Accession Number : ADA114492

Title :   Ocean Acoustic Tomography Mooring Design Study.

Descriptive Note : Technical rept.,

Corporate Author : CHARLES STARK DRAPER LAB INC CAMBRIDGE MA

Personal Author(s) : Scholten,James R ; Chhabra,Narender K

PDF Url : ADA114492

Report Date : Apr 1982

Pagination or Media Count : 89

Abstract : Ocean Acoustic Tomography requires deep-ocean moorings whose horizontal excursions are either small or accurately measured. The present study rigorously investigates the former case: the design of stiff moorings to meet any particular horizontal excursion goal (e.g., 25 meters) under two typical ocean current-versus-depth profiles. Moorings are considered for tomographic transmitters and receivers at depths ranging from one thousand to four thousand meters. Mooring components considered include steel sphere, glass ball, and syntactic foam buoyancy; jacketed 3 x 19 wire and electromagnetic cable; and a realistic (large) battery pack for the acoustic transmitter. Kevlar mooring line was considered and rejected. The basic tool of this study is a well-verified computer program that simulates mooring motion. Many runs of this program have yielded enough data to make plots showing mooring cost as a function of excursion, depth, and mooring type. It has been found that cost and excursion are very sensitive to the current profile. For moderate currents (15 cm/sec), placing instruments at lesser depths (1000-2000 m) is expensive ($50,000 to $100,000 for wire and buoyancy alone). Deep deployments are much less expensive (about $15,000).

Descriptors :   *Mooring, Tomography, Acoustic measurement, Oceanographic equipment, Acoustic equipment, Underwater acoustics, Deep Oceans, Mechanical cables, Buoyancy, Motion, Stability, Ocean currents, Internal waves

Subject Categories : Physical and Dynamic Oceanography

Distribution Statement : APPROVED FOR PUBLIC RELEASE