Fast Time Domain Imaging for Bistatic SAR Including Motion Errors

In this paper, a fast time domain imaging for the bistatic synthetic aperture radar (BSAR) including the motion errors is presented. This method is called the fast factorized backprojection (FFBP) algorithm, which not only precisely handles the large spatial-variance, serious range-azimuth coupling and complicated motion errors, but also greatly improves the imaging efficiency compared with the backprojection (BP) algorithm. In addition, it requires the local beamforming from radar echoes as an intermediate processing in the slant range plane instead of the ground plane, which can be accurately referenced to tracks of the transmitter and receiver considering the platform altitudes. Moreover, it analyzes the bistatic range error considering motion errors to derive the requirement for selecting sizes of the subaperture and subimage, which can offer a near-optimum tradeoff between imaging precision and efficiency. Experiment results prove that the proposed method outperforms the BP algorithm in the terms of the efficiency improvement.