【转】地球坐标系 (WGS-84) 到火星坐标系 (GCJ-02) 的转换算法 C#

//
 
// Copyright (C) 1000 - 9999 Somebody Anonymous
 
// NO WARRANTY OR GUARANTEE
 
//
 
using System;
 
namespace Navi
 
{
 
    class EvilTransform
 
    {
 
        const double pi = 3.14159265358979324;
 
        //
 
        // Krasovsky 1940
 
        //
 
        // a = 6378245.0, 1/f = 298.3
 
        // b = a * (1 - f)
 
        // ee = (a^2 - b^2) / a^2;
 
        const double a = 6378245.0;
 
        const double ee = 0.00669342162296594323;
 
        //
 
        // World Geodetic System ==> Mars Geodetic System
 
        public static void transform(double wgLat, double wgLon, out double mgLat, out double mgLon)
 
        {
 
            if (outOfChina(wgLat, wgLon))
 
            {
 
                mgLat = wgLat;
 
                mgLon = wgLon;
 
                return;
 
            }
 
            double dLat = transformLat(wgLon - 105.0, wgLat - 35.0);
 
            double dLon = transformLon(wgLon - 105.0, wgLat - 35.0);
 
            double radLat = wgLat / 180.0 * pi;
 
            double magic = Math.Sin(radLat);
 
            magic =  - ee * magic * magic;
 
            double sqrtMagic = Math.Sqrt(magic);
 
            dLat = (dLat * 180.0) / ((a * ( - ee)) / (magic * sqrtMagic) * pi);
 
            dLon = (dLon * 180.0) / (a / sqrtMagic * Math.Cos(radLat) * pi);
 
            mgLat = wgLat + dLat;
 
            mgLon = wgLon + dLon;
 
        }
 
        static bool outOfChina(double lat, double lon)
 
        {
 
            if (lon < 72.004 || lon > 137.8347)
 
                return true;
 
            if (lat < 0.8293 || lat > 55.8271)
 
                return true;
 
            return false;
 
        }
 
        static double transformLat(double x, double y)
 
        {
 
            double ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * Math.Sqrt(Math.Abs(x));
 
            ret += (20.0 * Math.Sin(6.0 * x * pi) + 20.0 * Math.Sin(2.0 * x * pi)) * 2.0 / 3.0;
 
            ret += (20.0 * Math.Sin(y * pi) + 40.0 * Math.Sin(y / 3.0 * pi)) * 2.0 / 3.0;
 
            ret += (160.0 * Math.Sin(y / 12.0 * pi) +  * Math.Sin(y * pi / 30.0)) * 2.0 / 3.0;
 
            return ret;
 
        }
 
        static double transformLon(double x, double y)
 
        {
 
            double ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * Math.Sqrt(Math.Abs(x));
 
            ret += (20.0 * Math.Sin(6.0 * x * pi) + 20.0 * Math.Sin(2.0 * x * pi)) * 2.0 / 3.0;
 
            ret += (20.0 * Math.Sin(x * pi) + 40.0 * Math.Sin(x / 3.0 * pi)) * 2.0 / 3.0;
 
            ret += (150.0 * Math.Sin(x / 12.0 * pi) + 300.0 * Math.Sin(x / 30.0 * pi)) * 2.0 / 3.0;
 
            return ret;
 
        }
 
    }
 
}