NBUI

The NBUI operator algorithm computes the New Built-Up Index from a given product.

The NBUI results from the following equation:

NBUI = ((S1 - N) / (10.0 * pow((T + S1) , 0.5))) - (((N - R) * (1.0 + l)) / (N - R + l)) - (G - S1) / (G + S1)

, where:

The bands are:

- G is the Green band
- R is the Red band
- N is the NIR band
- S1 is the SWIR 1 band
- T is the Thermal band

and the coefficients are:

- l is the Canopy background adjustment coefficient

NBUI-Flags

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

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