基于矩量法的目标近场散射特性仿真分析

发布时间：2019-07-07 07:13

【摘要】：目标的散射特性主要表现为目标的RCS值,传统测量目标的RCS值是在目标的散射远区场进行测量。相比于远场测量,近场测量方法具有操作方便、信息量大、保密性高等优点。本文通过RWG矩量法对目标的单站散射近场分布情况进行仿真计算,然后通过近远场变换方法由目标的单站近场值求解出目标的单站远场RCS分布情况。文章主要工作如下:首先,本文推导了由目标的单站散射近场值计算其单站远区RCS分布的近远场变换算法以及相关的降维算法,并介绍了通过RWG矩量法仿真计算目标单站散射近场的具体过程。其次,以一个平板目标为例,通过近远场变换算法计算其单站RCS值。将半波振子作为收发天线,利用RWG矩量法进行仿真计算出平板目标在半波振子照射下的散射近场分布情况,再根据近远场变换算法计算出平板目标的单站RCS值,并与平板目标的远场单站RCS值进行对比。分别研究了VV极化与HH极化下平板的近远场变换单站RCS分布情况。在用RWG矩量法计算目标的散射近场时,研究了目标与天线分别建模与统一建模方法之间的误差。发现误差值会随着近场测试距离的增加而减小,并且分别建模可以减少计算时间,所以采用分别建模的方法计算目标散射近场。最后,分析了用单站近远场变换算法求解目标单站RCS值的误差情况。分别研究不同近场测试距离,采样点间隔和频率间隔对单站近远场变换算法结果的影响。然后模拟远场测量RCS时的定标过程,用平板作为标准体,对一个多面体目标近远场变换算法的结果进行定标,可以得到多面体的真实的单站RCS值,将定标后的结果与远场单站RCS值进行对比,验证了定标方法的准确性。
[Abstract]:The scattering characteristics of the target are mainly the RCS value of the target, and the RCS value of the traditional measured target is measured in the scattering far field of the target. Compared with far-field measurement, near-field measurement method has the advantages of convenient operation, large amount of information and high confidentiality. In this paper, the RWG moment method is used to simulate the near field distribution of the single station scattering of the target, and then the RCS distribution of the target is solved by the near and far field transformation method from the single station near field value of the target. The main work of this paper is as follows: firstly, this paper deduces the near-far field transformation algorithm and the related dimension reduction algorithm to calculate the RCS distribution of the single station far region from the single station scattering near field value of the target, and introduces the concrete process of calculating the target single station scattering near field by RWG moment method. Secondly, taking a flat target as an example, the single station RCS value is calculated by near-far field transformation algorithm. Using the half-wave oscillator as the receiving and receiving antenna, the scattering near-field distribution of the plate target irradiated by the half-wave oscillator is simulated by RWG moment method, and then the single station RCS value of the plate target is calculated according to the near-far field transformation algorithm, and compared with the far-field single-station RCS value of the plate target. The unistatic RCS distribution of plate near-far field transformation under VV polarization and HH polarization is studied respectively. When the RWG moment method is used to calculate the scattering near field of the target, the error between the modeling method of the target and the antenna and the unified modeling method is studied. It is found that the error value decreases with the increase of near-field test distance, and the calculation time can be reduced by modeling separately, so the method of modeling separately is used to calculate the scattering near-field of the target. Finally, the error of solving the single station RCS value by using the single station near and far field transformation algorithm is analyzed. The effects of different near-field test distance, sampling point interval and frequency interval on the results of single station near-far field transformation algorithm are studied respectively. Then the calibration process of far-field measurement of RCS is simulated, and the results of a polyhedral target near-far-field transformation algorithm are calibrated by using the plate as the standard body, and the real single-station RCS value of the polyhedral object can be obtained. the calibration results are compared with the far-field single-station RCS value, and the accuracy of the calibration method is verified.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN011;TN95

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