acted on a request from NOAA's National Weather Service to 

 interrogate one of these buoys on a daily basis to obtain operational 

 weather forecasts for the Alaska region. 



In response to requests from several State and academic 

 organizations, NASA's Langley Research Center in Virginia 

 fabricated several free-drifting buoys for studies of water 

 movements near the mouth of Chesapeake Bay and along the 

 Virginia coastline. The weight of the buoys was kept below 500 

 pounds to facilitate their deployment by small ships or helicopters. 

 Techniques originally developed for the tracking of spacecraft were 

 applied to the tracking of the buoys. The buoys are of three general 

 types, classified in terms of the systems used to track their 

 movements: radio buoys, radar buoys, and satellite buoys. 



Radio buoys were used by the Virginia Institute of Marine 

 Sciences (VIMS) to study the flow of nutrients through barrier 

 island inlets, the flow of fresh water in Chesapeake Bay during the 

 aftermath of hurricane Agnes, and the drift of shelf water. The 

 movement of the buoys was tracked from an aircraft. 



Radar buoys were used to obtain information on the circulation of 

 water around Newport News Point for the Virginia Department of 

 Highways for use in the planning of the second James River bridge- 

 tunnel crossing. Radar buoys were also used by NOAA to study the 

 influence of water movement on the formation of near-shore sand 

 ridges. These buoys carried active radar transponders to permit 

 tracking with a portable van-mounted radar system on shore. 



Satellite buoys are being used by VIMS and the Woods Hole 

 Oceanographic Institution to study continental shelf circulation. 

 These buoys are equipped with transponders that work in 

 conjunction with a platform tracking and data collection system on 

 the French EOLE satellite which was launched by NASA. The most 

 productive use of free drifting buoys and the EOLE satellite was 

 made by NOAA's Atlantic Oceanographic and Meteorological 

 Laboratories in Miami, Florida. A group of buoys placed in the 

 Sargasso Sea operated successfully for periods of up to eight months 

 and provided previously unavailable information on the extreme 

 variability of surface currents in the ocean. Analysis of the results 

 indicate that if a real coherence between current measurements at 

 sea is expected, the measuring devices can be no farther apart than 

 150 km. During the sixth and seventh months of this experiment one 

 of the buoys drifted to the Mid-Ocean Dynamics Experiment 

 (MODE) area and provided an unexpected dividend to that project. 

 The transponders used in all of these experiments were loaned to 

 NASA and NOAA by the French space agency. 



Technology development in spaceborne systems for position- 

 location and data collection has advanced to the point where it will 

 be possible to produce buoy transponder packages weighing one to 

 two pounds with an operational lifetime of several months. Such a 



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