general importing info

Thomas Foster htf1 at
Wed Jul 2 15:58:14 EDT 1997

that helps a lot.    i will try those steps.    However, the dem import
that you gave was for a 1 deg DMA (1:250,000) wasn't it?    How would it be
diffferent for a 7.5 min (which is in UTM's)?    thanks

At 09:23 AM 7/2/97 -0500, you wrote:
>In message < at>  writes:
>> I have tried a number of methods to import some USGS data (dem and dlg)
>> without success.  
>Here's what I've come up with for these two types of data:
>Steps for importing USGS DLG files
>1. Download from EROS Data Center (keep .gz suffix)
>2. Unzip file using gzip -d fname
>3. Divide into 80 character lines: fold fname > newfname
>4. Import into GRASS: v.import
>   Options:
>        1
>        newfname
>        y  UTM projection (sometimes not asked)
>        n  Lines, not Areas
>        n  Don't do multiple attribute (runs out of memory)
>        n  Don't snap
>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
> [-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
>Hope this helps.
>Michael Hanratty                           Phone: (612) 627-4590
>St. Anthony Falls Laboratory               Fax: (612) 627-4609
>Dept. of Civil Engineering
>University of Minnesota
>Mississippi River @ 3rd Ave. SE
>Minneapolis, MN 55414

Thomas Foster                            email: htf1 at
Pennsylvania State University       voice: 814-865-1231
Department of Anthropology        fax:  814-863-1474  
409 Carpenter Bldg.
University Park, PA 16802

More information about the grass-user mailing list