[GRASS-user] Generalizing SRTM DEM for hillshading

Hamish hamish_nospam at yahoo.com
Tue Jun 20 09:58:48 EDT 2006


Lars:
> I'm trying to generalize the 90m SRTM DEM for use in cartography, e.g.
> for a hillshading in a 1:700.000 map. Emphasis is on a good-looking
> map, not on a hydrologic correct model.  For this scale, there is too
> much detail in the SRTM DEM, so I tried different filtering
> approaches: r.neigbors, r.resample.rst and other methods like
> resolution-bumping, but the output looks to soft: all the main ridges,
> which should give a quite crisp image have disappeared. I would like
> to keep the main structures (like high peaks and long ridges) and drop
> the small structures like short ridges, small gullys and channels. I
> know, automated generalizing of elevation models is one of the biggest
> topics in modern cartography, but maybe someone has a good hint :-)


r.neighbors method=maximum 

before resample

?


Hamish




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