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