高斯投影正、反算 代碼

 

 
//高斯投影正、反算 
//////6度帶寬 54年北京座標系 
//高斯投影由經緯度(Unit:DD)反算大地座標(含帶號，Unit:Metres) 

void GaussProjCal(double longitude, double latitude, double *X, double *Y) 
{
 int ProjNo=0; int ZoneWide; ////帶寬 
 double longitude1,latitude1, longitude0,latitude0, X0,Y0, xval,yval;
 double a,f, e2,ee, NN, T,C,A, M, iPI;
 iPI = 0.0174532925199433; ////3.1415926535898/180.0; 
 ZoneWide = 6; ////6度帶寬 
 a=6378245.0; f=1.0/298.3; //54年北京座標系參數 
 ////a=6378140.0; f=1/298.257; //80年西安座標系參數 
 ProjNo = (int)(longitude / ZoneWide) ; 
 longitude0 = ProjNo * ZoneWide + ZoneWide / 2; 
 longitude0 = longitude0 * iPI ;
 latitude0=0; 
 longitude1 = longitude * iPI ; //經度轉換爲弧度
 latitude1 = latitude * iPI ; //緯度轉換爲弧度
 e2=2*f-f*f;
 ee=e2*(1.0-e2);
 NN=a/sqrt(1.0-e2*sin(latitude1)*sin(latitude1));
 T=tan(latitude1)*tan(latitude1);
 C=ee*cos(latitude1)*cos(latitude1);
 A=(longitude1-longitude0)*cos(latitude1); 


 M=a*((1-e2/4-3*e2*e2/64-5*e2*e2*e2/256)*latitude1-(3*e2/8+3*e2*e2/32+45*e2*e2
  *e2/1024)*sin(2*latitude1)
  +(15*e2*e2/256+45*e2*e2*e2/1024)*sin(4*latitude1)-(35*e2*e2*e2/3072)*sin(6*l
  atitude1));
 xval = NN*(A+(1-T+C)*A*A*A/6+(5-18*T+T*T+72*C-58*ee)*A*A*A*A*A/120);
 yval = M+NN*tan(latitude1)*(A*A/2+(5-T+9*C+4*C*C)*A*A*A*A/24
  +(61-58*T+T*T+600*C-330*ee)*A*A*A*A*A*A/720);
 X0 = 1000000L*(ProjNo+1)+500000L; 
 Y0 = 0; 
 xval = xval+X0; yval = yval+Y0; 
 *X = xval;
 *Y = yval;
} 

 


//高斯投影由大地座標(Unit:Metres)反算經緯度(Unit:DD)
void GaussProjInvCal(double X, double Y, double *longitude, double *latitude) 字串9 

{
 int ProjNo; int ZoneWide; ////帶寬 
 double longitude1,latitude1, longitude0,latitude0, X0,Y0, xval,yval;
 double e1,e2,f,a, ee, NN, T,C, M, D,R,u,fai, iPI;
 iPI = 0.0174532925199433; ////3.1415926535898/180.0; 
 a = 6378245.0; f = 1.0/298.3; //54年北京座標系參數 
 ////a=6378140.0; f=1/298.257; //80年西安座標系參數 
 ZoneWide = 6; ////6度帶寬 
 ProjNo = (int)(X/1000000L) ; //查找帶號
 longitude0 = (ProjNo-1) * ZoneWide + ZoneWide / 2; 
 longitude0 = longitude0 * iPI ; //中央經線
 X0 = ProjNo*1000000L+500000L; 
 Y0 = 0; 
 xval = X-X0; yval = Y-Y0; //帶內大地座標
 e2 = 2*f-f*f;
 e1 = (1.0-sqrt(1-e2))/(1.0+sqrt(1-e2));
 ee = e2/(1-e2);
 M = yval;
 u = M/(a*(1-e2/4-3*e2*e2/64-5*e2*e2*e2/256));
 fai = u+(3*e1/2-27*e1*e1*e1/32)*sin(2*u)+(21*e1*e1/16-55*e1*e1*e1*e1/32)*sin(
  4*u)
  +(151*e1*e1*e1/96)*sin(6*u)+(1097*e1*e1*e1*e1/512)*sin(8*u);
 C = ee*cos(fai)*cos(fai);
 T = tan(fai)*tan(fai);
 NN = a/sqrt(1.0-e2*sin(fai)*sin(fai)); 字串1 
  R = a*(1-e2)/sqrt((1-e2*sin(fai)*sin(fai))*(1-e2*sin(fai)*sin(fai))*(1-e2*sin
  (fai)*sin(fai)));
 D = xval/NN;
 //計算經度(Longitude) 緯度(Latitude)
 longitude1 = longitude0+(D-(1+2*T+C)*D*D*D/6+(5-2*C+28*T-3*C*C+8*ee+24*T*T)*D
  *D*D*D*D/120)/cos(fai);
 latitude1 = fai -(NN*tan(fai)/R)*(D*D/2-(5+3*T+10*C-4*C*C-9*ee)*D*D*D*D/24
  +(61+90*T+298*C+45*T*T-256*ee-3*C*C)*D*D*D*D*D*D/720); 
 //轉換爲度 DD
 *longitude = longitude1 / iPI; 
 *latitude = latitude1 / iPI;
} 

 


//NN卯酉圈曲率半徑，測量學裏面用N表示 

//M爲子午線弧長，測量學裏用大X表示 字串2 

//fai爲底點緯度，由子午弧長反算公式得到，測量學裏用Bf表示 字串4 

//R爲底點所對的曲率半徑，測量學裏用Nf表示