Joint physical and virtual STAP for strong ground clutter suppression and imaging

Clutter suppression is a mandatory step in order to detect slow moving targets embedded in strong ground clutter. Multichannel systems allow for sufficient spatial degrees of freedom to be available and as a consequence, allow for STAP processing to be applied. In recent times, a processing scheme that exploits a single channel SAR system with high PRF to emulate a multichannel SAR system is developed. The synthesis of a virtual multichannel SAR system is of considerable importance since it allows for avoiding multiple receiving chains and all the issues related to the cross-channel calibration. The price to be paid is a reduction of the non-ambiguity Doppler region. In this paper a solution that jointly exploits both the virtual and the physical channels of the SAR system is presented. The proposed solution represents a trade-off between the multichannel SAR system complexity and the constraint in radar design caused by the virtualization of a single channel SAR system.