Research On Fine Deceptive Jamming Technology Of SAR

With the advantages of all-weather,all-weather,strong penetration and high resolution,SAR system plays an important role in modern military reconnaissance.The SAR deceptive jamming technology uses jammer to transmit jamming signals and generates false targets on SAR images,which can reduce the ability of SAR system to obtain information.Up to now,most of the false targets generated by SAR deceptive jamming technology have some shortcomings,such as low similarity of targets,low fusion of scenes,obvious artificial traces,and so on.Therefore,the research of high similarity SAR jamming technology has become an important topic in this field.This thesis studies the deceptive jamming technology with high similarity based on SAR target and SAR scene,and the jamming effect is improved.The specific work and innovation are as follows:Based on the principle of SAR imaging,the mechanism of deception jamming and the basic characteristics of SAR image,the classic scene reconstruction method is studied on the basis of the best fit statistical distribution model.The experimental results show that the reconstruction scene can not meet the requirements of high similarity.In this thesis,the electromagnetic simulation software is used to simulate the scattering distribution of the tank,and the scattering distribution data of the target under the radar irradiation is obtained.In the case that the real imaging results of enemy SAR can not be obtained,this thesis studies three kinds of real scene replacement methods needed by high similarity jamming.Comparing the advantages and disadvantages of the three methods,it is found that it is a feasible method to choose the imaging results of our own radar with complete information as the replacement of real scene.According to the actual radar and jammer parameters,the similarity of the alternative scene can be improved by appropriate amplitude modulation.In order to meet the requirement of real-time interference,the fast generation technology of false scene based on image quilting technology is studied.This method combines the scattering data of real scene.By adjusting the amplitude and contrast of the false scene,the situation that the incremental deception interference increment may be negative is reduced.The transition processing of false scene edge can also improvethe similarity of deception scene.The deceptive jamming technology based on the increment of scattering distribution is studied.Through the interference simulation experiments of SAR scene and SAR target,it is proved that this technology can improve the similarity of deception scene.This thesis also studies and solves the problem of shadow disappearance of false target.And compared with the existing deception jamming methods,the deception jamming effect is better.The deception jamming technology of SAR target based on active shadow elimination is studied.In this thesis,the method of superimposing background in the shadow area of real tank target by using ejection jamming or active deception jamming is put forward to eliminate the shadow feature of real target,so that the real target is more similar to the false target generated by deception jamming.And the effect that the real target and the false target are difficult to distinguish is achieved.The above work has been verified by simulation experiments and measured data.The results show that these methods can solve the problem of low similarity of false targets and improve the jamming effect of deception scene and false targets.