The NSDSI3 operator algorithm computes the Normalized Shortwave-Infrared Difference Bare Soil Moisture Index 3 from a given product.

The NSDSI3 results from the following equation:

NSDSI3 = (S1 - S2) / (S1 + S2)

, where:

The bands are:

- S1 is the SWIR 1 band
- S2 is the SWIR 2 band

Also the processor computes an additional flags band called 'nsdsi3_flags' with the following bit coding:

Bit Position	Description
Bit 0	The computed value for NSDSI3 is NAN or is Infinite
Bit 1	The computed value for NSDSI3 is less than -1 (minus one)
Bit 2	The computed value for NSDSI3 is greater than 1 (one)