Research On Synthetic Aperture Radar Moving Targets Detection And Relocation

This dissertation studies Synthetic Aperture Radar(SAR) moving targets detection and relocation especially slow targets. Moving targets detection is a hot topic in the area of SAR,so many countries in the world are making great efforts to develop moving targets detection and relocation systems and explore high efficient moving targets detection and relocation algorithms. The history and the development of SAR are reviewed first. With the analysis of SAR imaging principle and SAR reflection model for still target,SAR reflection model for moving target is obtained. And the dissertation discusses the effect of moving target on echoes and imaging. This dissertation studies thoroughly two typical methods of multi-channel SAR moving targets detection--Displaced Phase Center Antenna(DPCA) and Along-Track Interferometry (ATI). This dissertation proposes a new method of SAR moving targets detection in complex image field combining DPCA with interferometric processing after studying DPCA and interferometric processing technique. The formula of interferometric phase and radial velocity is derived. The radial velocity and real azimuth position of the moving targets that are masked by ground clutter can be accurately determined using the interferometric phase. This method is independent of IMU and needn't strictly satisfy the constraint of DPCA. When the DPCA condition is not satisfied,the error of sampling position can be compensated by a linear phase in Doppler frequency domain. Also,the new method has the advantages of less computation and easy implementation.