Underwater navigation using an acoustic spiral wave front beacon

Abstract

A spiral wave front beacon consists of an array of transducers which produce a signal whose phase depends on the azimuthal angle at which it is received and a reference signal with constant phase [J. Acoust. Soc. Am. 131, 3748 (2012)]. A vehicle can determine aspect to the beacon by comparing the phase of the two signals. Progress in the development of this navigation technique will be discussed including results from experiments at Dodge Pond in Connecticut where an unmanned surface vehicle determined its aspect to within 10° by receiving signals from the beacon. Also, tests of a new spiral beacon design [J. Acoust. Soc. Am. 130, 2506 (2011)] in laboratory and underwater environments will be presented. Underwater experiments are performed at the Navy’s Seneca Lake facility in upstate New York using an UUV to record signals. Overall, these results demonstrate that intrinsic phase shifts in the beacon can be handled by signal processing at the receiving vehicle and that the spiral navigation technique is robust in reverberant environments. [Work supported by the Office of Naval Research.]