Ament Model for Multiple Rebounds From Rough Sea Surfaces in a Stratified Medium and Validation From the MoM-Based Multilevel SDIM

In this paper, the well-known Ament model is generalized to multiple rebounds (reflections) from rough sea surfaces in a stratified medium. To solve this propagation-scattering problem in the radar microwave domain, the physical optics (PO) approximation is applied to determine the currents on the rough sea surface. Next, to solve the propagation problem, i.e., to calculate the scattered field in the duct, an appropriate Green function of the duct (which is a stratified medium with linear-square refraction index profile) is used to radiate the currents from Huygens' principle. Due to refraction phenomenon, this field induces new currents on the surface (second rebound), which are again evaluated by PO. The process is iterated. Then, for each rebound, the coherent components of the surface currents and the scattered field are calculated and compared with those of a flat surface in order to derive the generalized Ament model. In addition, this model is compared with the results computed by the rigorous method of moments and accelerated by the multilevel subdomain decomposition iterative method combined with the adaptive cross approximation.