Acoustic communications for
deep-sea observatories

Lee Freitag
Woods Hole Oceanographic Institution

Wednesday, September 18, 2002
3:00 p.m.–Pacific Forum

Deep-Sea Observatory with acoustic communications
 for AUVs and instruments

Undersea observatories connected to shore with fiber-optic cable will provide scientists with long-term measurements from deep-ocean sensors. Proposed regional observatories include NEPTUNE which will traverse a three thousand kilometer path on the Juan de Fuca plate in the North Pacific. The NEPTUNE backbone includes nodes spaced approximately 100 kilometers apart where additional branches may be added, and a variety of sensors supporting different scientific disciplines will be located at each node and along the branches.The fiber optic and power cable creates a backbone that easily supports many smaller regions (cells) covered by wireless communication. An acoustic system extends the reach of the observatory in the area around each cell, allowing additional instruments to be added without installing dedicated cables. The utility of the wireless extension is highly dependent upon the range of the link, its energy efficiency, and the total capacity of a cell. In this talk an acoustic communication system for NEPTUNE is proposed and the issues associated with implementation and performance are explored.

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