Experimental study on source direction finding using a cylindrical array considering scattered sound fields

Abstract

A circular array is widely used for source direction finding due to its more compact configuration and smaller angular dependency compared to a linear array. In underwater environments, however, high drag forces make it difficult to utilize the circular array especially for the case where there is high-speed ocean current or the platform with the array is moving. To overcome this operational difficulty an array of hydrophones flush mounted on a cylindrical structure may be applied. A recent numerical study shows that the beamforming performance is improved by considering the scattered sound field by a cylinder. Recently a tank experiment using an array of eight receiver element on a cylindrical structure has been done for underwater source direction finding. In the experiment narrowband and wideband signals are used for the sound transmitter. The experimental results also show that the lower side-lobes are obtained when the scattering effect is considered during beamforming analysis.