wgs84、gcj02、bd09 坐标系转换
1、简述
-
wgs84 84年提出，大地坐标，也是原始坐标。
-
gcj02 02年提出，火星坐标，经过加密算法。大多数非百度中国地图厂商基本都是使用的火星坐标：高德，腾讯，谷歌中国cn
-
bd09 09年提出，百度坐标，经过火星坐标再次加密，相当于对大地坐标经过了二次加密。百度自己使用
-
一般的算法，没有直接bd09->wgs84或者wgs84->bd09，都需要借助wgs84->gcj02或者gcj02->wgs84算法推导。
2.实现
/**
* wgs84 84年提出，大地坐标，也是原始坐标。
* gcj02 02年提出，火星坐标，经过加密算法。大多数非百度中国地图厂商基本都是使用的火星坐标：高德，腾讯，谷歌中国cn
* bd09 09年提出，百度坐标，经过火星坐标再次加密，相当于对大地坐标经过了二次加密。百度自己使用
* 一般的算法，没有直接bd09->wgs84或者wgs84->bd09，都需要借助wgs84->gcj02或者gcj02->wgs84算法推导。
*
* description: 常用坐标系转换
* author: chengpengai
* date: 2023-10-07 周六 14:03
*/
public class GpsTransfer {
//π的定义
public static double pi = 3.1415926535897932384626;
//椭球长半径，依据克拉索索夫斯基椭球系数计算
public static double a = 6378245.0;
//第一偏心率的平方
public static double ee = 0.00669342162296594323;
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;
}
/***
* 判断是否在中国范围之内
* @param lat
* @param lon
* @return
*/
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;
}
/***
* 把公式部分抽取出来
* @param lat
* @param lon
* @return
*/
public static Gps transform(double lat, double lon) {
if (outOfChina(lat, lon)) {
return new Gps(lat, lon);
}
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 Gps(mgLat, mgLon);
}
/***
* wgs84到gcj02转换
* @param lat
* @param lon
* @return
*/
public static Gps wgs84_To_Gcj02(double lat, double lon) {
return transform(lat, lon);
}
/***
* 简单的gcj02到wgs84坐标类型转换，只做了一次迭代
*/
public static Gps gcj02_To_Wgs84(double lat, double lon) {
Gps gps = transform(lat, lon);
double lontitude = lon * 2 - gps.getLon();
double latitude = lat * 2 - gps.getLat();
return new Gps(latitude, lontitude);
}
/***
* 稍微精确一点的gcj02到wgs84转换
* @param lat
* @param lon
* @return
*/
public static Gps gcj02_To_Wgs84_exact(double lat,double lon) {
if (outOfChina(lat, lon)) {
return gcj02_To_Wgs84(lat, lon);
}
double initDelta = 0.01;
double threshold = 0.000001;
double dLat = initDelta;
double dLon = initDelta;
double mLat = lat - dLat;
double mLon = lon - dLon;
double pLat = lat + dLat;
double pLon = lon + dLon;
double wgsLat = 0;
double wgsLon = 0;
int i = 0;
while (true) {
wgsLat = (mLat + pLat) / 2;
wgsLon = (mLon + pLon) / 2;
Gps tmp = wgs84_To_Gcj02(wgsLat, wgsLon);
dLat = tmp.getLat() - lat;
dLon = tmp.getLon() - lon;
if ((Math.abs(dLat) < threshold) && (Math.abs(dLon) < threshold)) {
break;
}
if (dLat > 0) { pLat = wgsLat; } else { mLat = wgsLat;}
if (dLon > 0) { pLon = wgsLon; } else { mLon = wgsLon;}
if (++i > 1000) break;
}
return new Gps(wgsLat, wgsLon);
}
/***
* 百度坐标是在火星坐标基础上做的二次加密
* @param gg_lat
* @param gg_lon
* @return
*/
public static Gps 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 Gps(bd_lat, bd_lon);
}
/***
* 百度坐标与火星坐标逆向转换
* @param bd_lat
* @param bd_lon
* @return
*/
public static Gps 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 Gps(gg_lat, gg_lon);
}
public static void main(String[] args) {
Gps gps = new Gps(31.782706, 119.947057);
System.out.println("wgs:"+gps);//{39.9072885060602,116.39123343289631}
Gps gps2 = wgs84_To_Gcj02(gps.getLat(), gps.getLon());
System.out.println("gch02:"+gps2);//{39.9086897410389,116.39747455259267}
// Gps gps3 = gcj02_To_Wgs84(gps2.getLat(), gps2.getLon());
// System.out.println(gps3);//{39.907286247736586,116.39123098626051}
// Gps gps4 = gcj02_To_Wgs84_exact(gps2.getLat(), gps2.getLon());
// System.out.println(gps4);//{39.907288984202964,116.3912337078661} 相对一次迭代是精确了，但是好像也不是完全还原
}
}
import lombok.Data;
/**
* description: GPS点位详情
* author: chengpengai
* date: 2023-10-07 周六 14:10
*/
@Data
public class Gps {
double lat,lon;
public Gps() {
}
public Gps(double lat,double lon){
this.lat = lat;
this.lon = lon;
}
@Override
public String toString() {
return "{" + lat + "," + lon + "}";
}
}
