[GRASS-user] Generalizing SRTM DEM for hillshading

David Finlayson david.p.finlayson at gmail.com
Tue Jun 20 12:38:45 EDT 2006


In situations like these, always turn to the GOD of shaded relief:

http://www.shadedrelief.com/

You may find the CleanTOPO2 data set what you need.

David

On 6/20/06, Hamish <hamish_nospam at yahoo.com> wrote:
> 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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-- 
David Finlayson




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