A versatile tracking system for AUV testing

Testing and development of AUVs and AUV-based systems can be greatly accelerated with access to a suitable underwater tracking range area. A tracking system was recently developed jointly by the NSWCCD Acoustic Research Detachment (ARD) and the University of Idaho (UI). Located on Lake Pend Oreille, the system is used routinely to test AUVs being developed at UI. The system includes four acoustic tracking nodes which are held stationary near the lake floor. Three transducers are mounted on each node and cabled to a dockside tracking and control station. Acoustic pings are emitted from the test vehicle at periodic intervals. These pings are received at multiple tracking nodes allowing 3-D tracking solutions to be computed. The test area covers approximately 23,000 square meters, with a nominal water depth of 15 meters. The system is versatile enough to accommodate special testing needs and changing user requirements. Tracking nodes can reply back to the AUV, emulating a transponder recognized by onboard navigation systems. Tracking can be synchronous (known ping time) or asynchronous (unknown ping time). Many different ping waveforms are supported, over a broad range of frequencies. System components and capabilities are discussed, along with unique features and attributes. Tracking performance is discussed and test results are presented. Operating the tracking system is very cost-effective. The system is easily accessible and can be quickly set up and broken down. This allows a paradigm shift in AUV development where less time is spent developing simulation software in favor of time spent performing in-water testing.