此功能已有一段时间没有维护了,后面重新写了一个。
有疑问可以给我留言或者联系我的q 951973194;感谢大家的关注。
最近一直在弄关于卫星轨道及卫星扫描的功能,但是又没提供轨道的具体坐标,后端也不提供轨道根数计算轨道坐标的接口。没办法,自己翻阅了好多资料,找出了一个比较冷门的方法,通过卫星的两行参数,结合sgp4来模拟出一段时间的轨道坐标;这次就不晒出结合的方法了,只演示下如何模拟卫星扫描;
先晒出成果图:
思路:这里我将卫星和下面的椎体分成了两个entity,通过Cesium.SampledPositionProperty将坐标和时间进行关联,通过插值算法,让轨道平滑,最终达到了这个效果;
以下为代码:
var viewer = new Cesium.Viewer('map');
var data = [];
data = [{
longitude: 116.405419,
dimension: 39.918034,
height: 700000,
time: 0
}, {
longitude: 115.2821,
dimension: 39.918145,
height: 700000,
time: 40
}, {
longitude: 114.497402,
dimension: 39.344641,
height: 700000,
time: 100
}, {
longitude: 107.942392,
dimension: 35.559967,
height: 700000,
time: 280
}, {
longitude: 106.549265,
dimension: 34.559967,
height: 700000,
time: 360
}, {
longitude: 95.2821,
dimension: 32.918145,
height: 700000,
time: 400
}, {
longitude: 94.497402,
dimension: 30.344641,
height: 700000,
time: 450
}, {
longitude: 87.942392,
dimension: 25.559967,
height: 700000,
time: 550
}, {
longitude: 66.549265,
dimension: 24.559967,
height: 700000,
time: 600
}];
// 起始时间
var start = Cesium.JulianDate.fromDate(new Date(2017, 7, 11));
// 结束时间
var stop = Cesium.JulianDate.addSeconds(start, 600, new Cesium.JulianDate());
// 设置始时钟始时间
viewer.clock.startTime = start.clone();
// 设置时钟当前时间
viewer.clock.currentTime = start.clone();
// 设置始终停止时间
viewer.clock.stopTime = stop.clone();
// 时间速率,数字越大时间过的越快
viewer.clock.multiplier = 10;
// 时间轴
viewer.timeline.zoomTo(start, stop);
// 循环执行
viewer.clock.clockRange = Cesium.ClockRange.LOOP_STOP;
var property = computeFlight(data);
// 添加模型
var planeModel = viewer.entities.add({
// 和时间轴关联
availability: new Cesium.TimeIntervalCollection([new Cesium.TimeInterval({
start: start,
stop: stop
})]),
position: property,
// 根据所提供的速度计算点
orientation: new Cesium.VelocityOrientationProperty(property),
// 模型数据
model: {
uri: '../gltfModel/weixin.gltf',
minimumPixelSize: 128
},
path: {
resolution: 1,
material: new Cesium.PolylineGlowMaterialProperty({
glowPower: .1,
color: Cesium.Color.YELLOW
}),
width: 10
}
});
planeModel.position.setInterpolationOptions({ //设定位置的插值算法
interpolationDegree: 5,
interpolationAlgorithm: Cesium.LagrangePolynomialApproximation
});
var property2 = computeFlight2(data);
var entity_ty = viewer.entities.add({
availability: new Cesium.TimeIntervalCollection([new Cesium.TimeInterval({
start: start,
stop: stop
})]),
position: property2,
orientation: new Cesium.VelocityOrientationProperty(property2),
cylinder: {
HeightReference: Cesium.HeightReference.CLAMP_TO_GROUND,
length: 700000,
topRadius: 0,
bottomRadius: 700000 / 2,
material: Cesium.Color.RED.withAlpha(.4),
outline: !0,
numberOfVerticalLines: 0,
outlineColor: Cesium.Color.RED.withAlpha(.8)
},
});
entity_ty.position.setInterpolationOptions({
interpolationDegree: 5,
interpolationAlgorithm: Cesium.LagrangePolynomialApproximation
});
function computeFlight(source) {
var property = new Cesium.SampledPositionProperty();
for (var i = 0; i < source.length; i++) {
var time = Cesium.JulianDate.addSeconds(start, source[i].time, new Cesium.JulianDate);
var position = Cesium.Cartesian3.fromDegrees(source[i].longitude, source[i].dimension, source[i].height);
// 添加位置,和时间对应
property.addSample(time, position);
}
return property;
}
function computeFlight2(source) {
var property = new Cesium.SampledPositionProperty();
for (var i = 0; i < source.length; i++) {
var time = Cesium.JulianDate.addSeconds(start, source[i].time, new Cesium.JulianDate);
var position = Cesium.Cartesian3.fromDegrees(source[i].longitude, source[i].dimension, source[i].height / 2);
// 添加位置,和时间对应
property.addSample(time, position);
}
return property;
}
其中computeFlight 和 computeFlight2最大的区别就在于椎体的height的高度为卫星的一半;
本文转自 https://blog.csdn.net/caozl1132/article/details/86287900,如有侵权,请联系删除。