google地图、高德地图基于基站定位位置纠偏

GPS纠偏算法，适用于google,高德体系的地图,精确度还比较高。我试了一下比高德本身的纠偏还精确点。

  
 
/** 
 * gps纠偏算法，适用于google,高德体系的地图 
 * @author Administrator 
 */ 
public class GpsCorrect { 
	final static double pi = 3.14159265358979324; 
	final static double a = 6378245.0; 
	final static double ee = 0.00669342162296594323; 
 
	public static void transform(double wgLat, double wgLon, double[] latlng) { 
		if (outOfChina(wgLat, wgLon)) { 
			latlng[0] = wgLat; 
			latlng[1] = wgLon; 
			return; 
		} 
		double dLat = transformLat(wgLon - 105.0, wgLat - 35.0); 
		double dLon = transformLon(wgLon - 105.0, wgLat - 35.0); 
		double radLat = wgLat / 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); 
		latlng[0] = wgLat + dLat; 
		latlng[1] = wgLon + dLon; 
	} 
 
	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 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; 
	} 
}