Research On The Polar Format Algorithm In Spotlight SAR

Synthetic Aperture Radar(SAR) is a kind of imaging radar with fine resolution capability and the possibility of day/night operation in all weather, which is of great importance to the modernization of national defence technology and national economy development. Spotlight Mode SAR is an important imaging mode of SAR, which can obtain high azimuth resolution that might be hardly obtained by the conventional stripmap SAR. This dissertation studies the Polar Format Algorithm(PFA) which is typically used in the image formation of the Spotlight Mode SAR through the processing of the simulated data and live data. The main contents of this dissertation are as follows.Chapter 1 introduces the development and reaearch situation of SAR and Spotlight Mode SAR in detail. Finally, the main research contents of this paper are summarized.Chapter 2 introduces the image formation theory of SAR and analyzes the resolution problem under the stripmap mode and the spotlight mode.Chapter 3 explains the theory of dechirp technic used in the Spotlight SAR at length and introduces the practical realization procedure of eliminating the residual video phase.Chapter 4 elaborates on the image formation theory of PFA and shows the images formed through the point targets simulation and live data. Paticularly, a data convertion method from stripmap raw data to the equivalent spotlight data is introduced and the limitation of PFA is also analyzed.Chapter 5 analyzes the image formation theory of Range Migration Algorithm(RMA) and compares the image forming performance of PFA with that of RMA in detail.