Acoustic Communications and Naviagtion for Under-Ice Sensors
Arctic Research Initiative
2009 Funded Project
The proposed work is motivated by the needs of researchers who perform studies in the Arctic. The goal is to perform research and initial demonstrations that will directly impact existing and planned scientific investigations by WHOI scientists in the Arctic, and that will also allow us to obtain funding for future, longer-range systems as well. The ranges of interest fall into three regimes, 1-10 km, 10-50 km, and 50-400 km.
Research with autonomous sensors such as gliders and AUVs is more difficult under ice than in the open ocean because the vehicles cannot surface to receive GPS positions or to send data to shore via Iridium. There is also significant risk in sending vehicles under the ice, and at least one expensive vehicle has been lost (Autosub 2 from the UK National Oceanography Centre in 2005). Enabling vehicles to operate under the ice requires reliable acoustic navigation and communication.
Example uses of underwater vehicles in the Arctic include mapping the extent of the ice and measuring chemical or physical parameters of the water at different range scales. Communications range, navigational range and accuracy, and communications throughput are the key parameters, and they differ depending on the mission. For gliders transiting deep under the ice for long periods of time, navigation is the most important capability. However, a simple communications capability so that the glider can report its status and receive commands would make it possible to pilot the gliders remotely under ice. In addition, the capability to command a glider at ranges of several hundred kilometers would make it possible to navigate them far under the ice cap, then direct them to pick-up areas at the edge of the ice, or where an ice-breaker is positioned.During this project, we will work with Arctic scientists to define requirements and applications, develop prototype signals and experimental hardware, test the signals during a cruises of opportunity, analyze the data, and then develop a first-generation test system. The results will be directly useful for WHOI scientists engaged in Arctic research.