[GRASSLIST:1033] Re: srtm

[Sandro Klippel]

On Tue, 2003-08-26 at 18:56, Gustavo Alcides Concheiro Perez wrote:
> Ian Macmillan escribió:
> 
> > I have downloaded some SRTM data from the USGS web site, and it so happens that
> > my data is near the coast.  My trouble is that SRTM actually records some
> > anomalous data out in the oceans.  I have bathymetry data that i would like to
> > view along with topography, but the ocean data is a bit difficult to get rid of
> > from the SRTM.  My thought is that I might be able to take the coast lines
> > generated from GMT, import those into GRASS, and then somehow mask out all data
> > from the SRTM that lies outside of those coastlines.
> 
> I never got to do it because of a major hardware failure and other more 
> urgent commitments, but you came out with my very plan.  Another thing I 
> planned to do was to `mend' the STRM holes both with mapcalc(?) using 
> adjacent STRM data and GLOBE data to fill the holes.
> 
> What bathymetry data are you using?  My plan was to use ETOPO2.  [I'd 
> already patched GLOBE on top of ETOPO2 for a decent global DEM.]
> 
> Problem I found was---if I got this right---that GMT's shorelines don't 
> get imported as closed polygons so I could not export them as a raster 
> mask, and also that I couldn't get rid of the inland water bodies.

As I explain before, shorelines/lakes/.. can be exported to raster with
'grdlandmask/grdreformat/r.in.bin'. After that, vector areas can be
extracted with 'r.poly'

> 
> Please let me know how it goes for you.
> 
> 
> Best,
> 
> -Gustavo
-- 
Sandro Klippel <sandro.klippel at talha-mar.com.br>

talha-mar projetos ambientais
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