Those are digital numbers. On Mon, Sep 13, 2010 at 6:38 AM, Daniel Victoria <daniel.victo...@gmail.com> wrote: > Hi Nikos, > > I did not use i.landsat.toar. I converted the DN values to radiance > manually, using r.mapcalc and the formula and coefficients provided. > > Are you going to use i.atcorr? I'm still trying to figure out which is > the correct procedure for i.atcorr: > > 1) Convert DN to radiance and run i.atcorr (wiki example) > 2) Use DN values in i.atcorr (man page exemple) > > And also, what are the output units since they appear to be scaled from 1 to > 255 > > Cheers > Daniel > > 2010/9/12 Nikos Alexandris <nikos.alexand...@felis.uni-freiburg.de>: >> Daniel Victoria: >> >>> I haven't tryed i.landsat.toar addon but from what I read in the wiki >>> (http://grass.osgeo.org/wiki/Atmospheric_correction) I could either >>> use i.landsat.toar or a DN - Radiance conversion formula that is >>> given... >> >>> Will try to recalculate the images, I might have done something wrong >> >> Hi Daniel! >> >> Did you finally used i.landsat.toar for the Landsat5 - TM bands? >> >> I am trying to use the module on the LT51830332007248MOR00 image(s) and have >> several (expected) problems, like: >> >> (note that the metadata file I downloaded via GLOVis has a ".meta" extension) >> >> 1. the "LT51830332007248MOR00.meta" isn't read correctly or the module is >> looking for a string other than the "date_acquired = 20070905" string which >> is >> the only "date-string" included in the ".meta" file >> >> 2. does not recognize the solar elevation value >> >> (the above "cases" are mentioned in the manual, so manual feed is required >> here) >> >> 3. after manually providing the "solar_elevation" and the "product_date" and >> using the "-v" flag, some random (?) segfaults occur. >> >> 4. without the "-v" flag it runs but seems to take too much time? OK, the >> image set is large ( 7654 cols x 7127 rows x 7 bands). --- Is it really >> taking >> so long or is there something wrong? >> >> Nikos >> > _______________________________________________ > grass-user mailing list > grass-user@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/grass-user >
-- Stephen Sefick ____________________________________ | Auburn University | | Department of Biological Sciences | | 331 Funchess Hall | | Auburn, Alabama | | 36849 | |___________________________________| | sas0...@auburn.edu | | http://www.auburn.edu/~sas0025 | |___________________________________| Let's not spend our time and resources thinking about things that are so little or so large that all they really do for us is puff us up and make us feel like gods. We are mammals, and have not exhausted the annoying little problems of being mammals. -K. Mullis "A big computer, a complex algorithm and a long time does not equal science." -Robert Gentleman _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
