Non-stationary Clutter Suppression Approach Based on Cascading Cancellation for Bistatic Forward-looking SAR

Clutter suppression in synthetic aperture radar (SAR) is an attractive but challenging problem in SAR applications. When it comes to the Bistatic forward-looking SAR (BFSAR), the strong ground clutter is range-dependent, Doppler ambiguous and it will migrate multiple range and Doppler cells due to the system features, which vastly aggravate the difficulty of ground clutter suppression. In this paper, a non-stationary Clutter Suppression approach based on Cascading Cancellation for BFSAR is proposed. This approach is based on cascading the clutter cancellation in space-time domain and image domain. First, the Doppler ambiguity and range cell migration will be eliminated via deramp filtering and keystone transform, respectively. Then, the non-stationary clutter can be first suppressed in space-time domain via time-division spacetime adaptive processing (TD-STAP), which removes the effect of Doppler cell migration. Finally, the residual clutter can be further suppressed in image domain via displaced phase center antenna (DPCA) based on keystone-back projection (KBP). Simulations are given to verify the effectiveness of the proposed approach.