Research On Clutter Suppression Algorithms For Airborne Multi-channel SAR/GMTI

In the recent years, ground moving target detection has become a hot topic in the field ofSynthetic Aperture Radar (SAR), and has been highly valuable for both military and civilianapplication.The dissertation mainly studies multi-channel SAR/GMTI techniques, and focuses onseveral algorithms for clutter suppression.The main work of this dissertation is as follows:In chapter1, the research background and current situation of SAR/GMTI technique are firstlyreviewed, and then the background and main contents of this research are addressed.In chapter2, the stationary and moving targets’echo models are firstly investigated, and then theimpacts of doppler parameters of moving target on the convential SAR image are discussed in detail.In chapter3,firstly,the basic principle and signal processing flaw of algorithm for two-channelairborne SAR/GMTI radar based on the clutter suppression interferometry technique is discussed,thenthe parameter estimation methods for the detected moving target are studied.Secondly,according tothe performance degradation caused by the phase and amplitude errors between different receivingchannels,several calibtration algorithms in image domain are introduced.These algorithmscancalibrate various kinds of errors and have strong robuetness, which is also supported by simulationas well as experimental results.Finally,According to the current engineering needs,the abovementioned three-channel interferometric SAR/GMTI technique is presented,followed by the IF andthe relocation accuracy for slowly moving target.In chapter4, the clutter model for airborne radar is firstly built up and the clutter characteristic isanalyzed, then the model for multi-channel SAR-STAP is built up. Based on the post-DopplerSAR-STAP method (MSAR) proposed by Ender, the image domain SAR-STAP technique isintroduced to detect moving target after SAR imaging.Then the algorithms of MNE based on EVDand MNE based on PAST are introduced, whose peoformance for clutter suppression is verified byexperimental results with respect to the three-channel SAR system.At last, the performance forreal-time processing of these two algorithms is analyzed and compared.In chapter5, the work is concluded and the possible problems to be further researched are alsopointed out.