Synthetic Aperture Radar Imaging Algorithm Research

Synthetic Aperture Radar (SAR) is a sort of high resolution imaging radar. Using SAR we can obtain radar images independent of all time, all weather, and long distance conditions, SAR plays a key role in military and civil applications.Compared with the monostatic case, bistatic SAR has many advantages, such as abundant field information, high security, and fine anti-jamming performance, etc. Therefore, the first part of my research is focused on bistatic SAR imaging using pulse signal. The geometry model and signal model of the general bistatic SAR are presented and studied. Besides, the Loffeld model and the method of series reverse (MSR), are used to deduce the two dimensional (2D) spectrum of the bistatic SAR. Furthermore, to handle azimuth-variant cases, the non-linear chirp scaling (NLCS) algorithm is used.Frequency modulated continuous wave (FMCW) SAR, which combines continuous wave radar technique and SAR technique, can satisfies the demand of small-size, light-weight and low-cost. Gradually, FMCW SAR is becoming a hotspot in the field of SAR. The theory and model of FMCW SAR system are provided in the following chapter. We not only analyze the difference between the pulsed SAR and FMCW-SAR system, but also present the improved R-D algorithm andω-k algorithm for FMCW-SAR system.In addition, obtaining 2-D and 3-D SAR images by antenna array is studied in the last part. A single-frequency holographic image reconstruction method is proposed, scanning the target in a plane, two different orientation resolutions are obtained in this part. In the meanwhile, the multipass technique using linear modulated frequency signal is studied to generate three views of the target.