Imaging spatial heterogeneity of solar-induced chlorophyll fluorescence (sif) with very high spatial resolution drone imagery

Here, we present one of the first datasets recorded by a drone based prototype dual camera system based on narrow band high-quality optical filters, hereafter named SIFcam. The camera allows for sensing solar-induced chlorophyll fluorescence (SIF) at 760 nm (F-760) with centimeter ground sampling distance. The system performance was evaluated against simultaneous observations of a wheat-bean mixed canopy carried out using a mobile ground-based nonimaging system FloX (R-2 = 0.84, RMSE = 0.17 mWm(-2)nmsr(-1)) and SIF imagery acquired by the airborne imager HyPlant (R-2 = 0.52, RMSE = 0.24 mWm(-2)nm-lsr(-1)). The analysis of near-infrared reflectance allowed us to quantify on average 95.4% contribution of F-760 signal originating from sun-lit pixels of investigated canopies. Additional multispectral imagery facilitated calculation of fractional vegetation cover (FVC) of >88%. Spatial patterns of sunlit pixels are systematically consistent, indicating the plausibility of the SIFcam measurements.