Table 2 Definitions of the features extracted from different imagery
Feature | Features | Formulation | References |
|---|---|---|---|
Spec. Info | Blue (B), Green (G), Red (R), Red-Edge (RE), Near-infrared (NIR) | The raw value of each band | – |
Ratio vegetation index | RVI = NIR/R | [31] | |
Green chlorophyll index | GCI = (NIR/G)−1 | [32] | |
Red-edge chlorophyll index | RECI = (NIR/RE)−1 | [32] | |
Normalized difference vegetation index | NDVI = (NIR−R)/(NIR + R) | [33] | |
Green normalized difference vegetation index | GNDVI = (NIR−G)/(NIR + G) | [34] | |
Green–red vegetation index | GRVI = (G−R)/(G + R) | [31] | |
Normalized difference red-edge | NDRE = (NIR−RE)/(NIR + RE) | [35] | |
Normalized difference red-edge index | NDREI = (RE−G)/(RE + G) | [36] | |
Simplified canopy chlorophyll content index | SCCCI = NDRE/NDVI | [37] | |
Optimized soil adjusted vegetation index | OSAVI = (NIR−R)/(NIR + R + L) (L = 0.16) | [38] | |
Modified chlorophyll absorption in reflectance index | MCARI = [(RE−R)−0.2*(RE−G)] *(RE/R) | [39] | |
Transformed chlorophyll absorption in reflectance index | TCARI = 3*[(RE−R)−0.2*(RE−G) *(RE/R)] | [40] | |
MCARI/OSAVI | MCARI/OSAVI | [39] | |
TCARI/OSAVI | TCARI/OSAVI | [40] | |
Wide dynamic range vegetation index | WDRVI = (a*NIR−R)/(a*NIR + R) (a = 0.12) | [41] | |
Struc. Info | Canopy Height Model (m) | CHM = DSM−DEM | / |
Therm. Info | Normalized relative canopy temperature index | \(NRCT = \frac{{T_{i} - T_{\min } }}{{T_{\max } - T_{\min } }}\) | [42] |