Sonar
Parametric sources use the non-linearity of water to generate the difference frequency between two high frequencies. A virtual end-fire array is formed. Such a projector has advantages of broad bandwidth, narrow beamwidth, and when fully developed and carefully measured it has no obvious sidelobes: see Parametric array. Its major disadvantage is very low efficiency of only a few percent.[17]. P.J. Westervelt's seminal (and brief!) 1963 JASA paper summarizes the trends involved. In theory, a parametric receiver is possible but there is no known implementation.
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See also
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Notes
- ^ The Rotary Bowcap
- ^ W Hackmann, Seek & Strike: Sonar, anti-submarine warfare and the Royal Navy 1914-54 (HMSO, London, 1984)
- ^ A. Frantzis (5 March 1998). "Does acoustic testing strand whales?". Nature 392 (392): 29. doi:.
- ^ Southall et al, Marine mammal noise exposure criteria: Initial scientific recommendations, Aquatic Mammals 33(4), 411-521 (2007).
- ^ P. D. Jepson et al. (9 October 2003). "Gas-bubble lesions in stranded cetaceans". Nature 425 (425): 575. doi:.
- ^ a b Appeals court rejects sonar waiver for Navy
- ^ Joint Interim Report Bahamas Marine Mammal Stranding Event of 15-16 March 2000. NOAA and United States Navy (December 2001). Retrieved on 2007-11-22.
- ^ LFAS / Active Sonar In the News. Act Now for Ocean Natives. Retrieved on 2007-06-23.
- ^ Natural Resources Defense Council v. United States Navy (2005-10-19). Retrieved on 2007-06-23.
- ^ US navy sonar takes precedence over whales: Bush
- ^ Navy not exempt from California sonar curbs: judge - President George W. Bush should not have exempted the Navy from obeying laws intended to protect endangered whales and other marine mammals by curbing the use of sonar off the California coast, a federal judge ruled on Monday.
- ^ Judge to Navy: Limit sonar training - Judge overrules Bush on Navy sonar training
- ^ Southall et al, Marine Mammal Noise Exposure Criteria: Initial Scientific Recommendations, Aquatic Mammals 2007, 33(4), 411-521
- ^ Proc. SPIE Vol. 3711, p. 2-10, Information Systems for Navy Divers and Autonomous Underwater Vehicles Operating in Very Shallow Water and Surf Zone Regions, Jody L. Wood; Ed. http://www.spie.org/
- ^ Lent, Keith (2002-06-26). Very High Resolution Imaging Diver Held Sonar. Storming Media. Retrieved on 2006-06-23.
- ^ Krueger, Kenneth L. (2003-05-05). Diver Charting and Graphical Display. TEXAS UNIV AT AUSTIN APPLIED RESEARCH LABS. Retrieved on 2006-06-23.
- ^ H O Berktay, Some Finite Amplitude Effects in Underwater Acoustics in V M Albers "Underwater Acoustics" 1967
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References
- "R. J. Urick, Principles of Underwater Sound, 3rd edition (Peninsula Publishing, Los Altos, 1983)"
Fisheries Acoustics References
- Fisheries Acoustics Research (FAR) at University of Washington http://www.acoustics.washington.edu/
- NOAA Protocols for Fisheries Acoustics Surveys http://www.st.nmfs.gov/st4/protocol/Acoustic_protocols.pdf
- Fisheries Acoustics (2nd Edition) http://store.blackwell-professional.com/063205994x.html
- "ACOUSTICS IN FISHERIES AND AQUATIC ECOLOGY" http://www.ifremer.fr/sympafae/
- "Hydroacoustic Protocol - Lakes, Reserviors and Lowland Rivers" (for fish assessment) http://www.pnamp.org//web/workgroups/FPM/meetings/2005_1205/2005_1202Hydroacoustics-Lakes.doc
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Bibliography
- Hackmann, Willem D. Seek & Strike: Sonar, Anti-submarine Warfare, and the Royal Navy, 1914-54. (London: HMSO, 1984)
- Hackmann, Willem D. "Sonar Research and Naval Warfare 1914-1954: A Case Study of a Twentieth-Century Science.” Historical Studies in the Physical and Biological Sciences’’ 16#1 (1986) 83-110
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External links
- Sonar Tutorial for Robots
- Profiling Sonar: Inspecting In-Service, Submerged Pipes
- Sonars and the marine environment by Norwegian Defence Research Establishment (FFI)
- Single Beam Sonars
- Sonar "Primer"
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