Ship Target Detection And Imaging Methods For Passive Radar With Satellite Illuminators

Compared with active radar and passive radar using terrestrial base stations,passive radar using satellite illuminators of opportunity shows a number of advantages,such as cost-effectiveness,good concealment,strong anti-interference capability,and wide signal coverage.Therefore,the passive radar with satellite illuminators enables to achieve the information perception of detection area silently.These characteristics make it highly valuable in both military and civil applications.Ship target detection and imaging via passive radar with satellite illuminators aim to distinguish and detect the moving ship target by signal processing of the received echoes from the surveyed sea area,and to further acquire the radar imagery of the ship target and the background scene.Echo model,signal synchronization,signal integration,and imaging processing are the critical elements for the passive radar ship target detection and imaging.Focusing on the above researches,this dissertation presents the theory analysis,method research,and experiment verification.The main contents are as follows:1.The signal model of the passive radar with satellite illuminators is established,after which the signal migration and Doppler characteristics are analyzed.And the signal synchronization preprocessing of the passive radar is studied,which solves the problems of the opportunistic signal and the time-frequency synchronization error.It lays the model foundation and prerequisite for the ship target detection and imaging.2.A single-transmitter signal integration and target detection method based on joint estimation of multi-frame parameters is proposed,which solves the problem of higherorder migration correction and phase compensation of ship target with constant velocity or constant acceleration;The single-transmitter signal integration and target detection method based on multi-frame range-Doppler state prediction is proposed,which solves the problem of complex state trajectory estimation for the noncooperative ship target with jerk or maneuvering motion.3.A multi-transmitter signal integration and target localization method based on target position and velocity coordinate projection is proposed.Through the Doppler parameter equalization and the range parameter compensation processing,the coupling between the range-Doppler parameter and the satellite illuminator can be eliminated,after which the ship target detection and localization under the condition of multiple satellite illuminators can be achieved.4.A large field-of-view imaging method for the background scene based on the optimal selection of satellite transmitter set is proposed.The transmitter set for different view angle is determined via the criterion of minimum area of the multistatic resolution cell,which solves the problem of the imaging resolution variation with the view angle.As a result,the radar imagery of the large field-of-view background scene with balanced spatial resolution can be acquired using the passive radar with satellite illuminators.5.A ship target imaging method based on multi-transmitter joint estimation of target velocity is proposed.By uniformly mapping the echo data pertaining to multiple satellite illuminators to the target local plane and optimally solving the ship target velocity,the problems of imagery shift and defocusing are solved,after which the focused image of the moving ship target can be obtained using the passive radar with satellite illuminators.So that the imagery fusion of ship target and background scene can be realized.The effectiveness of the above methods is validated by theory analysis,simulated and experimental results.The results demonstrate that,by means of the proposed methods,the moving ship target can be effectively detected and localized,and the radar images of the ship target and scene can be achieved.