| MCARI Algorithm Specification | |
The Modified Chlorophyll Absorption Ratio Index
algorithm was developed by Daughtry et al. (2000) to be responsive to chlorophyll variation.
This algorithm is responsive to both leaf chlorophyll concentrations and ground reflectance.
The MCARI results from the following equation:
MCARI = ((red_factor2 * red2 - red_factor1 * red1) - 0.2 * (red_factor2 * red2 - green_factor * green)) * (red_factor2 * red2 / red_factor1 * red1)
For Sentinel-2 the formula is:
[(B5 - B4) - 0.2 * (B5 - B3)] * (B5 / B4), where (Central wavelength/Bandwidth): B5 = 705 nm (15 nm), B4 = 665 nm (30 nm), B3 = 560 nm (35 nm)
Also the processor computes an additional flags band called 'mcari_flags' with the following bit coding:
| Bit Position | Description |
|---|---|
| Bit 0 | The computed value for MCARI is NAN or is Infinite |
| Bit 1 | The computed value for MCARI is less than -1 (minus one) |
| Bit 2 | The computed value for MCARI is greater than 1 (one) |