Study On Key Technology Of Deceptive Jamming Against Synthetic Aperture Radar

As a kind of microwave imaging radar,Synthetic Aperture Radar(SAR)can acquire high resolution images of targets with all-weather and all-day.Having the unique advantages of high resolution and strong projection,SAR has been widely used in military fields such as military reconnaissance,intelligence search,precision guidance,and so on.With the development of SAR imaging technology and the wide application of SAR system,electronic countermeasures against SAR have become a hotspot in the field of electronic countermeasures.Taking the deception jamming of SAR as the research object,this paper thoroughly studied the deceptive jamming against multi-mode and high-resolution SAR by means of theoretical analysis and simulation.And the main research contents include:(1)The basic theory of deceptive jamming against SAR.The thesis studied the theoretical foundation of SAR imaging and analyzed the echo signal of SAR.Then the article discussed the physical mechanism of jammer.The jammer forming false is mathematically modelled as a linear system with jammer modulation function.(2)Deceptive jamming algorithm based on spatial spectrum analysis.Aiming at the problems of insufficient flexibility,low computational efficiency and ideal trajectory setting,a deception jamming algorithm against multi-mode and high-resolution SAR with non-linear trajectory is designed.Based on the function decomposition of modulation function,the algorithm transformed the calculation of modulation function into transfer function.And then replaced the two-dimensional convolution integral with one-dimensional curve integral on the two-dimensional spatial spectrum.And the modulation function of jammer can be calculated efficiently by the operations including fast Fourier transform,Stolt interpolation and curve integral.Thus,the efficiency,precision and flexibility of SAR deceptive jamming can be greatly improved.What's more,this algorithm can be well applied to condition with large magnitude of trajectory deviation.(3)Efficient modulation method based on the inverse backward projection algorithm.Aiming at the contradictions between computational complexity and accuracy,flexibility and accuracy,an inverse back projection algorithm for multi-mode and high-resolution SAR with no-linear trajectory is proposed.The modulation method realizes the conversion of the pixel and range compression signal by interpolation,and then obtains the jammer modulated signal by inverse pulse compression operation in the range frequency domain.This method can utilize parallel processing technology to obtain high computational efficiency,and has the advantages of high precision and flexibility.In addition,the modulation method is simple,flexible,suitable for multi-modes,multiple signal forms and beamforming.Having the advantages of easy implementation in parallel,the computation efficiency of this method is much higher than the time domain modulation algorithm.