {for (const key in showFlyObject) {if (Object.prototype.hasOwnProperty.call(showFlyObject, key)) {const element = showFlyObject[key];if (element.entity === null) element.entity = createFlyLine(key)element.entity.show = element.show}}
}
function createFlyLine(id: string) {var material = new PolylineTrailLinkMaterialProperty({color: Cesium.Color.fromCssColorString('#7ffeff'),duration: 3000,});const line = Connection.entities.add({id: id,polyline: {positions: new Cesium.CallbackProperty(() => {return Cesium.Cartesian3.fromDegreesArrayHeights([showFlyObject[id].po1.longitude,showFlyObject[id].po1.latitude,showFlyObject[id].po1.height,showFlyObject[id].po2.longitude,showFlyObject[id].po2.latitude,showFlyObject[id].po2.height,])}, false),width: 8,material}})return line
}

完整代码

<template><Map @onViewerLoaded="onViewerLoaded" :options="options" />
</template>
<script lang="ts" setup>
import Map from "@/components/Cesium/lib/Map.vue";
import * as Cesium from "cesium";
import { message } from 'ant-design-vue'
import {twoline2satrec, gstime, eciToGeodetic,PositionAndVelocity, propagate, EciVec3,degreesLong
} from 'satellite.js';
import LCesiumApi from "@lib/main";
//@ts-ignore
import { PolylineTrailLinkMaterialProperty } from './PolylineTrailMaterialProperty.js'
const options = {imageryProvider: new Cesium.ArcGisMapServerImageryProvider({url: 'https://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer'}),
}
let viewer: Cesium.Viewer
let start: Cesium.JulianDate
let stop: Cesium.JulianDate
let handler: Cesium.ScreenSpaceEventHandler;
const communicationRange = 3580000;
const time = new Date()
let max = time.getTime()
let year = 31622400000;
let min = max - year;
type Obj = {[index: string]: {country: string;times: number[];positions: [[number, number, number]] | number[][]}
}
const showFlyObject: {[index: string]: any
} = {}
let obj: Obj = {}
const radarpoints: {id: string;lon: number;lat: number;radius: number
}[] = [{ id: 'radar1', lon: 104, lat: 34, radius: 300000 },{ id: 'radar2', lon: -100, lat: 55, radius: 300000 },{ id: 'radar3', lon: 109.70841, lat: 19.365791, radius: 300000 },]
const onViewerLoaded = (Viewer: Cesium.Viewer) => {viewer = Viewerhandler = new Cesium.ScreenSpaceEventHandler(viewer.canvas);//设置时间轴setTimeline()//读取卫星分布两行数据const nowTime = time.getTime()fetch("data/points.json").then(res => res.json()).then(data => {for (const key in data) {if (Object.prototype.hasOwnProperty.call(data, key)) {const element = data[key];const satrec = twoline2satrec(element.data[0], element.data[1]);const positionAndVelocity: PositionAndVelocity = propagate(satrec, time);const positionEci = positionAndVelocity.position as EciVec3<number>;obj[key] = {country: element.country,times: [],positions: []};let lon, lat, alt;//一年365天 一天为间隔for (let index = min; index <= nowTime; index = index + 86400000) {const gmst = gstime(new Date(index));const positionGd = eciToGeodetic(positionEci, gmst)lon = positionGd.longitude,lat = positionGd.latitude,alt = positionGd.height;obj[key].times.push(index)obj[key].positions.push([degreesLong(lon), degreesLong(lat), alt])}}}computeCirclularFlight(obj)})//添加点击事件addPick()//添加雷达radarpoints.forEach(i => {createRadar(i.id, i.lon, i.lat, i.radius)})//添加过境扫描; (viewer as any).frameUpdate.addEventListener((delta: any) => {computeRange()});
}
function setTimeline() {start = Cesium.JulianDate.fromDate(new Date(min));  // 获取当前时间 这不是国内的时间start = Cesium.JulianDate.addHours(start, 8, new Cesium.JulianDate());  // 添加八小时，得到我们东八区的北京时间stop = Cesium.JulianDate.fromDate(new Date(max));  // 设置一个结束时间，意思是360秒之后时间结束viewer.clock.startTime = start.clone();   // 给cesium时间轴设置开始的时间，也就是上边的东八区时间viewer.clock.stopTime = stop.clone();     // 设置cesium时间轴设置结束的时间viewer.clock.currentTime = start.clone(); // 设置cesium时间轴设置当前的时间viewer.clock.clockRange = Cesium.ClockRange.LOOP_STOP;  // 时间结束了，再继续重复来一遍//时间变化来控制速度 // 时间速率，数字越大时间过的越快viewer.clock.multiplier = 1;//给时间线设置边界viewer.timeline.zoomTo(start, stop);
}
const satellites = new Cesium.CustomDataSource("satellite");
const polylines = new Cesium.CustomDataSource("statelliteLine");
const radars = new Cesium.CustomDataSource("radar");
const Connection = new Cesium.CustomDataSource("connection");
function computeCirclularFlight(arr: Obj, hasLine: boolean = true) {for (const key in arr) {if (Object.prototype.hasOwnProperty.call(arr, key)) {const element = arr[key];const property = new Cesium.SampledPositionProperty();const length = element.positions.lengthconst positions: number[] = []let p, tfor (let index = 0; index < length; index++) {p = element.positions[index]t = element.times[index]property.addSample(Cesium.JulianDate.addHours(Cesium.JulianDate.fromDate(new Date(t)), 8, new Cesium.JulianDate()), Cesium.Cartesian3.fromDegrees(p[0], p[1], p[2]));positions.push(...element.positions[index])}satellites.entities.add({id: key,model: {uri: element.country === 'US' ? 'models/satellite/satellite1/Satellite.gltf': element.country === 'PRC' ? 'models/satellite/satellite2/10477_Satellite_v1_L3.gltf' : 'models/satellite/satellite3/satellite.gltf',minimumPixelSize: 32},position: property,});if (hasLine)polylines.entities.add({id: key,polyline: {width: 1,material: Cesium.Color.BLUE.withAlpha(.5),positions: Cesium.Cartesian3.fromDegreesArrayHeights(positions)}})}}viewer.dataSources.add(satellites);viewer.dataSources.add(polylines);viewer.dataSources.add(Connection)
}
const addPick = () => {handler.setInputAction((movement: any) => {const pickedObject = viewer.scene.pick(movement.position);if (Cesium.defined(pickedObject)) {message.info(pickedObject.id.id)}}, Cesium.ScreenSpaceEventType.LEFT_CLICK)
}
function createRadar(id: string, lon: number, lat: number, radius: number) {radars.entities.add({id: id,model: {uri: 'models/antenna_07.glb',minimumPixelSize: 32,},position: Cesium.Cartesian3.fromDegrees(lon, lat),})viewer.dataSources.add(radars)new LCesiumApi.RadarPrimitive({radius: radius,stackPartitions: 10,slicePartitions: 10,stackDegrees: {x: 0,y: 90,},sliceDegrees: {x: 0,y: 360,},color: Cesium.Color.GREEN.withAlpha(0.2),lineColor: Cesium.Color.RED,scanColor: Cesium.Color.YELLOW.withAlpha(0.2),scanLineColor: Cesium.Color.RED,scene: viewer.scene,center: Cesium.Cartesian3.fromDegrees(lon, lat),scanSpeed: 5000,show: true,scan: true,});
}
function computeRange() {satellites.entities.values.forEach(i => {radars.entities.values.forEach(j => {const po1 = i.position?.getValue(viewer.clock.currentTime)const po2 = j.position?.getValue(viewer.clock.currentTime)if (po1 && po2) {const len = LCesiumApi.Tool.getDistanceFromCartesian3(po1, po2)if (len <= communicationRange) {if (showFlyObject[`${i.id}-${j.id}`]) {showFlyObject[`${i.id}-${j.id}`].show = trueshowFlyObject[`${i.id}-${j.id}`].po1 = LCesiumApi.Tramsform.degreesFromCartesian(po1)showFlyObject[`${i.id}-${j.id}`].po2 = LCesiumApi.Tramsform.degreesFromCartesian(po2)}else {showFlyObject[`${i.id}-${j.id}`] = {entity: null,show: true,po1: LCesiumApi.Tramsform.degreesFromCartesian(po1),po2: LCesiumApi.Tramsform.degreesFromCartesian(po2)}}} else {if (showFlyObject[`${i.id}-${j.id}`]) showFlyObject[`${i.id}-${j.id}`].show = false}}})})setLine()
}
function setLine() {for (const key in showFlyObject) {if (Object.prototype.hasOwnProperty.call(showFlyObject, key)) {const element = showFlyObject[key];if (element.entity === null) element.entity = createFlyLine(key)element.entity.show = element.show}}
}
function createFlyLine(id: string) {var material = new PolylineTrailLinkMaterialProperty({color: Cesium.Color.fromCssColorString('#7ffeff'),duration: 3000,});const line = Connection.entities.add({id: id,polyline: {positions: new Cesium.CallbackProperty(() => {return Cesium.Cartesian3.fromDegreesArrayHeights([showFlyObject[id].po1.longitude,showFlyObject[id].po1.latitude,showFlyObject[id].po1.height,showFlyObject[id].po2.longitude,showFlyObject[id].po2.latitude,showFlyObject[id].po2.height,])}, false),width: 8,material}})return line
}
</script>