IBI

The IBI operator algorithm computes the Index-Based Built-Up Index from a given product.

The IBI results from the following equation:

IBI = (((S1 - N) / (S1 + N)) - (((N - R) * (1.0 + l) / (N + R + l)) + ((G - S1) / (G + S1))) / 2.0) / (((S1 - N) / (S1 + N)) + (((N - R) * (1.0 + l) / (N + R + l)) + ((G - S1) / (G + S1))) / 2.0)

, 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

and the coefficients are:

- l is the Canopy background adjustment coefficient

IBI-Flags

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

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