Study Of The Suppression Methods For Radar Active Blanket Jamming And Field Data Analysis

Blanket jamming plays an important role in radar electronic warfare, it is oftenused to mask either the range or the presence of targets by transmitting noise ornoise-like waveforms. Generally, the radar working performance will fall sharply whenencountered blanket jamming. To address this problem, this dissertation focuses on thestudy of counter-measures of blanket jamming based on jamming recognition andjamming suppression. The main work of this dissertation is as follows:(1) Models of spot jamming, barrage jamming, swept jamming and comb jammingbased on the noise FM signal are analyzed, and the jamming characteristics acting onthe radar receiver are discussed. Multiple effective characteristic parameters areextracted from time domain and frequency domain, and their distributions underdifferent conditions are analyzed.Using the extracted characteristic parameter and thedecision tree method individually, effective detection of jamming and identification ofthe four blanket jamming are realized; the probability of jamming detection and correctidentification is highly acceptable. The characteristic parameters and the jammingrecognition method are verified by field measured data.(2) The jamming suppression method based on blind source separation is studied.Based on echo and jamming characteristics, blanket jamming radiated from the supportjammer is suppressedusing the joint approximate diagonalization of eigen-matrices(JADE) blind source separation technology. The results of simulation and performanceanalysis validate the proposed method’s effectiveness.(3) The jamming suppression method based on thehybrid useof stretch processingand empirical mode decomposition (EMD) is studied. Based on the echo signal feature,and combined with the radar working mode and the specific blanket jamming, stretchprocessing following EMD filtering is applied to the received complex noisy signals,resulting in a effective jamming suppression performance.With the processing andanalysis of the measured data, the effectiveness of this method is verified, andtheapplication scenario of this jamming suppression method is expanded. (4) The jamming suppression method based on the jamming signal reconstructionis studied. Based on theinherent characteristics of noise FM jamming, the jammingsignal is reconstructed by the estimate of the amplitude and instantaneous phase, andthen the jamming component of received signal can be canceled.