Monitoring of Wheat Scab Using the Specific Spectral Index from ASD Hyperspectral Dataset

Table 1

Definitions of vegetation indices and spectral differential characteristics.

Vegetation indices/spectral differential characteristics	Calculation formulas	References
NDVI	(R840 − R675)/(R840 + R675)	[17]
RVSI	[(R712 + R752)/2] − R732	[18]
TVI	0.5[120(R750 − R550)−200(R670 − R550)]	[19]
MCARI	[(R700 − R670)−0.2(R700 − R550)] × (R700/R670)	[20]
TCARI	3 × [(R700 − R670)−0.2 × (R700 − R550) × (R700/R670)]	[21]
PRI	(R570 − R531)/(R531 + R570)	[22]
NRI	(R570 − R670)/(R570 + R670)	[23]
GNDVI	(R747 − R537)/(R747 + R537)	[24]
PSRI	(R680 − R500)/R750	[25]
SIPI	(R800 − R445)/(R800 − R680)	[26]
NBNDVI	(R850 − R680)/(R850 + R680)	[27]
Db	Maximum first-order differential value of the blue edge (490–530 nm)	[28]
Dy	Maximum first-order differential value of the yellow edge (550–582 nm)
Dr	Maximum first-order differential value of the red edge (670–737 nm)
SDb	The sum of first-order differential value of the blue edge
SDy	The sum of first-order differential value of the yellow edge
SDr	The sum of first-order differential value of the red edge
SDg	The sum of first-order differential value of the green peak (510–560 nm)	[29]
SDg/SDb	The ratio of SDg to SDb
SDy/SDb	The ratio of SDy to SDb
(SDr − SDy)/(SDr + SDy)	Normalized ratio of SDr and SDy
(SDg − SDb)/(SDg + SDb)	Normalized ratio of SDg and SDb