Improving the beamforming performance of a vector sensor line array with a coprime array configuration

Abstract

Coprime arrays provide appealing performance in many scenarios. In this paper, we show the benefits of spatially undersampled acoustic vector hydrophone coprime line arrays over traditional uniform hydrophone line arrays for beamforming and direction-of-arrival (DOA) estimation. This paper presents the perceptiveness of the theoretical performance of an underwater vector sensor coprime line array (vCLA) in the physical array domain. Based on the Product and Min methods, an array extending approach for the vCLA has been proposed to reduce the area of grating lobes of beam output leading to unambiguous DOA estimates. To minimize the sidelobe and improve the left–right suppression ability of the array, we present a data-independent weighting design method based on sound pressure and vibration velocity joint processing (PVJP) and evaluate its performance in detail. The results suggest that the proposed method can improve the vCLA beam output directivity, enhance the spatial resolution, benefit the left–right ambiguity rejection capability, and productively mitigate the influence of side and grating lobes, thus promoting the DOA estimation accuracy.