Hi, I'm trying to interpolate a DEM to match my imagery. The images are approximately 60 cm resolution of about 829,490,277 cells!
GRASS 6.2.2cvs (phil_geog):~ > g.region rast=infanta_qb.rgb -pm projection: 3 (Latitude-Longitude) zone: 0 datum: wgs84 ellipsoid: a=6378137 es=0.006694379990141316 north: 14:47:20.445994N south: 14:38:29.85632N west: 121:33:58.254452E east: 121:44:02.028909E nsres: 0.60401006 ewres: 0.58788111 rows: 26999 cols: 30723 cells: 829490277 My input dem points contain 20800 points. I tried interpolation in smaller region and it seems to work OK. This time trying at full region setting, I am getting segmentation fault using v.surf.rst. v.surf.rst input=dem_pt_fin layer=0 dmax=0.000014 dmin=0.000003 elev=dem_surf.rst maskmap=MASK zmult=1.0 tension=40. segmax=40 npmin=300 A few questions: 1. Is the segfaults caused by my limited hardware (1 GB ram and 2 GB swap)? Does v.surf.rst temporarily writes to hardrive? My PC reports a limited hardisk space while running v.surf.rst (drive freespace 10 GB). Probable solution: do v.surf.rst with smaller regions the r.patch 2. Are there size limits to the number of vector points and output raster? http://www.dinama.gub.uy/grass/gdp/html_grass63/r.in.xyz.html reports: "Interpolation into a DEM The vector engine's topographic abilities introduce a finite memory overhead per vector point which will typically limit a vector map to approximately 3 million points (~ 1750^2 cells)" 3. Would bigger DEM pixel resolution say 10-30 meters be OK for orthorectification? cheers, maning _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user