Design and testing of an acoustic ranging technique applicable for an underwater positioning system

摘要

The design and preliminary testing of a prototype ranging system, capable of being utilised by an underwater positioning system, is presented in this paper. The system extends the reach of the terrestrial global positioning system (GPS) to the subsea environment. The prototype system incorporates a topside surface buoy that receives and relays the GPS data, via acoustic signals, to the subsurface receiver. The receiver calculates the range from the topside buoy using the coded acoustic signal. Key operating characteristics of the system are experimentally investigated: long- and short-range accuracy, repeatability and resolution. The prototype ranging system also demonstrates the feasibility of a full-up underwater vehicle positioning system (comprising three topside buoys and a receiver). The ranging system's experimental performance has been extrapolated to show that a theoretical position accuracy of 6.5m will be attainable for an unlimited number of underwater receivers operating within a 1 km2 workspace.