GPS坐标转大地坐标

根据网上EXCEL表格给出的关系，生成的C语言代码。计算结果和软件【万能坐标转换980】计算出的结果很接近。

 double B = 39.3926;
 double L = 117.4514;
 //double B = 0;
 //double L = 117;
 double L0 = ;

 /*
 ************************************************************************************************************************
 * Description: This function convert longitude/latitude(xx度xx分xxxxxx秒) to longitude/latitude(xx.xxxxxxxx度).
 *
 * Arguments  :     gps_x_y
                 longitude/latitude(xx度mm分ssssss秒) 输入形式为： xx.mmssssss
 *
 * Note(s)    : none
 ************************************************************************************************************************
 */
 double CALC_GPS_angle(float gps_x_y)
 {
     /*
     double min,sec;
     min = (floor(gps_x_y*100)-floor(gps_x_y)*100)/60;
     sec = (gps_x_y*10000-floor(gps_x_y*100)*100)/3600;
     printf("min = %.6lf\r\n",min);
     printf("sec = %.6lf\r\n",sec);
     */
     return (floor(gps_x_y)+(floor(gps_x_y*)-floor(gps_x_y)*)/+(gps_x_y*-floor(gps_x_y*)*)/);
 }

 /*
 ************************************************************************************************************************
 * Description: 角度转换为弧度.
 *
 * Arguments  : angle
                 输入形式(xx.xxxxxxxx度)
 *
 * Note(s)    : none
 ************************************************************************************************************************
 */
 double Angle2RAD(double angle)
 {
     return (angle*3.1415926/);
 }

 /*
 ************************************************************************************************************************
 * Description:     该函数调用以上2个函数完成计算功能.
 *
 * Arguments  :    input L :    经度longitude -> (xx度mm分ssssss秒) 输入形式为： xx.mmssssss
                 input B :    纬度latitude -> (xx度mm分ssssss秒) 输入形式为： xx.mmssssss
                 input L0:    中央子午线Central meridian -> (xx度mm分ssssss秒) 输入形式为： xx.mmssssss
                 output X:    坐标系的y轴
                 output Y    坐标系的x轴
 *
 * Note(s)    :     none
 ************************************************************************************************************************
 */
 void GpsGrid2GaussGrid(double L0, double B, double L, double* X, double* Y)
 {
     double E2,F2,G2,H2,I2,J2,K2,L2,M2,N2,O2,P2,Q2,R2;

     E2 = CALC_GPS_angle(B);
     #ifdef PRINT_DEG
     printf("E2 = %.9lf\r\n",E2);
     #endif
     F2 = CALC_GPS_angle(L);
     #ifdef PRINT_DEG
     printf("F2 = %.9lf\r\n",F2);
     #endif
     G2 = F2 - CALC_GPS_angle(L0);
     #ifdef PRINT_DEG
     printf("2G = %.9lf\r\n",G2);
     #endif
     H2 = 0.01744444444*G2;
     #ifdef PRINT_DEG
     printf("H2 = %.9lf\r\n",H2);
     #endif
     I2 = tan(Angle2RAD(fabs(E2)));
     #ifdef PRINT_DEG
     printf("I2 = %.9lf\r\n",I2);
     #endif
     J2 = cos(Angle2RAD(fabs(E2)));
     #ifdef PRINT_DEG
     printf("J2 = %.9lf\r\n",J2);
     #endif
     K2 = 0.006738525415*J2*J2;
     #ifdef PRINT_DEG
     printf("K2 = %.9lf\r\n",K2);
     #endif
     L2 = I2*I2;
     #ifdef PRINT_DEG
     printf("L2 = %.9lf\r\n",L2);
     #endif
     M2 =  + K2;
     #ifdef PRINT_DEG
     printf("M2 = %.9lf\r\n",M2);
     #endif
     N2 = 6399698.9018/sqrt(M2);
     #ifdef PRINT_DEG
     printf("N2 = %.9lf\r\n",N2);
     #endif
     O2 = H2*H2*J2*J2;
     #ifdef PRINT_DEG
     printf("O2 = %.9lf\r\n",O2);
     #endif
     P2 = I2*J2;
     #ifdef PRINT_DEG
     printf("P2 = %.9lf\r\n",P2);
     #endif
     Q2 = P2*P2;
     #ifdef PRINT_DEG
     printf("Q2 = %.9lf\r\n",Q2);
     #endif
     R2 = (32005.78006+Q2*(133.92133+Q2*0.7031));
     #ifdef PRINT_DEG
     printf("R2 = %.9lf\r\n",R2);
     #endif

     *X = 6367558.49686*E2/57.29577951308-P2*J2*R2+((((L2-)*L2+)* O2/+(*K2+)*M2-L2)*O2/+)*N2*I2*O2/;
     *Y = ((((L2-)*L2-(*L2-)*K2+)*O2/+M2-L2)*O2/+)*N2*(H2*J2)+;

 }