12 days under ice – an historic AUV deployment in the Canadian High Arctic

In March and April 2010, an International Submarine Engineering (ISE) Explorer Autonomous Underwater Vehicle (AUV), built for Natural Resources Canada (NRCan), was deployed to Canada's High Arctic. Its mission was to undertake under-ice bathymetric surveys in support of Canada's United Nations Convention on the Law of the Sea (UNCLOS) Outer Continental Shelf claim. During this deployment several under-ice records were broken and several new technologies were demonstrated. This achievement was in part the result of the development work that ISE and Defence Research and Development Canada (DRDC) undertook from 1993 to 1996 on the Theseus AUV during the Spinnaker program. During this program Theseus successfully completed two 200 km under-ice missions from CFS Alert on Ellesmere Island. NRCan's AUV is an ISE Explorer class vehicle, with several innovative additions to make it suitable for Arctic survey work. Most notable are a 4000 m depth rated variable ballast system, a 1500 Hz long range homing system, and under ice charging and data transfer capabilities. A Short Range Localization (SRL) system was also developed for close range positioning. The homing and SRL systems were developed by Canadian defense scientists and engineers at DRDC. The Explorer's range was extended to approximately 400 km by adding an additional hull section to accommodate extra batteries. The Main Camp near Borden Island (78°13.50'N, 112°38.87'W) was the launch site for the AUV. It was launched from an 8 m by 2.5 m ice-hole, cut through 2 - 3 m of thick ice. After several test dives its first mission was a transit to a Remote Camp, over 300 km to the northwest. The AUV autonomously homed into the Remote Camp and was successfully docked at the ice-hole where, without being removed from the water, it was charged and survey data was downloaded, all through a 1.5 m square ice hole. Subsequently, a second survey mission greater than 300 km in round trip length was undertaken, after which the AUV returned back to the Remote Camp. Finally, the vehicle embarked on a return mission to the Main Camp for recovery. From beginning to end, the AUV spent nearly 12 days under the ice before being successfully recovered. In total, close to 1000 km of under ice survey was accomplished between the AUV launch, Remote Camp mission, and recovery. The AUV reached depths of 3160 m and transited at an average speed of 1.5 m/s at an altitude of 130 m off the seabed. ISE and DRDC are now preparing for a 2011 deployment to collect additional data UNCLOS data. Aspects of the pre-deployment that will be presented include fail-safe provisions, mission planning, risk assessment, and mission logistics. Operational aspects to be discussed will include dealing with AUV operations in the extreme cold, initialization of the inertial navigation system, under-ice acoustics, acoustic homing to the recovery site and the procedures for recovery.