Electromagnetic Scattering and Doppler Spectrum Simulation of Land–Sea Junction Composite Rough Surface

Abstract

In this paper, a weighted arctangent function is used in conjunction with the spectral method to generate a land–sea junction composite rough surface under the spatially homogeneous and time-stationary hypotheses. The exponential correlation function and the Joint North Sea Wave Project (JONSWAP) spectrum, combined with an experiment-verified shoaling coefficient, are applied to model the land surfaces and the time-varying sea surfaces separately. The second-order small slope approximation (SSA-II) with tapered wave incidence is utilized for evaluating the electromagnetic scattering characteristics and Doppler characteristics of the generated composite rough surface. The influence of land–sea interface factors on radar cross-section (RCS) and Doppler shift of radar echoes is investigated in detail by comparing the RCS and Doppler spectra of the land–sea junction composite rough surfaces with those of finite-depth sea surfaces. It can be found that the Doppler spectra of the land–sea junction composite rough surface is narrower than that of the finite-depth sea surface under upwind directions and wider than that of the finite-depth sea surface under crosswind directions.

A Fast Coupled Iterative Approach for Computing 3D Composite Scattering from Dielectric Rough Surfaces and Target

“…Paper [28] generated the rough surface based on the weighted tangent function and spectrum method to simulate the composite rough surface at the actual land-sea interface and applied a more accurate second-order small slope approximation (SSA-II) to calculate the electromagnetic scattering of the model. The Doppler spectra of this composite rough surface and the sea surface are compared, and it is found that the scattering coefficients of the land-sea composite rough surface are smaller than those of the sea surface under certain polarization modes.…”