Optimized design of wideband beamformer using interpolation technique for vertical acoustic array

This paper proposes an optimized design procedure of wideband constant beamwidth beamformer (WCBB) using robust array interpolation technique for a shallow water vertical acoustic array. With the incorporation of harmonic nesting and array interpolation, a nearly constant mainlobe response is achieved over the design band with compact array size, smaller number of sensors and improved array directivity. The robust interpolation matrices design problem can be converted to the efficient form of second-order cone programming (SOCP) and be solved with the interior point method. An interpolation-based WCBB is implemented in frequency domain with frequency bin dependent weighting of the elements. Representative design examples are presented to demonstrate the dramatic improvement of beamforming performance under far-field condition.