Robust supergain beamforming in mode space for an arbitrary baffled circular array

Abstract

Circular array used in practical applications often have sensors mounted on an arbitrary acoustic baffle. In this paper a model is presented for calculating the noise cross spectral matrix of such an array, thus array gain computation and weighting vector design for supergain beamformer can incorporate the baffle scatter effects by using the exact noise cross spectral matrix. However, supergain beamformer may be extremely sensitive to slight errors in array characteristics. Therefore, a new robust supergain beamforming method in mode space which adopts the white noise constraint and low mode orders under low frequencies is also presented. Results of computer simulation indicated that this method can provide a better beampattern performance than both conventional method and robust beamforming method in sensor space simultaneously.