[GRASSLIST:2415] vector/sites mismatch

[Steven Stoddard]

I have 2 related questions that hopefully someone can cast some insight 
on.  I am not sure if they are a result of a naive oversight or not, 
but ...
I have (attached) a sites file and a vector file both created in Arc -- 
the vector file is supposedly a polygon representation of the sites 
file (green crosses), but pulling these into GRASS, I find that the 
polygons and the sites don't correspond.  There seems to be a 
semi-consistent N-S displacement of about 200 m, though not in all 
cases.  Is this perhaps a result of a misprojection?  I have this same 
problem with a SPOT image.

What would be the best way to correct the mismatch and ensure that the 
maps are lined up properly?

Similar to that question, I did sub-sampling of a set of sites using 
d.sites.pg -- which gave me the new subsets as separate site files but 
they do not align with the original sites!  There is a 205m 
displacement due south.  ???

What am I missing here?

Thanks for any help/advice in advance,

Steve

-------------- next part --------------
A non-text attachment was scrubbed...
Name: pastedGraphic1.tiff
Type: image/tiff
Size: 9734 bytes
Desc: not available
Url : http://lists.osgeo.org/pipermail/grass-user/attachments/20040130/58766407/pastedGraphic1.tiff
-------------- next part --------------


---
Steven T. Stoddard

Program in Ecology and Evolutionary Biology
University of Illinois at Urbana-Champaign
302 Shelford Vivarium
606 E. Healy Ave
Champaign, IL  61820
(217) 333-2235
(847) 433-6396
(217) 778-9692 (cel.)