How to interpolate an elevation raster from vector data set?

[Martin Ameskamp]

> > 	How to interpolate the vector data set to generate a raster
> > 	data set representing the elevation information?
> > 
> s.surf.tps offers the most control over such interpolations. Use v.to.rast to
> convert your contour lines to raster at an appropriate resolution (20m ?), then
> use r.stats -1zg input=raster_file_name | s.in.ascii sites=new_sitesfile_name .
> We found it helpful to thin out the raster data a little with r.random; we ended
> up using 30% of the original raster cells to get good results. The unused cells
> can be used to check the interpolated output.

	I agree that s.surf.tps is a good tool for converting contours to
	raster elevation data, but why use v.to.rast at all?
	We used v.to.sites to convert our contours to site lists and used
	that as an input to s.surf.tps. If you want to reduce the number of
	points, use either v.purge on the contour vector data or
	use the dmin option to s.surf.tps (we did both)

	Martin
--
Martin Ameskamp, Inst. f. Informatik I (Computing Dept.)
Kiel University, Olshausenstr. 40, 24118 Kiel, Germany
Fax: ++49 431 8804054, Voice: ++49 431 8804474, 
email: ma at informatik.uni-kiel.d400.de