Radar LGA scattering above a sea surface in a stratified medium solved by physical optics

This paper presents an asymptotic method based on the physical optics (PO) approximation in order to calculate the currents on the perfectly conducting (PC) sea surface in the microwave Radar applications. Then, knowing the appropriate Green function of the stratified medium (which forms a duct described by a linear-square refraction index profile) above the sea surface, the scattered field in this medium is calculated by applying Huygens´ principle. Due to the negative gradient of the refraction index profile, the reflected field can be trapped in the duct inducing new currents on the surface. The PO approximation is then applied again to calculate these currents. In this paper, the case of TE polarization is discussed and PO is validated by a rigorous method based on the Method of Moments (MoM) and accelerated by the Forward-Backward.