Detecting plant physiological changes under stress using sun-induced chlorophyll fluorescence from mid-spectral resolution imagery

Sun-induced chlorophyll fluorescence (SIF) serves as a valuable indicator for remote sensing of plant physiology. Recent studies have shown that far-red SIF at 761 nm (hereafter SIF) from mid spectral resolution (SR) imagers (3–7 nm full width half maximum (FWHM)) derived reliable fluorescence emission in relative levels. Such mid SR based SIF (SIF MS ; the subscript MS refers to mid SR basis) has been extensively utilized for assessing fluorescence variability in precision agriculture and plant stress detection across various platforms. However, the uncertainties regarding the ability of SIF MS to detect physiological SIF yield (ΦF) remain inadequately investigated. Here, we evaluated various retrieval techniques (i.e., Fraunhofer line depth (FLD), its variant methods, and spectral fitting method (SFM)) under theoretical condition (SCOPE simulation), stress condition (DCMU experiment at…