[GRASS-user] interpolation from massive vector point input

[Vincent Bain]

Johannes,
what about first generating a tin with breaklines (=your shoreline)
running a Delaunay constrained triangulation :

http://grass.osgeo.org/wiki/TIN_with_breaklines

then output a raster from this tin ?

(just a suggestion, I never used/tested v.triangle AddOnn)

Vincent.


Le lundi 27 août 2012 à 11:58 +0200, Johannes Radinger a écrit :
> Hi,
> 
> I get a text file from a hydromorphological model which includes
> an massive amount of geographical points with attributes (velocity,depth,..),
> which I input using v.in.ascii (around 120000 points).
> The points are located in a river (20 m widht) in a resolution of
> appr. 20x20 cm,
> but this is not fixed and depending on their location within in the river
> (points in the outer bends show rougher resolution then points in the
> inner bends).
> So these points are not regularly (in the sense of raster map) distributed.
> 
> Anyway I want to generate a raster surface (resolution = appr. 0.25)
> from the vector points attributes, e.g  a surface of velocity and one
> for depth.
> Additionally to the vector points there is a line vector indicating
> the shore line
> of the river (depth=0 and velocity = 0).
> 
> Now I am looking for a method for interpolation of these points. I
> found v.surf.icw
> which would take into account that there is a shoreline which is not overflown
> by the water (interpolates within the river). But it is not recommended for such
> massive data point input. Is there any other recommendable way fur such
> a purpose (considering the shore line and that there is 0 velocity and
> 0 depth on land?
> 
> Any suggestions are welcome!
> 
> Thank you,
> 
> /johannes
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