-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi,
I'd like to create a DEM from contours using r.surf.contours. Maybe I am trying something to ambitious here because the region is quite large and the relief is rather complex with lots of human made modifications to the terrain. I used standard contours and contours describing terrain features in combination with elevation points. The region is: nsres: 1 ewres: 1 rows: 12000 cols: 16000 cells: 192000000 and the calculation took amazing five days (or was it six days?). Anyway, the result is unfortunately not what I would like to have gotten. There links to three images with accompanying contour lines [1][2][3] for some of the problems I encounter with the result, which is btw. a hillshade computed from the DEM. To me it seems that the contour lines are sometimes to dense and sometimes to far spaced for the algorithm. And there are those straight line artefacts you can find all over the place and some patterns that vaguely look like quadtree pattern. And then there are those contour like black lines, especially in [1] and [3] which I really can't explain. Well I am willing to give it a second try and now I wonder what I can do better. Increase resolution? Leave out some contour lines? So any help is greatly appreciated :-) Frank PS Grass is version 6.4.3 on Ubuntu 12.04 [1] http://www.geometrico.lu/devel/grass/hillshade1.jpeg [2] http://www.geometrico.lu/devel/grass/hillshade2.jpeg [3] http://www.geometrico.lu/devel/grass/hillshade3.jpeg - -- Frank BRONIEWSKI METRICO s.à r.l. géomètres technologies d'information géographique rue des Romains 36 L-5433 NIEDERDONVEN tél.: +352 26 74 94 - 28 fax.: +352 26 74 94 99 http://www.metrico.lu -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBAgAGBQJTYLuXAAoJEHopqW0d1cQVPU8IAKDS5E2lC8txxVrMOSkzEBAA cKVTTOghKJt2K63hVO7TGrAwaK2LFVAKsdeb+wLMS/TisnP5cFlCrN8lZNzGNxg8 v1+o4qZBgUHZP6RmIHsAQzOgTlNHqjlK8vxvWWdtTOaf4GESQlBbUehzF2nW6eRg cIbPp1H3Tbel2wSnEM9nuc/Kqy9/wgGwrf9G0N2C7XeM2CnfMFRyj45e4BILjQMb tPpyLfnhdjOk3Eg+3PiC5CtZDpn6AFBxFqq6F6yDUxm5MrUJe6uvKqADTd8dReDs Nwj2xOwLRGQdIXayeHHnam2HYtzjXQO+UEhu+v+SRqWJEb6lSR1u8OvP3uG0PbE= =RAFt -----END PGP SIGNATURE----- _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
