Comparing hyperspectral BRDF data of grass derived from three different laboratory- and field-goniometer systems

The study compares hyperspectral BRDF data of grass vegetation acquired in the laboratory and field with three different goniometric systems. Reflectance measurements of relatively sparse prairie grass were comparable to measurements taken over a dense grass lawn surface only after correction for the soil influences determined by the canopy gap probability function. Nadir-normalized BRDF data consistently revealed a strong wavelength dependence. In addition, a distinctive relationship between BRDF effects and the canopy reflectance signature was observed in all three grass canopies. These phenomena are due to multiple scattering effects which occur within the grass canopy. Since the canopy structure and multiple scattering effects are ultimately related, the potential for deriving canopy architecture parameters from hyperspectral BRDF data is suggested