[GRASS-user] Discrepancies between Location Wizard and Projection Values (WXPython vs TCLTK)

[Casey Vandenberg]

Hi everyone,

I have been noticing some discrepancies in the PROJ_INFO files that are 
created using Grass6.4 RC4 between the projection values option in the 
tcltk interface and the location wizard option using the wxpython interface.

For example, inputting the projection info:

Coordinate System=UTM
Datum=Nad27 - T04 (Transformation Parameters for Alaska)
Ellipse: Clark66
Zone=8

I get the following PROJ_INFO files created.

tcltk interface results:

name: UTM
datum: nad27
nadgrids: alaska
proj: utm
ellps: clark66
a: 6378206.4000000004
es: 0.0067686580
f: 294.9786982000
zone: 8

wxpython results:

name: Universe Transverse Mercator
proj: utm
ellps: clark66
zone: 8
no_defs: defined

The summary at the end of the wxpython location wizard method says the 
proj.4 definition is:
+proj=utm, +zone=8, +a= 6378206.4000000004, +rf=294.9786982000, +dx=-22, 
+dy=157.0, +dz=176.0, +no_defs, +nadgrids=alaska
but if I run g.proj -j -f, I get the following output (which matches the 
PROJ_INFO file):
+proj=utm +no_defs +zone=8 +a=6378206.4 +rf=294.9786982 +to_meter=1

Has anyone noticed this as well? It doesn't seem as if the PROJ_INFO 
files are being populated properly using the Location Wizard with WXPython.

Thanks,

Casey