Multichannel-two pulse cancellation method based on NLCS imaging for bistatic forward-looking SAR

This paper proposes a clutter suppression method for the bistatic forward-looking SAR(BFSAR). The proposed method relies on a proper processing of the received echoes. First, keystone transform (KT) and the higher-order RCM correction are applied to correct the range cell migration (RCM). Then, azimuth nonlinear chirp scaling (NLCS) and azimuth dechirp are applied to suppress the spatial-variant Doppler spectrum extension. After the aforesaid two steps, the moving targets and clutter can be separated in the space-time domain, and the clutter signal with different pulses contains only one constant phase difference. Thus, the two-pulse clutter canceller can be designed to suppress the clutter. Finally, it is suggested that this proposed method can improve the signal to clutter ratio (SCR) and are beneficial for the subsequent signal processing, e.g. target detection. Simulation results are provided to validate the effectiveness of the clutter cancellation method.