Source Ranging and Direction of Arrival Estimation using Accelerometer based Implementation of Prototype Acoustic Vector Sensor

Acoustic emissions from underwater sources are used to detect, locate, and track targets by passive surveillance sensors. The "vector" sensors measure the scalar pressure as well as the orthogonal components of particle velocity and offer distinct advantages over the traditional solution of array of hydrophones due to their smaller size and frequency independent performance over the frequency range specified for constituent elements. This paper presents studies on an in-house implemented prototype vector sensor employing tri-axial accelerometer as constituent element. The tests undertaken include Direction of Arrival (DoA) estimation and application of modified Fast Orthogonal Search technique on a single Vector Sensor for improvement in spectral resolution. We also propose a configuration involving just two Vector Sensors (composed solely of accelerometers) that offers ease of design and obviates the requirement of a pressure sensor in setup for obtaining DoA estimate while also providing range to the source.