Design and experimentation with acoustic vector sensors

Directional underwater sensors have two appealing capabilities; the ability to selectively reject noise emitted from discrete interfering noise sources and the ability to localize, track, and range targets using suitable signal processing algorithms. Specifically, “acoustic vector sensors” are directional underwater sensors that measure acoustic pressure as well as the acoustic particle velocity to estimate the acoustic intensity. The acoustic intensity which is a vector quantity represents the magnitude and direction of the active or propagating part of an acoustic field thus indicating the DOA (Direction of arrival) of a received signal. Hence, a single vector sensor is capable of localizing a sound source and implementation of robust hardware and associated signal processing algorithms can provide valuable gains in comparison to traditionally used omni-directional pressure sensor arrays. This paper covers briefly the theory, advantages, design, applications, signal processing associated with vector sensors and results of experimentation carried out at CARE, IIT Delhi.