Development of Autonomous Vehicles for Long Term Ocean Eddy Observation

摘要

Developing unmanned underwater vehicles for performing underwater operations, anddesigning 'smart' instruments, adopted to a specific ocean environment to measure sea properties and monitor a large area, are the major current challenges in marine exploration and utilization. Another significant phenomenon, requiring extensive observation through the use of smart underwater probes, is the presence of large scale vortices practically everywhere in the ocean. The need for continuous observation of such vortical patterns led to the present study for the development of underwater vehicles capable of optimum motion within a rotating gyre, for long term observation of the flow and its properties (Triantafyllou 1988). One of the principal limitations of underwater vehicles is their powering. The development of efficient, power-dense batteries is a slow process, and for immediate progress one has to turn to other improvements, such as increasing the efficiency of the propulsors. Even a very efficient vehicle, however, can not cover the three dimensional extent of a large eddy fast enough so as to map its properties globally and as they evolve in time. The necessity for a grid of vehicles to provide detailed information in a moving frame of reference (as the eddy moves erratically in the ocean, its boundaries constantly changing with time) becomes obvious after some reflection on the problem.