已知一点经纬度，方位角，距离，求另一点经纬度

参考了博文：http://blog.csdn.net/pyx6119822/article/details/52298037

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package hellotest;

public class LonLatTest3 {

	/*
	 * 大地坐标系资料WGS-84 长半径a=6378137 短半径b=6356752.3142 扁率f=1/298.2572236
	 */
	/** 长半径a=6378137 */
	private double a = 6378137;
	/** 短半径b=6356752.3142 */
	private double b = 6356752.3142;
	/** 扁率f=1/298.2572236 */
	private double f = 1 / 298.2572236;

	/**
	 * 计算另一点经纬度
	 * 
	 * @param lon
	 *            经度
	 * @param lat
	 *            维度
	 * @param lonlat
	 *            已知点经纬度
	 * @param brng
	 *            方位角
	 * @param dist
	 *            距离（米）
	 */
	public void computerThatLonLat(double lon, double lat, double brng, double dist) {

		double alpha1 = rad(brng);
		double sinAlpha1 = Math.sin(alpha1);
		double cosAlpha1 = Math.cos(alpha1);

		double tanU1 = (1 - f) * Math.tan(rad(lat));
		double cosU1 = 1 / Math.sqrt((1 + tanU1 * tanU1));
		double sinU1 = tanU1 * cosU1;
		double sigma1 = Math.atan2(tanU1, cosAlpha1);
		double sinAlpha = cosU1 * sinAlpha1;
		double cosSqAlpha = 1 - sinAlpha * sinAlpha;
		double uSq = cosSqAlpha * (a * a - b * b) / (b * b);
		double A = 1 + uSq / 16384 * (4096 + uSq * (-768 + uSq * (320 - 175 * uSq)));
		double B = uSq / 1024 * (256 + uSq * (-128 + uSq * (74 - 47 * uSq)));

		double cos2SigmaM=0;
		double sinSigma=0;
		double cosSigma=0;
		double sigma = dist / (b * A), sigmaP = 2 * Math.PI;
		while (Math.abs(sigma - sigmaP) > 1e-12) {
			cos2SigmaM = Math.cos(2 * sigma1 + sigma);
			sinSigma = Math.sin(sigma);
			cosSigma = Math.cos(sigma);
			double deltaSigma = B * sinSigma * (cos2SigmaM + B / 4 * (cosSigma * (-1 + 2 * cos2SigmaM * cos2SigmaM)
					- B / 6 * cos2SigmaM * (-3 + 4 * sinSigma * sinSigma) * (-3 + 4 * cos2SigmaM * cos2SigmaM)));
			sigmaP = sigma;
			sigma = dist / (b * A) + deltaSigma;
		}

		double tmp = sinU1 * sinSigma - cosU1 * cosSigma * cosAlpha1;
		double lat2 = Math.atan2(sinU1 * cosSigma + cosU1 * sinSigma * cosAlpha1,
				(1 - f) * Math.sqrt(sinAlpha * sinAlpha + tmp * tmp));
		double lambda = Math.atan2(sinSigma * sinAlpha1, cosU1 * cosSigma - sinU1 * sinSigma * cosAlpha1);
		double C = f / 16 * cosSqAlpha * (4 + f * (4 - 3 * cosSqAlpha));
		double L = lambda - (1 - C) * f * sinAlpha
				* (sigma + C * sinSigma * (cos2SigmaM + C * cosSigma * (-1 + 2 * cos2SigmaM * cos2SigmaM)));

		double revAz = Math.atan2(sinAlpha, -tmp); // final bearing

		System.out.println(revAz);
		System.out.println(lon+deg(L)+","+deg(lat2));
	}

	/**
	 * 度换成弧度
	 * 
	 * @param d
	 *            度
	 * @return 弧度
	 */
	private double rad(double d) {
		return d * Math.PI / 180.0;
	}

	/**
	 * 弧度换成度
	 * 
	 * @param x
	 *            弧度
	 * @return 度
	 */
	private double deg(double x) {
		return x * 180 / Math.PI;
	}
	
	
	public static void main(String[] args) {
		LonLatTest3 test=new LonLatTest3();
		double lon=121.62486;
		double lat=29.87816;
		double brng=90;
		double dist=50;
		
		test.computerThatLonLat(lon, lat, brng, dist);
	}

}

效果：