[GRASS-user] shapefile, TIGER, or what for a dlg that is stored in .e00 format

Hamish hamish_b at yahoo.com
Thu Jul 9 01:17:39 EDT 2009


> stephen sefick wrote:
> > I am trying to make a DEM from contour lines downloaded from here
> > http://csat.er.usgs.gov/statewide/layers/contours.html

fwiw, v.in.ogr's SDTS driver might help to import DLGs more directly.
??


Nikos wrote:
> Perhaps you do not even need to rasterise. Have a look at v.surf.rst
> [2]. Of course I am no expert with DEM's, v.surf.rst might not be what
> you need.

v.surf.rst does not do all that well with contour lines. due to the
adaptive grid size / quadtree design it focuses detail on where the data points are. In this case that's the vertices along the contour lines.

r.surf.contour does a nice job with them though, just read in the help
page about overcoming the lack of floating-point support, if that is
needed.


also, as mentioned there is probably a higher resolution DEM already out
there for free, e.g. SRTM 1" (~30m) resolution or USGS quads.


Hamish



      



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