Research On Ship InISAR Imaging And Feature Extraction Technology

Inverse Synthetic Aperture Radar(ISAR)can perform high-resolution imaging for non-cooperative moving targets with all-day,all-weather,high-precision,long-distance and other advantages.It has important value and significance for military field and civil application.The traditional ISAR image is the projection of the target in the distance-Doppler two-dimensional plane.It is difficult to obtain the true size of the target and the relative position between the scattering points,which has certain limitations.With the continuous development of actual needs,three-dimensional ISAR imaging technology has gradually become a research hotspot,and the feature extraction work of ISAR images is becoming more and more important.In order to meet the needs of practical applications,this paper mainly studies the ISAR ship imaging,ISAR motion compensation,interferometric ISAR three-dimensional imaging and feature extraction.The first chapter of this paper is the introduction,which briefly introduces the research background and significance of the work of this paper,the research progress of ISAR imaging technology and InISAR imaging technology at home and abroad,and the content arrangement of the full text.The second chapter introduces the basic principles of ISAR imaging.The simulation warship point model is constructed,the basic scene of ISAR imaging on the ship is analyzed,echo mathematics derivation is carried out,and the effects of rolling,pitching and yaw three-dimensional swing on ship imaging are studied.The third chapter focuses on the motion compensation technology.The principle of ISAR imaging motion compensation is analyzed.The motion compensation is divided into two steps:envelope alignment and phase compensation.Through coarse compensation and fine compensation,the adverse effects of target translation on imaging are eliminated.Theoretical analysis and verification of measured data are performed for different methods of envelope alignment and phase compensation.The fourth chapter is the focus of this paper.The InISAR three-dimensional imaging algorithm based on joint translation compensation is proposed.The problem of phase winding and image registration is solved by the interference of imaging between different antenna echoes.Simulation experiments were performed on different targets and compared with correlation-based 3D imaging method.The fifth chapter mainly studies the feature extraction of ship target ISAR images.ISAR images are different from ordinary optical images and require image preprocessing to suppress noise and interference.At the same time,the target and background need to be segmented in the ISAR image,and the target area is filled and connected.At the same time,the cross-range scaling problem of the ISAR image is studied and the geometric features of the measured ship image are extractedThe sixth chapter,the work of the full text is summarized and the problems to be further studied are pointed out.