On Jan 25, 2008 12:08 AM, Hamish <[EMAIL PROTECTED]> wrote: > > Eric Patton wrote: > > > I was updating the r.colors docs, as the given rules in the html > > > are out of sync with the program. > > > I'm not sure how to describe some of the canned rules, particularly > > > curvature and evi. ... > It is enhanced vegetation index from eg MODIS data like NDVI. > see http://earthobservatory.nasa.gov/Library/MeasuringVegetation/
EVI (enhanced vegetation index) is used to monitor vegetation. EVI was developed with improved sensitivity in areas of dense, green vegetation with large amounts of chlorophyll (where NDVI tends to saturate). Additionally, it is less sensitive to haze and atmospheric effects since the blue channel is included in the denominator. It also minimizes the influence of background interference caused by bare soil reflecting off the ground. chees Markus _______________________________________________ grass-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-dev
