The Study Of Ground Moving Target Detection With Synthetic Aperture Radar

Ground Moving Target Indication (GMTI) with SAR is highly valuable for bothmilitary and civilian application. Now many countries are making great efforts in thefield to develop novel GMTI systems and explore high efficient and practical GMTImethods.Based on the analyses of evolution for SAR/GMTI techniques, this dissertationstudies thoroughly several currently prevalent GMTI methods, especially ATI. At thesame time, this dissertation presents several methods that are more efficient andpractical to solve some difficult problems in ATI/GMTI. The primary work of thedissertation is as follows:1. The dissertation analyzes the model of moving target echoes, and discussesin detail the effect of moving target Doppler center frequency and Doppler rate on theconventional SAR image, which is verified by simulation.2. The dissertation discusses several currently prevalent GMTI methods,including single-channel methods, ATI, DPCA and STAP, and analyzes the processingscheme and some key issues of each method. These methods are compared in sense ofperformance, practicability and affordability in the paper.3. Detection performance of ATI and several key issues of ATI are in-depthstudied, such as phase-unwrapping, antenna transmission mode, Image registrationand phase denoise etc. A novel phase-unwrapping method is proposed whichcombines the merits of spectral-filter method and dual-channel ATI method. Sincethis method neither need ground controlled object nor high system complexity, it ismore practicable than conventional phase-unwrapped method of dual-channel ATI.This method can also be adapted to DPCA.4. After analyzing the fundamental principle of target detection. Thedissertation studies the dual-threshold GMTI approach which remedies theshortcomings of conventional single-threshold methods of dual-channel ATI. A novelapproach is proposed which combines the conventional interferometric phasedetection with the complex correlation coefficient detection. In this dissertation, the theory of the method is deduced; the flow and the advantage of the method areintroduced. The simulated results demonstrate that this method can greatly reduce thefalse alarm rate of moving object detection.5. The multi-channel SAR GMTI based on ATI is deeply analyzed. A novelmethod is presented that can take full advantage of the abundant phase information ofmulti-channel ATI system. In the method, a straight line is applied to fit the phasechange, and then the moving object detection is performed by using the slope andresidual error sum of the fit line. The simulated results demonstrate that this methodcan detect moving object more effectively.