| NDWI2 Algorithm Specification | |
The second Normalized Difference Water Index
algorithm was developed by McFeeters (1996) to detect surface waters in wetland environments and to allow for the measurement of surface water extent .
The NDWI2 results from the following equation:
NDWI2 = (green_factor * green - IR_factor * near_IR) / (green_factor * green + IR_factor * near_IR)
Also the processor computes an additional flags band called 'ndwi2_flags' with the following bit coding:
| Bit Position | Description |
|---|---|
| Bit 0 | The computed value for NDWI2 is NAN or is Infinite |
| Bit 1 | The computed value for NDWI2 is less than -1 (minus one) |
| Bit 2 | The computed value for NDWI2 is greater than 1 (one) |