地图坐标系转换-526互联


/**
 * 各地图API坐标系统比较与转换;
 * 
 * WGS84坐标系：即地球坐标系，国际上通用的坐标系。设备一般包含GPS芯片或者北斗芯片获取的经纬度为WGS84地理坐标系,
 * 谷歌地图采用的是WGS84地理坐标系（中国范围除外）;
 * 
 * GCJ02坐标系：即火星坐标系，是由中国国家测绘局制订的地理信息系统的坐标系统。由WGS84坐标系经加密后的坐标系。
 * 高德地图、腾讯地图、谷歌中国地图和搜搜中国地图采用的是GCJ02地理坐标系;
 * 
 * BD09坐标系：即百度坐标系，GCJ02坐标系经加密后的坐标系;
 * 
 * 搜狗坐标系、图吧坐标系等，估计也是在GCJ02基础上加密而成的。
 * 
 * @author 
 * 
 */
public class PositionUtil {
	private static double pi = 3.1415926535897932384626;
	private static double a = 6378245.0;
	private 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 Gps gps84_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 Gps(mgLat, mgLon);
	}

	/**
	 * 火星坐标系 (GCJ-02) to 84
	 * 
	 * @param lon
	 * @param lat
	 * @return
	 */
	public static Gps gcj02_To_Gps84(double lat, double lon) {
		Gps gps = transform(lat, lon);
		double lontitude = lon * 2 - gps.getWgLon();
		double latitude = lat * 2 - gps.getWgLat();

		return new Gps(latitude, lontitude);

	}

	/**
	 * 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 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);
	}

	/**
	 * 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 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);
	}

	private 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;
	}

	private 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);
	}

	private 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;
	}

	private 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;
	}

}