Modified back projection reconstruction for circular FMCW SAR

In this paper, we develop the modified back projection reconstruction algorithm for circular frequency modulated continuous wave synthetic aperture radar (FMCW SAR) which moves along circular trajectory. Regarding circular FMCW SAR signal processing, the movement during the transmission of a pulse is expected to be one of the major problems. The platform movement during the pulse leads to the emergence of range migration error. Numerical simulations illustrate the performance of the traditional back projection (BP) algorithm with stop-and-go approximation and the proposed modified algorithm, showing that the stop-and-go approximation is not valid for circular FMCW SAR any more, whereas the modified back projection algorithm works well.