各地圖座標系轉換(WGS84座標系,GCJ02座標系,BD09座標系)

package position;

import org.junit.Test;

/**
 * 各地圖API座標系統比較與轉換;
 * 
 * WGS84座標系：即地球座標系，國際上通用的座標系。設備一般包含GPS芯片或者北斗芯片獲取的經緯度爲WGS84地理座標系,谷歌地圖採用的是WGS84地理座標系（中國範圍除外）;
 * 
 * GCJ02座標系：即火星座標系，是由中國國家測繪局制訂的地理信息系統的座標系統。由WGS84座標系經加密後的座標系。谷歌中國地圖和搜搜中國地圖採用的是GCJ02地理座標系;
 * 
 * BD09座標系：即百度座標系，GCJ02座標系經加密後的座標系;
 * 
 * 搜狗座標系、圖吧座標系等，估計也是在GCJ02基礎上加密而成的。
 * 
 * @author chenhua
 * 
 */
public class PositionUtil
{
	private static double pi = 3.1415926535897932384626;
	private static double a = 6378245.0;
	private static double ee = 0.00669342162296594323;

	@Test
	public void t1()
	{
		// 北斗芯片獲取的經緯度爲WGS84地理座標 31.426896,119.496145

		Gps gps = new Gps(31.426896, 119.496145);
		System.out.println("gps :" + gps);

		Gps gcj = gps84_To_Gcj02(gps.getWgLat(), gps.getWgLon());
		System.out.println("gcj :" + gcj);

		Gps star = gcj_To_Gps84(gcj.getWgLat(), gcj.getWgLon());
		System.out.println("star:" + star);

		Gps bd = gcj02_To_Bd09(gcj.getWgLat(), gcj.getWgLon());
		System.out.println("bd  :" + bd);

		Gps gcj2 = bd09_To_Gcj02(bd.getWgLat(), bd.getWgLon());
		System.out.println("gcj :" + gcj2);

	}

	/**
	 * 84 to 火星座標系 (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);
	}

	/**
	 * 火星座標系 (GCJ-02) to 84
	 * 
	 * @param lon
	 * @param lat
	 * @return
	 */
	public Gps gcj_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);

	}

	/**
	 * 火星座標系 (GCJ-02) 與百度座標系 (BD-09) 的轉換算法
	 * 
	 * 將 GCJ-02 座標轉換成 BD-09 座標
	 * 
	 * @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);
	}

	/**
	 * 火星座標系 (GCJ-02) 與百度座標系 (BD-09) 的轉換算法
	 * 
	 * 將 BD-09 座標轉換成GCJ-02 座標
	 * 
	 * @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 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;
	}

}

package position;

public class Gps
{

	private double wgLat;
	private double wgLon;

	public Gps(double wgLat, double wgLon)
	{
		setWgLat(wgLat);
		setWgLon(wgLon);
	}

	public double getWgLat()
	{
		return wgLat;
	}

	public void setWgLat(double wgLat)
	{
		this.wgLat = wgLat;
	}

	public double getWgLon()
	{
		return wgLon;
	}

	public void setWgLon(double wgLon)
	{
		this.wgLon = wgLon;
	}

	@Override
	public String toString()
	{
		return wgLat + "," + wgLon;
	}

}