The GARI operator algorithm computes the Green Atmospherically Resistant Vegetation Index from a given product.

The GARI results from the following equation:

GARI = (N - (G - (B - R))) / (N - (G + (B - R)))

, where:

The bands are:

- B is the Blue band
- G is the Green band
- R is the Red band
- N is the NIR band

Also the processor computes an additional flags band called 'gari_flags' with the following bit coding:

Bit Position	Description
Bit 0	The computed value for GARI is NAN or is Infinite
Bit 1	The computed value for GARI is less than -1 (minus one)
Bit 2	The computed value for GARI is greater than 1 (one)