Hi,<div><br></div><div>I have an ASTER GDEM (Latlong, 30 m resolution, from NASA web site) imagery. I want to produce 10m res DEM from it. Here is what I have done and what my problem is. I really appreciate suggestions. </div>
<div><br></div><div>- I reprojected the imagery into a UTM location (using the 'nearest' method),</div><div>- Using 'g.region', I set my region to match the original DEM </div><div>- I set my computational extents from the display,</div>
<div>- then, I sampled 50% of the original imagery (in r.random) and created a vector map (it took long time to do this and it has around 5 million points in it), </div><div>- I set the resolution to 10 meters using 'g.region',</div>
<div>- then, using 'v.surf.rst', I tried to make a new DEM -10m resol- from the sampled vector map and masking the operation with the original -30m- DEM. I do not change the default settings and I use a smoothing parameter of '.1' and i use the "value" column from the vector map for approximation in the process.</div>
<div><br></div><div>I get a lot of error messages during interpolation, like;</div><div><br></div><div>G_ludcmp() failed! n=0</div><div>taking too long to find points for interpolation--please change the region to area where your points are. Continuing calculations...</div>
<div><br></div><div><br></div><div>I am not sure but may be my region settings is wrong (i.e., too wide) although I used the imagery to set them. I never waited for interpolation to run completely.</div><div><br></div><div>
Thank you for suggestions!</div><div><br></div><div><br>-- <br>BÜLENT ARIKAN<br>School of Human Evolution and Social Change<br>Arizona State University<br>Tempe - AZ<br>85287-2402<br>
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