坐標系間的轉換

一、各大坐標系

　　目前地圖開發離不開定位，定位又離不開坐標系的選取和轉換，所以有必要簡單說一下啦。

世界大地坐標（WGS84）

　　1.國際上采用的標准，是為GPS全球定位系統使用而建立的坐標系統，可從專業GPS設備中獲取數據。

　　2.國際地圖使用的坐標系。

       3.谷歌國外地圖、osm地圖

火星坐標（GCJ-02）

　　1.中國采用的標准，准確是叫國測局坐標系，可從國行移動設備定位獲得數據

　　2.國內出版的各類地圖都至少采用GCJ-02對地理位置進行加密偏移

　　3.高德地圖、天地圖、搜搜地圖等

百度坐標（BD-09）

　　1.百度地圖自己采用的坐標標准。

　　2.百度坐標是在GCJ-02的基礎上再次加密

　　3.百度地圖

二、各大坐標系間的轉換

通用實體 

    /// <summary>
    /// 經度和緯度
    /// </summary>
    public class StationGps
    {
        /// <summary>
        /// 經度
        /// </summary>
        public double longitude { get; set; }
        /// <summary>
        /// 緯度
        /// </summary>
        public double latitude { get; set; }
    }

 

1、火星坐標轉百度

       private static double x_pi = 3.14159265358979324 * 3000.0 / 180.0;

        public static StationGps HxToBd(double lon, double lat)
        {
            var result = new StationGps();
            double x = lon, y = lat;
            var z = Math.Sqrt(x * x + y * y) + 0.00002 * Math.Sin(y * x_pi);
            var theta = Math.Atan2(y, x) + 0.000003 * Math.Cos(x * x_pi);
            result.longitude = z * Math.Cos(theta) + 0.0065;
            result.latitude = z * Math.Sin(theta) + 0.006;
            return result;
        }

2、百度轉火星坐標

        private static double x_pi = 3.14159265358979324 * 3000.0 / 180.0;
          
        public static StationGps BdToHx(double lon, double lat)
        {
            var result = new StationGps();
            double x = lon - 0.0065, y = lat - 0.006;
            var z = Math.Sqrt(x * x + y * y) - 0.00002 * Math.Sin(y * x_pi);
            var theta = Math.Atan2(y, x) - 0.000003 * Math.Cos(x * x_pi);
            result.longitude = z * Math.Cos(theta);
            result.latitude = z * Math.Sin(theta);
            return result;
        }

3、世界大地坐標轉火星坐標

        private static double pi = 3.14159265358979324;
        private static double a = 6378245.0;
        private static double ee = 0.00669342162296594323; 

        public static StationGps WgsToHx(double lon, double lat)
        {
            var result = new StationGps();
            double dLat = TransformLat(lat - 35.0, lon - 105.0);
            double dLon = TransformLon(lat - 35.0, lon - 105.0);
            double radLat = lat / 180.0 * pi;
            double magic = Math.Sin(radLat);
            magic = 1 - ee * magic * magic;
            var sqrtMagic = Math.Sqrt(magic);
            dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * pi);
            dLon = (dLon * 180.0) / (a / sqrtMagic * Math.Cos(radLat) * pi);
            result.latitude = lat + dLat;
            result.longitude = lon + dLon;
            return result;
        }

        private static double TransformLat(double lon, double lat)
        {
            var ret = -100.0 + 2.0 * lat + 3.0 * lon + 0.2 * lon * lon + 0.1 * lat * lon + 0.2 * Math.Sqrt(Math.Abs(lat));
            ret += (20.0 * Math.Sin(6.0 * lat * pi) + 20.0 * Math.Sin(2.0 * lat * pi)) * 2.0 / 3.0;
            ret += (20.0 * Math.Sin(lon * pi) + 40.0 * Math.Sin(lon / 3.0 * pi)) * 2.0 / 3.0;
            ret += (160.0 * Math.Sin(lon / 12.0 * pi) + 320 * Math.Sin(lon * pi / 30.0)) * 2.0 / 3.0;
            return ret;
        }
        private static double TransformLon(double lon, double lat)
        {
            var ret = 300.0 + lat + 2.0 * lon + 0.1 * lat * lat + 0.1 * lat * lon + 0.1 * Math.Sqrt(Math.Abs(lat));
            ret += (20.0 * Math.Sin(6.0 * lat * pi) + 20.0 * Math.Sin(2.0 * lat * pi)) * 2.0 / 3.0;
            ret += (20.0 * Math.Sin(lat * pi) + 40.0 * Math.Sin(lat / 3.0 * pi)) * 2.0 / 3.0;
            ret += (150.0 * Math.Sin(lat / 12.0 * pi) + 300.0 * Math.Sin(lat / 30.0 * pi)) * 2.0 / 3.0;
            return ret;
        }

4、世界大地坐標轉為百度坐標

        private static double pi = 3.14159265358979324;
        private static double a = 6378245.0;
        private static double ee = 0.00669342162296594323;
        private static double x_pi = 3.14159265358979324 * 3000.0 / 180.0; 

        public static StationGps WgsToBd(double lon, double lat)
        {
            var hx = WgsToHx(lon, lat);
            var bd = HxToBd(hx.longitude, hx.latitude);
            return bd;
        }

        public static StationGps HxToBd(double lon, double lat)
        {
            var result = new StationGps();
            double x = lon, y = lat;
            var z = Math.Sqrt(x * x + y * y) + 0.00002 * Math.Sin(y * x_pi);
            var theta = Math.Atan2(y, x) + 0.000003 * Math.Cos(x * x_pi);
            result.longitude = z * Math.Cos(theta) + 0.0065;
            result.latitude = z * Math.Sin(theta) + 0.006;
            return result;
        } 

        public static StationGps WgsToHx(double lon, double lat)
        {
            var result = new StationGps();
            double dLat = TransformLat(lat - 35.0, lon - 105.0);
            double dLon = TransformLon(lat - 35.0, lon - 105.0);
            double radLat = lat / 180.0 * pi;
            double magic = Math.Sin(radLat);
            magic = 1 - ee * magic * magic;
            var sqrtMagic = Math.Sqrt(magic);
            dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * pi);
            dLon = (dLon * 180.0) / (a / sqrtMagic * Math.Cos(radLat) * pi);
            result.latitude = lat + dLat;
            result.longitude = lon + dLon;
            return result;
        }

        private static double TransformLat(double lon, double lat)
        {
            var ret = -100.0 + 2.0 * lat + 3.0 * lon + 0.2 * lon * lon + 0.1 * lat * lon + 0.2 * Math.Sqrt(Math.Abs(lat));
            ret += (20.0 * Math.Sin(6.0 * lat * pi) + 20.0 * Math.Sin(2.0 * lat * pi)) * 2.0 / 3.0;
            ret += (20.0 * Math.Sin(lon * pi) + 40.0 * Math.Sin(lon / 3.0 * pi)) * 2.0 / 3.0;
            ret += (160.0 * Math.Sin(lon / 12.0 * pi) + 320 * Math.Sin(lon * pi / 30.0)) * 2.0 / 3.0;
            return ret;
        }

        private static double TransformLon(double lon, double lat)
        {
            var ret = 300.0 + lat + 2.0 * lon + 0.1 * lat * lat + 0.1 * lat * lon + 0.1 * Math.Sqrt(Math.Abs(lat));
            ret += (20.0 * Math.Sin(6.0 * lat * pi) + 20.0 * Math.Sin(2.0 * lat * pi)) * 2.0 / 3.0;
            ret += (20.0 * Math.Sin(lat * pi) + 40.0 * Math.Sin(lat / 3.0 * pi)) * 2.0 / 3.0;
            ret += (150.0 * Math.Sin(lat / 12.0 * pi) + 300.0 * Math.Sin(lat / 30.0 * pi)) * 2.0 / 3.0;
            return ret;
        }