| PISI Algorithm Specification | |
The PISI operator algorithm computes the
Perpendicular Impervious
Surface Index from a given
product.
The PISI results from the following equation:
PISI = 0.8192 * B - 0.5735 * N + 0.0750
, where:
The bands are:
- B is the Blue band
- N is the NIR band
Also the processor computes an additional flags band called 'pisi_flags' with the following bit coding:
| Bit Position | Description |
|---|---|
| Bit 0 | The computed value for PISI is NAN or is Infinite |
| Bit 1 | The computed value for PISI is less than -1 (minus one) |
| Bit 2 | The computed value for PISI is greater than 1 (one) |