A coupled vegetation-soil bidirectional reflectance model for a semiarid landscape

A model for the bidirectional reflectance over soils is coupled with a vegetation reflectance model to predict the bidirectional reflectance of semiarid landscape. The vegetation model is a hybrid of geometric optical and radiative transfer (GORT) model for bidirectional reflectance over discontinuous plant canopies. The coupling is done by relaxing the assumption of Lambertian background into a non-lambertian case in the vegetation GORT model. The non-Lambertian soil background is modeled by a soil BRDF model. The coupled model is validated with POLDER and AVHRR imagery collected in a semiarid: site during the Jornada PROVE'97 campaign with good accuracy. It is a very simple but analytical model for bidirectional reflectance over a semiarid landscape and has the potential for surface parameter retrieval for the study of biosphere-atmosphere interaction. (C) Elsevier Science Inc., 2000.