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A hydrophone is a sound-to-electricity transducer for use in water or other liquids, analogous to a microphone for air. Note that a hydrophone can sometimes also serve as a projector (emittor), but not all hydrophones have this capability, and may be destroyed if used in such a manner. A schematic representation of hearing. ...
Lightning strikes during a night-time thunderstorm. ...
A transducer is a device, usually electrical or electronic, that converts one type of energy to another. ...
A girl in a swimming pool Water (from the Old English waeter; c. ...
A liquid will assume the shape of its container. ...
A microphone, sometimes called a mic (pronounced mike), is a transducer that converts sound into an electrical signal. ...
History The first working sonar was built by Reginald Fessenden in the United States in 1914. It used an electromagnetic moving-coil oscillator that would emit a low frequency noise, then switch to listening mode to receive the echoes. Because of its crude technology, it could not precisely determine direction. Reginald Aubrey Fessenden (October 6, 1866 - July 22, 1932) was a Canadian inventor born in East Bolton, Quebec, the son of a Protestant minister. ...
Electromagnetism is the physics of the electromagnetic field: a field, encompassing all of space, which exerts a force on those particles that possess the property of electric charge, and is in turn affected by the presence and motion of such particles. ...
Low Frequency or LF (sometimes called longwave) refers to Radio Frequencies (RF) in the range of 30–300 kHz. ...
The first device to be called a "hydrophone" was developed when the technology matured, and used ultrasonic waves, which would provide for higher overall acoustic output, as well as increasing detection. The ultrasonic waves were produced by a mosaic of thin quartz crystals glued between two steel plates, having a resonant frequency of about 150 kHz. Contemporary hydrophones more often use barium titanate, a piezoelectric ceramic material, giving higher sensitivity than quartz. Ultrasound is sound with a frequency greater than the upper limit of human hearing, approximately 20 kilohertz. ...
Quartz is amongst one of the most common minerals in the Earths continental crust. ...
The Tacoma Narrows Bridge (shown twisting) in Washington collapsed spectacularly, under moderate wind, in part because of resonance. ...
A kilohertz (kHz) is a unit of frequency equal to 1,000 hertz (1,000 cycles per second). ...
Barium titanate is an oxide of barium and titanium with the chemical formula BaTiO3. ...
Piezoelectricity is the ability of certain crystals to generate a voltage in response to applied mechanical stress. ...
Hydrophones are an important part of the SONAR system used to detect submarines by both surface vessels and other submarines. A large number of hydrophones were used in the building of various fixed location detection networks such as SOSUS. The F70 type frigates (here, La Motte-Picquet) are fitted with VDS (Variable Depth Sonar) type DUBV43 or DUBV43C tugged sonars SONAR (SOund Navigation And Ranging) — or sonar — (British ASDIC) is a technique that uses sound propagation under water to navigate or to detect other vessels. ...
German UC-1 class World War I submarine A model of Gunter Priens Unterseeboot 47 (U-47), German WWII Type VII diesel-electric hunter-killer (SSK) submarine Typhoon class ballistic-missile carrying (SSBN) submarine, compared to a man USS Virginia, a Virginia-class nuclear attack (SSN) submarine A submarine...
SOSUS, an acronym for SOund SUrveillance System, was a chain of underwater listening posts located for the most part across the northern Atlantic Ocean near Greenland, Iceland and the United Kingdom -- the so-called GIUK gap. ...
Directional hydrophones A single cylindrical ceramic transducer can achieve near perfect omnidirectional reception. Directional hydrophones increase sensitivity from one direction using two basic techniques: A transducer is a device, usually electrical or electronic, that converts one type of energy to another. ...
Damping and reflecting This method uses a single transducer element with a dish or conical-shaped sound reflector to further focus the signals. This type of hydrophone can be produced from a low-cost omnidirectional type, but must be used while stationary, as the reflector impedes its movement through water. A transducer is a device, usually electrical or electronic, that converts one type of energy to another. ...
Arrays Multiple hydrophones can be arranged in an array so that it will add the signals from the desired direction while subtracting signals from other directions. Most commonly, arrays are arranged in a "line array." In computer programming, an array, also known as a vector or list (for one-dimensional arrays) or a matrix (for two-dimensional arrays), is one of the simplest data structures. ...
Geophysics Hydrophones are used by geologists and geophysicists in detecting seismic energy. They are combined to form streamers that are towed by seismic vessels or deployed in a borehole. Geophysics, the study of the earth by quantitative physical methods, especially by seismic reflection and refraction, gravity, magnetic, electrical, electromagnetic, and radioactivity methods. ...
References - Pike, John (1999). SOSUS Retrieved Jan. 28, 2005.
- Unknown. hydrophone Retrieved Jan. 28, 2005.
- Unknown. (2005) Oilfield Glossary: Term 'hydrophone' Retrieved Jan. 28, 2005.[[zh:This method uses a single transducer element with a dish or conical-shaped sound reflector to further focus the signals. This type of hydrophone can be produced from a low-cost omnidirectional type, but must be used while stationary, as the reflector impedes its movement through water.
A transducer is a device, usually electrical or electronic, that converts one type of energy to another. ...
Arrays Multiple hydrophones can be arranged in an array so that it will add the signals from the desired direction while subtracting signals from other directions. Most commonly, arrays are arranged in a "line array." In computer programming, an array, also known as a vector or list (for one-dimensional arrays) or a matrix (for two-dimensional arrays), is one of the simplest data structures. ...
Geophysics Hydrophones are used by geologists and geophysicists in detecting seismic energy. They are combined to form streamers that are towed by seismic vessels or deployed in a borehole. Geophysics, the study of the earth by quantitative physical methods, especially by seismic reflection and refraction, gravity, magnetic, electrical, electromagnetic, and radioactivity methods. ...
References - Pike, John (1999). SOSUS Retrieved Jan. 28, 2005.
- Unknown. hydrophone Retrieved Jan. 28, 2005.
- Unknown. (2005) Oilfield Glossary: Term 'hydrophone' Retrieved Jan. 28, 2005.
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