[Qgis-user] NDVI creation from LANDSAT

[RNanclares]

Hi John, 

You don't need to perform atmospheric correction because you're using a
surface reflectance data set (that's what the SR in the file name stands
for), so it's already corrected.

NDVI values usually range from 0 to 1 but you can also find negative values.
This typically is a side effect of the atmospheric correction algorithm.
Don't worry you're doing it right. 

When you talk about red and greens it doesn't really make any sense unless
two different users are using the same color ramp. You should get high NDVI
values in the vegetation and low in water bodies/urban areas/bare ground,
and thus you will see lighter tones of grey in vegetation areas and darker
tones of grey in urban areas/bare ground while water usually displays black
o near black tones. 

Hope this helps,

Cheers.




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