SAR Active Jamming Evaluation Key Technology Research

Synthetic Aperture Radar(SAR)is a high-resolution imagery radar with many advantages such as all-day,all-weather,multi-mode,and strong penetration,which is widely used in military and civilian fields.SAR active jammers prevent or delay the enemy by transmitting RF jamming signals to the SAR system to detecting and identifying targets or extracting useful information from SAR images,making SAR images difficult or even impossible to decipher.In recent years,various novel SAR jamming methods have emerged and gained rapid development and application,but the research on SAR jamming effect evaluation techniques has lagged relatively behind.The paper addresses some of the prominent problems in the current SAR jamming effect evaluation,and the main work is as follows.1.Typical jamming styles of SAR images and evaluation methods of jamming effects are studied.First,three classical SAR jamming styles and working principles of noise barrage jamming,convolutional modulation jamming and frequency shift jamming are introduced,and their jamming characteristics on SAR images are analyzed;then,typical SAR jamming evaluation methods are analyzed from two perspectives of SAR image quality index and SAR information utilization,and on this basis,the influence of noise barrage jamming on target detection performance is studied,and it is found that the change of target It is found that the change of the detection performance is not only related to the jamming intensity,but also related to the distribution of the targets signal-to-noise ratio and the signal-to-noise ratio of the false alarm units,and the trend of the change of the target detection performance under three different distribution cases is given;finally,the correctness of the analysis results is verified through simulation experiments,which provides a basis for the accurate evaluation of the noise barrage jamming effect and lays a foundation for the subsequent research on the prediction technology of the noise barrage jamming effect.2.To address the problem that the existing SAR jamming evaluation techniques are only applicable to post-event evaluation and cannot provide guidance for the optimal selection of jamming strategies for jammers on the battlefield,the National Image Interpretability Rating Scale(NIIRS)and SAR image target detection performance are used as jamming effect index and the two noise barrage jamming effect prediction models based on NIIRS and target detection performance are constructed.Firstly,the factors with the most significant influence on the evaluation index are selected as the model parameters;then,the influence of each parameter on NIIRS and target detection performance is analyzed separately,and the corresponding jamming prediction models are established;finally,the effective estimation of the model parameters is achieved by using jamming images under different conditions,and the validity of the models is verified by simulation experiments.3.In response to the lack of relevance of current SAR jamming effect evaluation methods for scene deceptive jamming evaluation,a fuzzy comprehensive evaluation method of jamming effect based on dynamic weights is proposed.First,five SAR image features characterizing the scene deceptive interference effect are proposed as the factor set of the fuzzy comprehensive evaluation method,and suitable quantitative indexes are selected to quantify the factors;then,the affiliation calculation function of each factor is constructed by combining the application context,and the idea of dynamic weighting is introduced to solve the problem of inaccurate evaluation results due to the floating importance of some factors;simulation experiments show that the proposed The simulation experiments show that the evaluation results obtained by the proposed method are consistent with the subjective evaluation results,which verifies the validity of the method.4.a MATLAB-based software system for SAR jamming and evaluation is built.The system contains three modules: SAR imaging,SAR jamming and jamming effect evaluation.Among them,the imagery module can realize point target and scene simulation;SAR jamming can simulate 11 kinds of jamming styles to realize jamming simulation with SAR images.The jamming effect evaluation module includes noise barrage jamming effect prediction,SAR deception scene jamming effect evaluation and other common evaluation methods.