Vector sensors—over 40 and still hot

Abstract

Acoustic vector sensors and gradient arrays have been in use in underwater acoustics for more than 4 decades, so one may wonder why they are featured in a session entitled ‘‘Hot Topics.’’ The reason lies in the recent resurgence in their use. This, in turn, is due primarily to major advances in engineering and signal processing that have been applied to these devices. Historically, theoretical gains have been difficult to achieve with these sensors due to their susceptibility to uncorrelated noise. That is to say, the very process of making a localized measurement of the vector acoustic field lowers the signal-to-noise ratio, relative to a simple pressure measurement. However, with today’s advances in design, manufacturing, and digital signal processing, high-quality performance can be achieved in a very small package size. Moreover, the current interest in these devices is not limited to underwater acoustic applications; rather, it extends across a number of technical areas within the acoustics community. This presentation will begin with a brief introduction to the theoretical foundation and history of these devices. Then, some current applications in both underwater and airborne acoustics will be highlighted.