Rigorous Simulations of Microwave Scattering From Finite Conductivity Two-Dimensional Sea Surfaces at Low Grazing Angles

Abstract

Abstract-We present a boundary integral method for the solution of the rigorous problem of microwave scattering from finite conductivity sea surfaces under grazing illumination. Following the locally perturbated plane approach, the roughness is flattened at the edges of a finite patch, allowing us to use a plane wave as incident field. Both theoretical formulation and numerical implementation are addressed. We present simulations of full-polarization radar cross-sectional diagrams for 2-D ocean-like surfaces in both bistatic and monostatic configurations. The conductivity of the sea water is taken into account with a curved surface-impedance approximation, and results are compared with a perfectly conducting surface model. Simulations are finally confronted to approximate theories and empirical sea backscatter models for low grazing angles at L-band, vertical polarization, and a wind speed of 3 m/s.

Two‐Dimensional Spectra of Radar Returns from Sea: 1. Theoretical and Numerical Study of the Group Line

“…Similar plots are also obtained from a numerical solver based on a rigorous boundary integral formalism, devoted to scattering from one‐dimensional rough surfaces illuminated under grazing incidence Miret et al (). In Figure , sea surface is described by Pierson Moskowitz spectrum and computations are performed for horizontal polarization at L band.…”

Perfectly Matched Layer Boundary Integral Equation Method for Wave Scattering in a Layered Medium

“…Various types of compactly supported functions can be used to truncate the unbounded interfaces and to suppress the artifical reflections from the edges of the truncated sections. Existing methods in this category include the approximate truncation method [18,27], the taper function method [34,29,19], and the windowing function method [4,21,5,14]. In particular, the windowing function method of Bruno et al [5] can largely eliminate the artificial reflections, since the errors decrease superalgebraically as the window size is increased.…”

Windowed Green Function Method for Layered-Media Scattering

“…The approach proposed in this paper bears similarities with certain "finite-section" methods in the field of rough-surface scattering. These methods utilize approximations based on truncated portions of a given unbounded rough surface [14,22,19] and, in some cases, they incorporate a "taper" [22,21,15] to eliminate artificial reflections from the edges of the finite sections. In fact the smooth taper function utilized in [15] (Figure 2 in that reference) resembles the smooth windowing function we use (Figure 2 below and reference [3]).…”