Design Of External Radiation Source Location System Based On Short Wave DRM Signal

External radiation source radars are highly valued by various countries because of their anti-stealth,anti-reconnaissance,anti-destruction,and strong survivability.Because the radiation sources used by the system are mostly distributed in the VHF or UHF band,it also has the marits of conventional low-frequency radar.In recent years,digital video broadcasting(DVB)has gradually replaced traditional analog broadcasting.DRM(Digital Radio Mondiale)is currently a relatively mature medium and short wave digital technology,and is the only standard recognized by the ITU-R for global short wave digital sound broadcasting,which provides research for external radiation source radars that use DRM broadcast signals as opportunistic radiation sources.This paper focuses on the research of signal processing and target positioning and tracking methods of external radiation source radar based on shortwave digital amplitude modulation signal(DRM).The main work of this paper can be summarized as the following aspects:First,the characteristics of the DRM signal and its ambiguity function are analyzed,and the problems of clutter suppression and matched filtering in radar signal processing for external radiation sources are studied.After analyzing the conventional clutter suppression algorithm,simulation analysis of the convergence ability and clutter suppression performance of these several algorithms.According to the DRM signal using COFDM coding orthogonal frequency division multiplexing technology,a clutter suppression algorithm based on the subcarrier time domain orthogonal subspace projection theory(Extrnsive Cancallation Algorithm-Carrier,ECA-C)is proposed,and It is applied to the external radiation source radar of short-wave DRM signals,which confirms the effectiveness of the algorithm.Secondly,the problems of positioning methods and positioning accuracy in passive radar are analyzed.The relevant factors that affect the distribution of GDOP in single-station positioning are studied: baseline distance,angle measurement error,time measurement error,and station location error;In the case of multiple stations,the positioning errors of the multi-station cross-location and time-difference positioning systems are studied,and based on the simulation results,the measures that can be taken to optimize the station deployment are given;Finally,a positioning optimization algorithm based on GDOP fusion is given according to the positioning situation combining various measurement parameters,and the positioning performance of the algorithm is analyzed by simulation.Then,the passive radar target tracking and filtering algorithms are studied.Theoretical derivation of the realization process of EKF,UKF and PF three nonlinear filters in external radiation source radar.The simulation analyzes the tracking performance of the three filtering methods,and discusses the advantages and disadvantages of the three methods.Finally,the tracking and filtering process of the particle filter on the moving target in the passive radar in single and multiple stations is studied,and the superiority of the tracking performance is verified by simulation.Finally,the interface design of the external radiation source radar system is completed,and the functions of detecting target information and obtaining the working status of the system are realized.