Markus, > AFAIK LANDSAT is sun-synchronous, it passes in the local morning time > (something like 10:30-11:00). > > Maybe this helps: > http://earthobservatory.nasa.gov/MissionControl/overpass.html
Since it is an overpass predictor, it doesn't provide information on previous landsat overpass. Can I use this as a proxy to the hh:mm for i.atcorr (me thinks no)? Or set an arbitrary time say between 10:30 to 11:00? > i.atcorr is the sophisticated correction, i.landsat.dehaze only a simple > approach based on image statistics. > >> 3. correction for topographic/terrain effects (most of my study area >> are in maountainous regions) >> use book 2nd ed. (page 226) "cosine correction" >> using r.sunmask, r.mapcalc >> Problem: again, no image acquisition time > > (see above). "cosine correction" is a simple approach. See also > i.topo.corr (from GRASS AddOns). Thank you for this one. >> 4. removal of clouds >> use i.landsat.acca >> https://svn.osgeo.org/grass/grass-addons/imagery/i.landsat.acca/ > > Never tried, please report back. Will do, via wiki. > I have collected all this now in > http://grass.osgeo.org/wiki/Image_processing#Preprocessing > > Feel free to further improve that Wiki page. > Markus As usual, thank you very much. cheers, maning -- |---------|----------------------------------------------------------| | __.-._ |"Ohhh. Great warrior. Wars not make one great." -Yoda | | '-._"7' |"Freedom is still the most radical idea of all" -N.Branden| | /'.-c |Linux registered user #402901, http://counter.li.org/ | | | /T |http://esambale.wikispaces.com| | _)_/LI |---------|----------------------------------------------------------| _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user