Hi,
for orthorectifying aerial photographs I tried using the srtm data.
Unfortunately the coarse resolution leads to remarkably distortions
expecially in steep areas. It appears that the photograph is projected
on the 90x90 m squares of the dem. For a certain area I got a 25 m dem
this leads to better results, but still mosaiked to the dem resolution.
I tried to resample the dem with a resolution of 1m (which is the
resolution of the aerial photographs). First this attempt didn't succeed
with r.resample neither with r.resample.rst. Finally I managed it
(actually I don't know anymore, I believe it was by mapcalculating the
dem multiplying by 1 and a region resolution of 1m and resample(rst) it
afterwards).
Whatsoever it didn't help. Has anyone an idea how to interpolate a dem
with a finer resolution? or how I can orthorectify the photographs
without the mentioned distortions. I can live with a slight error in
steep areas, but I need a continuous photograph.
thanks for your consideration, best regards and a merry christmas
Stefan
_______________________________________________
grass-user mailing list
[email protected]
http://lists.osgeo.org/mailman/listinfo/grass-user
