rajat, i am doing something similar: Landsat 8 for landcover classification.
although not an answer to your specific qn, here are a couple of other links i found useful for GRASS/landsat workflow: http://landsat.usgs.gov/L8_band_combos.php http://courses.neteler.org/processing-landsat8-data-in-grass-gis-7/ Best, Vishal On Wed, Jul 2, 2014 at 12:16 PM, Jiao Wang <[email protected]> wrote: > Forgot the link: > > http://www.exelisvis.com/Home/NewsUpdates/TabId/170/ArtMID/735/ArticleID/13592/Digital-Number-Radiance-and-Reflectance.aspx > > > > On Wed, Jul 2, 2014 at 8:59 AM, Jiao Wang <[email protected]> wrote: > >> Hi Rajat, >> >> Surface reflectance should be used for calculating NDVI. >> Here is a link that explains the difference between radiance and surface >> reflectance. >> >> Best, >> Jiao >> >> >> On Tue, Jul 1, 2014 at 11:59 PM, Rajat Nayak <[email protected]> >> wrote: >> >>> Dear All, >>> I am trying to calculate NDVI for my study area using landsat 8 >>> products. >>> I calibrated images using i.landsat.toar. Now I'm a little confused. >>> If I use -r flag, I get radiance values at the sensor. If -r flag is not >>> used >>> I will get reflectance values. >>> Now the question is which one of the two, >>> radiance (obtained using -r flag) or surface reflectance (without any >>> flags) >>> should I use for calculating NDVI. >>> It will also be great if you can let me know the difference between the >>> two >>> and how it will influence my NDVI calculations. >>> >>> Thanking you >>> Regards >>> Rajat Nayak >>> >>> _______________________________________________ >>> grass-user mailing list >>> [email protected] >>> http://lists.osgeo.org/mailman/listinfo/grass-user >>> >> >> > > _______________________________________________ > grass-user mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/grass-user > -- Vishal K. Mehta, PhD Scientist Stockholm Environment Institute - US 133 D St Suite F Davis CA 95616 www.sei-us.org
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