[OSRS-PROJ] Problem in geodesic to planar conversion

[Laurent Garnier]

I want to convert geodesic coordinates from a GPS to planar coordinates in Lambert 2 étendu system. So my GPS coordinates are in WGS84 geodesic system and when I apply my projection, the planar coordinates result are the same as I have my GPS coordinates in a NTF geodesic system and my planar coordinates are approximatively 40 meters horizontal shift.


My question is, how can I specify the source geodesic system in start of proj ?

The use of proj :

static char *parms[] = {"proj=lcc","ellps=clrk80","lat_0=46d8'0.0\"",
                                       "lon_0=2d20'14.025\"","lat_1=41d33'37.00\"",
                                       "lat_2=47d41'45.65\"","x_0=600000.0","y_0=2200000.0"};
    ...
    putenv ("PROJ_LIB=C:\\Temp\\proj-4.4.3\\ess");
    if (ref = pj_init(sizeof(parms)/sizeof(char*), parms))
       {
       data.u *= DEG_TO_RAD;       // latitude
       data.v *=  DEG_TO_RAD;      // longitude
       data = pj_fwd(data, ref);
       ...


Thanks to help me

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