Study on the extraction of plant biochemical information from canopy reflectance spectra

Leaf biochemical concentrations influence both leaf and canopy spectra at their absorption bands. Leaf scale model PROSPECT, canopy scale model SAIL and their coupled model PROSAIL are used to generate simulated reflectance an transmittance spectra to study the influence of biochemical concentrations. Three biochemical input variables of PROSPECT model, concentration of chlorophyll, leaf water and dry matters, are studied in this paper. Figures show that their influences on both leaf reflectance spectra and canopy reflectance spectra are similar. The influence of chlorophyll is located at visible region, leaf water at near infrared region especially centered at 1400 nm and 1900 nm, and dry matters at near infrared region especially at some reflectance peaks. Reflectance at canopy scale is generally less than that at leaf scale. Other non-biochemical factors also influence the spectra at both scales and some of them may cover biochemical signals in canopy reflectance spectra to some extent.