Research Of Moving Target Focused Imaging Technology On High Resolution SAR

The Synthetic Aperture Radar(SAR)imaging technology is becoming more and more mature,and the azimuth and distance resolution have been greatly improved.In the field of battlefield reconnaissance,radar not only needs high-resolution imaging in the surveillance area,but also needs to detect,image and locate the moving target.Moving targets are submerged by clutter and can't be detected.And azimuth shift and defocus will appear in SAR image.How to improve the detection ability and imaging effect has become the research hotspot.Based on the high-resolution SAR simulation and measured data,the focused imaging of moving targets is taken as the main research content.The specific work is summarized as follows:1.As the basis of the research,the imaging model of SAR for stationary target is established,and the determinants of azimuth and range resolution are discussed.In the imaging algorithm,the classical RD,CS and ?-k algorithms are introduced,and the imaging process and adaptive scene of each algorithm are compared.2.Based on previous model,the model of moving target is established,and the influence of Doppler center frequency and modulation frequency on the image is analyzed from echo.In order to detect moving target,single channel and multi-channel ground moving target indication(GMTI)technology is derived.Four kinds of multi-channel clutter suppression and detection techniques are analyzed in detail.Meanwhile the importance of channel equalization is discussed and how to use CFAR to detect moving target.3.In order to focus image of moving targets,a new algorithn based on CSI-MD algorithm is proposed in this paper.The estimation process of Doppler center frequency and modulation frequency is analyzed,and then the moving target is refocused and relocated.For the phenomenon of distance unit migration,using the Inverse Synthetic Aperture Radar(ISAR)algorithm for reference,an algorithm based on ACSI-ISAR is proposed.The target envelope and phase compensation are used to realize the refocusing of moving targets.Finally,the paper summarizes the work of the full text,and analyzes the further development prospects in the field of focused image of moving targets.