关于 GCJ-02 和 BD-09 ，请参考 http://developer.baidu.com/map/question.htm#qa0043 。
算法代码如下，其中 bd_encrypt 将 GCJ-02 坐标转换成 BD-09 坐标， bd_decrypt 反之。
- #include <math.h>
- const double x_pi = 3.14159265358979324 * 3000.0 / 180.0;
- void bd_encrypt(double gg_lat, double gg_lon, double &bd_lat, double &bd_lon)
- {
- double x = gg_lon, y = gg_lat;
- double z = sqrt(x * x + y * y) + 0.00002 * sin(y * x_pi);
- double theta = atan2(y, x) + 0.000003 * cos(x * x_pi);
- bd_lon = z * cos(theta) + 0.0065;
- bd_lat = z * sin(theta) + 0.006;
- }
- void bd_decrypt(double bd_lat, double bd_lon, double &gg_lat, double &gg_lon)
- {
- double x = bd_lon - 0.0065, y = bd_lat - 0.006;
- double z = sqrt(x * x + y * y) - 0.00002 * sin(y * x_pi);
- double theta = atan2(y, x) - 0.000003 * cos(x * x_pi);
- gg_lon = z * cos(theta);
- gg_lat = z * sin(theta);
- }