低可探测性目标电磁散射特性测试中的若干基础问题研究

With the development and applications of stealth technology， more and more requirements for electromagnetic (EM) scattering measurement and performance evaluation of full-sized low observable targets appear. It is recognized that there exist two cases which severely limit the technique development of EM scattering measurement and processing for low observable targets. The first is that up to this point, the investigation of several fundamental issues for outdoor range test were still not systematically conducted. The second is that radar cross section (RCS) techniques were strictly forbidden to be output to China by the western countries. To meet with the ever increasing technical needs, the current research proposal suggests that the several fundamental issues for outdoor ground plane range tests of low observable targets are to be investigated. Based on the amplitude and phase measurement for target wideband EM scattering,exact mathematical models for outdoor scattering measurement, background vector subtraction and RCS calibration are to be formulated. Through theoretical analysis, numerical simulation as well as outdoor range test and validation, critical factors and formulation for outdoor measurement uncertainty analysis are to be obtained. Methods，techniques and algorithms for outdoor EM scattering measurement accuracy enhancement are to be developed. It is expected that the completion of the proposed research will lead to the breaking of both technique forbidden from the western countries and several technique bottlenecks. The application of research results will also meet with the urgent needs for outdoor EM scattering test and evaluation of low observable targets, as well as provide with technique support in theoretical models, measurement methodology and signal processing algorithms.

随着我国目标隐身技术的发展和应用，对全尺寸低可探测性目标的电磁散射特性测试和性能评估技术提出了迫切需求。目前国内对外场条件下低可探测性目标电磁散射特性测试与处理中的若干基础问题尚未开展系统性研究，而先进国家长期以来在该领域对我实行技术禁运，严重影响了我国相关技术的发展。针对这一现状，本课题将系统地开展外场地平场条件下电磁散射测试中若干基础问题研究。基于目标宽带电磁散射的幅相测量，建立外场测量、背景相减与雷达散射截面(RCS)定标处理的精确数学模型；通过理论分析、数值仿真和外场测量试验验证，形成分析影响外场测量不确定度主要因素的方法，发展用于提高外场测量精度的技术和信号处理方法、算法。期望通过本项研究，在一定程度上打破国外技术封锁，突破若干技术瓶颈，满足我国的迫切技术需求，为显著提高我国低可探测性目标电磁散射测量与处理的技术水平提供理论模型、测量方法和信号处理算法支持。

本课题针对我国隐身武器系统研制、试验和性能评估对低可探测性目标电磁散射特性测试与处理的迫切技术需求，针对外场地平场条件下电磁散射测试中若干基础问题，重点围绕三个方面的问题开展了研究工作：.（1）开展了基础理论研究，提出“目标散射函数”和“目标散射分布函数”两个新概念及其定义，并提出在目标电磁散射测量与定标处理数学模型中引入时变传递函数，在此基础上建立了地平场条件下目标电磁散射测量、背景抵消与定标处理过程的精确数学模型，可较好解决传统雷达散射截面(RCS)概念和定义难以全面适应现代宽带雷达信号处理、外场测量系统和测试环境时变影响的消除与不确定度分析问题。.（2）开展了用于提高外场测量精度的测量技术和信号处理方法、算法研究，并取得多项创新性研究成果，主要包括：（a）提出一种新型多用途定标体外形设计以及相应的多重定标测量处理新方法，可提高低信杂比测量条件下RCS定标精度；（b）提出一种背景辅助测量、提取和抵消处理的通用方法和处理流程，并提出一类基于最大概率统计量门限处理的背景提取处理新方法及其具体实现技术，拓展了背景辅助测量、提取与背景抵消的途径；（c）提出一种用于实时精确计算金属圆柱定标体理论RCS值的新方法并得到推广应用；（d）发明了一种同时完成极化校准与背景提取的无源极化校准装置及其测量处理技术、一类可用于单站和双站极化校准测量的有源极化校准测量装置及其测量处理方法，在机载、星载和靶场测量雷达极化校准中具有重要的应用前景；（e）提出一种MIMO-SAR高分辨率诊断成像近场测量新体制雷达，可大幅提高近场成像测量效率。.（3）开展了研究成果的推广应用研究，部分成果在国内现有两个RCS测试外场得到了验证和推广应用。.本课题所形成的部分理论、模型、方法与算法研究成果已总结成为《雷达目标散射特性测量与处理新技术》专著由国防工业出版社公开出版发行，可为国内从事目标电磁散射测量与处理相关实验室、研究机构和高等院校等提供参考，在一定程度上打破了国外在该领域对我国的技术封锁，为显著提高我国低可探测性目标电磁散射测量与处理的技术水平提供了理论模型、测量技术和信号处理算法支持。