In message <Pine.3.89.9607251028.A20842-0100000@alize.ERE.UMontreal.CA> writes
:
Hi everyone,
I want to transfer some USGS 1:250k DEM data to grass. Is there an
available method to do that?Thanks in advance!
Daiyuan Pan
To convert USGS dem files to GRASS format:
1. convert ascii file to binary:
m.dmaUSGSread top=1 bottom=1201 left=1 right=1201 output=binfname
logfile=logfname < demfname
2. Rotate binary file 90 degrees, creating dem in lat-long format
m.rot90 [-q] input=binfname output=llfname rows=1201 cols=1201
bpc=2
3. Convert from lat-long to UTM projection and put in GRASS database
r.in.ll [-s] input=llfname output=rastfname bpc=2
corner=corner,lat,lon dimension=1201,1201
res=3,3 spheroid=wgs72
The latitude and longitude of the sw corner is the first pair of
the 6-digit values in the header of the original dem file. These six
digit values are arc-seconds. Divide by 3600 to get degrees. Enter
these values in the corner= input value for r.in.ll.
I hope this helps.
Mike
Michael Hanratty Phone: (612) 627-4590
Dept. of Civil Engineering (612) 626-0024
University of Minnesota Fax: (612) 627-4609
St. Anthony Falls Laboratory
Mississippi River at 3rd Ave SE
Minneapolis, MN 55414