地球是一个近乎标准的椭球体,它的赤道半径为6378.140千米,极半径为 6356.755千米,平均半径6371.004千米。
/// <summary> /// 给定的经度1,纬度1;经度2,纬度2. 计算2个经纬度之间的距离。 /// </summary> /// <param name="lat1">纬度1</param> /// <param name="lon1">经度1</param> /// <param name="lat2">纬度2</param> /// <param name="lon2">经度2</param> /// <returns>距离(公里、千米)</returns> private double Distance(double lat1, double lon1, double lat2, double lon2) { double EARTH_RADIUS = 6371.0; //用haversine公式计算球面两点间的距离。 //经纬度转换成弧度 lat1 = ConvertDegreesToRadians(lat1); lon1 = ConvertDegreesToRadians(lon1); lat2 = ConvertDegreesToRadians(lat2); lon2 = ConvertDegreesToRadians(lon2); //差值 var vLon = Math.Abs(lon1 - lon2); var vLat = Math.Abs(lat1 - lat2); // h is the great circle distance in radians, great circle // 就是一个球体上的切面,它的圆心即是球心的一个周长最大的圆。 var h = HaverSin(vLat) + Math.Cos(lat1) * Math.Cos(lat2) * HaverSin(vLon); var distance = 2 * EARTH_RADIUS * Math.Asin(Math.Sqrt(h)); return distance; } /// <summary> /// 将角度换算为弧度。 /// </summary> /// <param name="degrees">角度</param> /// <returns>弧度</returns> private double ConvertDegreesToRadians(double degrees) { return degrees * Math.PI / 180; } /// <summary> /// 将弧度换算为角度。 /// </summary> /// <param name="radian"></param> /// <returns></returns> private double ConvertRadiansToDegrees(double radian) { return radian * 180.0 / Math.PI; } /// <summary> /// HaverSin /// </summary> /// <param name="theta"></param> /// <returns></returns> private double HaverSin(double theta) { var v = Math.Sin(theta / 2); return v * v; }
在线计算经纬度距离工具 http://www.gpsspg.com/distance.htm