Hi Markus,
you may contact
Maria Brovelli <maria@ipmtf4.topo.polimi.it>
She is working on such topics. She and her
institute organized the "Italian GRASS Day" recently
in January.Kind regards
Markus Neteler
PS: Did you generate the DEM from stereo pairs within GRASS
or externally? I am very interested in such topic.
DEM was generated by SPOT Corp. And originaly was in ERDAS IMAGINE raster
format.
Rado
On Sat, Mar 25, 2000 at 06:29:25PM -0600, Rado Bonk wrote:
> Hi GRASSusers,
> I need to examine the DEM error, before using the DEM for future
> analysis.
> I have a big 140x 80km,20mx20m resolution elevation grid from vertically
> highly exaggerated montain area. Vertical exaggeration is almost
> 5000m, and slope angles go up-to 85-90 degrees. The grid was computed from
> stereo pair of two satellite images, and control points from ground
> photogrammetry were used to decrease the error in DEM.
> Using just visual control in nviz2.2 I have found that, on same places are
> smooth-like areas (very smooth surfaces) among the typical terrain
> features. Since accuracy of the whole DEM is good enough (elevation error
> is less than 10m) I would like just to examine these local errors in DEM.
> Any ideas?
>
> Thanks,
>
> Rado
>
> Rado Bonk
> Geography and Geology
> UNO, Nebraska, 68182-0199,
> rado@cosmos.unomaha.edu
>