从google maps的脚本里扒了段代码,没准啥时会用上。大家一块看看是怎么算的。
private const double
EARTH_RADIUS = 6378.137;
private static double rad(double
d)
{
return d * Math.PI / 180.0;
}
public static double GetDistance(double lat1, double lng1, double lat2,
double lng2)
{
double radLat1 =
rad(lat1);
double radLat2 =
rad(lat2);
double a = radLat1 -
radLat2;
double b = rad(lng1) -
rad(lng2);
double s = 2 *
Math.Asin(Math.Sqrt(Math.Pow(Math.Sin(a/2),2) +
Math.Cos(radLat1)*Math.Cos(radLat2)*Math.Pow(Math.Sin(b/2),2)));
s
= s * EARTH_RADIUS;
s = Math.Round(s * 10000) /
10000;
return s;
}