[GRASS-user] NDVI from landsat 5 TM

[stephen sefick]

I would like to calculate NDVI and EVI from ladsat 5 data.  The data
is scaled 0-255.  Do I need to convert this to watts/meter sqaured
before I proceed?  I have done this calculation
(band4-band3)/(band5+band3) and get a map filled with zeros.  What am
I doing wrong.

-- 
Stephen Sefick

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