【作者】 陈鹏；

【导师】 杨海光；

【作者基本信息】 电子科技大学 ， 电子信息（专业学位）， 2023， 硕士

【摘要】 合成孔径雷达(Synthetic Aperture Radar,SAR)可以全天时、全天候提供地海面目标的高质量雷达图像,是军事侦察中常用的手段之一。同时,在现代电子对抗当中SAR面临复杂的电磁环境,容易受到各种干扰,信息获取受到影响。其中,间歇采样转发干扰(Interrupted Sampling Repeater Jamming,ISRJ)是现代电子对抗中典型的干扰措施,它通过在一个脉冲时间内多次采样和转发可以快速、灵活地以较小功率在SAR图像中产生压制或欺骗效果,同时还不受波形捷变等抗干扰手段的影响,因此针对该类干扰展开抗干扰方法的研究具有十分重要的应用价值。间歇采样干扰的信号模型与特性、干扰检测方法、干扰参数估计与抑制方法是抗间歇采样转发干扰的核心要素。本文针对上述研究内容开展了理论分析、抗干扰方法研究和仿真实验,具体内容如下:1、建立了间歇采样干扰的信号模型,分析了其原理及特性,探讨了间歇采样干扰在SAR中分别对距离向和距离&方位向联合干扰的原理及效果。2、研究了间歇采样干扰分别在时频域和图像域的干扰特性,分析了不同采样周期和采样时长对干扰效果影响的机理,为抗间歇采样转发干扰方法研究奠定了理论基础。3、研究了基于时频分析的信号域干扰抑制方法。分析了干扰信号的时频特性,实现了采样周期、采样时长和采样起始时间的估计,根据所估参数构建了滤波器,从信号域实现了对SAR的间歇采样转发干扰抑制。4、提出了基于图像域特征的干扰鉴别方法,利用间歇采样干扰成像结果的特征信息实现了从图像中直接鉴别出干扰虚假目标,同时构建了ISRJ的SAR图像数据集。最后分析了本方法对不同强度虚假目标的鉴别性能。最后基于干扰鉴别的结果,实现了从图像中直接消除干扰虚假目标并对干扰抑制效果进行了评估。本文对以上干扰模型和抗干扰方法均已完成了理论分析和仿真验证,结果表明,本文所提方法可以有效抑制SAR中的间歇采样转发干扰。更多还原

【Abstract】 Synthetic Aperture Radar(SAR)can obtain clear radar images of surface targets allday and all-weather which is one of the commonly used means in military reconnaissance.At the same time,in modern electronic countermeasures,SAR faces a complex electromagnetic environment,which is susceptible to various jamming and affects information acquisition.Among them,interrupted sampling repeater jamming(ISRJ)can quickly and flexibly produce suppression or deception effect in SAR images with small power by sampling and forwarding multiple times in one pulse time,and is not affected by traditional anti-jamming methods such as waveform agility,so it has great value and current significance for the research of anti-jamming methods.The signal model and characteristics of interrupted sampling repeater jamming,jamming detection method,jamming parameter estimation and suppression method are the core elements of anti-interrupted sampling repeater jamming.In this thesis,theoretical analysis,anti-interference method research and simulation experiments are carried out for the above research content,and the specific contents are as follows:1.The signal model of interrupted sampling repeater jamming is established,its principle and characteristics are analyzed,and the principle and effect of interrupted sampling repeater jamming on distance direction and distance & azimuth joint in SAR are discussed.2.The jamming characteristics of interrupted sampling repeater jamming in the signal domain and image domain are studied,and the mechanism of the influence of different sampling period and sampling duration on the jamming effect is analyzed,which lays a theoretical foundation for the research of anti-interrupted sampling repeater jamming method.3.An interference suppression method based on time-frequency analysis to construct a non-matched filter is proposed.The time-frequency characteristics of the jamming signal are analyzed.The sampling period,sampling duration and sampling start time are estimated,and a filter is constructed according to the estimated parameters,so as to realize the ISRJ suppression of SAR from the signal domain.4.A jamming identification method based on image domain features is proposed,and the feature information of interrupted sampling repeater jamming imaging results is used to directly identify jamming false targets from images,and the SAR image dataset of ISRJ is constructed.Finally,the identification performance of the proposed method for false targets of different intensities is analyzed.Based on the results of jamming identification,the jamming false target is directly eliminated from the image and the jamming suppression effect is evaluated.The results of this thesis,which have been achieved through theoretical analysis and simulation verification of the aforementioned jamming models and anti-jamming methods,demonstrate that the proposed method is capable of effectively suppressing the ISRJ in SAR.更多还原