A Study On the Shift-Frequency Jamming to SAR

The inherent coupling property between time-delay and frequency-shift of the pulse compression signal is analyzed.Then,the jamming output of SFJ to SAR,which works with pulse compression signal system,is deduced.Both theoretic analysis and simulation show that the frequency-shift of the SFJ has no touch with the Doppler bandwidth at azimuth compression of SAR and the imaging output of SFJ is point target or line target.To overcome the deficiency that the conventional SFJ can't cover distributed target,two improved SFJ styles to SAR are presented.Random-shift-frequency jamming and stepped-shift-frequency jamming whose imaging output through SAR are both jamming area.Theoretic analysis and simulation show that the improved SFJ styles can protect distribute target and have better jamming effects than noise jamming for getting one-dimension or two-dimensions SAR's processing gains.