MEMS Underwater Acoustic Vector Sensor Operating in Near Neutral Buoyancy Configuration

This paper reports on the functionality of an acoustic vector sensor (AVS) for underwater use. The AVS is comprised of two micro-electromechanical systems (MEMS) acoustic directional sensors coupled with an omnidirectional hydrophone and can determine direction of arrival (DOA) of acoustic waves in water. The MEMS sensors are contained in air-filled, water-tight housings and are operated in a nearly neutrally buoyant configuration. In this configuration, the acoustic sensors act as inertial sensors, detecting the vibration of the housing rather than the pressure wave directly. This paper discusses the design of the AVS as well as its DOA accuracy. The AVS demonstrated an average DOA error, over a full 360-degree azimuth, as low as 7.8 degrees.