Research On Imaging Algorithm Of Circular Scanning SAR

Synthetic Aperture Radar (SAR) is a kind of imaging radar with fine resolution and the capability of day/night operation in all weather conditions, which is of great importance to the modernization of national defence and national economic development. Common SAR imaging modes include stripmap, spotlight and scanning, in which the imaging area is on one side of radar platform. However, for some particular applications, such as scene matching, etc., we need images of circular area under the radar platform, which gives birth to circular scanning SAR. Imaging algorithms of circular scanning SAR is presented in this dissertation. The main contents are as follows:Chapter 1 retrospects development and research situation of SAR at home and abroad. The main contents of this dissertation are outlined.Chapter 2 introduces the linear range Doppler (RD) algorithm and the polar format algorithm (PFA) in detail, which meet the imaging requirements in high squint- mode SAR.Chapter 3 analyzes the mechanism of geometric distortion, and two methods of geometric distortion correction for Linear RD as well as PFA are presented respectively.Chapter 4 discusses imaging algorithm of circular scanning SAR. For the radar platform moves with a constant velocity along rectilinear trajectory, examples using point-targets simulations and live data processing prove the validity of the proposed algorithm.An imaging algorithm under highly maneuvering condition is presented in Chapter 5, which is based on PFA and combined with geometric distortion correction, point-targets simulations prove the validity of the algorithm under highly maneuvering condition. In Chapter 6, the dissertation is summarized and the possible future work is pointed out.