Electromagnetic Bistatic Scattering Features of Shallow Water Waves Over Upslope Submarine Topography

Abstract

This paper focuses on improving the understanding of the electromagnetic (EM) scattering from water waves modulated by shoaling effect arising from different upslope submarine topography in the nearshore zone. Simulation of EM bistatic scattering from water waves in the nearshore zone where the water depth becomes gradually shallower is presented. The shallow water waves with periodic sinusoidal type are simulated by the model that is based on Boussinesq approximation theory, which can accurately construct the detailed wave structure in the nearshore zone, and the analytical model-the second-order small slope approximation is applied to modeling the EM bistatic scattering from the shallow water waves. Comparisons of the bistatic scattering coefficient (BSC) between water waves corresponding to different submarine plane-upslope topography in the nearshore zone have shown that the angular position of harmonics of BSC will change as upslope varies: higher-order harmonics for plane-upslope cases would be far away from the specular peaks for flat topography case. Moreover, the wave height of the shallow water waves and nonlinear effect will greatly impact changing trend of the BSC. Simulations for TMA spectrum-based water waves also support the fact that the transfer of wave energy from low frequency to higher frequency wave components would be intensified in the shallow water zone with the upslope submarine topography. The results in this paper indicate that shallow water waves would reflect some interesting scattering features that traditional deep-sea waves didn't show, which will be helpful to the further quantitative investigation of scattering characteristics of nearshore waves.

A facet-based model and Doppler analysis for bistatic electromagnetic scattering from 3-D time-evolving sea surface

“…Yanlei Du et al [5] used the combined IEM、AIEM and the improved wave spectrum model to simulate the bistatic electromagnetic scattering characteristics of a full polarization at the sea surface and analyzed the influence of various factors on bistatic electromagnetic scattering from anisotropic sea surface. Xiaoxiao Zhang et al [6] used the physical optics method to obtain the scattering field and a slope criterion for high sea condition to modify the sea surface with breaking waves, which presented a composite bistatic scattering model of the sea surface ship under different sea conditions. Ding Nie et al [7] used a model based on Boussinesq approximation theory to construct a detailed wave structure in the near shore zone and the second-order small slope approximation to model the electromagnetic bistatic scattering from the shallow water waves.…”