Moored Array Technology: Mooring Design Investigation for the Autonomous Ocean Sampling Network Experimental Program

摘要

The long-term goal of the Moored Array Technology program is the development and at-sea testing of new mooring and telemetry techniques for use in oceanography. Areas of concentration include mooring and buoy designs, in- water telemetry techniques, and application of emerging satellite and networking technologies. The specific objective for 1998 was the design and development of a coastal telemetry mooring to be used in conjunction with the Odyssey AUV to expand the AOSN concept. On the mooring component level, the objective in 1998 was to develop stretch hoses and stretch conductors with up to five times higher elongation levels. A stretch hose design with 150 percent elongation at maximum working loads is under construction. Such a hose will find applications for coastal telemetry moorings exposed to high sea states. The AOSN concept makes use of a variety of autonomous platforms to collect spatial and time series environmental data. These data need to be telemetered in near real time to the system users. One way to accomplish this telemetry is to moor surface buoys in the measurement area and use them as platforms for RF links to either satellites or local nodes. A difficulty with this approach has been the cost, complexity, and special-purpose nature of these moored buoy systems. Our goal in 1998 was to devise a very simple, low-cost coastal mooring system that combined flexibility and ease of use while providing the necessary telemetry links through the water and the atmosphere. Our approach was to use a small, rugged surface platform that contained an off-the-shelf RF modem that was integrated directly with one of our WHOI-developed acoustic modems. The telemetry buoys can receive and transmit acoustically as well as receive and transmit via RF. By concentrating on simplicity and ease of use, we were able to develop a coastal telemetry mooring at a cost of less than $10,000. It can be deployed from a small boat by two people.