HELP!! Clark66->WGS84 ???#%@*!

[W. Fredrick Limp]

> 
> Date sent:  24-AUG-1992 12:09:56 
> 
> Hello grassusers:
> 	I was wondering if someone would be kind enough to explain the method
> I should take to transform a lat-lon site dataset which is referenced to
> clark66 spheroid into a UTM location so that it will be correctly located with
> respect to new lat-lon data referenced to the WGS84 spheroid and also converted
> to UTM. I want to do this so that the historic data will be correctly
> referenced to new data collected with GPS.

Hope this helps....
If I understand your question it is quite easy to get the results you want
the site data from the clark66 data set should be routed through m.ll2u
with the spheroid set to clark66 while the WGS84 stuff would be routed through
with the spheroid set to wgs84.  Both will come out in the correct UTM zone
with the differences in the spheroids corrected.  Even then, if it is a
really serious issue, you may need to correct for the elevation you are
dealing with.  But I don't think that this is your problem.  You can use
awk to parse the sites list into a form that m.ll2u likes

> 
> 	I've read through the GRASS Reference Manual and can't get a good
> enough handle on this to be sure I'm going about it the correct way. I also
> don't understand the dx,dy,dz parameters in the m.datum.shift program. Any
> help would be GREATLY APPRECIATED!
> 
> Thanks for your time.
> 
> Gerry Hatcher                   
> 
> Ocean Mapping Development Center|      gerry at omdc.gso.uri.edu {Internet}
> University of Rhode Island      |            cbeam::gerry {span}
> voice (401)-792-6940            |            fax (401)-792-6849
> 
> 


-- 
W. Fredrick Limp,   Director                     FAX: (501) 575-3846
CAST, Center for Advanced Spatial Technologies   TEL: (501) 575-6159     
12 Ozark Hall, University of Arkansas         
Fayetteville AR 72701                             fred at kirk.uark.edu