A Spectral Invariant Approach to Modelling Radiative Transfer Of Sun-Induced Chlorophyll Fluorescence

Sun-induced chlorophyll fluorescence (SIF) observations are strongly affected by canopy structure. Modelling the radiative transfer of SIF provides an approach to quantifying the canopy structure effects and a better estimation of photosynthesis from SIF. The spectral invariant approach allows for the separation of reflectance into spectrally dependent parameters and spectrally independent parameters. We extend the spectral invariant theory to model the radiative transfer of SIF. The spectral invariant approach gives similar simulations of SIF emission and scattering of far-red SIF as the SCOPE model does. This work can help to disentangle the part of SIF signal that is dependent on the structure from that which is dependent on physiology.