The WI1 operator algorithm computes the Water Index 1 from a given product.

The WI1 results from the following equation:

WI1 = (G - S2) / (G + S2)

, where:

The bands are:

- G is the Green band
- S2 is the SWIR 2 band

Also the processor computes an additional flags band called 'wi1_flags' with the following bit coding:

Bit Position	Description
Bit 0	The computed value for WI1 is NAN or is Infinite
Bit 1	The computed value for WI1 is less than -1 (minus one)
Bit 2	The computed value for WI1 is greater than 1 (one)