GPS点之间的距离

Question

我正在尝试以km为单位计算两点之间的距离。

但是我觉得我的公式可能有误，我用Google地图计算了距离（所以我觉得我有有效的测试数据）

TESTDATA

职位1： 50.123248,8.847602

职位2： 50.120132,8.841926

距离（根据谷歌地图）： 531,34米

我的方法

public double distanceTo(Location location) {
    final int EARTH_RADIUS_KM = 6371;

    double lng1 = this.longitude;
    double lng2 = location.getLongitude();
    double lat1 = this.latitude;
    double lat2 = location.getLatitude();

    double theta = lng1 - lng2;

    double dist = Math.sin(deg2rad(lat1)) * Math.sin(deg2rad(lat2)) + Math.cos(deg2rad(lat1)) * Math.cos(deg2rad(lat2)) * Math.cos(deg2rad(theta));

    dist = Math.acos(dist);

    dist = rad2deg(dist);

    dist = dist * 60 * 1.1515;

    dist = dist * 1.609344; //for Kilometers

    return (dist);

}

/**
 * decimal degrees to radians
 *
 * @param deg
 * @return
 */
private double deg2rad(double deg) {

    return (deg * Math.PI / 180.0);

}


/**
 * radians to decimal degrees
 *
 * @param rad
 * @return
 */
private double rad2deg(double rad) {

    return (rad * 180.0 / Math.PI);

}

测试用例：

@Before
public void setup() {

    location1 = new Location(50.123248, 8.847602);
    location2 = new Location(50.120132, 8.841926);


}

@Test
public void testDistanceTo() {
//TODO No real assertion yet
    System.out.print(location1.distanceTo(location2));

// Expecting 531,34 m - 0.531 KM
}

但实际结果为0.7179858613314315