Need help importing DEM data

William A Perkins perk at
Wed Mar 20 07:00:00 EST 1996

>>>>> "James" == James Curry <jcurry at> writes:

    James> Hi,

    James> I'm a new grass user and would like to import some USGS DEM
    James> data.  This is what I have done:

    James> downloaded las_vegas-e.gz from
    James> decompressed with
    James> gzip

    James> dd if=las_vegas-e ibs=10240 | m.dmaUSGSread top=1 bottom=1201 \
    James> left=1 right=1201 output=las_vegas-e.dat logfile=las_vegas-e.log

These are not the options I use with dd.  From

    The DEM files do not contain record delimiters.  You can add delimiters by 
    using the following UNIX command:

    dd if=inputfilename of=outputfilename ibs=4096 cbs=1024 conv=unblock

I'm not sure that would explain your results, though.  Is the strip
about 1/10th the correct size (1024/10240)?  

    James> [deleted stuff looks OK ...]

    James> All that is displayed is a single very narrow strip.
    James> I'd appreciate some pointers to where I am going wrong. I've tried
    James> get information from moon but can't seem to download any of the arch
    James> material or help docs.

    James> Thanks.

    James> *******************************************************************
    James> James Curry
    James> Lawrence Livermore National Laboratory
    James> P.O. Box 808, MS: L-183
    James> Livermore, California  94550

    James> (510) 423-1106
    James> *******************************************************************

Bill Perkins
Battelle Pacific Northwest Laboratories
Environmental Technologies Division, Subsurface Flow and Transport
P.O. Box 999 MSIN K9-36
Richland, Washington, USA  99352
voice: (509) 372-6131 fax: (509) 372-6328 email: wa_perkins at

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