SCATTERING BEHAVIOR OF LUNAR LAKE PLAYA DETERMINED FROM PARABOLA BIDIRECTIONAL REFLECTANCE DATA

Bidirectional reflectance data obtained with the PARABOLA instrument at Lunar Lake, Nevada, were analyzed to determine the scattering properties of playas. The data are approximated by a Lambertian function, except at high phase angles in the solar principal plane, where Fresnel reflectance appears to dominate. The data also depart slightly (15%) from a Lambertian function at high emission angles in all azimuthal planes. No published photometric model accounts for the observed data. It is hypothesized that the observed scattering behavior is the superposition of volume and surface (Fresnel) scattering mechanisms.