HELP with Projection/Datum(?) Problem

[Gerald I. Evenden]

>Date:         Tue, 19 Apr 94  10:52:39 CDT
>From: "Chris D Garvin -- Ft Sill,OK" <GARVINC at SILL-EMH.ARMY.MIL>
>Subject:      HELP with Projection/Datum(?) Problem
>To: <grassu-list at max.cecer.army.mil>
>
>     PROBLEM: I currently have Oklahoma State Plane Coordinates in the NAD83
>datum, I need to convert them into UTM NAD27 datum. The v/m.proj programs work
>fine as long as both are in the same datum, however, I would like to know if
>it is possible to convert from one datum to the other directly.
>
>     The problem also seems to be tied to the PROJ_INFO file in PERMANENT. It
>seems to affect all files in all mapsets. That is to say, PROJ_INFO can only
>be one datum type. Any help on this area would be appreciated. Thanks in
>advance.
>
>Chris D Garvin (garvinc at sill-emh.army.mil)
>Ft Sill, OK
>(405) 442-3314/6174

At the moment, a solution is probably not in GRASS.  The program
nad2nad in the PROJ.4 system will convert data in geographic
coordinates (lat/lon), UTM and SPCS systems (any mix) between datums.
The PROJ.4 system can be found at charon.er.usgs.gov in directory
pub/PROJ.4.  Check details in the README file for description of
distribution files.

Gerald (Jerry) I. Evenden   Internet: gie at charon.er.usgs.gov
voice: (508)563-6766          Postal: P.O. Box 1027
  fax: (508)457-2310                  N.Falmouth, MA 02556-1027