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Underwater acoustics

Index Underwater acoustics

Underwater acoustics is the study of the propagation of sound in water and the interaction of the mechanical waves that constitute sound with the water and its boundaries. [1]

128 relations: A-weighting, Absolute threshold of hearing, Acoustic impedance, Acoustic release, Acoustic tag, Acoustical oceanography, Albert Beaumont Wood, Alpheidae, Ambient noise level, Annales de chimie et de physique, Astroparticle Physics (journal), Audiogram, Autonomous underwater vehicle, Bandwidth (signal processing), Beamforming, Bioacoustics, Biome, Blue whale, Boric acid, Center frequency, Centre for Maritime Research and Experimentation, Cetacea, Cold War, Decade (log scale), Decibel, Deep sea, Diversity scheme, Dolphin, Doppler effect, Ear, Echo sounding, Equator, Euclidean vector, European Conference on Underwater Acoustics, Explosive material, Fin whale, Fish, France, Fred Tappert, Fresh water, Hertz, Hydroacoustics, Hydrophone, Iceberg, Intensity (physics), Jacques Charles François Sturm, Jean-Daniel Colladon, Johnson–Nyquist noise, Journal of the Acoustical Society of America, Killer whale, ..., Kilometre, Knot (unit), Lake Geneva, Latitude, Leonardo da Vinci, Lobster, Low frequency, Magnesium sulfate, Mathematician, Mechanical wave, Microphone, Millionth, Nature (journal), Naval mine, Neutrino, Noise (electronics), Ocean acoustic tomography, Ocean Tracking Network, Octave, Pascal (unit), Paul Langevin, Physical acoustics, Physicist, Piezoelectricity, Plankton, Plume (fluid dynamics), Precipitation, Pressure, Propagation loss, Radar, Rain gauge, Refraction (sound), Reginald Fessenden, Remotely operated underwater vehicle, Reverberation, RMS Titanic, Root mean square, Salinity, Scalar (mathematics), Scarlet wrasse, Seawater, Seismic source, Seismology, Side-scan sonar, Signal processing, SOFAR channel, Sonar, Sonoluminescence, Sound, Sound intensity, Sound pressure, Sound speed gradient, Spectral density, Speed of sound, Sperm whale, Submarine, Submersible, Swiss people, Target strength, Telecommunication, Telemetry, Temperate climate, Temperature, Thermocline, Tonality, Toothed whale, Transducer, Turbulence, U-boat, Underwater acoustic communication, Underwater acoustic positioning system, Viscosity, Water, Water tank, Wind, Woods Hole Oceanographic Institution, World War I, World War II. Expand index (78 more) »


A-weighting is the most commonly used of a family of curves defined in the International standard IEC 61672:2003 and various national standards relating to the measurement of sound pressure level.

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Absolute threshold of hearing

The absolute threshold of hearing (ATH) is the minimum sound level of a pure tone that an average human ear with normal hearing can hear with no other sound present.

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Acoustic impedance

Acoustic impedance and specific acoustic impedance are measures of the opposition that a system presents to the acoustic flow resulting of an acoustic pressure applied to the system.

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Acoustic release

An acoustic release is an oceanographic device for the deployment and subsequent recovery of instrumentation from the sea floor, in which the recovery is triggered remotely by an acoustic command signal.

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Acoustic tag

Acoustic tags are small sound-emitting devices that allow the detection and/or remote tracking of fish in three dimensions for fisheries research.

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Acoustical oceanography

Acoustical oceanography is the use of underwater sound to study the sea, its boundaries and its contents.

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Albert Beaumont Wood

Albert Beaumont Wood DSc (1890 – 19 July 1964), better known as A B Wood, was a British physicist, known for his pioneering work in the field of underwater acoustics and sonar.

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Alpheidae is a family of caridean snapping shrimp characterized by having asymmetrical claws, the larger of which is typically capable of producing a loud snapping sound.

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Ambient noise level

In atmospheric sounding and noise pollution, ambient noise level (sometimes called background noise level, reference sound level, or room noise level) is the background sound pressure level at a given location, normally specified as a reference level to study a new intrusive sound source.

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Annales de chimie et de physique

Annales de chimie et de physique (French for Annals of Chemistry and of Physics) is a scientific journal that was founded in Paris, France, in 1789 under the title Annales de chimie.

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Astroparticle Physics (journal)

Astroparticle Physics is a peer-reviewed scientific journal covering experimental and theoretical research in the interacting fields of cosmic ray physics, astronomy and astrophysics, cosmology, and particle physics.

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An audiogram is a graph that shows the audible threshold for standardized frequencies as measured by an audiometer.

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Autonomous underwater vehicle

An autonomous underwater vehicle (AUV) is a robot that travels underwater without requiring input from an operator.

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Bandwidth (signal processing)

Bandwidth is the difference between the upper and lower frequencies in a continuous band of frequencies.

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Beamforming or spatial filtering is a signal processing technique used in sensor arrays for directional signal transmission or reception.

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Bioacoustics is a cross-disciplinary science that combines biology and acoustics.

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A biome is a community of plants and animals that have common characteristics for the environment they exist in.

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Blue whale

The blue whale (Balaenoptera musculus) is a marine mammal belonging to the baleen whale parvorder, Mysticeti.

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Boric acid

Boric acid, also called hydrogen borate, boracic acid, orthoboric acid and acidum boricum, is a weak, monobasic Lewis acid of boron, which is often used as an antiseptic, insecticide, flame retardant, neutron absorber, or precursor to other chemical compounds.

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Center frequency

In electrical engineering and telecommunications, the center frequency of a filter or channel is a measure of a central frequency between the upper and lower cutoff frequencies.

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Centre for Maritime Research and Experimentation

Previously known as NATO Undersea Research Centre (NURC), the Centre for Maritime Research and Experimentation (CMRE) is a scientific research and experimentation NATO facility that organizes and conducts scientific research and technology development, centered on the maritime domain, to address defense and security needs of the Alliance.

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Cetacea are a widely distributed and diverse clade of aquatic mammals that today consists of the whales, dolphins, and porpoises.

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Cold War

The Cold War was a state of geopolitical tension after World War II between powers in the Eastern Bloc (the Soviet Union and its satellite states) and powers in the Western Bloc (the United States, its NATO allies and others).

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Decade (log scale)

One decade (symbol dec) is a unit for measuring frequency ratios on a logarithmic scale, with one decade corresponding to a ratio of 10 between two frequencies (an order of magnitude difference).

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The decibel (symbol: dB) is a unit of measurement used to express the ratio of one value of a physical property to another on a logarithmic scale.

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Deep sea

The deep sea or deep layer is the lowest layer in the ocean, existing below the thermocline and above the seabed, at a depth of 1000 fathoms (1800 m) or more.

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Diversity scheme

In telecommunications, a diversity scheme refers to a method for improving the reliability of a message signal by using two or more communication channels with different characteristics.

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Dolphins are a widely distributed and diverse group of aquatic mammals.

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Doppler effect

The Doppler effect (or the Doppler shift) is the change in frequency or wavelength of a wave in relation to observer who is moving relative to the wave source.

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The ear is the organ of hearing and, in mammals, balance.

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Echo sounding

Echo sounding is a type of sonar used to determine the depth of water by transmitting sound pulses into water.

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An equator of a rotating spheroid (such as a planet) is its zeroth circle of latitude (parallel).

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Euclidean vector

In mathematics, physics, and engineering, a Euclidean vector (sometimes called a geometric or spatial vector, or—as here—simply a vector) is a geometric object that has magnitude (or length) and direction.

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European Conference on Underwater Acoustics

The European Conference on Underwater Acoustics (ECUA) was a conference on underwater acoustics that took place in Europe every two years, until 2012, when it was held in Edinburgh (Scotland), and organized by the Institute of Acoustics.

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Explosive material

An explosive material, also called an explosive, is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure.

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Fin whale

The fin whale (Balaenoptera physalus), also known as finback whale or common rorqual and formerly known as herring whale or razorback whale, is a marine mammal belonging to the parvorder of baleen whales.

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Fish are gill-bearing aquatic craniate animals that lack limbs with digits.

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France, officially the French Republic (République française), is a sovereign state whose territory consists of metropolitan France in Western Europe, as well as several overseas regions and territories.

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Fred Tappert

Frederick Drach Tappert (April 21, 1940 – January 9, 2002) was an American physicist whose primary contributions were in underwater acoustics.

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Fresh water

Fresh water (or freshwater) is any naturally occurring water except seawater and brackish water.

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The hertz (symbol: Hz) is the derived unit of frequency in the International System of Units (SI) and is defined as one cycle per second.

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Hydroacoustics is the study and application of sound in water.

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A hydrophone (Ancient Greek ὕδωρ.

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An iceberg or ice mountain is a large piece of freshwater ice that has broken off a glacier or an ice shelf and is floating freely in open water.

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Intensity (physics)

In physics, intensity is the power transferred per unit area, where the area is measured on the plane perpendicular to the direction of propagation of the energy.

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Jacques Charles François Sturm

Jacques Charles François Sturm ForMemRS (29 September 1803 – 15 December 1855) was a French mathematician.

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Jean-Daniel Colladon

Jean-Daniel Colladon (15 December 1802, Geneva – 30 June 1893) was a Swiss physicist.

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Johnson–Nyquist noise

Johnson–Nyquist noise (thermal noise, Johnson noise, or Nyquist noise) is the electronic noise generated by the thermal agitation of the charge carriers (usually the electrons) inside an electrical conductor at equilibrium, which happens regardless of any applied voltage.

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Journal of the Acoustical Society of America

The Journal of the Acoustical Society of America (abbreviated J. Acoust. Soc. Am. or JASA) is a scientific journal in the field of acoustics, published by the Acoustical Society of America.

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Killer whale

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The kilometre (International spelling as used by the International Bureau of Weights and Measures; SI symbol: km; or) or kilometer (American spelling) is a unit of length in the metric system, equal to one thousand metres (kilo- being the SI prefix for). It is now the measurement unit used officially for expressing distances between geographical places on land in most of the world; notable exceptions are the United States and the road network of the United Kingdom where the statute mile is the official unit used.

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Knot (unit)

The knot is a unit of speed equal to one nautical mile per hour, exactly 1.852 km/h (approximately 1.15078 mph).

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Lake Geneva

Lake Geneva (le lac Léman or le Léman, sometimes le lac de Genève, Genfersee) is a lake on the north side of the Alps, shared between Switzerland and France.

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In geography, latitude is a geographic coordinate that specifies the north–south position of a point on the Earth's surface.

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Leonardo da Vinci

Leonardo di ser Piero da Vinci (15 April 14522 May 1519), more commonly Leonardo da Vinci or simply Leonardo, was an Italian polymath of the Renaissance, whose areas of interest included invention, painting, sculpting, architecture, science, music, mathematics, engineering, literature, anatomy, geology, astronomy, botany, writing, history, and cartography.

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Lobsters comprise a family (Nephropidae, sometimes also Homaridae) of large marine crustaceans.

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Low frequency

Low frequency (low freq) or LF is the ITU designation for radio frequencies (RF) in the range of 30 kilohertz (kHz)–300 kHz.

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Magnesium sulfate

Magnesium sulfate is an inorganic salt with the formula MgSO4(H2O)x where 0≤x≤7.

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A mathematician is someone who uses an extensive knowledge of mathematics in his or her work, typically to solve mathematical problems.

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Mechanical wave

A mechanical wave is a wave that is an oscillation of matter, and therefore transfers energy through a medium.

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A microphone, colloquially nicknamed mic or mike, is a transducer that converts sound into an electrical signal.

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One millionth is equal to 0.000 001, or 1 x 10−6 in scientific notation.

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Nature (journal)

Nature is a British multidisciplinary scientific journal, first published on 4 November 1869.

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Naval mine

A naval mine is a self-contained explosive device placed in water to damage or destroy surface ships or submarines.

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A neutrino (denoted by the Greek letter ν) is a fermion (an elementary particle with half-integer spin) that interacts only via the weak subatomic force and gravity.

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Noise (electronics)

In electronics, noise is an unwanted disturbance in an electrical signal.

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Ocean acoustic tomography

Ocean acoustic tomography is a technique used to measure temperatures and currents over large regions of the ocean.

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Ocean Tracking Network

The Ocean Tracking Network is a research effort using implanted acoustic transmitters to study fish migration patterns.

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In music, an octave (octavus: eighth) or perfect octave is the interval between one musical pitch and another with half or double its frequency.

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Pascal (unit)

The pascal (symbol: Pa) is the SI derived unit of pressure used to quantify internal pressure, stress, Young's modulus and ultimate tensile strength.

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Paul Langevin

Paul Langevin (23 January 1872 – 19 December 1946) was a prominent French physicist who developed Langevin dynamics and the Langevin equation.

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Physical acoustics

Physical acoustics is the area of acoustics and physics that studies interactions of acoustic waves with a gaseous, liquid or solid medium on macro- and micro-levels.

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A physicist is a scientist who has specialized knowledge in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe.

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Piezoelectricity is the electric charge that accumulates in certain solid materials (such as crystals, certain ceramics, and biological matter such as bone, DNA and various proteins) in response to applied mechanical stress.

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Plankton (singular plankter) are the diverse collection of organisms that live in large bodies of water and are unable to swim against a current.

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Plume (fluid dynamics)

In hydrodynamics, a plume is a column of one fluid moving through another.

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In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravity.

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Pressure (symbol: p or P) is the force applied perpendicular to the surface of an object per unit area over which that force is distributed.

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Propagation loss

In underwater acoustics, propagation loss is a measure of the reduction in sound intensity as the sound propagates away from an underwater sound source.

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Radar is an object-detection system that uses radio waves to determine the range, angle, or velocity of objects.

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Rain gauge

A rain gauge (also known as an udometer, pluviometer, or an ombrometer) is an instrument used by meteorologists and hydrologists to gather and measure the amount of liquid precipitation over a set period of time.

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Refraction (sound)

Refraction, in acoustics, comparable to the refraction of electromagnetic radiation, is the bending of sound propagation trajectories (rays) in inhomogeneous elastic media (gases, liquids, and solids) in which the wave velocity is a function of spatial coordinates.

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Reginald Fessenden

Reginald Aubrey Fessenden (October 6, 1866 – July 22, 1932) was a Canadian-born inventor, who did a majority of his work in the United States and also claimed U.S. citizenship through his American-born father.

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Remotely operated underwater vehicle

A remotely operated underwater vehicle (ROV) is a tethered underwater mobile device.

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Reverberation, in psychoacoustics and acoustics, is a persistence of sound after the sound is produced.

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RMS Titanic

RMS Titanic was a British passenger liner that sank in the North Atlantic Ocean in the early hours of 15 April 1912, after colliding with an iceberg during its maiden voyage from Southampton to New York City.

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Root mean square

In statistics and its applications, the root mean square (abbreviated RMS or rms) is defined as the square root of the mean square (the arithmetic mean of the squares of a set of numbers).

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Salinity is the saltiness or amount of salt dissolved in a body of water (see also soil salinity).

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Scalar (mathematics)

A scalar is an element of a field which is used to define a vector space.

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Scarlet wrasse

Pseudolabrus miles, the scarlet wrasse, is a species of wrasse endemic to the waters around New Zealand.

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Seawater, or salt water, is water from a sea or ocean.

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Seismic source

A seismic source is a device that generates controlled seismic energy used to perform both reflection and refraction seismic surveys.

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Seismology (from Ancient Greek σεισμός (seismós) meaning "earthquake" and -λογία (-logía) meaning "study of") is the scientific study of earthquakes and the propagation of elastic waves through the Earth or through other planet-like bodies.

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Side-scan sonar

Side-scan sonar (also sometimes called side scan sonar, sidescan sonar, side imaging sonar, side-imaging sonar and bottom classification sonar) is a category of sonar system that is used to efficiently create an image of large areas of the sea floor.

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Signal processing

Signal processing concerns the analysis, synthesis, and modification of signals, which are broadly defined as functions conveying "information about the behavior or attributes of some phenomenon", such as sound, images, and biological measurements.

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SOFAR channel

Sound speed as a function of depth at a position north of Hawaii in the Pacific Ocean derived from the 2005 World Ocean Atlas. The SOFAR channel axis is at ca. 750-m depth The SOFAR channel (short for Sound Fixing and Ranging channel), or deep sound channel (DSC), is a horizontal layer of water in the ocean at which depth the speed of sound is at its minimum.

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Sonar (originally an acronym for SOund Navigation And Ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, communicate with or detect objects on or under the surface of the water, such as other vessels.

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Sonoluminescence is the emission of short bursts of light from imploding bubbles in a liquid when excited by sound.

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In physics, sound is a vibration that typically propagates as an audible wave of pressure, through a transmission medium such as a gas, liquid or solid.

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Sound intensity

Sound intensity level also known as acoustic intensity is defined as the power carried by sound waves per unit area in a direction perpendicular to that area.

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Sound pressure

Sound pressure or acoustic pressure is the local pressure deviation from the ambient (average or equilibrium) atmospheric pressure, caused by a sound wave.

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Sound speed gradient

In acoustics, the sound speed gradient is the rate of change of the speed of sound with distance, for example with depth in the ocean, or height in the Earth's atmosphere.

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Spectral density

The power spectrum S_(f) of a time series x(t) describes the distribution of power into frequency components composing that signal.

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Speed of sound

The speed of sound is the distance travelled per unit time by a sound wave as it propagates through an elastic medium.

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Sperm whale

The sperm whale (Physeter macrocephalus) or cachalot is the largest of the toothed whales and the largest toothed predator.

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A submarine (or simply sub) is a watercraft capable of independent operation underwater.

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A submersible is a small vehicle designed to operate underwater.

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Swiss people

The Swiss (die Schweizer, les Suisses, gli Svizzeri, ils Svizzers) are the citizens of Switzerland, or people of Swiss ancestry. The number of Swiss nationals has grown from 1.7 million in 1815 to 7 million in 2016. More than 1.5 million Swiss citizens hold multiple citizenship. About 11% of citizens live abroad (0.8 million, of whom 0.6 million hold multiple citizenship). About 60% of those living abroad reside in the European Union (0.46 million). The largest groups of Swiss descendants and nationals outside Europe are found in the United States and Canada. Although the modern state of Switzerland originated in 1848, the period of romantic nationalism, it is not a nation-state, and the Swiss are not usually considered to form a single ethnic group, but a confederacy (Eidgenossenschaft) or Willensnation ("nation of will", "nation by choice", that is, a consociational state), a term coined in conscious contrast to "nation" in the conventionally linguistic or ethnic sense of the term. The demonym Swiss (formerly in English also Switzer) and the name of Switzerland, ultimately derive from the toponym Schwyz, have been in widespread use to refer to the Old Swiss Confederacy since the 16th century.

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Target strength

The target strength or acoustic size is a measure of the reflection coefficient of a sonar target.

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Telecommunication is the transmission of signs, signals, messages, words, writings, images and sounds or information of any nature by wire, radio, optical or other electromagnetic systems.

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Telemetry is an automated communications process by which measurements and other data are collected at remote or inaccessible points and transmitted to receiving equipment for monitoring.

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Temperate climate

In geography, the temperate or tepid climates of Earth occur in the middle latitudes, which span between the tropics and the polar regions of Earth.

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Temperature is a physical quantity expressing hot and cold.

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A thermocline (also known as the thermal layer or the metalimnion in lakes) is a thin but distinct layer in a large body of fluid (e.g. water, such as an ocean or lake) or air (such as an atmosphere) in which temperature changes more rapidly with depth than it does in the layers above or below.

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Tonality is the arrangement of pitches and/or chords of a musical work in a hierarchy of perceived relations, stabilities, attractions and directionality.

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Toothed whale

The toothed whales (systematic name Odontoceti) are a parvorder of cetaceans that includes dolphins, porpoises, and all other whales possessing teeth, such as the beaked whales and sperm whales.

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A transducer is a device that converts energy from one form to another.

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In fluid dynamics, turbulence or turbulent flow is any pattern of fluid motion characterized by chaotic changes in pressure and flow velocity.

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U-boat is an anglicised version of the German word U-Boot, a shortening of Unterseeboot, literally "undersea boat".

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Underwater acoustic communication

Underwater acoustic communication is a technique of sending and receiving messages below water.

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Underwater acoustic positioning system

An underwater acoustic positioning system is a system for the tracking and navigation of underwater vehicles or divers by means of acoustic distance and/or direction measurements, and subsequent position triangulation.

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The viscosity of a fluid is the measure of its resistance to gradual deformation by shear stress or tensile stress.

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Water is a transparent, tasteless, odorless, and nearly colorless chemical substance that is the main constituent of Earth's streams, lakes, and oceans, and the fluids of most living organisms.

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Water tank

A water tank is a container for storing water.

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Wind is the flow of gases on a large scale.

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Woods Hole Oceanographic Institution

The Woods Hole Oceanographic Institution (WHOI, acronym pronounced) is a private, nonprofit research and higher education facility dedicated to the study of all aspects of marine science and engineering and to the education of marine researchers.

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World War I

World War I (often abbreviated as WWI or WW1), also known as the First World War, the Great War, or the War to End All Wars, was a global war originating in Europe that lasted from 28 July 1914 to 11 November 1918.

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World War II

World War II (often abbreviated to WWII or WW2), also known as the Second World War, was a global war that lasted from 1939 to 1945, although conflicts reflecting the ideological clash between what would become the Allied and Axis blocs began earlier.

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Underwater Acoustics, Underwater sound.


[1] https://en.wikipedia.org/wiki/Underwater_acoustics

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