[GRASS-user] shapefile, TIGER, or what for a dlg that is stored
in .e00 format
dylan.beaudette at gmail.com
Thu Jul 9 11:20:11 EDT 2009
On Wed, Jul 8, 2009 at 10:17 PM, Hamish<hamish_b at yahoo.com> wrote:
>> 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
>> . 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
> also, as mentioned there is probably a higher resolution DEM already out
> there for free, e.g. SRTM 1" (~30m) resolution or USGS quads.
Right. On the seamless.usgs.gov server you should be able to get the
most recent 10m resolution DEM for free in GeoTiff or Arc Grid format.
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