Research On The Anti-interference Performance Of Multiple Parameter-agility Radar

With the rapid development of jammers in recent years,there are more requirements for modern radar's anti-interference ability in the field of target detection and recognition.Nowadays,the jamming strategy and active jamming equipment for fixed-parameter pulse Doppler radar system are becoming more and more mature at home and abroad.Due to wide application of digital radio-frequency memory(DRFM),jammers have the ability of generating jamming signal instantly based on the intercepted radar signal,which have a significant negative effect on target detection and recognition.In order to improve the anti-interference ability of radar,this thesis proposes a method of multi-parameter joint agility about carrier frequency,pulse repetition frequency(PRF),polarization coding and waveform coding based on fixed-parameter pulse Doppler radar system.The proposed method can not only reduce interception probability effectively,but also improve anti-jamming performance of radar greatly.However,carrier frequency agility and PRF jittering cause problems for signal coherent accumulation.Compressed sensing signal model is adopted to replace Fourier transform for coherent processing in this thesis.Signal processing of multi-parameter joint agile radar is studied as follows:1)Signal model of multi-parameter joint agile radar is constructed.Meanwhile,ambiguity function of transimitted signal and advantages of multi-parameter joint agile system in jamming suppression are analyzed respectively.2)Based on general flow of coherent radar signal processing,the basic principle of traditional coherent radar signal processing method is introduced.Meanwhile,reasons of Fourier Transform failure in coherent processing for multi-parameter joint agile signal are analyzed.Based on compressed sensing model,a method of coherent signal processing and target detection in multi-parameter joint agile radar are proposed.Then,according to the principle of angle measurement by single pulse amplitude comparison with four antennas,an algorithm of optimizing angle measurement accuracy is proposed.Finally,the effectiveness of multi-parameter joint agile radar coherent processing method is verified by simulation experiments and field experiments.3)This thesis assesses the anti-jamming effect of multi-parameter joint agile radar.In addition,the influence of various jamming on target detection in multi-parameter joint agile radar is analyzed.Finally,this thesis compares the anti-interference performance between the multi-parameter joint agile radar and the traditional fixed-parameter Doppler radar to show advantages of multi-parameter joint agile radar in jamming suppression.