Characterisation of reflectance and chlorophyll fluorescence anisotropy – defining requirements for an experimental setup

Over the last two decades, sun-induced fluorescence (SIF), a part of energy absorbed by chlorophyll and reemitted at longer wavelengths (red and far-red) than for excitation, has been studied by many researchers, considered a proxy for light-use efficiency (LUE) and functioning of photosynthesis machinery. Although many studies support the use of SIF as a tool for monitoring of photosynthetic activity, SIF measurements are still a challenging task. The anisotropy of SIF emission was not yet fully characterised, which could potentially help to relate SIF to photosynthetic processes and refine the influence of plant traits (e.g. leaf structure) on SIF signal, therefore, we focused on defining experimental design requirements for characterisation of SIF bidirectional behaviour