source: pacpusframework/trunk/include/Pacpus/PacpusTools/transf_lamb_93.h@ 64

// This file is part of the PACPUS framework distributed under the
// CECILL-C License, Version 1.0.
// 
/// @author  Firstname Surname <firstname.surname@utc.fr>
/// @date    Month, Year
/// @version $Id: transf_lamb_93.h 64 2013-01-09 16:41:12Z kurdejma $
/// @copyright Copyright (c) UTC/CNRS Heudiasyc 2006 - 2013. All rights reserved.
/// @brief Brief description.
///
/// Detailed description.

#include <math.h>
#define pi 3.141592653589793
double atanh(double  z)
{
        return (0.5 * log((z+1)/(1-z)));
}

double  abs_me(double x)
{
        if(x<0) x=-x;
        return x;
}

//transformation des longitudes tatitudes en Lambert93
void lonlattolam(double lon, double lat, double & lam93x, double & lam93y)
        {
                double GRS_a = 6378137;
                double GRS_f = 1./298.257222101;

                double GRS_b = GRS_a*(1-GRS_f);
                double GRS_bb= GRS_b*GRS_b;
                double GRS_aa= 40680631590769.;
                double GRS_e = sqrt((GRS_aa - GRS_bb) / (GRS_aa));

                double n = 0.725607765053267;
                double C = 11754255.4261;
                double XS = 700000;
                double YS = 12655612.0499;

                double latiso;
                latiso = atanh(sin(lat)) - GRS_e*atanh(GRS_e*sin(lat));
                double gamma;
                gamma = (lon - 0.0523598775598299)*n;
                double R;
                R = C * exp(-n*latiso);

                lam93x = R *sin(gamma)+XS;
                lam93y = -R *cos(gamma)+YS;
                //printf("x: %.20lf\n y: %.20lf\n",lam93x,lam93y);

        }



//Transformation des coordonnees de Lambert93 en Longitude lattitude

void lamtolonlat(double lamx, double lamy, double & lon, double & lat)
{

        double GRS_a = 6378137;
        double GRS_f = 1./298.257222101;
        double GRS_b = GRS_a*(1-GRS_f);
        double GRS_bb= GRS_b*GRS_b;
        double GRS_aa= 40680631590769.;
        double GRS_e = sqrt((GRS_aa - GRS_bb) / (GRS_aa));

        //double n = 0.725607765053267;
        //double C = 11754255.4261;
        //double XS = 700000;
        //double YS = 12655612.0499;


        //lamx = lamx-700000;
        //lamy = lamy-12655612.0499;

        double gamma;
        gamma = atan(-(lamx-700000)/(lamy-12655612.0499));


        lon = gamma/0.725607765053267 + 0.0523598775598299;
        double R;
        R = sqrt((lamx-700000) * (lamx-700000) + (lamy-12655612.0499) * (lamy-12655612.0499));

        double latiso;
        latiso = log((11754255.4261)/R)/(0.725607765053267);

        double phiNew, phiOld;
        phiOld =1;
        phiNew= asin (tanh ( latiso + GRS_e * atanh(GRS_e * sin(phiOld))));
        //printf("\nphiNew: %.20lf",phiNew);
        while (abs_me(phiOld-phiNew) > 1e-10)
        {

                if(abs_me(phiOld-phiNew) > 1e-10)
                {

                        phiOld = phiNew;
                        phiNew = asin(tanh(latiso+GRS_e*atanh(GRS_e*sin(phiOld))));
                }
                else
                        phiOld = phiNew;
        }

        lat = phiNew;

}