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电大目标雷达散射截面的研究
Study on the Radar Cross Section for Large Electric Objects
【作者】 陈晓洁;
【导师】 史小卫;
【作者基本信息】 西安电子科技大学 , 电磁场与微波技术, 2006, 硕士
【摘要】 随着隐身技术和反隐身技术的发展,电大目标雷达散射截面(RCS)的测量和计算方法也在不断发展。在测量方面,由于直接测量电大尺寸的目标所需费用较高,所以越来越多的人开始采用缩比测量方法,通过测量缩比模型的RCS从而得到原型目标的RCS。而研究缩比模型和原型目标的RCS的关系依赖于缩比理论的研究。在电磁计算方面,基于NURBS建模,采用物理光学方法计算的NURBS_PO技术是目前国内外应用较多的一种电磁计算方法。而NURBS_PO技术的关键就是物理光学方法中积分式的求解。电大目标的RCS研究是一个很实际的工程问题,对于电大目标,无论测量还是计算都是一个难点。因此本文的工作围绕电大目标雷达散射截面(RCS)的研究展开,采用缩比技术减轻测量的负担,采用高频近似算法PO方法减少了计算量。缩比技术可以有效的降低测量的负担与工作量,然而以往缩比理论的研究大多是基于目标位于全空间的情况下的。在实际工程中,目标有时处于半空间中,比如军舰等,因此作者研究了半空间中的缩比模型,并给出了半空间目标RCS缩比因子的计算公式。本文还采用了常用的电磁计算方法计算目标的RCS:基于三角面元建模的Gordon算法,和基于NURBS建模的驻相法和LUDWIG方法。并且,作者提出了用驻相法和LUDWIG方法结合计算NURBS模型物理光学积分公式。最后,为了提高计算精度,本文考虑了目标的各个面片之间二次散射的作用,推导了PO_PO法计算二次散射的公式。本文主要研究了电大目标和缩比模型的缩比关系,基于NURBS建模的目标的一次散射场和二次散射场的计算。其中半空间缩比理论,基于NURBS建模的驻相法结合LUDWIG方法计算目标的RCS及基于NURBS建模的PO_PO方法计算NURBS面片的二次散射场均属本文的创新点,每种方法都给出了具体算例来验证方法的有效性。
【Abstract】 With the development of stealthy and anti-stealthy technique, the measuring and computational methods for the Radar Cross Section (RCS) of large electric objects are growing. In measurement, because of the cost of measuring a large electric object is very high, so the method measuring the scaling model becomes a hotspot in electromagnetic field. In computation, PO technique has been widely used to get the RCS of large electric objects modeled by NURBS both at home and abroad.The study of the RCS of large electric objects is a practical and difficult engineering problem. The paper applies the scaling method to reduce the measurement and high frequency approximation to simplify the calculation. The traditional scaling model lies in total space, but in practice, one usually faces some objects in half space, for example, a ship. So the formulas used to calculate the RCS scaling factors of some objects lying in half space are derived in this paper.The method commonly used for computing the RCS is as follows: the Gordon algorithm for objects described in flat facets; the stationary phase method and the Ludwig algorithm for objects modeled in NURBS. The author presents the method that merges the stationary phase method and the Ludwig algorithm together to calculate the PO integral formula. Finally, to improve the accuracy, the author studies the double reflection between the patches of an object, and derives the formulas in PO_PO.The scaling method of large electric objects and the single and double reflection of NURBS surfaces are mainly presented in this paper. The scaling method in half space, the method for merging the stationary phase method and the Ludwig algorithm to calculate the RCS of a NURBS surface and the PO_PO method to compute the double reflection of two NURBS surfaces are presented in this paper for the first time. The results shown in this paper proves that the methods are feasible.
【Key words】 RCS; SCALING; STATIONARY PHASE METHOD; LUDWIG ALGORITHM; DOUBLE REFLECTION;
- 【网络出版投稿人】 西安电子科技大学 【网络出版年期】2007年 06期
- 【分类号】TN953
- 【被引频次】3
- 【下载频次】395