Radar backscattering modeling of oil slicks at Sea based on the model of local balance

This paper aims at presenting a refined electromagnetic modeling based on a physical hydrodynamic model of surface damping by the presence of oil films, the model of local balance (MLB). It focuses on the case of one-dimensional (1D) surfaces, corresponding to two-dimensional problems, for a more thorough study which makes it possible to use a numerical reference method (PILE method), based on the Method of Moments. In this context, for an effective modeling of the complex double-layer problem (air/oil and oil/sea surfaces), two simplifying asymptotic approaches are presented and tested: the so-called “thin-layer” and “classical” approaches, which make it possible to treat this problem as a much more simple single-layer problem, just like the clean sea surface case. Then, the validity of the two approaches is studied by comparison with the PILE method. The main conclusion of this study is that, for the typical thicknesses studied here, the “thin-layer” approach is the most reliable for near-nadir incidence configurations and can then be used for altimeter applications, whereas the “classical” approach is the most reliable for moderate incidence angles and can be successfully used for satellite applications.