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Computer Modeling in Engineering & Sciences 2024年第8期140卷 2079-2102页

作者： Yujing Ma Zhongwang Wang Jieyuan Zhang Ruijin Huo Xiaohui Yuan College of Architecture and Civil Engineering Xinyang Normal UniversityXinyang464000China Henan International Joint Laboratory of Structural Mechanics and Computational Simulation College of Architecture and Civil EngineeringHuanghuai UniversityZhumadian463000China Academy of Military Sciences Beijing100091China Henan New Environmentally-Friendly Civil Engineering Materials Engineering Research Center Xinyang Normal UniversityXinyang464000China

In this paper,an adaptive polynomial chaos expansion method(PCE)based on the method of moments(MoM)is proposed to construct surrogate models for electromagnetic scattering and further sensitivity *** MoM is applied to accurately solve the electric field integral equation(EFIE)of electromagnetic scattering from homogeneous dielectric *** the bistatic radar cross section(RCS)as the research object,the adaptive PCE algorithm is devoted to selecting the appropriate order to construct the multivariate surrogate *** corresponding sensitivity results are given by the further derivative operation,which is compared with those of the finite difference method(FDM).Several examples are provided to demonstrate the effectiveness of the proposed algorithm for sensitivity analysis of electromagnetic scattering from homogeneous dielectric targets.

关键词： Adaptive polynomial chaos expansion method method of moments radar cross section electromagnetic scattering

electromagnetic scattering from two parallel 2D targets arbitrarily located in a Gaussian beam

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Chinese Physics B 2006年第8期15卷 1755-1765页

作者：王运华郭立新吴琼 School of Science Xidian University Xi'an 710071 China

In this paper based on the equivalence principle and the reciprocity theorem, the scattered field up to second-order by two parallel 2D targets arbitrarily located in a Gaussian beam is considered. The first-order solution can easily be obtained by calculating the scattered field from isolated targets when illuminated by a Gaussian beam. However, because of the difficulty in formulating the couple scattering field, it is almost impossible to find an analytical solution for the second-order scattered field if the shapes of 2D targets are not canonical geometries. In order to overcome this problem, in this paper, the second-order solution is derived by using the technique based on the reciprocity theorem and the equivalence principle. Meanwhile, the relation between the secondary scattered field from target #1 and target #2 is obtained. Specifically, the bi- and mono-static scattering of Gaussian beam by two parallel adjacent inhomogeneous plasma-coated conducting circular cylinders is calculated and the dependence of attenuation of the scattering width on the thickness of the coated layer, electron number density, collision frequency and radar frequency is discussed in detail.

关键词： reciprocity theorem equivalence theorem electromagnetic scattering inhomogeneous plasma-coated conducting cylinders Gaussian beam

electromagnetic　scattering　from　Fractal　Multilayered　Cylinde　rat　　Normal　Incidence

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Journal of Systems Engineering and Electronics 1997年第1期8卷 1-6页

作者： Wu Zhensen & Guo LixinXidian ( University, Xi’an 710071 , P. R. China) Xidian University Xi'an 710071 P. R. China

this paper, a more stable and accurate recursing equation and computing procedure are proposed to calculate scattering width of the multilayered cylinder. This procedure is applied to compute the distribution of the scattering width and to analyze the characteristic of scattering from fractal multilayered cylinder. The connection between the characteristic of scattering and fractal dimension is discussed, and some important results are obtained.

关键词： electromagnetic scattering Fractal Fractal dimension Numerical recursion.

Polarization ratio characteristics of electromagnetic scattering fromsea ice inpolar areas

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Chinese Physics B 2018年第12期27卷 265-276页

作者： Li Zhao Tao Xie Lei Meng William Perrie Jin-Song Yang He Fang Han Chen Run-Bing Ai School of Manne Sciences Nanjing University of Information Science and TechnologyNanjing 210044China Laboratory for Regional Oceanography and Numerical Modeling Qingdao National Laboratory for Marine Science and TechnologyQingdao 266000China School of Remote Sensing and Geomatics Engineering Nanjing University of Information Science and TechnologyNanjing 210044China Beijing City 5111Mailbox Beijing100094China Fisheries&Oceans Canada Bedford Institute of OceanographyDartmouthNova ScotiaB2Y 4A2Canada State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of OceanographyState Oceanic AdministrationHangzhou 310012China

In the global climate system, the polar regions are sensitive indicators of climate change, in which sea ice plays an important role. Satellite remote sensing is a significant tool for monitoring sea ice. The use of synthetic aperture radar(SAR) images to distinguish sea ice from sea water is one of the current research hotspots in this topic. To distinguish sea ice from the open sea, the polarization ratio characteristics of sea ice and sea water are studied for L-band and C-band radars, based on an electromagnetic scattering model of sea ice derived from the integral equation method(IEM) and the radiative transfer(RT) model. Numerical experiments are carried out based on the model and the results are given as follows. For L-band, the polarization ratio for sea water depends only on the incident angle, while the polarization ratio for sea ice is related to the incident angle and the ice thickness. For C-band, the sea water polarization ratio is influenced by the incident angle and the root mean square(RMS) height of the sea surface. For C-band, for small to medium incident angles,the polarization ratio for bare sea ice is mainly determined by the incident angle and ice thickness. When the incident angle increases, the RMS height will also affect the polarization ratio for bare sea ice. If snow covers the sea ice, then the polarization ratio for sea ice decreases and is affected by the RMS height of snow surface, snow thickness, volume fraction and the radius of scatterers. The results show that the sea ice and the open sea can be distinguished by using either L-band or C-band radar according to their polarization ratio difference. However, the ability of L-band to make this differentiation is higher than that of C-band.

关键词： sea ice electromagnetic scattering polarization ratio

Investigation on electromagnetic scattering from rough soil surface of layered medium using the small perturbation method

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Chinese Physics B 2008年第7期17卷 2491-2498页

作者：任新成郭立新 School of Science Xidian University College of Physics and Electronic Information Yanan University

electromagnetic scattering from a rough surface of layered medium is investigated, and the formulae of the scattering coefficients for different polarizations are derived using the small perturbation method. A rough surface with exponential correlation function is presented for describing a rough soil surface of layered medium, the formula of its scattering coefficient is derived by considering the spectrum of the rough surface with exponential correlation function; the curves of the bistatic scattering coefficient of HH polarization with variation of the scattering angle are obtained by numerical calculation. The influence of the permittivity of layered medium, the mean layer thickness of intermediate medium, the roughness surface parameters and the frequency of the incident wave on the blstatic scattering coefficient is discussed. Numerical results show that the influence of the permittivity of layered medium, the mean layer thickness of intermediate medium, the rms and the correlation length of the rough surface, and the frequency of the incident wave on the bistatic scattering coefficient is very complex.

关键词： electromagnetic scattering rough soil surface with exponential correlation function layered medium the small perturbation method

An angular cutoff composite model for investigation on electromagnetic scattering from two-dimensional rough sea surfaces

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Chinese Physics B 2010年第7期19卷 216-220页

作者：聂丁张民 School of Science Xidian University

Based on the local configuration angle division to select the corresponding method for electromagnetic scattering calculation from rough sea surface, this paper presents an angular cutoff composite model： when the local scattered angle is in the specular region that is given by an approximately 20 degrees cone around the specular direction, the Kirchhoff approximation is applied to evaluate the specular reflection, which dominates the total scattering in this region; the small perturbation method is employed to handle the diffuse reflection which is predominant as the local scattered angle is situated out of the specular region. Numerical results are compared with those of experimental and theoretical models in several configurations as a function of incident angle, wind speed, wind direction. The comparison of numerical results of other experimental and theoretical models in several configurations shows that the new composite model is robust to give accurate numerical evaluations for the sea surface scattering.

关键词： electromagnetic scattering composite surface model rough sea surface angular cutoff

Fast and accurate analysis of electromagnetic scattering from targets situated in dielectric half space

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Journal of Systems Engineering and Electronics 2010年第1期21卷 37-40页

作者： Yongpin Chen Zaiping Nie Jun Hu School of Electronic Engineering University of Electronics Science and Technology of China Chengdu 610054 E R. China

electromagnetic scattering from targets situated in half space is solved by applying fast inhomogeneous plane wave algorithm combined with a tabulation and interpolation method. The integral equation is set up based on derivation of dyadic Green＇s functions in this environment. The coupling is divided into nearby region and well-separated region by grouping. The Green＇s function can be divided into two parts： primary term and reflected term. In the well-separated region, the two terms are both expressed as Sommerfeld integral, which can be accelerated by deforming integral path and taking interpolation and extrapolation. For the nearby region, the direct Sommerfeld integral makes the filling of impedance matrix time-expensive. A tabulation and interpolation method is applied to speed up this process. This infinite integral is pre-computed in sampling region, and a two-dimensional table is then set up. The impedance elements can then be obtained by interpolation. Numerical results demonstrate the accuracy and efficiency of this algorithm.

关键词： electromagnetic scattering dielectric half space fast inhomogeneous plane wave algorithm tabulation and interpolation.

Analytical solution for electromagnetic scattering from a sphere of uniaxial left-handed material

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第1期7卷 99-104页

作者：耿友林何赛灵 Institute of Antenna and Microwaves Hangzhou Dianzi UniversityHangzhou 310018 China School of Electrical Engineering Xidian University Xi’an 710071 China Centre for Optical and electromagnetic Research Center of Electromagnetic Research Zhejiang UniversityHangzhou 310027 China Division of Electromagnetic Theory Alfven Laboratory Royal Institute of Technology Stockholm S-100 44 Sweden

Based on the analytical solution of electromagnetic scattering by a uniaxial anisotropic sphere in the spectral domain, an analytical solution to the electromagnetic scattering by a uniaxial left-handed materials (LHMs) sphere is obtained in terms of spherical vector wave functions in a uniaxial anisotropic LHM medium. The expression of the analytical solution contains only some one-dimensional integral which can be calculated easily. Numerical results show that Mie series of plane wave scattering by an isotropic LHM sphere is a special case of the present method. Some numerical results of electromagnetic scattering of a uniaxial anisotropic sphere by a plane wave are given.

关键词： electromagnetic scattering Uniaxial anisotropic LHM Spherical vector wave functions Radar cross section (RCS)

Numerical Solutions of the electromagnetic scattering by Overfilled Cavities with Inhomogeneous Anisotropic Media

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Communications in Computational Physics 2023年第7期34卷 530-562页

作者： Meiling Zhao Jiahui He Liqun Wang Department of Mathematics and Physics North China Electric Power UniversityBaoding071003China Hebei Key Laboratory of Physics and Energy Technology North China Electric Power UniversityBaoding071003China Department of Mathematics College of ScienceChina University of PetroleumBeijing102249China Beijing Key Laboratory of Optical Detection Technology for Oil and Gas China University of PetroleumBeijing102249China

In this paper,the electromagnetic scattering from overfilled cavities with inhomogeneous anisotropic media is *** solve the scattering problem,a Petrov-Galerkin finite element interfacemethod on non-body-fitted grids is *** reduce the infinite domain of scattering to a bounded domain problem by introducing a transparent boundary *** level set function is used to capture complex boundary and interface geometry that is not aligned with the ***-fitted grids allow us to save computational costs during mesh generation and significantly reduce the amount of computer memory *** solution is built by connecting two linear polynomials across the interfaces to satisfy the jump *** proposed method can handle matrix coefficients produced by permittivity and permeability tensors of anisotropic *** final linear system is sparse,making it more suitable for most iterative *** experiments show that the proposed method has good convergence and ***,we discover that the absorbing properties of anisotropic media clearly and positively influence the reduction of radar cross *** has also been demonstrated that the method can achieve second-order accuracy.

关键词： electromagnetic scattering overfilled cavity inhomogeneous anisotropicmedia nonbody-fitted grids Petrov-Galerkin finite element interface method

Research on the electromagnetic scattering Near the Field

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Wuhan University Journal of Natural Sciences 2002年第2期7卷 182-184页

作者： Xia Ying-qing Yang He-lin Xu Peng-gen Liu wu Department of Physics Central China Normal UniversityWuhan 430079China School of Electronic Information Wuhan UniversityWuhan 430072China

We calculate and analyze the scattering near the field from some simple and complex targets using the method of picture elements (PEL), based upon the method of high-frequency approximation. It introduces the critical distance of the near field and the far field which is related with the dimension of the target. The problem of the EMS near field from large size objects can be transformed to the problem of the far field by parting it to many very small size elements. By calculating the EMS near fields of some simple and complex targets based on the SCTE (scattering from complex targets and environments) system, the results show that there are much difference between the near field and the far field. And the characteristics of the near field are more complicated. This work has practical engineering value in the area of the electromagnetic compatibility (EMC), electromagnetic interference (EMI) prediction and electromagnetic scattering (EMS).

关键词： electromagnetic scattering vector scattering function method of picture elements