SAR Moving Targets Detection And Parameters Estimation Based On FrFT

Synthetic Aperture Radar (SAR) has been widely used in both military affairs and civilian fields because of its high-resolution, independence of both time and weather conditions, etc. Usually, SAR could only be used to detect and image static targets instead of moving targets for the reason that the position drifting will make local mistake in the general SAR image, which is usually caused by the velocity of the moving targets in the ground range direction, and when it comes to the target with strong scatter coefficient right in the drifting position, the moving target could not be detected at all. Meanwhile, the application in military affairs needs the capability of SAR to detect and image moving targets that makes the detection and imaging of moving targets become a hotspot in the field of SAR.In this paper, the main problem is to detect the position and velocity of moving target by fractional Fourier transform which could be concluded by three parts, the echo model establishment of moving target, the realization of fractional Fourier transform and parameters estimation of moving target, detailed contents are as follows.Firstly, the paper analyses the echo model of SAR static target and introduces a kind of SAR imaging algorithm, Range-Doppler (R-D) Algorithm. Based on the above, the paper analyses the echo model of SAR moving target and the impact that caused by the velocity of moving target in SAR image with imaging theory. Then the paper gives the intensity image of the real part of the echo for both static and moving targets, and the paper gives their imaging picture generated by R-D Algorithm as well.Secondly, the paper has a brief description of time-frequency analysis and fetches out the fractional Fourier transform and analyses its advantage. To make fractional Fourier transform apply to digital signal processing, the paper analyses discrete fractional Fourier transform and the realization of its fast algorithm.Finally, the paper analyses the theory of velocity detection and localization based on fractional Fourier transform and gives the whole block diagram of...