Reflection models for soil and vegetation surfaces from multiple-viewing angle photopolarimetric measurements

The reflection properties of soil and vegetation surfaces have been investigated using airborne photopolarimetric data from the research scanning polarimeter (RSP). For both surface types, it was found that the ratios of total reflectances taken at two different wavelengths from visible and short-wave infrared channels are the same for different illumination and scattering geometries, and in general independent of the scattering angle. From an analysis of the angular and spectral dependencies of the intensity and polarization, we show that the modeled total and polarized reflectances can be expressed in the same form both for soil and vegetation surfaces, namely, as the product of geometrical scattering term depending only on illumination and viewing angles, and a term that varies solely with wavelength and scattering angle.