给你一组坐标 116.397477,39.908692 你能确认他的准确位置吗? 答案是不能 ! 为什么呢? 因为你不知道他使用的是哪种坐标系统.
现在主要有这么几种坐标系 : 美国标准(国际共识)WGS-84坐标系统(地球坐标)、中国标准(加密过后的坐标系统)GCJ-02坐标系统(火星坐标)。 (注:我们在业内将前者称之为地球坐标,后者称之为火星坐标)
但是各大地图又有自己不同的坐标系统:
地图坐标系统百度地图百度坐标 (BD-09)腾讯搜搜地图火星坐标搜狐搜狗地图搜狗坐标阿里云地图火星坐标图吧MapBar地图图吧坐标高德MapABC地图火星坐标灵图51ditu地图火星坐标扫盲参考地址 -speedboy007的专栏
其中百度地图作为国内最大运营商, 它的坐标系统需要单独提一下 . 百度官方解释 : 国际经纬度坐标标准为WGS-84,国内必须至少使用国测局制定的GCJ-02,对地理位置进行首次加密。百度坐标在此基础上,进行了BD-09二次加密措.
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地理坐标类:
public class Geo { private double lon; private double lat; public Geo() { super(); } public Geo(double lon, double lat) { this.lon = lon; this.lat = lat; } public double getLon() { return lon; } public void setLon(double lon) { this.lon = lon; } public double getLat() { return lat; } public void setLat(double lat) { this.lat = lat; } @Override public String toString() { return lon + "," + lat; } }坐标转换工具:
public class GeoUtil { public static double pi = 3.1415926535897932384626; public static double a = 6378245.0; public static double ee = 0.00669342162296594323; /** * 84 to 火星坐标系 (GCJ-02) World Geodetic System ==> Mars Geodetic System * * @param lat * @param lon * @return */ public static Geo Geo84_To_Gcj02(double lat, double lon) { if (outOfChina(lat, lon)) { return null; } double dLat = transformLat(lon - 105.0, lat - 35.0); double dLon = transformLon(lon - 105.0, lat - 35.0); double radLat = lat / 180.0 * pi; double magic = Math.sin(radLat); magic = 1 - ee * magic * magic; double sqrtMagic = Math.sqrt(magic); dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * pi); dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * pi); double mgLat = lat + dLat; double mgLon = lon + dLon; return new Geo(mgLon, mgLat); } /** * * 火星坐标系 (GCJ-02) to 84 * * @param lon * @param lat * @return * */ public static Geo gcj_To_Geo84(double lat, double lon) { Geo Geo = transform(lat, lon); double lontitude = lon * 2 - Geo.getLon(); double latitude = lat * 2 - Geo.getLat(); return new Geo(lontitude, latitude); } /** * 火星坐标系 (GCJ-02) 与百度坐标系 (BD-09) 的转换算法 将 GCJ-02 坐标转换成 BD-09 坐标 * * @param gg_lat * @param gg_lon */ public static Geo gcj02_To_Bd09(double gg_lat, double gg_lon) { double x = gg_lon, y = gg_lat; double z = Math.sqrt(x * x + y * y) + 0.00002 * Math.sin(y * pi); double theta = Math.atan2(y, x) + 0.000003 * Math.cos(x * pi); double bd_lon = z * Math.cos(theta) + 0.0065; double bd_lat = z * Math.sin(theta) + 0.006; return new Geo(bd_lon, bd_lat); } /** * * 火星坐标系 (GCJ-02) 与百度坐标系 (BD-09) 的转换算法 * * 将 BD-09 坐标转换成GCJ-02 坐标 * * @param * bd_lat * @param bd_lon * @return */ public static Geo bd09_To_Gcj02(double bd_lat, double bd_lon) { double x = bd_lon - 0.0065, y = bd_lat - 0.006; double z = Math.sqrt(x * x + y * y) - 0.00002 * Math.sin(y * pi); double theta = Math.atan2(y, x) - 0.000003 * Math.cos(x * pi); double gg_lon = z * Math.cos(theta); double gg_lat = z * Math.sin(theta); return new Geo(gg_lon, gg_lat); } /** * (BD-09)-->84 * @param bd_lat * @param bd_lon * @return */ public static Geo bd09_To_Geo84(double bd_lat, double bd_lon) { Geo gcj02 = GeoUtil.bd09_To_Gcj02(bd_lat, bd_lon); Geo map84 = GeoUtil.gcj_To_Geo84(gcj02.getLat(), gcj02.getLon()); return map84; } public static boolean outOfChina(double lat, double lon) { if (lon < 72.004 || lon > 137.8347) return true; if (lat < 0.8293 || lat > 55.8271) return true; return false; } public static Geo transform(double lat, double lon) { if (outOfChina(lat, lon)) { return new Geo(lon, lat); } double dLat = transformLat(lon - 105.0, lat - 35.0); double dLon = transformLon(lon - 105.0, lat - 35.0); double radLat = lat / 180.0 * pi; double magic = Math.sin(radLat); magic = 1 - ee * magic * magic; double sqrtMagic = Math.sqrt(magic); dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * pi); dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * pi); double mgLat = lat + dLat; double mgLon = lon + dLon; return new Geo(mgLon, mgLat); } public static double transformLat(double x, double y) { double 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 * pi) + 20.0 * Math.sin(2.0 * x * pi)) * 2.0 / 3.0; ret += (20.0 * Math.sin(y * pi) + 40.0 * Math.sin(y / 3.0 * pi)) * 2.0 / 3.0; ret += (160.0 * Math.sin(y / 12.0 * pi) + 320 * Math.sin(y * pi / 30.0)) * 2.0 / 3.0; return ret; } public static double transformLon(double x, double y) { double 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 * pi) + 20.0 * Math.sin(2.0 * x * pi)) * 2.0 / 3.0; ret += (20.0 * Math.sin(x * pi) + 40.0 * Math.sin(x / 3.0 * pi)) * 2.0 / 3.0; ret += (150.0 * Math.sin(x / 12.0 * pi) + 300.0 * Math.sin(x / 30.0 * pi)) * 2.0 / 3.0; return ret; } public static void main(String[] args) { // 北斗芯片获取的经纬度为WGS84地理坐标 116.397477,39.908692 Geo Geo = new Geo(116.397477,39.908692); System.out.println("Geo :" + Geo); Geo gcj = Geo84_To_Gcj02(Geo.getLat(), Geo.getLon()); System.out.println("gcj :" + gcj); Geo star = gcj_To_Geo84(gcj.getLat(), gcj.getLon()); System.out.println("star:" + star); Geo bd = gcj02_To_Bd09(gcj.getLat(), gcj.getLon()); System.out.println("bd :" + bd); Geo gcj2 = bd09_To_Gcj02(bd.getLat(), bd.getLon()); System.out.println("gcj :" + gcj2); } }(注 : 在这些坐标准换过程中, 由于精度问题, 会导致转换几次后结果不一致)
高德API-坐标转换API URL : http://lbs.amap.com/api/webservice/guide/api/convert 高德-拾取坐标系统 URL : http://lbs.amap.com/console/show/picker
百度API-坐标转换API URL : http://lbsyun.baidu.com/index.php?title=webapi/guide/changeposition 百度-拾取坐标系统 URL : http://api.map.baidu.com/lbsapi/getpoint/index.html
(注: 拾取坐标系统 - 可通过坐标反查位置, 也可用位置信息查询对应坐标)
