用于GPS換算世界上任意兩點間距離
/// <summary>
/// 計算地球上任意兩點距離
/// </summary>
/// <param name="long1"></param>
/// <param name="lat1"></param>
/// <param name="long2"></param>
/// <param name="lat2"></param>
/// <returns>返回長度單位是米</returns>
private static double Distance(double long1, double lat1, double long2, double lat2)
{
double a, b, R;
R = 6378137; //地球半徑
lat1 = lat1 * Math.PI / 180.0;
lat2 = lat2 * Math.PI / 180.0;
a = lat1 - lat2;
b = (long1 - long2) * Math.PI / 180.0;
double d;
double sa2, sb2;
sa2 = Math.Sin(a / 2.0);
sb2 = Math.Sin(b / 2.0);
d = 2 * R * Math.Asin(Math.Sqrt(sa2 * sa2 + Math.Cos(lat1) * Math.Cos(lat2) * sb2 * sb2));
return d;
}
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posted on 2010-05-01 14:16
TiGERTiAN 閱讀(3048)
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