Modeling of atmospheric effects on the angular reflectance characteristics of vegetation canopies

The capabilities of off-nadir satellite observing directional variations in terrestrial surface reflectance, not yet sufficiently present in operational satellite series, are expected to be developed in the near future. The main objective of the paper is to study and modeling the atmospheric effects on the typical angular reflectance characteristics of vegetation surfaces in the visible and near-infrared regions. For the evaluation of the atmospheric contribution to the satellite data, radiative transfer model simulations, with ground radiometric measurements have been performed. The paper discusses the signatures that the atmosphere imposes on the angular distribution of the emerging solar radiation above aerosol-loaded atmosphere. The model calculations have also showed that some atmospheric-invariant features of the angular reflectance distribution, like the aerosol forward scattering peak or the hot spot in the antisolar direction, may be used as discriminant surface reflectance characteristics in the case of low aerosol- loaded atmosphere.