Nereid UI: A Light-Tethered Remotely Operated Vehicle for Under-Ice Telepresence

Abstract

Abstract We describe a new underwater vehicle for under-ice telepresence, NereidUI (Under Ice). This paper discusses potential applications, environmental and logistical constraints, and progress to date. Based on lightdata-only fiber tether technology, Nereid UI will provide operatorswith a capability to teleoperate a ~1000 kg remotely operated vehicle (ROV)under fixed ice at ranges up to 20 km distant from a support ship or otherdeployment site under direct human supervision. When operating from anicebound support vessel, the light fiber technology permits the vehicle toremain stationary on the seafloor or maneuver freely in the water column orunder the ice while its support ship drifts with the sea ice up to 20 kmaway. Nereid UI will facilitate its recovery autonomously in theevent that the tether is severed. Prior experience with the hybrid ROVNereus 11,000 m rated vehicle, along with trade studies and conceptdevelopment devoted to Nereid UI has revealed (1) the light fiberconcept is viable in polar waters; (2) battery operation and the need totransit result in an ROV that occupies a unique trade-space with respect todrag; (3) redundant systems and a focus on reliability are necessary to avoidexpensive losses in productivity or the vehicle itself. The Nereid UIproject is supported by the National Science Foundation and the Woods HoleOceanographic Institution. Introduction Polar scientists presently lack access to effective capabilities inice-margin and under-ice environments for examining the submerged features ofice shelves, icebergs, and sea ice as well as the seafloor under iceshelves. Close-up high-resolution inspection and survey operations inthese complex under-ice environments require a tether to provide high-bandwidthtelemetry between the underwater vehicle and its human operators. Long-range light-fiber ROV tether technology, as pioneered on theNereus vehicle (Bowen et al., 2009) for 11,000 m depth operation, provides the high bandwidth (Gigabit Ethernet) link necessary for real-timecontrol under the direction of the shipboard science party, and yet retainsextreme horizontal mobility of the host vehicle. The goal of theNereid UI system is to extend this capability to the Polar Regions, providing scientific access to under-ice and ice-margin environments that ispresently impractical or infeasible and enabling operators to extract maximumbenefit from every minute spent on-site in these harsh and otherwiseinaccessible environments. Funds for the project have been awarded by theNational Science Foundation (NSF) and the Office of Polar Programs (OPP) undera Major Research Instrumentation (MRI) program. Additional cost-share has beenprivately provided by Woods Hole Oceanographic Institution (WHOI).