Sensors logo

In-Lab demonstration of an underwater acoustic spiral source

R. VIEGAS(1), F. ZABEL(2) and A. SILVA(1)
(1) LARSyS, University of Algarve, 8005-139 Faro, Portugal
(2) Algarve Technological Research Center, Univeristy of Algarve, 8005-139 Faro, Portugal

Comments: pdf
Ref.: Sensors, 23, 4931, May 2023

Underwater acoustic spiral sources can generate spiral acoustic fields where the phase depends on the bearing angle. This allows estimating the bearing angle of a single hydrophone relative to a single source and implementing localization equipment, e.g., for target detection or unmanned underwater vehicle navigation, without requiring an array of hydrophones and/or projectors. A spiral acoustic source prototype made out of a single standard piezoceramic cylinder, which is able to generate both spiral and circular fields, is presented. This paper reports the prototyping process and the multi-frequency acoustic tests performed in a water tank where the spiral source was characterized in terms of the transmitting voltage response, phase, and horizontal and vertical directivity patterns. A receiving calibration method for the spiral source is proposed and showed a maximum angle error of 3 degrees when the calibration and the operation were carried out in the same conditions and a mean angle error of up to 6 degrees for frequencies above 25 kHz when the same conditions were not fulfilled