Numerical Simulations of Wave Scattering from Two-layered Rough Interface

Method of Moments (MOM) combining with the Kirchhoff Approximation(KA) for analysis of the problem of optical wave scattering by a stack of two one-dimensional Gaussian rough interfaces is solved. The scattered field from the upper interface is solved by MOM and the transmitted field from the lower one is expressed from the Kirchhoff approximation where the multiple scattering phenomenon is neglected. The advantage of this hybrid method is that it is more exact than Kirchhoff approximation. The two rough interfaces separate three lossless and homogeneous media. The bistatic scattered field and the scattering coefficient are derived in this paper for vertical and horizontal polarizations. The influence of the relative permittivity, the height rms and the correlative length, the average heights between the two interfaces on the bistatic scattering coefficient is discussed in detail. The application of this work is the study of electromagnetic modeling of oil slicks on ocean surfaces.