[GRASS-dev] v.surf.rst segment boundaries

[Helena Mitasova]

Anna is right, 
but there may be another case if you are interpolating from contours or isolines (such as isochrones as you may be doing) 
make sure your optimize the number of points on the contour - click on the two last images on the page below
to see the difference
http://www4.ncsu.edu/~hmitaso/grasswork/interpgen.html

Vasek may have a better example for this - we had to use this approach when interpolating temporal
surface from time series of contours.

If you see the segments only in some spots that don’t have data (e.g. bare ground lidar where buildings were removed)
Anna has written a v.surf.rst wrapper that does two passes interpolation to minimize the visible segments.

Perhaps if you could share the data and the command that you have used we can suggest a solution.

Helena


> On Nov 18, 2015, at 1:35 PM, Anna Petrášová <kratochanna at gmail.com> wrote:
> 
> 
> 
> On Wed, Nov 18, 2015 at 1:29 PM, Michael Barton <Michael.Barton at asu.edu> wrote:
> Helena (or anyone else),
> 
> I really like the amount of control over interpolation that comes with v.surf.rst. But it always gives me artifacts at the segment boundaries (little “cliffs”). Is there some way to prevent that?
> 
> Could you perhaps share the command you use and what type of data (sparse points or dense lidar) you run it for? From my experience, too low tension or low npmin can cause that. Default settings are usually not producing the segments, but it might be time inefficient.
> 
> Anna
> 
> Michael
> ____________________
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Helena Mitasova
Professor at the Department of Marine, 
Earth, and Atmospheric Sciences
and Center for Geospatial Analytics
North Carolina State University
Raleigh, NC 27695-8208
hmitaso at ncsu.edu
http://geospatial.ncsu.edu/osgeorel/publications.html

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