| Multiple Input Multiple Output(MIMO)radar of distributed moving platform detects,tracks targets remotely,when the platform is close to the target,the opposite side detects our signals and may implement jamming.In this case,the interference signals received by radar are often very strong,and mostly enter from the main lobe of antenna pattern.Conventional processing methods are difficult to suppress it effectively,which will seriously affect the detection and parameter measurement of targets to radar.The system framework about synergistic anti-jamming technology is studied based MIMO radar of distributed moving platform in thesis.The focus is on multi-platform collaboration to locate interference sources,main-lobe interference suppression techniques,angle measurement of targets,and data fusion methods for target tracking.The main contents include:1 ? Firstly,the principle of distributed MIMO radar is introduced.The multi-platform multi-channel mode and single-platform multi-channel mode in the distributed motion platform MIMO radar about synergistic anti-interference technology system framework are studied,and the system processing flow is analyzed.A signal modeling new method based on sub-array channel partition under irregular array is proposed.2?The interference source localization technology of distributed motion platform MIMO radar is studied,and a new cooperative positioning method is proposed.The method is based on the Direction Of Arrival(DOA)estimation of the interference source,combined with the ground inertial coordinate system,the platform station inertial coordinate system,the platform station coordinate system,the platform array coordinate system and conversion relationship,and the position ?attitude angle of flight of the multi-platform,to derive the positioning formula of the interference source.The positioning formula is verified.Simultaneously,the influence of the azimuth and elevation angle error on the RMS error of the positioning formula is analyzed.3?The main lobe jamming countermeasure technology of digital multi-channel array is studied.When interference direction that is measured by DOA is not in the main lobe,conventional adaptive beam-forming can effectively combat interference.When there is main lobe interference,the conventional adaptive beam-forming method will cause the main lobe distortion and side lobe elevation of the beam pattern.To solve this problem,the main lobe interference suppression algorithm based on blocking matrix preprocessing,feature projection preprocessing,feature projection and covariance matrix reconstruction,oblique projection preprocessing is studied.And the beam performance of these main lobe interference suppression algorithms is analyzed from the simulation.4?Target angle measurement and tracking filtering technology of MIMO radar based on distributed moving platform is studied.Because of the serious deterioration of angle measurement accuracy in the presence of main lobe interference in conventional mono-pulse angle measurement methods,a spatial adaptive mono-pulse angle measurement method is studied.It ensures that not only the interference can be effectively suppressed,but also the angle discrimination surface of pitch difference beam and azimuth difference beam can achieve the function of stable angle measurement without distortion by correcting the weight values of the elevation and azimuth difference beams.Aiming at the problem that the traditional single-station radar system has unstable target tracking performance and limited space,the tracking filtering technology of distributed motion platform MIMO radar is studied.The target track information by Kalman Filtering from the multi-platform is fused,which can improve the accuracy of the system tracking,thereby obtaining more accurate position information of the target. |
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