GPS坐标、火星坐标、百度坐标之间的转换--提供javascript版本转换代码

1、国内几种常用坐标系说明

WG-S84: GPS仪器记录的经纬度信息，Google Earth采用，Google Map中国范围外使用，高德地图中国范围外使用。
GCJ-02: 火星坐标系，中国国家测绘局制定的坐标系统，由WGS-84加密后的坐标。Google中国和搜搜地图，arcgis地图，高德地图
（在国内是不允许直接用WGS84坐标系标注的，必须经过加密后才能用。必须至少使用GCJ－02坐标系，或者使用在GCJ－02加密后再进行加密的坐标系，如百度坐标系）
BD-09:百度坐标，GCJ-02加密后的坐标系，只适用于百度地图

其他：MAPBAR:搜狗坐标系，图吧坐标等，估计也是在GCJ02基础上加密而成的，这里暂不涉及

2、下面给出前面3种坐标转换javascript算法

类命名为GPS,调用方法就是：

百度转高德：

var point=GPS.bd09_To_Gcj02(36.950656,114.556607)

百度转gps：

var point=GPS.bd09_To_Gps84(36.950656,114.556607)

var GPS = {
    PI : 3.14159265358979324,
    x_pi : 3.14159265358979324 * 3000.0 / 180.0,
    delta : function (lat, lon) {

        var a = 6378245.0; //  a: 卫星椭球坐标投影到平面地图坐标系的投影因子。
        var ee = 0.00669342162296594323; //  ee: 椭球的偏心率。
        var dLat = this.transformLat(lon - 105.0, lat - 35.0);
        var dLon = this.transformLon(lon - 105.0, lat - 35.0);
        var radLat = lat / 180.0 * this.PI;
        var magic = Math.sin(radLat);
        magic = 1 - ee * magic * magic;
        var sqrtMagic = Math.sqrt(magic);
        dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * this.PI);
        dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * this.PI);
        return {'lat': dLat, 'lon': dLon};
    },

    //84 to 火星坐标系 (GCJ-02)
    gps84_To_Gcj02 : function ( wgsLat , wgsLon )
    {
        if (this.outOfChina(wgsLat, wgsLon))
            return {'lat': wgsLat, 'lon': wgsLon};

        var d = this.delta(wgsLat, wgsLon);
        return {lat : wgsLat + d.lat,lon : wgsLon + d.lon};
    },

    //火星坐标系 (GCJ-02) to 百度坐标系 (BD-09)
    gcj02_To_Bd09:function(lat, lng)
    {
        let x_pi = 3.14159265358979324 * 3000.0 / 180.0;
        let x = lng;
        let y = lat;
        let z = Math.sqrt(x * x + y * y) + 0.00002 * Math.sin(y * x_pi);
        let theta = Math.atan2(y, x) + 0.000003 * Math.cos(x * x_pi);
        let lngs = z * Math.cos(theta) + 0.0065;
        let lats = z * Math.sin(theta) + 0.006;
        return {lat: lats,lon: lngs};
    },
    //百度坐标系 (BD-09) to 火星坐标系 (GCJ-02)
    bd09_To_Gcj02:function (lat, lng)
    {
        let x_pi = 3.14159265358979324 * 3000.0 / 180.0;
        let x = lng - 0.0065;
        let y = lat - 0.006;
        let z = Math.sqrt(x * x + y * y) - 0.00002 * Math.sin(y * x_pi);
        let theta = Math.atan2(y, x) - 0.000003 * Math.cos(x * x_pi);
        let lngs = z * Math.cos(theta);
        let lats = z * Math.sin(theta);

        return {lat: lats,lon: lngs}
    },
    gcj02_to_gps84:function (lat, lng)
    {
        var lat = +lat;
        var lng = +lng;
        if (this.outOfChina(lat, lng)) {
            return [lng, lat]
        } else {
            var dlat = this.transformLat(lng - 105.0, lat - 35.0);
            var dlng = this.transformLon(lng - 105.0, lat - 35.0);
            var radlat = lat / 180.0 * PI;
            var magic = Math.sin(radlat);
            magic = 1 - ee * magic * magic;
            var sqrtmagic = Math.sqrt(magic);
            dlat = (dlat * 180.0) / ((a * (1 - ee)) / (magic * sqrtmagic) * PI);
            dlng = (dlng * 180.0) / (a / sqrtmagic * Math.cos(radlat) * PI);
            var mglat = lat + dlat;
            var mglng = lng + dlng;
            return [lng * 2 - mglng, lat * 2 - mglat]
        }
    },
    gps84_To_Bd09 : function ( wgsLat , wgsLon )
    {
        let point=this.gps84_To_Gcj02(wgsLat,wgsLon);
        return this.gcj02_To_Bd09(point.lat,point.lon);
    },

    bd09_To_Gps84 : function ( wgsLat , wgsLon )
    {
        let point=this.bd09_To_Gcj02(wgsLat,wgsLon);
        return this.gcj02_to_gps84(point.lat,point.lon);
    },

     outOfChina : function (lat, lon) {
        if (lon < 72.004 || lon > 137.8347)
            return true;
        if (lat < 0.8293 || lat > 55.8271)
            return true;
        return false;
    },
    transformLat : function (x, y) {
        var ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * Math.sqrt(Math.abs(x));
        ret += (20.0 * Math.sin(6.0 * x * this.PI) + 20.0 * Math.sin(2.0 * x * this.PI)) * 2.0 / 3.0;
        ret += (20.0 * Math.sin(y * this.PI) + 40.0 * Math.sin(y / 3.0 * this.PI)) * 2.0 / 3.0;
        ret += (160.0 * Math.sin(y / 12.0 * this.PI) + 320 * Math.sin(y * this.PI / 30.0)) * 2.0 / 3.0;
        return ret;
    },
    transformLon : function (x, y) {
        var ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * Math.sqrt(Math.abs(x));
        ret += (20.0 * Math.sin(6.0 * x * this.PI) + 20.0 * Math.sin(2.0 * x * this.PI)) * 2.0 / 3.0;
        ret += (20.0 * Math.sin(x * this.PI) + 40.0 * Math.sin(x / 3.0 * this.PI)) * 2.0 / 3.0;
        ret += (150.0 * Math.sin(x / 12.0 * this.PI) + 300.0 * Math.sin(x / 30.0 * this.PI)) * 2.0 / 3.0;
        return ret;
    }
};

调用的html示例如下：

<!DOCTYPE html>
<html>
<head>
    <title>Quick Start - Leaflet</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link rel="shortcut icon" type="image/x-icon" href="docs/images/favicon.ico" />
    <link rel="stylesheet" type="text/css" href="https://unpkg.com/leaflet@1.7.1/dist/leaflet.css">
    <script type="text/javascript" src="https://unpkg.com/leaflet@1.7.1/dist/leaflet.js"></script>
    <script type="text/javascript" src="../lib/GPS.js"></script>
     <style type="text/css">
    body {
        padding: 0;
        margin: 0;
    }
    html,
    body
    {
        height: 100%;
    }
    #mapid
    {
        height: 75%;
     }
    </style>
</head>
<body>

<div id="mapid" style="float:left;width:100%;height: 100%;">

</div>

<script>
    var point=GPS.bd09_To_Gcj02(36.950656,114.556607)

    var mymap = L.map('mapid').setView([point.lat,point.lon], 14);

    this.baseLayer=L.tileLayer("http://webrd0{s}.is.autonavi.com/appmaptile?lang=zh_cn&size=1&scale=1&style=8&x={x}&y={y}&z={z}",{
        attribution: '&copy; 高德地图',
        maxZoom: 18,
        minZoom: 4,
        subdomains: "1234"
    }).addTo(mymap);

    L.circleMarker([point.lat,point.lon], {
        stroke: true,
        color: '#aaaaaa',
        weight: 1,
        opacity:1,
        fillColor: '#00E400',
        fillOpacity: 1,
        radius:10
    }).addTo(mymap).bindPopup("<b>Hello world!</b><br />I am a popup.");

</script>
</body>
</html>