Table 5.

Typical vegetation indices used for field-based phenotyping with UAV platform.

Vegetation index	Formula	Related crop traits	References
BGI2 (Blue Green Pigment Index 2)	R450/R550	LAI, chlorophyll	Aasen et al., 2015
CSI (Canopy Structure Index)	2sSR−sSR2 +sWI2 WI = R900/R970 SR = R800/R680	Water	Aasen et al., 2015
DVI (Difference Vegetation Index)	Rnir−Rred	Nitrogen, chlorophyll	Jordan, 1969
EVI (Enhanced Vegetation Index)	2.5(Rnir−Rred)/(Rnir+6Rred−7.5Rblue+1)	Chlorophyll	Huete et al., 1997
GNDVI (Green Normalized Difference Vegetation Index)	(Rnir−Rgreen)/(Rnir+Rgreen)	LAI, chlorophyll, nitrogen, protein content, water content	Gitelson et al., 1996; Garcia-Ruiz et al., 2013
NDVI (Normalized Difference Vegetation Index)	(R※nir−Rred)/(Rnir+Rred)	LAI, yield, biomass	Aasen et al., 2015; Zaman-Allah et al., 2015
OSAVI (Optimized Soil-Adjusted Vegetation Index)	1.16(R800−R670)/(R800+R670+0.16)	Chlorophyll	Gitelson et al., 1996; Berni et al., 2009b
PRI (Photochemical Reflectance Index)	(R570−R530)/(R570+R530)	Chlorophyll, nitrogen, water	Suarez et al., 2009
PSRI (Plant Senescence Reflectance Index)	(R680−R500)/R750	Chlorophyll, nitrogen	Gitelson et al., 1996
PVI (Perpendicular Vegetation Index)	(NIR−aR−b)/$\sqrt{1+a^2}$	Chlorophyll	Richardson and Wiegand, 1977
RDVI (Renormalized Difference Vegetation Index)	(R800−R670)/$\sqrt{{\text{R}}_{800}-{\text{R}}_{670}}$	LAI, biomass, nitrogen	Tucker, 1979
RVI (Ratio Vegetation Index)	Rnir/Rred	Water content, yield, chlorophyll, nitrogen	Rondeaux et al., 1996
TCARI (Transformed CAR Index)	3*[(R700−R670)−0.2*(R700−R550)*(R700/R670)]	Chlorophyll	PeÑUelas et al., 1993
VDI(Vegetation Drought Index)	(R970−R900)/(R970−R900)	Water stress	Suarez et al., 2009

R^※ means spectral reflectance.