地海交界分区域复合粗糙面建模及电磁散射特性研究

发布时间：2018-10-25 14:31

【摘要】：研究了地海交界分区域复合粗糙面的建模方法及其电磁散射特性。采用蒙特卡罗方法建立地海交界分区域复合粗糙面模型,采用高斯谱模拟实际地面,采用变浅系数与北海联合海浪计划(joint north sea wave project,JONSWAP)谱结合而成的有限水深海谱模拟实际近海海面,基于分区域复合粗糙面建模理论,运用多种加权反正切函数处理实现了线型、月牙型、峡谷型自然环境。考虑了各介质区域内部的面元耦合以及区域之间和交界处面元的耦合作用,对地海交界分区域复合粗糙面的散射问题,提出了一种基于分区域面元的迭代物理光学法,采用快速远场近似(fast far field approximation,FaFFA)与局部耦合技术加速其迭代过程。对比了陆地粗糙面、海面和地海交界分区域复合粗糙面的电磁散射特性,计算了分区域复合粗糙面的散射系数,并讨论了极化方式、入射角、边界形状、陆地粗糙面的均方根高度、相关长度和近海海面的风速对地海交界分区域复合粗糙面电磁散射特性的影响。基于迭代物理光学法所获取的分区域复合粗糙面总散射场,采用正侧视条带式成像模式,选用距离多普勒算法对不同特点的地海分区域复合粗糙面进行合成孔径雷达(synthetic aperture radar,SAR)成像,并讨论了陆地粗糙面与海面各自的相对介电常数对SAR成像的影响。该研究包括了地海交界环境的建模、电磁散射特性的求解及其SAR成像,由仿真结果得到了地海交界分区域复合粗糙面的SAR像特点,对反演地海交界环境的电磁特性以及遥感、探测具有借鉴意义。
[Abstract]:The modeling method and electromagnetic scattering characteristics of the complex rough surface in the boundary area of the ground sea are studied. Monte Carlo method is used to establish the complex rough surface model of the boundary area between the ground and sea, and Gao Si spectrum is used to simulate the actual ground surface. The finite water deep sea spectrum, which combines the shallowness coefficient with the North Sea combined Wave Planning (joint north sea wave project,JONSWAP) spectrum, is used to simulate the actual offshore sea surface. Based on the modeling theory of the composite rough surface in the sub-region, the linear shape is realized by using various weighted inverse tangent functions. Crescent, canyon natural environment. In this paper, considering the coupling of surface elements in various media regions and the coupling between regions and interfaces, an iterative physico-optical method based on sub-area elements is proposed for scattering complex rough surfaces at the boundary of the ground and sea. Fast far field approximation (fast far field approximation,FaFFA) and local coupling technique are used to accelerate the iterative process. In this paper, the electromagnetic scattering characteristics of the complex rough surface of land, sea and sea are compared, the scattering coefficient of the composite rough surface is calculated, and the polarization mode, incidence angle and boundary shape are discussed. The effects of the root-mean-square height of the land rough surface, the correlation length and the wind speed of the offshore sea surface on the electromagnetic scattering characteristics of the composite rough surface at the boundary of the ground and sea. Based on the total scattering field of composite rough surface obtained by iterative physical optics method, the forward side strip imaging mode is used. The synthetic Aperture Radar (synthetic aperture radar,SAR) imaging of composite rough surfaces in different ground and sea regions is performed by using range Doppler algorithm. The effects of the relative dielectric constants of the land rough surfaces and the sea surface on the SAR imaging are discussed. The research includes the modeling of the boundary environment of the ground and sea, the solution of the electromagnetic scattering characteristics and the SAR imaging. From the simulation results, the characteristics of the SAR images of the complex rough surface in the boundary area of the ground and sea are obtained, and the electromagnetic characteristics of the boundary environment of the ground sea and the remote sensing are obtained. Detection has reference significance.
【作者单位】：空军工程大学防空反导学院;东南大学毫米波国家重点实验室;
【基金】：国家自然科学基金(61372033)资助课题
【分类号】：TN011

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