yes, I am changing various values, including dmin. I get different sizes of the rectangular artefacts, but they never really disappear, regardless of the values I used. I still hope I can find a better parameter combination where the artefacts aren't visible.

Andreas

Andrea Ricci wrote:
Andreas Neumann wrote:
Hello,

I am trying to interpolate a raster DTM from contour lines. I like the
results from v.surf.rst, however, this algorithm, at least with my
settings seams to generate rectangular artefacts in the resulting DTM. See
a hillshade of my result at
http://www.carto.net/neumann/temp/hs_dtm_tension5_smooth2.png - if it
weren't for these artefacts I would like the results very much.

Here are the parameters I used:
v.surf.rst input=hl layer=1 zcolumn=elev_m dmax=10 dmin=0.5
elev=dtm_tension5_smooth2 zmult=1.0 tension=5 smooth=2 segmax=40 npmin=300
--overwrite

The idea is to get a smooth, not too detailed DTM, hence the small tension
and higher smooth values.

Are there any parameters or postprocessing steps that would help me remove these rectangular artefacts? Or alternatively, are there better methods to
interpolate DTMs from contour lines?

Thanks for any ideas,
Andreas


Try with increasing dmin= 2 or try with other values. Normally, in case of visible segmentation, this value must be increased.
hope that's helpful
Andrea Ricci

--

--
Andreas Neumann
Böschacherstrasse 6
CH-8624 Grüt (Gossau ZH)
Switzerland
Phone: ++41-44-2736668
Email: [EMAIL PROTECTED]

Web: http://www.carto.net/neumann/
SVG Examples: http://www.carto.net/papers/svg/samples/
SVG.Open: http://www.svgopen.org/

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