Preliminary Polar Sea Trials of Nereid-UI: A Remotely Operated Underwater Vehicle for Oceanographic Access Under Ice

Wednesday, 17 December 2014
Louis L Whitcomb1,2, Michael Jakuba1, Christopher R German1, Andrew Bowen1, Dana Yoerger1, James C Kinsey1, Larry Mayer1,3, Christopher McFarland2, Stefano Suman1, John Bailey1, Christopher Judge1, Stephen Elliott1, Daniel Gomez-Ibanez1, Christopher L Taylor1, Casey Machado1, Jonathan C Howland1, Carl Kaiser1, Matthew Heintz1, Clifford Pontbriand1, Loral O'Hara1, Glenn McDonald1 and Antje Boetius4,5, (1)Woods Hole Oceanographic Inst., Woods Hole, MA, United States, (2)Johns Hopkins Univ, Baltimore, MD, United States, (3)University of New Hampshire, Center for Coastal and Ocean Mapping, Durham, NH, United States, (4)Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany, (5)MARUM University Bremen, Bremen, Germany
We report the development and deployment of a remotely-controlled underwater robotic vehicle capable of being teleoperated under ice under real-time human supervision. The Nereid Under-Ice (Nereid-UI or NUI) vehicle enables exploration and detailed examination of biological and physical environments including the ice-ocean interface in marginal ice zones, in the water column of ice-covered seas, at glacial ice-tongues, and ice-shelf margins, delivering realtime high definition video in addition to survey data from on board acoustic, optical, chemical, and biological sensors. The vehicle employs a novel lightweight fiber-optic tether that will enable it to be deployed from a ship to attain standoff distances of up to 20 km from an ice-edge boundary. We conducted NUI’s first under-ice deployments during the July 2014 F/V Polarstern PS86 expedition at 86° N 6 W° in the Arctic Ocean - near the Aurora hydrothermal vent site on the Gakkel Ridge approximately 200 km NE of Greenland. We conducted 4 dives to evaluate and develop NUI’s overall functioning and its individual engineered subsystems. On each dive, dead-reckoning (Ice-locked Doppler sonar and north-seeking gyrocompass) complemented by acoustic ranging provided navigation, supporting closed-loop control of heading, depth, and XY position relative to the ice. Science operations included multibeam transects of under-ice topography, precision vertical profiles for the bio-sensor suite and IR/radiance sensor suite, IR/radiance/multibeam transects at constant depth interlaced with vertical profiles and upward-looking digital still-camera surveys of the ice, including areas rich with algal material. The fiber-optic tether remained intact throughout most of all 4 dives. Consistent with the NUI concept of operations, in 3 of 4 dives the fiber-optic tether eventually failed, and the vehicle was then commanded acoustically in a series of short-duration maneuvers to return to Polarstern for recovery. These preliminary dives ranging up to 800 m from Polarstern at a max. depth of 45 m, and traveling up to 3.7 km under moving sea ice. SUPPORT: NSF OPP (ANT-1126311), NOAA OER (NA14OAR4320158), WHOI, James Family Foundation, George Frederick Jewett Foundation East, PS86 Chief Scientist Antje Boetius, and the Captain and Crew of F/V Polarstern PS86.