The SR3 operator algorithm computes the Simple Ratio (860, 550 and 708 nm) from a given product.

The SR3 results from the following equation:

SR3 = pow(N , 2) / (G * RE1)

, where:

The bands are:

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

Also the processor computes an additional flags band called 'sr3_flags' with the following bit coding:

Bit Position	Description
Bit 0	The computed value for SR3 is NAN or is Infinite
Bit 1	The computed value for SR3 is less than -1 (minus one)
Bit 2	The computed value for SR3 is greater than 1 (one)