GPS 坐标距离计算
CREATE FUNCTION [dbo].[Rad]( @d float ) RETURNS float BEGIN return @d * PI()/ 180.00; End
CREATE FUNCTION [dbo].[DISTANCE]( @lat1 float, @lng1 float, @lat2 float, @lng2 float ) RETURNS float BEGIN Declare @radLat1 float,@radLat2 float, @radLon1 float,@radLon2 float, @x1 float,@x2 float, @y1 float,@y2 float, @z1 float,@z2 float, @d float,@theta float,@dist float, @EARTH_RADIUS float = 6378.137; set @radLat1 = dbo.Rad(@lat1); set @radLat2 = dbo.Rad(@lat2); set @radLon1=dbo.Rad(@lng1); set @radLon2=dbo.Rad(@lng2); if @radLat1<0 set @radLat1 = PI() / 2 + ABS(@radLat1);-- south if @radLat1>0 set @radLat1 = PI() / 2 - ABS(@radLat1);-- north if @radLon1<0 set @radLon1 = PI() * 2 - ABS(@radLon1);-- west if @radLat2<0 set @radLat2 = PI() /2 -ABS(@radLat2);-- south if @radLat2>0 set @radLat2 = PI() / 2 - ABS(@radLat2);-- north if @radLon2<0 set @radLon2 = PI() * 2 - ABS(@radLon2);-- west set @x1= @EARTH_RADIUS * COS(@radLon1) * SIN(@radLat1); set @y1= @EARTH_RADIUS * SIN(@radLon1) * SIN(@radLat1); set @z1= @EARTH_RADIUS * COS(@radLat1); set @x2= @EARTH_RADIUS * COS(@radLon2) * SIN(@radLat2); set @y2= @EARTH_RADIUS * SIN(@radLon2) * SIN(@radLat2); set @z2= @EARTH_RADIUS * COS(@radLat2); set @d= SQRT( (@x1 - @x2) * (@x1 - @x2) + (@y1 - @y2) * (@y1 - @y2) + (@z1 - @z2) * (@z1 - @z2) ); --余弦定理求夹角 set @theta= ACOS((@EARTH_RADIUS * @EARTH_RADIUS + @EARTH_RADIUS * @EARTH_RADIUS - @d * @d) / (2 * @EARTH_RADIUS * @EARTH_RADIUS)); set @dist= @theta * @EARTH_RADIUS; return @dist; End
测试
select dbo.DISTANCE(113.52271, 22.263208, 113.520257, 22.245865)
/// <summary> /// 转化为弧度(rad) /// </summary> /// <param name="d"></param> /// <returns></returns> private static double rad(double d) { return d * Math.PI / 180.0; }
/// <summary> /// 基于余弦定理求两经纬度距离 /// </summary> /// <param name="lon1">第一点的经度</param> /// <param name="lat1">第一点的纬度</param> /// <param name="lon2">第二点的经度</param> /// <param name="lat2">第二点的纬度</param> /// <returns>返回的距离,单位km </returns> public static double LantitudeLongitudeDist(double lon1, double lat1, double lon2, double lat2) { var EARTH_RADIUS = 6378.137; double radLat1 = rad(lat1); double radLat2 = rad(lat2); double radLon1 = rad(lon1); double radLon2 = rad(lon2); if (radLat1 < 0) radLat1 = Math.PI / 2 + Math.Abs(radLat1);// south if (radLat1 > 0) radLat1 = Math.PI / 2 - Math.Abs(radLat1);// north if (radLon1 < 0) radLon1 = Math.PI * 2 - Math.Abs(radLon1);// west if (radLat2 < 0) radLat2 = Math.PI / 2 + Math.Abs(radLat2);// south if (radLat2 > 0) radLat2 = Math.PI / 2 - Math.Abs(radLat2);// north if (radLon2 < 0) radLon2 = Math.PI * 2 - Math.Abs(radLon2);// west double x1 = EARTH_RADIUS * Math.Cos(radLon1) * Math.Sin(radLat1); double y1 = EARTH_RADIUS * Math.Sin(radLon1) * Math.Sin(radLat1); double z1 = EARTH_RADIUS * Math.Cos(radLat1); double x2 = EARTH_RADIUS * Math.Cos(radLon2) * Math.Sin(radLat2); double y2 = EARTH_RADIUS * Math.Sin(radLon2) * Math.Sin(radLat2); double z2 = EARTH_RADIUS * Math.Cos(radLat2); double d = Math.Sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2) + (z1 - z2) * (z1 - z2)); //余弦定理求夹角 double theta = Math.Acos((EARTH_RADIUS * EARTH_RADIUS + EARTH_RADIUS * EARTH_RADIUS - d * d) / (2 * EARTH_RADIUS * EARTH_RADIUS)); double dist = theta * EARTH_RADIUS; return dist; }
[TestMethod] public void GPS() {var s = LantitudeLongitudeDist(113.52271, 22.263208, 113.520257, 22.245865); }
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