| In order to overcome the limitation of detection area for onshore High Frequency Surface Wave Radar(HFSWR)and improve the ability of target detection in specific sea area,the target detection on mobile and distributed netted radar has become the research hotspot and a trend of HFSWR in recent years.Coast/Ship bistatic HFSWR combines the advantages of over-the-horizon Radar and maneuverability of shipborne platform.It not only has the anti-interference and concealment advantages,but also is the basic unit of network detection.Due to the combined modulation of shipborne platform movement and transceiver separation,the characteristics and interaction between the first-order sea echo spectrum and target signal of Coast/Ship bistatic HFSWR are more complex than that of monostatic HFSWR,which increases the difficulty of target detection.Based on the characteristics of Coast/Ship bistatic HFSWR,the target detection and continuous tracking are studied.Main contents and conclusions in this paper are summarized as follows:1.The first-order sea echo spectrum characteristics of Coast/Ship bistatic HFSWR system are researched,and the broadening of first-order sea echo spectrum and its effect on target track are studied.Firstly,the scattering cross section equation and the theoretical formula of Doppler frequency shift of moving target are deduced.On this basis,the modeling and simulation methods of target and first-order sea echo spectrum under monostatic/bistatic HFSWR are researched,and the influence of parameters such as double bistatic angle and shipborne platform velocity on radar echo spectrum is analyzed.Based on experimental data of the Coast/Ship bistatic HFSWR,the broadening range of the first-order sea echo and the target frequency shift are analyzed and the correctness of the theoretical analysis is verified by comparing with the simulation results of the same parameter configuration.2.According to the broadening effect of target echo and first-order sea echo spectrum of Coast/Ship bistatic HFSWR,the methods of track detection is carried out.Firstly,based on the position of Bragg peak frequency in the first order sea echo spectrum and real data we can detect the broadening range and target effectively at different distance.Secondly,the target track is simulated with the AIS data,and the target track detection in the polar coordinates is analyzed by the influence of bistatic system configuration.For further research on simulation and experiment,the Coast/Ship bistatic HFSWR can make the target far away from range of broadening of the first-order sea echo spectrum by adjusting the status of platform,thus improving the continuity of target tracking.3.The holistic process applicable to target tracking by Coast/Ship bistatic HFSWR is proposed.According to the matching results of measured data and AIS data,the target location and track detection errors of Coast/Ship bistatic HFSWR are analyzed.The tracking results show that the measurement errors of ellipse distance and azimuth under sailing are much larger than that under anchoring.The movement of shipborne platform makes it difficult to find and locate the target track,which is the primary cause of track fracture and target loss.The results of simulation and measured data shows that the validity of the target and first-order sea echo model of the Coast/Ship bistatic HFSWR is used in this paper.According to the method of target area identification and detection and target tracking processing,it is found that the method presented in this paper on measured data is effective. |
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