COUPLED SURFACE-ATMOSPHERE REFLECTANCE (CSAR) MODEL .2. SEMIEMPIRICALSURFACE MODEL USABLE WITH NOAA ADVANCED VERY HIGH-RESOLUTION RADIOMETER DATA

A new semiempirical model to describe the bidirectional reflectance of arbitrary natural surfaces using only three parameters has been devel oped. This model successfully accounts for the observed variability of reflectance measurements in laboratory and field conditions, ranging from bare soil to full canopy cover, in both the visible and the near- infrared bands. Coupled with a simple atmospheric radiation transfer m odel, this model has been inverted against actual NOAA/advanced very h igh resolution radiometer (AVHRR) data from several desert sites in no rthern Africa. This procedure allows the retrieval of surface properti es and average amounts of atmospheric constituents (aerosol optical th ickness and water vapor) for the duration of the measurement period. F urther work is required to expand the usability of the coupled model t o other locations and shorter periods of time, but the paper demonstra tes the feasibility of inverting a coupled surface-atmosphere model ag ainst existing AVHRR data and documents the current limits of this app roach.