Navigation on an unmanned surface vehicle using an acoustical spiral wave front beacon.

Abstract

An acoustical spiral wave front beacon described previously [Dzikowicz and Hefner, J. Acoust. Soc. Am. 127, 1748 (2010)] is tested using an unmanned surface vehicle (USV). The beacon transmits from two transducers, one with a signal whose phase varies with aspect and a reference signal whose phase is constant with aspect. A remote hydrophone’s aspect relative to the beacon’s can be determined by comparing the phase of the two signals. The beacon is positioned at a fixed depth, location, and orientation in the acoustic test pond at the Naval Surface Warfare Center, Panama City Division. A remotely operated USV is equipped with a hydrophone at the same depth as the beacon. The vehicle is also equipped with a differential global positioning system (DGPS) receiver to determine its exact position. The USV is driven in several routes including areas of varying water depth and reverberation levels. The DGPS positions are then compared to the aspect as calculated by the spiral wave font beacon. Single, dual, and swept frequency beacon signals are tested and compared. [Work supported by the Office of Naval Research.]