Study On Synthetic Aperture Radar Imaging Techniques

Synthetic Aperture Radar (SAR) is a new type of radar system developed since 1950's.With the principle of synthetic aperture and the pulse compression technology, it breaksthrough the resolution limitation imposed by the real aperture and two-dimensional highresolution to distant targets can be realized. SAR has evolved to satisfy a variety ofapplications for both civilian and military with its high resolution capability and possibilityof day and night operation in all weather.This thesis focused on the imaging algorithms of SAR. First, we make researches onthe imaging geographical model of SAR, and then the Range Doppler algorithm, theω-kalgorithm, the Chirp Scaling algorithm and the Step Transform algorithm are analyzedcarefully in theory. The performances of different imaging algorithms are studied. The maincontents of the thesis are described as following:The history, the present and the future of SAR is provided and the history of SARimaging algorithms is discussed. Then we introduced the basic principle of SAR whichincludes: the resolution theory, the mathematics model of the echo data and the echo signal,the imaging methods and the range migration.Four range models are given, and four RD algorithms, fourω-k algorithms, two CSalgorithms are presented with the four models. Equivalent squint RD algorithm andmonochromatic squintω-k algorithm are provided by the author for the first time.Finally, the performances of these imaging algorithms are analyzed.SPECAN algorithm is introduced. Then we discuss the Step Transform algorithmwhich can modify the deficiency of the SPECAN algorithm. Finally, the time varying StepTransform algorithm is presented which can accommodate to the high squint SAR imagingand its simulation is given.