Source Localization Using Acoustic Vector Sensors
Joshua York Independant Study
Washington University Spring 2009

Acoustic Vector Sensors (AVS)

Washington University Spring 09'

The Acoustic Vector Sensor or (AVS) is a device that is capable of measuring acoustic particle velocity as well as pressure as in a standard microphone. This combination makes it possible for the device to measure the complete sound field. In the previous research, we were primarily concerned with source localization determined from the TDOA (Time Delay of Arrival) method between four standard microphones in a linear array configuration. This set up allowed us to determine the position of an acoustic source in 2D. The AVS device has great advantages over the previous construct in that it allows us to determine the direction of arrival of an acoustic source in 3D. The most important aspect of this is the ability for the device to accomplish this task on its own, without the aid of an additional microphone. By using the AVS in a array configuration a great deal more information can be obtained from the situation and therefore, better results for localization can be achieved.

The goal was to estimate the position or direction of an acoustic source using spatial and temporal measurements of pressure and particle acoustic field. An additional goal was to explore the use of Acoustic Vector Sensor(AVS) technology in a similar setting to that of the previous experiment in acoustic source localization using a four microphone array. This research utilizes equipment graciously loaned to our team by Microflown Technologies, consisting of 4 Acoustic Vector Sensors and the required signal conditioning devices. The goal is to explore the concept of source identification in 3D for specific frequencies. To accomplish these goals concepts in beam forming as well as acoustic mechanics have been explored.

The data from the probe is passed to a signal conditioning device via 7 pin LEMO connection. The conditioner then splits the data across 4 channels corresponding to the pressure, and X Y Z particle velocity signals. These 4 channels are then provided to four BNC outputs.