[GRASS-user] patching dems together

stephen sefick ssefick at gmail.com
Thu Jul 9 14:36:11 EDT 2009

I followed the directions all set to srtm, computation region set to
resolution of the coarsest (they are all the same and 00:00:01).  The
map is still coming out as 7 different solid color blocks.

On Thu, Jul 9, 2009 at 12:58 PM, Markus
Metz<markus.metz.giswork at googlemail.com> wrote:
> stephen sefick wrote:
>> values range from ~-9 to ~800 there is a tile which has no elevation.
>> The patched dem only ranges from 0-296.  This may be the problem.
> It seems that the current computational region did not include all tiles.
> Try setting the computational region to include all tiles with g.region
> rast=<all your tiles>.
> Check the resolution of each tile with r.info -s. If they are not all
> the same, use the coarsest resolution to be safe.
> Check the resolution of the computational region. It must be the same
> like the coarsest resolution, if not, set it to that.
> Set the same color rules for all tiles. Use srtm or etopo2 but not
> elevation because elevation will be different for each tile.
> Display all tiles, zoom to the computational region.
> Patch all tiles.
> Set the same color rules to the patched DEM like to the tiles.
> Add the patched DEM to the display, it should look like the previous
> display with all the tiles.
> Good luck,
> Markus M

Stephen Sefick

Let's not spend our time and resources thinking about things that are
so little or so large that all they really do for us is puff us up and
make us feel like gods.  We are mammals, and have not exhausted the
annoying little problems of being mammals.

								-K. Mullis

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