Hi Colin,after converting the Jeeps "C" code to "Delphi" Pascal I failed to get the exact results when trying to get the UTM NE numbers from WGS84 Lat-Lon.My test usedREFERENCE_DATUM = "WGS84" REFERENCE_ELLIPSOID = "WGS84"Lat +52.4995609Lon +7.0821584and THE RESULTS SHOULD BEUTM N 5818332.000UTM E 369816.000Zone 32 Terrashape does this conversion very exactly using the Jeeps routines.But MY RESULTS ARE VERY BAD:UTM N 5820605.5254UTM E 301948.09647Zone 32 UTM_zc "U"There are 3 possibilities what happens wrong1. I use the wrong routines or I oversee anything - YOU MAY HELP ME WITH A HINT :-)2. My Delphi code is wrong although I debugged it several times - my problem, do it again and again :-(3. Delphi math is bad for scientific work - worsest scenario but I could build a DLL with MSVC and use it with Delphi :-((SO PLEASE IF YOU COULD HAVE A LOOK AT THE NEXT LINES!If you could confirm that this is the right way I do it then I could go on with Nr 2 or Nr 3 on my list.(I use the same names for the routines as in Jeeps "C")I call (with the lat-lon parameters) GPS_Math_WGS84_To_UTM_EN (52.4995609,7.0821584,UTM_E,UTM_N,Zone,UTM_zc);which calls the subroutines GPS_Math_WGS84_To_Known_Datum_M(lat,lon,0, phi,lambda,H,77); (Transform WGS84 to other datum using Molodensky) Data used: //GPS_ODatum GPS_Datum[]= 077 { "North America 83",21,0,0,0}, //GPS_SEllipse { "GRS80", 6378137.000, 298.257222101 }, and afterwards calls GPS_Math_NAD83_To_UTM_EN(phi,lambda,E,N,zone,zc);from where I get the results (E,N,zone,zc). Thank you very much in advance!RegardsGeorg HeliFLYer EDDW

Hi GeorgI'll take a look at my source code and get back to you.RegardsColin

Thank you very much, Colin, that will help me to spare much time!Best regardsGeorg HeliFLYer EDDW

Hi to all reading this post!There has been generous help from COLIN sending me some Terrashape code to have a look at it and therefore I could solve my problem. There is still much work to do until I can offer the program but now I can go on with the work. Once again, thank you very much, Colin!Georg HeliFLYer EDDWFor the interested FLYers here is what I wrote to COLIN:<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>