Research On Effect Of Electromagnetic Jamming For Multiple-Beam Synthetic Aperture Radar Imaging

The thesis dived into the effect of electromagnetic jamming for multiple beam synthetic aperture radar (SAR) imaging. Imaging gain of MBSAR and electromagnetic jamming (EJ) modes were discussed, jamming methods and jamming effect of man-made EJ were studied via the analysis and simulation.The thesis presented the 2-dimension imaging compression theory, pointed out the advantage of MBSAR, which could deal with the contradiction between wide imaging swath and high resolution in classic single beam (SB) SAR. Imaging modes of MBSAR was discussed. Moreover, the imaging principle of MBSAR was presented, in order to show the difference in echo path between SB SAR and MB SAR. The thesis discussed the equivalent condition in the echo processing for the transforming from MB SAR to SB SAR, if this condition is not satisfied, the imaging algorithm consist of nonuniform sampling reconstruction and 2-dimensional compression was also been studied.The EJ modes are divided into environment effect and man-made jamming, and the different effect mechanisms of the two aspects were discussed respectively. The thesis focused on the effect of man-made jamming for MBSAR imaging, and studied two typical jamming methods, including noise compression jamming and deceptive jamming. The processing gains of echo signal and noise jamming signal in the MBSAR system were different compare with the classic SB SAR, therefore, the thesis was interested in the signal-to-jamming of MB SAR, and studied the radio frequency gauss noise and modulated noise were analyzed. The thesis used the real radar parameter as the simulation basis, and analyzed the effect on the imaging for point target and lattice target. Besides, the different effect degree for SB SAR and MB SAR by different noise modes was also evaluated via quantitative analysis according to certain standards, the evaluation results proved the conclusions ideally.Effect of MB SAR imaging caused by deceptive jamming was also a main work in this thesis. The relation between the location of false targets and modulated parameters has been discussed, meanwhile and response function of jammer for echo in the image processing was presented. According to the different echo path in nonstop transmit jamming and scatter echo jamming, the integrated expression of jamming signal has been discussed. Considering the different jamming methods, the simulation was fulfilled on the basis of simulative lattice, and was achieved respectively. A special assessment way, which used to evaluation area target, was taken as a reasonable method to analyze the effect capability of deceptive jamming.