A fast back-projection algorithm for bistatic forward-looking low frequency UWB SAR imaging

Bistatic forward-looking low frequency ultrawideband synthetic aperture radar (UWB SAR) has the complicated range-azimuth coupling, which limits the application of frequency-domain algorithms. In this paper, an extended fast back-projection algorithm is presented to focus the bistatic forward-looking low frequency UWB SAR data. First, the imaging geometry and signal model are established. Then, the phase error of the fast back-projection (FBP) algorithm for processing the bistatic forward-looking SAR (BFSAR) is analyzed, and the implementation of the FBP algorithm is given. Finally, the simulation experiment is carried out to prove the validity of the proposed approach.