A Sustained Beaufort Sea Acoustic Navigation and Communications System for Under-Ice Platforms

Autonomous subsea platforms operating in the Arctic throughout the winter require a long-range acoustic navigation system to substitute for GPS while under ice and not able to surface. To allow the autonomous platforms to sample a large portion of the Beaufort, the navigation system must span several hundred kilometers, which in turn requires multiple sources with acoustic ranges of at least 100 km each. To enable vehicles such as gliders to navigate while performing their missions also requires an onboard acoustic receiver and accurate clock, plus processing to compute geolocations. Over the past four years an operational system that includes multiple fixed source moorings and compact, low-power receivers has been maintained in the deep area of the Beaufort Sea north of Alaska. The navigation system has been used to successfully allow gliders and profiling floats to operate throughout the winter, performing science missions and augmenting data collected on instrumented fixed moorings in the center of the Beaufort.