Towed and AUV technologies for Arctic operations

Summary

Hanumant Singh, Ryan Eustice, Susan Humphris, Michael Jakuba, Clayton Kunz, Christopher Murphy, Koichi Nakamura, Robert Reves-Sohn, Christopher Roman, Taich Sato, Timothy Shank and Claire Willis, Towed and AUV technologies for Arctic operations. In EOS: Transactions of the American Geophysical Union Fall Meeting Supplement, 2007. (Abstract).

Abstract

The 2007 AGAVE expedition included a suite of vehicles specifically designed and adapted for under-ice operations. These include the towed vehicle CAMPER, and the Puma and Jaguar autonomous underwater vehicles. The CAMPER (CAMera and samPlER) towed system was designed for high resolution imaging and sampling of the seafloor. It utilizes the oceanographic standard 0.68" electro-optical cable with three fibers and three copper conducting cables. The system consists of five cameras - a bottom looking high definition camera, a forward looking high definition camera system, a forward looking obstacle avoidance camera, a pan and tilt driving camera and a camera for instrumentation- and associated HMI and HID lighting systems. Sampling is accomplished by two hydraulically actuated systems. One of the samplers is a clam shell bucket design that is primarily intended for sampling rocks and sessile biological organisms. The other sampler uses a suction based mechanism and is intended for sampling fluids and motile biological organisms. The two AUVs, Puma and Jaguar, are identical in their base design but were outfitted with different sensor suites. These vehicles are a two hull design with most of the weight in the lower hull and most of the floatation in the top hull yielding a design that is passively stable in pitch and roll. Three thrusters, one for the vertical axis and two main thrusters allow for decoupled control in the vertical and horizontal axes. The 6 kWH battery packs are good for 24 hour operations. Both vehicles are equipped with acoustic modems, four channel long baseline receivers, doppler velocity logs, a high resolution depth sensor, three axes north seeking fiber optic gyroscopes and a pumped CTD. In addition, Puma, which is intended primarily for mid-water column work, also supports an Eh sensor, an optical backscatter sensor and an experimental long range optical backscatter sensor. The Jaguar vehicle, with a focus on near bottom measurements, is equipped with a 230 kHz multibeam, a digital still camera and strobe, a magnetometer and an Eh sensor. Several drift dives were carried out with the CAMPER towed vehicle at two different sites on the Gakkel Ridge this summer and yielded considerable high definition and video imagery as well as geological and biological samples. Several dives were also carried for mapping the mid-water column and the seafloor with the two AUVs and these successfully returned water column CTD, Eh, optical backscatter, magnetic and multibeam data.

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