| Electronic spectrum warfare has been classified as the sixth operational domain and has become one of the strategic development directions of future military science and technology.With the rapid development of electronic interference technology,airborne radar faces an increasingly complex electromagnetic environment.In particular,the main lobe interference which from the main lobe of the radar antenna into the receiving system is a key factor limiting the detection capability of airborne radar.Thus,the airborne radar anti-main lobe jamming technology has been an important and difficult research issues in the radar field.Aiming at the problem of main lobe interference suppression of airborne radar,this thesis focuses on the problems of target detection,angle of arrival（DOA）estimation and positioning.The main work and innovations are as follows:1 、 For the problem of airborne radar target detection in the case of mainlobe-supported jamming,an anti-mainlobe supported jamming and DOA estimation method based on multi-subarray space-time domain joint signal separation is proposed.First,the interference suppression is performed by the joint diagonalization of feature matrix（JADE）algorithm.Then,the signals of each subarray after blind separation build sum-difference beams to obtain target angle information,which improve target detection capability of airborne radar under main lobe-supported jamming.2、Aiming at the problem of airborne radar target detection in the case of main lobe self-defense jamming,the signal separation against main lobe self-defense interference method based on the joint space-time-polarization domain of multiple subarrays is improved.First,the signal model of the joint space,time and polarization domain is established.Secondly,the received signal is separated by the blind source separation algorithm,called JADE,which suppresses the main lobe jamming.Then,sum-difference beam angle measurement is performed by combining the signals of each subarray after blind separation,and it can obtain target angle information.Which improve radar goniometric performance under main lobe self-defense jamming environment.3、Aiming at the problem of target detection and localization when airborne radar is exposed to suppression-range deception compound jamming,this thesis improve an method based on space-time joint signal separation and homology positioning to against suppression-range deception compound jamming.First,the signal receiving model under suppression-range deception compound interference is established.Secondly,the received signals are separated by the joint space-time domain JADE algorithm,which can clean the suppression jamming.Then,the localization is performed using the TOA localization method.Finally,the suppression of range decption interference is performed according to the homology principle to obtain the true target.The above methods are verified by simulation experiments.The experimental results verify the effectiveness of the above methods,which can suppress the main lobe supported and main lobe self-defense interference,and can improve the anti-jamming performance of radar. |
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