Theoretical modelling of ocean radar backscatter for wind speed retrieval from SAR, scatterometer and altimeter data

We discuss the development of a physically based model for wind-field retrieval which is applicable to radar altimeters, synthetic-aperture radars (SAR) and scatterometers. We consider suitable choices for the scattering model and the description of the sea surface. The composite-surface model combined with the spectrum of Lemaire et al. [3] produces results in best agreement with all the observations tested, at both nadir and off-nadir incidence angles. This spectrum has a free parameter, namely the significant slope. However, the significant slope obtained from sample wave-model (WAM) data does not agree with the value required to fit radar data.