Precision acoustic navigation for remotely operated vehicles (ROV)

The ability to navigate a ROV to exact bottom locations or along a precise path is essential to many scientific and engineering tasks. Bottom and water column surveys along a precise and repeatable trajectory allow the monitoring of chemical and physical variables, and the study of sedimentation processes and biological phenomena. Precise navigation is also required for high-resolution synthetic sonar observations and for placement and retrieval of various devices on the bottom. This paper reviews principles behind acoustic navigation and provides a survey of commercially available Ultra-Short Baseline (USBL) navigation systems. A novel high precision navigation system is proposed that offers several advantages over the surveyed systems. Specifically, the precise position and trajectory of a ROV tethered by a cable to a bottom node is obtained using sensitive phase measurement of an acoustic signal. Proof of this concept through shallow-water and deep-water prototypes will be carried out shortly at the University of Victoria