/// <summary>
        /// (BD-09)-->GPS84
        /// </summary>
        /// <param name="bd_lat"></param>
        /// <param name="bd_lon"></param>
        /// <returns></returns>
        public static Gps BD09_To_GPS84(double bd_lat, double bd_lon)
        {
            Gps gcj02 = BD09_To_GCJ02(bd_lat, bd_lon);
            Gps map84 = GCJ02_To_GPS84(gcj02.Lat, gcj02.Lng);

            return(map84);
        }
        /// <summary>
        /// 火星坐标系 (GCJ-02) to 84
        /// </summary>
        /// <param name="lat"></param>
        /// <param name="lon"></param>
        /// <returns></returns>
        public static Gps GCJ02_To_GPS84(double lat, double lon)
        {
            Gps    gps       = Transform(lat, lon);
            double lontitude = lon * 2 - gps.Lng;
            double latitude  = lat * 2 - gps.Lat;

            return(new Gps(latitude, lontitude));
        }