【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 = 1 - ee * magic * magic;

            double sqrtMagic = Math.Sqrt(magic);


            dLat = (dLat * 180.0) / ((a * (1 - 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) + 320 * 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;

        }

    }

}