Effective approach to generate electrically large rough surfaces and the application to EM scattering problems

Abstract

The small slope approximation (SSA) is a widely employed way to analyse the electromagnetic (EM) scattering problems from rough surfaces. However, it requires a surface sampling interval less than one‐eighth of the wavelength, which makes it suffer from the problems of large memory consumption and low calculation efficiency for large rough surfaces, especially for higher microwave bands. In this study, a new way to generate the electrically large rough surfaces is proposed and its application to the calculation of EM scattering field is introduced on the base of first‐order SSA. The calculation accuracy and consumed computer memory of the proposed method analysed by numerical comparisons show good performance.

Modeling and SAR imaging of the sea surface: A review of the state-of-the-art with simulations

“…However, choosing the facet size depends primarily on the modeling of the EM scattering. Thus, the SSA method requires sizes of orders less than one-eighth/onetenth of the incident wavelength [33], [44], [45]. Within the two-scale model (TSM), the facet size must be large enough when compared to the wavelength of Bragg waves, but sufficiently small compared to the wavelength of long waves [94].…”

“…As the TSM has gained prominence many different improvements and additions have been introduced: simulation of multiview SAR wave synchronization data for azimuth cutoff wavelength compensation [37], polarimetric TSM [38], sea surface velocity of wind retrieval [39], improved TSM [40], [41], facet-based modification of TSM [42], application of modified TSM to breaking waves simulation [23], and finally interesting approaches which, although not directly related to TSM, use the same scale-splitting principle to generate sea surface for infrared imaging [43] and for improving SSA calculations [33], [44], [45].…”

Modeling and SAR Imaging of the Sea Surface: a Review of the State-of-the-Art with Simulations

“…dk (44) where Z(k) is the 2D Fourier transform of the sea surface model Z. The complex RAR modulation transfer function (MTF) is presented as a sum M (k) = M t (k) + M h (k), where for the left looking SAR scanning geometry [47], [53] M t (k) = 4 cot θ r 1 ± sin 2 θ r ik y (45) with the plus sign related to VV and minus sign to HH polarization, and…”

“…As the TSM has gained prominence many different im-provements and additions have been introduced: simulation of multiview SAR wave synchronization data for azimuth cutoff wavelength compensation [37], polarimetric TSM [38], sea surface velocity of wind retrieval [39], improved TSM [40], [41], facet-based modification of TSM [42], application of modified TSM to breaking waves simulation [23], and finally interesting approaches which, although not directly related to TSM, use the same scale-splitting principle to generate sea surface for infrared imaging [43] and for improving SSA calculations [33], [44], [45].…”

Quantitative Evaluation of the Effects of Large-Scale Sea Wave Components on Microwave Backscattering From Ocean Surface

“…The SSA scattering model can describe the scattering from both small-and large-scale surfaces within the single theoretical scheme and automatically taken into account the effect caused by the wave components at all scales inputted into the SSA model [28]- [30]. Considering the competence of SSA-1 model to cope with all scales wave components and its acceptable accuracy and efficiency in sea surface scattering simulations [31]- [33], the SSA-1 model is adopted in this study to simulate the NBCS from sea surface with different roughness. Therefore, to explore the effects of various large scale waves on NBCS, we calculate the backscattering coefficients under different sea surface roughness with the SSA-1 model at various wind speeds and different radar frequencies in an effort to clarify the backscattering source from the multiscale sea surface.…”