Research On Moving Target Detection Technology Of Passive Radar Based On DTMB

The passive radar system of the external radiation source utilizes the electromagnetic wave signal in the air to realize the detection,localization and tracking of the target.Compared with the traditional system of radar,passive radar in the hidden,anti-jamming,mobility,anti-radiation and so has a greater advantage,making it in the field of defense applications than traditional radar more extensive.With the continuous development of terrestrial digital television technology,the use of terrestrial digital television signals as an external radiation source research passive radar has become a new research direction.In this paper,DTMB is used as external radiation source,and several key technical problems in passive radar target detection are studied.The following is the main content of this paper:1.The digital TV standard is introduced in detail,and the characteristic of DTMB signal is analyzed in detail.The digital TV signal source for experiment simulation is generated by MATLAB.The autocorrelation function and fuzzy function of DTMB signal are analyzed to show that the DTMB signal can as a passive radar external radiation source signal.2.Based on the study of the structure of the passive radar system,a passive radar system model based on DTMB is established.The characteristics and key technologies of the passive radar system are analyzed,and the existing problems are analyzed.3.For the direct wave interference problem of the main channel of the passive radar,the necessity of direct wave suppression is analyzed,and the commonly used suppression method is introduced.The basic principle of using the adaptive countermeasure to suppress the direct wave is analyzed emphatically.Adaptive algorithm,and apply the new algorithm to the adaptive direct wave cancellation system.Theoretical analysis and simulation show that the new algorithm can suppress the direct wave interference.4.In order to solve the problem of multi-path interference in the reference channel of passive radar,the necessity of multipath suppression is analyzed firstly.Secondly,the multi-path suppression technique-equalization technique is introduced,and severaltypical equalization filters are analyzed.Finally,the improved LMS algorithm is applied to the adaptive equalization filter.The simulation results show that the new algorithm can suppress the multipath interference very well and realize the purification of the reference channel direct wave.