【作者】 王超；

【导师】 黄培康； 殷红成；

【作者基本信息】 中国传媒大学 ， 电磁场与微波技术， 2009， 博士

【摘要】 目标与环境电磁散射特性是军事信息中最重要、最基本的资源之一,而电磁散射建模是获取这种特性的一种重要手段。与数值方法相比,高频近似方法在计算复杂电大目标电磁散射特性方面具有物理意义清晰、计算效率高等显著的优势。本文围绕实际工程应用中所关注的雷达散射截面(RCS)、宽带雷达回波以及雷达目标角闪烁等特征的快速、高效、准确建模问题,对高频方法的关键技术、工程实现和方法的适用性等问题展开了系统的研究。首先综述了电磁散射建模的数值方法,时、频域高频方法以及角闪烁建模方法的发展现状,指出了电磁散射建模的应用方向以及需要解决的问题。围绕目标几何建模的工程化要求,研究了复杂目标的CAD建模方法、三角平面元网格和参数曲面网格的模型生成和处理技术,比较了各种几何建模技术的优缺点。针对电大复杂目标的电磁散射计算问题,研究了复杂目标电磁散射的频域高频建模理论和实现方法,主要包括基于三角平面元模型的一次反射、一次绕射和多次反(绕)射的的计算方法和工程实现,基于板块模型的区域投影法以及基于NURBS参数曲面模型的物理光学(PO)计算方法,并对这三类方法的适用范围及其工程应用方向进行了分析。针对雷达目标宽带RCS的快速计算和宽带雷达回波实时仿真等工程需求,研究了复杂目标电磁散射的时域高频建模理论和计算方法,提出了具有极高的效率的短脉冲等效和欠采样加速的计算方法。针对复杂目标角闪烁建模的问题,依据电磁散射理论,推导了相位梯度法(PGM)、坡印亭矢量法(PVM)以及基于单脉冲雷达测角原理的角闪烁一般计算公式,首次将天线的极化效应引入到角闪烁计算的PVM中。在此基础上,比较了三种方法之间的等价关系,从而完善了对角闪烁产生机理的解释。通过对上述成果的集成,开发了两套软件系统,即雷达目标特性预估系统和靶标目标特性分析系统,简要介绍了软件的功能、设计思想以及工程用例。目前,这两套软件已在实际工程中获得应用和持续的验证。最后,对本文的工作进行了总结,并指出了今后需要进一步完善和深入研究的工作。更多还原

【Abstract】 The electromagnetic (EM) scattering features of target and environment are one of the most important and essential resources for the martial information, and EM modeling is an important mean to obtain these features. Compared with the numerical method, high frequency method has the dominant advantages of clearer physical meaning and higher efficiency for the computation of EM scattering feature of electrically large complex target. Concerning the fast, efficient and accurate modeling of radar cross section (RCS), wide-band radar echo and radar target glint in actual engineering application, the key technique, realization and the applicability of high frequency method are studied by the numbers in this paper.Firstly, the status quo of numerical method, time and frequency domain high frequency methods, and computation of angular glint is summarized, and the applied fields and problems to be solved of EM modeling are presented.Concerning the engineering need of geometrical modeling, the CAD modeling method of complex target and the creating and handling techniques of the mesh based on the triangle plates and the parametric curved surfaces are studied, and the merits and demerits of these methods are compared.Aimed at the computation of scattering for the electrically large complex target, the theory and realization of high frequency method, including the computation and implementation of primary and multiple reflections, and diffractions, the region projection method based on polygon model, and physical optic (PO) method based on NURBS parametric surface model, is studied. Furthermore, the scope of application and the practical aspect of these methods are analyzed in detail.Concerning the fast computation of wide-band RCS for radar target and real time simulation of wide-band radar echo, the time domain high frequency method is researched. Furthermore, a high efficient method based on short pulse equivalence and subsampling acceleration is presented. For the computation of the complex target angular glint, the gengral formulaes of phase gradient method (PGM), poynting vector method (PVM) and monopulse radar angular glint base on angular measurement theory is deduced base on electromagnetic scattering theory. The polarization effect of the receiving antenna is firstly introduced into the PVM for angular glint computation to consummate three methods are compared and alalyzed.Two software suits, radar target signature prediction system and drones features analyzing system, have been developed by integrating all the theory mentioned above. The basic function, considerations in design and some example abe briefly introduced. At present, the software suites have been applied and verified in engineering practice.Finally, all works mentioned above are concluded and future researches are also addressed.更多还原