Research On Direction Of Arrival And Location Technology For The Passive Bistatic Radar

The passive bistatic radar system is a special bistatic radar system that uses a third-party radiation source to conduct reconnaissance on the target.Because the system itself does not send any signal,the concealment and anti-interference ability are extremely strong,so it has attracted widespread attention all over the world.However,after the third-party signal is reflected by the target,the energy will be greatly reduced and become extremely weak,which causes great difficulties in the estimation of the direction of arrival(DOA)of the signal and the target positioning.Aiming at this problem,this paper studies the DOA estimation and positioning algorithm based on the known characteristics of the passive bistatic source waveform,which greatly improves the estimation accuracy.The main work of this paper is as follows:1.Firstly,the model of the passive bistatic radar system is given,the influence of the direct wave on the passive bistatic radar is analyzed,and the type of the passive bistatic signal and the properties and uses of the ambiguity function are studied.Secondly,the FM broadcast signal is introduced emphatically,including its signal composition,spectrum structure and fuzzy function characteristics.Finally,aiming at the problem that the echo signal of the passive bistatic radar is easily submerged in the direct wave and multipath signal,two direct wave and multipath suppression algorithms are studied: ECA algorithm and ECA-B algorithm,and the simulation experiments are compared and verified.2.Aiming at the problem of DOA estimation of radar echo targets from external sources,a new idea of using reference channel information to fit waveforms is proposed.Three DOA estimation algorithms based on known waveforms are studied: CDEML algorithm,WDEML algorithm and LP algorithm,and three algorithms are compared with the MUSIC algorithm without waveform prior information,and it is proved that the algorithm based on the known waveform has higher estimation accuracy and anti-SNR capability.3.Aiming at the distributed DOA estimation and localization problem of the passive bistatic radar,the MLE algorithm is firstly studied,and the GS-SRACV algorithm based on the concept of group sparseness is proposed to solve the disadvantage of this algorithm being easily affected by the single sensor error.The sensor information is combined into a whole for processing,which greatly reduces the influence of each sensor error on the final DOA estimation or positioning.Finally,the KGS-SRACV algorithm based on group sparse known waveforms is proposed on this basis,and the simulation experiments verify that the algorithm has obvious estimation performance advantages.