[GRASSLIST:3109] RE: Which DEM module is best

David Mahoney mahoneyd at unbc.ca
Tue Apr 6 10:21:56 EDT 2004

Of the two methods (v.surf.rst, r.surf.contour), I found that v.surf.rst 
ran faster, unfortunately. I was hoping for more, because PCI Geomatica  
ran the same dataset in a half hour. On the other hand, that DEM was full 
of holes and spikes. The Grass DEM was much cleaner. The best bet is 
probably to tile the dataset and run it in the background on several 


-----Original Message-----
From: Hamish [mailto:hamish_nospam at yahoo.com]
Sent: Thursday, March 25, 2004 6:09 PM
To: David Mahoney
Subject: Re: [GRASSLIST:3031] Which DEM module is best

> I need to generate a DEM on a rather large dataset: 130x100km at
> 1:20000. The output resolution will be 20m. The area is very
> mountainous, and the input is contour lines. There appear to be a
> number of surface generation tools available. I am running v.surf.rst
> now, but it is very slow. Is there another, faster module that will
> generate acceptable results?

did you try


that does exactly what you are asking. It can be slow at times, I think
this happens if you have a big open space where it will spend a long
time searching for the nearest contour lines & not finding any?

I've got to do exactly the same thing next month (but a larger area at
10m resolution), so if you find a better solution, please let me know.
I was just budgeting for our fastest computer to be tied up for a week
or two..

good luck,

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