Tonpilz-type vector sensor for the estimation of underwater sound wave direction

Typical underwater Tonpilz transducers detect the magnitude of an acoustic pressure, a scalar quantity, by means of piezoceramic rings, and convert this pressure into a proportional electric voltage. The scalar sensor has no directional sensitivity. This paper proposes a new vector sensor based on the Tonpilz transducer that is sensitive to both the magnitude and direction of an incoming acoustic wave. The piezoceramic rings of the new Tonpilz-type vector sensor are divided into four quadrant segments. The direction of an incoming acoustic wave is identified by combining the output voltages of the four piezoceramic segments in a particular manner. The operation frequency range of the vector sensor follows that of conventional Tonpilz transducers. The feasibility of this new structural design has been confirmed through a three-dimensional simulation of the operation of the vector sensor with the finite element method. The validity of the new design is verified by fabricating and characterizing an experimental prototype of the vector sensor.