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Note the SOFAR channel axis at ca. 750 m depth, where sound speed is shown at its lowest. The SOFAR channel (short for sound fixing and ranging channel ), or deep sound channel ( DSC ), [1] is a horizontal layer of water in the ocean at which depth the speed of sound is at its minimum. The SOFAR channel acts as a waveguide for sound, and low ...
A fish fillet processor processes fish into a fillet. Fish processing starts from the time the fish is caught. Popular species processed include cod, hake, haddock, tuna, herring, mackerel, salmon and pollock . Commercial fish processing is a global practice. Processing varies regionally in productivity, type of operation, yield and regulation.
The interactions between marine mammals and sonar have been a subject of debate since the invention of the technology. Active sonar, the transmission equipment used on some ships to assist with submarine detection, is detrimental to the health and livelihood of some marine animals. [1] Research has recently shown that beaked and blue whales are ...
Popper AN and Fay RR (1993) "Sound detection and processing by fish: critical review and major research questions" (2 parts) Brain, behavior and evolution, 41 (1): 14–25. doi:10.1159/000338719 PDF part 1 PDF part 2; Stevens, Martin (2013) Sensory Ecology, Behaviour, and Evolution Oxford University Press. ISBN 9780199601783.
A medieval view of fish processing, by Peter Brueghel the Elder (1556). There is evidence humans have been processing fish since the early Holocene. For example, fishbones (c. 8140–7550 BP, uncalibrated) at Atlit-Yam, a submerged Neolithic site off Israel, have been analysed. What emerged was a picture of "a pile of fish gutted and processed ...
Underwater acoustic communication is a technique of sending and receiving messages in water. [1] There are several ways of employing such communication but the most common is by using hydrophones. Underwater communication is difficult due to factors such as multi-path propagation, time variations of the channel, small available bandwidth and ...
Underwater acoustics (also known as hydroacoustics) is the study of the propagation of sound in water and the interaction of the mechanical waves that constitute sound with the water, its contents and its boundaries. The water may be in the ocean, a lake, a river or a tank. Typical frequencies associated with underwater acoustics are between 10 ...
The first commercial side-scan system was the Kelvin Hughes "Transit Sonar", a converted echo-sounder with a single-channel, pole-mounted, fan-beam transducer introduced around 1960. In 1963 Dr. Harold Edgerton, Edward Curley, and John Yules used a conical-beam 12 kHz side-scan sonar to find the sunken Vineyard Lightship in Buzzards Bay ...