Superdirective beamforming for dual concentric circular hydrophone arrays

This paper proposes a superdirective beamforming method for dual concentric circular hydrophone arrays based on the previously established eigenbeam decomposition and synthesis model. The optimal solutions of superdirectivity, including the optimal beampattern, the global directivity factor, and the total sensitivity function, are all decomposed into corresponding sub-solutions termed eigenbeams, their directivity factors, and their sensitivity functions, respectively, based on the block matrix inversion lemma and the properties of the circulant matrix. The eigenbeams possess different directivities and robustness, and a robust scheme called the reduced-rank technique is then applied to achieve robust superdirective results based on these solutions. The feasibility and good performance of the proposed method are demonstrated in simulations.