The Detection And Imaging Of Moving Targets Based On Sar

Synthetic Aperture Radar is a kind of high resolution imaging technology, and it expanded connotation of classic radar. Compared with Traditional imaging techniques, SAR is a kind of active microwave remote sensing technology,with the capability of working in all weather and full time, so it was taken seriously by each country. The detection and imaging of moving targets based on SAR is attracting more and more sights with its important role in both military and civil, in that moving targets contained more information. On the basis of forefathers, this article thoroughly discusses the detection and imaging of moving targets based on SAR, simultaneously emphatic research on the detection and imaging of moving targets based on bi-channel SAR.SAR derives from Doppler Beam Sharpping, in order to get the"hologram"of targets with high resolution, it incorporated all the synthetic aperture technology,pulse compression techniques,digital processing technology to a full integrality.The main contents of this paper are:1) The stationary and moving targets'echo models are analyzed, while the impact of the velocity of the moving target on the azimuthal information of echo signals, and the specific reasons of the target imaging defocusing and the azimuthal displacement is discussed.2) Several moving target indication (MTI) methods at present, of which the indication performances are compared approximately, are introduced in details; Meanwhile, the frequency domain filtering method in single channel SAR MTI system are studied in depth, and a new range velocity estimation method is introduced following the simulation verification by the computer.3) The principle and the Performance of the SAR MTI system based on displaced phase center antenna(DPCA) with double channels are studied in depth. Due to its excellent time-frequency concentration to LFM signals, the fractional fourier transform is used in the estimation of moving target range velocity, and the computer simulation shows that an accurate azimuthal velocity can be obtained by FRFT, with which a defocusing moving target image can be focused to improve the resolution of the moving target. Restricted by the PRF, the method that solves the range velocity by estimating the doppler central frequency of the moving target is unsuitable in all cases, while the along track interference (ATI) technology can only indicate the range velocity of the moving target, so in this paper, the DPCA and ATI methods are combined to obtain the moving target azimuthal and rang velocity respectively.