Importing DEM data into GRASS

John Miller ccjwm at flying.jcu.edu.au
Wed Feb 10 21:46:46 EST 1993


Thank for your suggestions Jim.  I can report that I have done all
that you suggest.  Having done so, r.stats reports all points in 
the resulting raster file have the value zero.

I suspect the problem has something to do with the fact that the
LAT/LONG coordinates in my data file and site_lists file are 
expressed in degrees and thousandths of degrees and not degrees,
minutes and seconds.  Even so,  g.region seems to handle the
notation OK.  Also, I'm expressing the latitude as negative values
since the data is for the southern hemisphere.

Am I correct?

Here are a few sample records from my site_lists file:

146|-19.5|#320
146.005|-19.5|#313
146.01|-19.5|#315
146.015|-19.5|#322
146.02|-19.5|#340
146.025|-19.5|#347

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Jim writes:
>
>John Miller:
>  It looks like you have one of the easy-to-solve problems in GRASS
>data import.
>  Simply:
>    1. Use s.in.ascii to create a GRASS site list of your data (use
>the right flags to get lat and long in right order).
>    2. Edit the site list ($LOCATION/site_lists/name) to be
>sure that there is a '#' character before each elevation.
>    3. Set your region to be large enough and your resolution
>the same as the lat/long increments.
>    4. Use s.menu (option 6, I think) to create a raster map
>from the site data.
>    Note:  Use some care in setting the region boundaries so
>that the cell centers are at the lat/long coordinates of
>your site data.
>
>Good luck,
>Jim Hinthorne
>GIS Lab
>Central Washington Univ.
>GEOL1 at CWU.BITNET
>



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