Robust astronomical imaging in the presence of radio frequency interference

Radio astronomical observations are increasingly contaminated by radio frequency interference (RFI), rendering the development of effective RFI suppression techniques a pressing task. In practice, the existence of model mismatch makes the observing environment more challenging. In this paper, we develop a robust astronomical imaging method in the presence of RFI and model mismatch. The key contribution of the proposed method is the accurate estimation of the actual signal steering vector by maximizing the beamformer output power subject to a constraint that prevents the estimated steering vector from converging to the interference steering vectors. The proposed method is formulated as a quadratically constrained quadratic programming problem that can be solved using efficient numerical approaches. Simulation results demonstrate the effectiveness of the proposed method.