The ARI operator algorithm computes the Anthocyanin Reflectance Index from a given product.

The ARI results from the following equation:

ARI = (1.0 / G) - (1.0 / RE1)

, where:

The bands are:

- G is the Green band
- RE1 is the Red Edge 1 band
- R is the Red band

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

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