经纬度偏移转换

匿名 (未验证) 提交于 2019-12-02 22:06:11

在进行地图开发过程中,一般能接触到以下三种类型的地图坐标系:

1.WGS-84原始坐标系,一般用国际GPS纪录仪记录下来的经纬度,通过GPS定位拿到的原始经纬度,Google和高德地图定位的的经纬度(国外)都是基于WGS-84坐标系的;但是在国内是不允许直接用WGS84坐标系标注的,必须经过加密后才能使用;

2.GCJ-02坐标系,又名“火星坐标系”,是我国国测局独创的坐标体系,由WGS-84加密而成,在国内,必须至少使用GCJ-02坐标系,或者使用在GCJ-02加密后再进行加密的坐标系,如百度坐标系。高德和Google在国内都是使用GCJ-02坐标系,可以说,GCJ-02是国内最广泛使用的坐标系;

3.百度坐标系:bd-09,百度坐标系是在GCJ-02坐标系的基础上再次加密偏移后形成的坐标系,只适用于百度地图。(目前百度API提供了从其它坐标系转换为百度坐标系的API,但却没有从百度坐标系转为其他坐标系的API)

using System; using System.Collections.Generic; using System.Linq; using System.Web;  namespace Extensions {     public class GpsExtension     {         public static double pi = 3.1415926535897932384626;         public static double x_pi = 3.14159265358979324 * 3000.0 / 180.0;         public static double a = 6378245.0;         public static double ee = 0.00669342162296594323;          public 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;         }          public 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;         }         public static double[] transform(double lat, double lon)         {             if (outOfChina(lat, lon))             {                 return new double[] { lat, lon };             }             double dLat = transformLat(lon - 105.0, lat - 35.0);             double dLon = transformLon(lon - 105.0, lat - 35.0);             double radLat = lat / 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);             double mgLat = lat + dLat;             double mgLon = lon + dLon;             return new double[] { mgLat, mgLon };         }         public 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;         }         /**           * 84 to 火星坐标系 (GCJ-02) World Geodetic System ==> Mars Geodetic System           *           * @param lat           * @param lon           * @return           */         public static double[] gps84_To_Gcj02(double lat, double lon)         {             if (outOfChina(lat, lon))             {                 return new double[] { lat, lon };             }             double dLat = transformLat(lon - 105.0, lat - 35.0);             double dLon = transformLon(lon - 105.0, lat - 35.0);             double radLat = lat / 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);             double mgLat = lat + dLat;             double mgLon = lon + dLon;             return new double[] { mgLat, mgLon };         }           /// <summary>         /// 火星坐标系 (GCJ-02) to 84 * * @param lon * @param lat * @return          /// </summary>         /// <param name="lat"></param>         /// <param name="lon"></param>         /// <returns></returns>         public static double[] gcj02_To_Gps84(double lat, double lon)         {             double[] gps = transform(lat, lon);             double lontitude = lon * 2 - gps[1];             double latitude = lat * 2 - gps[0];             return new double[] { latitude, lontitude };         }         /**           * 火星坐标系 (GCJ-02) 与百度坐标系 (BD-09) 的转换算法 将 GCJ-02 坐标转换成 BD-09 坐标           *           * @param lat           * @param lon           */         public static double[] gcj02_To_Bd09(double lat, double lon)         {             double x = lon, y = lat;             double z = Math.Sqrt(x * x + y * y) + 0.00002 * Math.Sin(y * x_pi);             double theta = Math.Atan2(y, x) + 0.000003 * Math.Cos(x * x_pi);             double tempLon = z * Math.Cos(theta) + 0.0065;             double tempLat = z * Math.Sin(theta) + 0.006;             double[] gps = { tempLat, tempLon };             return gps;         }          /**           * * 火星坐标系 (GCJ-02) 与百度坐标系 (BD-09) 的转换算法 * * 将 BD-09 坐标转换成GCJ-02 坐标 * * @param           * bd_lat * @param bd_lon * @return           */         public static double[] bd09_To_Gcj02(double lat, double lon)         {             double x = lon - 0.0065, y = lat - 0.006;             double z = Math.Sqrt(x * x + y * y) - 0.00002 * Math.Sin(y * x_pi);             double theta = Math.Atan2(y, x) - 0.000003 * Math.Cos(x * x_pi);             double tempLon = z * Math.Cos(theta);             double tempLat = z * Math.Sin(theta);             double[] gps = { tempLat, tempLon };             return gps;         }          /**将gps84转为bd09           * @param lat           * @param lon           * @return           */         public static double[] gps84_To_bd09(double lat, double lon)         {             double[] gcj02 = gps84_To_Gcj02(lat, lon);             double[] bd09 = gcj02_To_Bd09(gcj02[0], gcj02[1]);             return bd09;         }         public static double[] bd09_To_gps84(double lat, double lon)         {             double[] gcj02 = bd09_To_Gcj02(lat, lon);             double[] gps84 = gcj02_To_Gps84(gcj02[0], gcj02[1]);             //保留小数点后六位               gps84[0] = retain6(gps84[0]);             gps84[1] = retain6(gps84[1]);             return gps84;         }          /**保留小数点后六位           * @param num           * @return           */         private static double retain6(double num)         {             String result = String.Format("%.6f", num);             return Convert.ToDouble(result);         }     } }

文章来源: 经纬度偏移转换
易学教程内所有资源均来自网络或用户发布的内容,如有违反法律规定的内容欢迎反馈
该文章没有解决你所遇到的问题?点击提问,说说你的问题,让更多的人一起探讨吧!