电大尺寸粗糙（海）面及其与目标复合电磁散射研究

发布时间：2018-03-01 19:18

本文关键词： 粗糙面电磁散射多区域模型破碎波内波复合散射　出处：《西安电子科技大学》2016年博士论文　论文类型：学位论文

【摘要】：本文围绕粗糙(海)面,以及其与目标复合电磁散射进行研究。针对实际探测中遇到的问题进行两大方面的研究,即减少粗糙(海)面电磁散射的求解时间和研究实际复杂动态海面及其与目标电磁散射特性。该研究在粗糙(海)面遥感,复杂环境预警,环境参数反演和目标检测与识别等领域有着十分重要的研究价值。论文的工作和研究成果如下：将多区域模型用于一维介质粗糙面与上方导体目标复合电磁散研究。首次将多区域模型与单积分方程矩量法相结合,不仅解决了多区域和传统积分方程矩量法结合时存在无法处理的函数的问题,而且大大减小了未知量,使得电大尺寸问题可以用个人计算机解决。多区域模型根据入射波的强度将粗糙面分为主区域和非主区域,主区域采用传统矩量法,非主区域只记和自己相邻的主区域的耦合作用。为了验证本文中单积分方程推导的正确性,将传统积分方程矩量法(Method of Moment,MoM)与单积分方程(Single Integral Equation, SIE)矩量法(SIE MoM)计算的散射结果进行了对比,结果显示两种方法计算结果十分吻合,验证了单积分方程的正确性；紧接着对比了SIEMoM和多区域SIE MoM的计算时间,粗糙表面感应电／磁流,目标表面感应电流以及散射系数,对比结果显示,多区域SIE MoM大幅度减小了内存消耗和计算时间,并且在中小散射角范围内可以保证计算精度。将多区域模型推广到一维介质粗糙面及其上／下方介质目标复合电磁散射的研究中。介质目标会使得问题更加复杂,对于导体目标,其上感应电流对总场的影响只需要直接添加进积分方程中,而对于介质目标,需要新建立一个介质目标内部等效模型,也就是说在建立积分方程时需要建立三个等效模型,积分方程数量也会随之增多,增加了推导的难度和复杂性。本文将多区域模型成功推广至介质目标与粗糙面散射中,推导了介质目标与介质粗糙面复合散射的单积分方程,并与传统积分方程MoM结果比较,验证SIE MoM的正确性,接着将多区域模型用在SIE MoM上,在中小散射角范围内可以获得了几乎准确的结果,并且达到减少未知量,降低内存需求,节约计算时间的目的。建立含碎浪的电大尺寸动态海面电磁散射模型,考虑破碎波对电大尺寸海面电磁散射特性的影响,对破碎波结构进行简化,使其既能形成引起回波‘海尖峰’现象的强散射源,又能体现模拟HH极化散射结果大于VV极化散射结果的特性；根据实际测量的白冠覆盖率及波浪破碎概率等,建立包含破碎波的电大尺寸海面电磁散射模型。同时对回波‘海尖峰’特性进行分析研究,模拟小擦地角下含碎浪电大尺寸二维动态海面电磁散射回波时间序列,从其中判定‘海尖峰’出现的概率,分析在何种雷达参数和海面参数下‘海尖峰’现象更容易出现,同时分析‘海尖峰’对时间相关函数和多普勒谱的影响。研究了内波影响下海面电磁散射,关于内波对散射系数和动态海面多普勒谱的影响鲜少有相关研究,作者基于Korteweg-de Vries (KdV)方程,建立内波传播模型；通过波流相互作用函数,基于波作用量方程,对表面毛细波的波谱进行修正；最后基于双尺度方法的面元模型,将内波对高频谱的修正作用考虑在内,计算内波的存在对大尺寸海面电磁散射特性的影响,分析了不同的内波参数,不同海况参数等对海面散射系数和多普勒的影响。提出一种更贴合海面双尺度面元模型的四路径方案,并计算电大尺寸海面及其上方目标的复合电磁散射。为了保证计算效率,采用MECA与PTD相结合的方法,计算目标散射场；本文第五章和第六章中提到的双尺度面元模型将用来预估电大尺寸海面的电磁散射场；再结合作者提出的反射系数修正方法,在四路径镜向等效思想的基础上,通过计算粗糙面上每个镜向反射单元的复反射系数,提出一种新的四路径复合散射预估方法。
[Abstract]:This paper focuses on the rough (SEA) surface, and the composite electromagnetic scattering is studied. The study was performed in two aspects to meet actual detection problems, reduce rough (SEA) surface electromagnetic scattering computation time and analyze the actual complex dynamic sea and electromagnetic scattering characteristics of target. The research on rough (SEA) surface remote sensing, complex environmental warning, the field of environmental parameter inversion and target detection and recognition is a very important research value. The work and research results are as follows: the multi zone model for one-dimensional dielectric rough surface with composite electromagnetic scattering of conducting objects above research. The combination will be the first multi zone model and single integral equation Moment quantity method, not only solves the combination of multi regional and traditional integral equation method of moments when function can't handle the problem, but also greatly reduces the amount of unknown, the problem with a large size One computer to solve the multi zone model. According to the intensity of the incident wave will be divided into rough surface area and non main area, using the traditional method of moments of main areas, the main regional non coupling main areas and their adjacent note only. In order to verify the correctness of the single integral equation, the traditional integral equation of moment method (Method of Moment, MoM) and the single integral equation (Single Integral Equation, SIE) method of moments (SIE MoM) calculation of scattering results were compared, the results showed that the two methods the calculation results are in good agreement, which validates the validity of the single integral equation; then compares the calculation time of SIEMoM and multi region SIE MoM, a rough surface induction electric / magnetic flow, surface induced current and scattering coefficient, the results showed that multi regional SIE MoM greatly reduces memory consumption and computation time, and can be kept in small angle scattering Certificate of accuracy. On the composite electromagnetic scattering medium target multi region model is extended to one-dimensional dielectric rough surface and bottom. / medium target will make the problem more complicated, the conductor target, its influence on the induced current on the field only need to add directly into the integral equation, and the target for the medium, to the new a medium internal equivalent model is established in the integral equation to establish three equivalent integral equation model, the number will be increased, increasing the difficulty and complexity is derived. In this paper, multi region model successfully extended to medium target and rough surface scattering, single integral equation for dielectric objects and dielectric rough surface the composite scattering is deduced, and compared with the traditional MoM integral equation results, verify the correctness of the SIE MoM, then the multi zone model used in SIE MoM, in the small angle scattering Can get almost accurate results, and to reduce the unknown quantity, reduce the memory requirement and computation time saving. The establishment of large scale dynamic model of electromagnetic scattering with breaking waves, considering the breaking wave impact on the electromagnetic scattering characteristic of the sea, the breaking wave structure is simplified, so that it can form a strong the scattering source caused by the "sea echo peak" phenomenon, and can reflect the characteristics of the HH simulation results than VV polarization scattering polarization scattering results; according to the actual measured whitecap coverage and wave breaking probability, includes the establishment of electrically large electromagnetic scattering model of wave breaking. At the same time analysis of the echo characteristics of "sea spike" with the surf, large dynamic two-dimensional electromagnetic scattering echo time sequence simulation of small grazing angle, from which to determine the "probability of sea spike 'there, in which radar analysis The parameters and parameters of "sea sea spike" phenomenon occurs more easily at the same time, analysis of "sea spike" on time correlation function and Doppler spectrum. The wave under the influence of electromagnetic scattering is studied, there are few studies about wave effect on the scattering coefficient and dynamic sea Doppler spectrum, based on Korteweg-de Vries (KdV) equation and establish internal wave propagation model; through the wave flow interaction function, wave action equation based on spectral surface capillary waves are corrected; finally based on surface element model of two scale method, will consider the modifying effect of internal waves on high frequency spectrum, there is the estimation of wave impact on the electromagnetic scattering characteristics of the large size of the sea, analysis the internal wave parameters, effects of different parameters on the scattering coefficient of sea surface and Doppler. Put forward four path scheme two scale surface element model of a more fitting surface Composite electromagnetic scattering, and calculation of electrically large targets above the sea. In order to ensure the efficiency of computation, using MECA and PTD combination, calculation of scattering field; the fifth chapter and the sixth chapter in the electromagnetic scattering field surface element model mentioned above will be used to estimate the two scale large sea; combined with the correction method of reflection coefficient the author, based on the idea of the equivalent to four path mirror, by calculating the rough surface of each mirror to the complex reflection coefficient reflecting unit, put forward a new path four composite scattering prediction method.

【学位授予单位】：西安电子科技大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TN011

【相似文献】