Paul Spong, a renowned whale expert, built an underwater recording system — called a hydrophone — to accompany the visuals.
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The sounds are being recorded by a hydrophone (an underwater microphone) researchers placed on the seafloor in 2180.
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The hydrophone hung out there for 23 days in July 2015, recording the sounds of the world's deepest crevasse.
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When researchers finally yanked the hydrophone back above the waves, they discovered a tape far noisier than they'd expected.
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The robots also have a temperature sensor, a pressure sensor, an onboard computer and an underwater microphone called a hydrophone.
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There they placed a "titanium-encased hydrophone" into the water and let it sink over 36,000 feet to the bottom.
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The hydrophone also picked up sound from ship propellers, likely from cargo ships headed to and from Guam, China and the Philippines.
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Guests travel with a crew of veteran naturalists, a certified photo instructor, and an undersea specialist equipped with a hydrophone and underwater video camera.
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When the researchers lowered a hydrophone, or underwater microphone, into the water, they were "quite surprised at how much song we heard," Dr. Constantine said.
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Over a hydrophone, from the seabed, a puzzled scientist told the mother ship that the volcanic site bore abundant life — contrary to the usual desertlike portrayals of the deep sea.
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That tool and a hydrophone for listening to sounds underwater allowed the team to collect data about two components of the whale's song: the sound pressure and the particle motion.
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To sample the reefs, Hydra, an environmental activist who studied biology at university, suspended a hydrophone, a microphone designed to record underwater sounds, from a boat down to a coral environment.
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That agreement alleges that Click diverted the morphine and hydrophone from the company's secured inventory by surreptitiously removing vials, withdrawing the drugs from the vials, and then adding liquid to replace it.
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According to MBARI, the very low pitch of some baleen whale vocalisations can only be heard with high quality speakers or headphones — the hydrophone can pick up sounds from 10 to 128,000 Hertz.
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Once, walking along the shore in that state, he purposefully lowered a hydrophone into the mouth area of a sea anemone, which sort of swallowed the device while he recorded its audible groan.
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Next, they developed a mooring system that would lower their audio gear—a titanium-encased hydrophone—at a slow, controlled speed, so that it could acclimate to the dramatic pressure buildup during its journey.
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He'd also like to use his high-pressure hydrophone to explore other uncharted waters, including remote areas of the deep Arctic Ocean that are now starting to open up to ships as the ice caps retreat.
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A. A towed hydrophone, an underwater listening device that looks a bit like a manta ray, was lowered by a cable to listen for pulses from the data recorder, which has a range of a couple of miles.
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And after successfully planting a hydrophone in Challenger Deep, and making recordings for 23 straight days, Dziak's team had to wait until November for the weather and ship traffic to clear so they could haul it back up.
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GIF: University of Cambridge/GizmodoTo solve this mystery, Agarwal and his colleagues set up an experiment to record droplets falling into a tank of water using an ultra-high-speed camera, a microphone, and a hydrophone (a microphone that works underwater).
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The super sensitive microphone, or hydrophone, is attached to MBARI's cabled ocean observatory, the Monterey Accelerated Research System (MARS), which both powers the instrument and provides it with a data connection for relaying the sounds back to shore, 24 hours per day.
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The water pressure at a depth of 7 miles is so great that the researchers had to drop the hydrophone through the water column at just 5 meters per second or less to avoid having the ceramic instrument be crushed by the pressure change.
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"Star Factory" draws upon sounds from the Miami Museum of Science and Space Transit Planetarium, whereas "Sounding the Bay" traces Biscayne Bay through hydrophone recordings — you can hear the gurgling of fish and the sound of cars driving above — and, most fascinatingly, there is "Greater Miami 1934," which translates an old map into electronic sounds — the map is played like music.
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Optical fibers are used as hydrophones for seismic and sonar applications. Hydrophone systems with more than one hundred sensors per fiber cable have been developed. Hydrophone sensor systems are used by the oil industry as well as a few countries' navies. Both bottom-mounted hydrophone arrays and towed streamer systems are in use.
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In naval warfare, an acoustic mine is defined as one being equipped with a hydrophone that functions as a listening device. This hydrophone listens for particular noises made by any ship or vessel's machinery (propellers). It can also detects structural sounds from the hull of a passing ship. An acoustic mine is mainly operated by a sensitive diaphragm located inside the hydrophone.
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Blocking water from coming out of a given hole produces a given note, which, in some embodiments, is electrically amplified by a hydrophone. In one embodiment there is a further processing of each hydrophone signal. Embodiments with various kinds of acoustic or optical pickups are also disclosed. Some hydraulophones include an underwater hydrophone pickup to allow the sounds produced by the water to be electrically amplified.
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Wood 1930,p. 457. The scientists set two goals: to develop a hydrophone that could hear a submarine despite the racket produced by a patrol ship carrying the hydrophone and to develop a hydrophone that could reveal the bearing of the submarine. A bidirectional hydrophone was invented at East London College. They mounted a microphone on each side of a diaphragm in a cylindrical case; when the sounds heard from both microphones have the same intensity, the microphone is in line with the sound source.Wood 1930,p. 457. Bragg's laboratory made such a hydrophone directional by mounting a baffle in front of one side of the diaphragm. It took months to discover that effective baffles must contain a layer of air.Van der Kloot 2014, p. 110.
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Since the pinger signal is relatively weak, the hydrophone must be within a nautical mile (about ) to detect it. The hydrophone is typically deployed about above the ocean floor, where it can scan a swath approximately wide, on a flat, level surface.
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In 1918, airships of the Royal Naval Air Service engaged in anti-submarine warfare experimented by trailing dipped hydrophones.Report AIR 1/645/17/122/304 - National Archives Kew. Airship Hydrophone experiments. Bragg tested a hydrophone from a captured German U-boat and found it inferior to British models.
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Similar methods may be used looking upward for wave measurement. Active sonar is also used to measure distance through water between two sonar transducers or a combination of a hydrophone (underwater acoustic microphone) and projector (underwater acoustic speaker). When a hydrophone/transducer receives a specific interrogation signal it responds by transmitting a specific reply signal. To measure distance, one transducer/projector transmits an interrogation signal and measures the time between this transmission and the receipt of the other transducer/hydrophone reply.
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SM UC-3 was the first submarine to be detected and sunk using a hydrophone. On 23 April 1916 she was detected using a hydrophone, trapped in a net, and then quickly sunk after a large explosion. The ship that sank her was the anti-submarine trawler Cheerio, captained by Thomson.
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This device uses a single transducer element with a dish or conical-shaped sound reflector to focus the signals, in a similar manner to a reflecting telescope. 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 new way to direct is to use a spherical body around the hydrophone. The advantage of directivity spheres is that the hydrophone can be moved within the water, ridding it of the interferences produced by a conical-shaped element.
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In addition, the noise of the diesel engines made the U-boat's own hydrophones much less effective and it is doubtful U-864 would have heard Venturer running slowly on her electric motors. Combined with the hydrophone reports of the strange noise, which he determined to be coming from a submerged vessel, Launders surmised they had found U-864. He tracked the U-boat by hydrophone, hoping she would surface and allow a clear shot. U-864 remained at snorkel depth, and as the hydrophone plot emerged, she was seen to be zigzagging.
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Acoustically tracked floats have a hydrophone on them to produce sound. Without the sensors, a float can cost about $25,000 US.
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CMUT performance is benchmarked using pitch-catch and pulse-echo experiments, and operation uniformity is tested in air and in immersion. In a pitch-catch experiment, the transducer is benchmarked using a hydrophone, and in a pulse- echo experiment, the transducer is used both for transmitting and receiving, while comparing the measured signal to the hydrophone response.
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She was equipped with three periscopes – an attack periscope, a surveillance periscope, and an auxiliary periscope – and a hydrophone for passive sonar.
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The Gruppenhorchgerät ('group listening device', abbreviated GHG) was a hydrophone array which was used on Nazi Germany's U-boats in World War II.
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A hydrophone A hydrophone () is a microphone designed to be used underwater for recording or listening to underwater sound. Most hydrophones are based on a piezoelectric transducer that generates an electric potential when subjected to a pressure change, such as a sound wave. Some piezoelectric transducers can also serve as a sound projector, but not all have this capability, and some may be destroyed if used in such a manner. A hydrophone can detect airborne sounds, but will be insensitive because it is designed to match the acoustic impedance of water, a denser fluid than air.
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It included the Australian physicist William Henry Bragg and the New Zealand physicist Sir Ernest Rutherford. They concluded that the best hope was to use hydrophones to listen for submarines. Rutherford's research produced his sole patent for a hydrophone. Bragg took the lead in July 1916 and he moved to the Admiralty hydrophone research establishment at Hawkcraig on the Firth of Forth.
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The US installed massive Fixed Surveillance System (FSS, also known as SOSUS) hydrophone arrays on the ocean floor, to track Soviet and other submarines.
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The following unidentified sounds have been detected by the U.S. National Oceanic and Atmospheric Administration (NOAA) using its Equatorial Pacific Ocean autonomous hydrophone array.
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In July 2015, members of the National Oceanic and Atmospheric Administration, Oregon State University, and the Coast Guard submerged a hydrophone into the deepest part of the Mariana Trench, the Challenger Deep, never having deployed one past a mile. The titanium-shelled hydrophone was designed to withstand the immense pressure 7 miles under.Schneider, Kate (2016), "Eerie sounds from the bottom of the Earth", News.com.au.
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The torpedoes shot past harmlessly, two exploding on the shore, and Clyde also dived to re-load. At this point Tarrafal bay had three submarines all submerged and searching for each other by hydrophone. Into this scene Müller- Stöckheim in U-67 arrived, expecting to find his two comrades. He was alerted by the explosions ashore, and he too dived to start a hydrophone search.
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He saw service during the First World War. Having been a naval cadet, he was appointed to the temporary rank of Midshipman in the Royal Naval Reserve on 2 May 1918.The National Archives, reference ADM 240/49/4. In July 1918 he attended a hydrophone officers' course, and in August served for a short time as First Class Hydrophone Officer aboard the trawler, Ninus.
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Aberdour: Aberdour Cultural Association. (Available online). He was posted to one of the Hydrophone shore stations at Freshwater on the Isle of Wight and, in 1918, promoted to Lieutenant. He volunteered to serve in the Royal Air Force in April 1918 but was considered too important to be spared by the Hydrophone Service which was playing a crucial role in combatting German U-boat attacks.
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There are two different types of hydroacoustic stations currently used in the IMS network; 6 hydrophone monitoring stations and 5 T-phase stations. These 11 stations are primarily located in the southern hemisphere, which is primarily ocean. Hydrophone monitoring stations consist of an array of three hydrophones suspended from cables tethered to the ocean floor. They are positioned at a depth located within the SOFAR in order to effectively gather readings.
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Although researchers were unable to retrieve the hydrophone until November, the data capacity was full within the first 23 days. After months of analyzing the sounds, the experts were surprised to pick up natural sounds like earthquakes, a typhoon and baleen whales along with man-made sounds such as boats. Due to the mission's success, the researchers announced plans to deploy a second hydrophone in 2017 for an extended period of time.
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Sonobuoys are ejected from aircraft in canisters and deploy upon water impact. An inflatable surface float with a radio transmitter remains on the surface for communication with the aircraft, while one or more hydrophone sensors and stabilizing equipment descend below the surface to a selected depth that is variable, depending on environmental conditions and the search pattern. The buoy relays acoustic information from its hydrophone(s) via UHF/VHF radio to operators on board the aircraft.
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Fox News. Retrieved on 16 May 2014. On 10 April, a signal recorded by one of the sonobuoys deployed with a hydrophone at 300 metres depth was found unlikely to have originated from Flight 370.
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The crew then threw a small TNT bomb off the ship's stern. It exploded at a depth of about , and a chronograph aboard the ship automatically recorded the time the explosion was heard at the ship. The sound traveled outward from the explosion, eventually reaching hydrophones at known locations – shore stations, anchored station ships, or moored buoys – at a distance from the ship. Each hydrophone was connected to a radio transmitter that automatically sent a signal indicating the time its hydrophone detected the sound.
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She is currently a doctoral candidate at Princeton University, and has been living in Marseille, France since 2017. In her free time, Smith enjoys hiking, backpacking, birding, playing capoeira, and making underwater recordings with a hydrophone.
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Her anti- submarine features included ASDIC, a hydrophone, and four depth-charge throwers. Her deck armour was , while her side belt armour was . Upon her commissioning, Tromp was arguably the most powerful ship in the Dutch navy.
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The vocalizations are recorded by a single hydrophone. This method allows researchers to better identify signature whistles when studying wild dolphins because it can be used in situations where many dolphins emit whistles at the same time.
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Like hydrophone stations, this information is sent to the shore and transmitted via satellite link for further analysis. Hydrophone stations have the benefit of gathering readings directly from the SOFAR, but are generally more expensive to implement than T-phase stations. Hydroacoustic stations monitor frequencies from 1 to 100 Hertz to determine if an underwater detonation has occurred. If a potential detonation has been identified by one or more stations, the gathered signals will contain a high bandwidth with the frequency spectrum indicating an underwater cavity at the source.
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Tragedy struck Pioneer on 11 October 1928 when a member of her crew -- Seaman Earl Forsberg—fell overboard and drowned during a survey of Heceta Bank off the coast of Oregon. In 1934 personnel aboard Pioneer developed a deep sea hydrophone in connection with the Survey's work developing radio acoustic ranging, a system in which a small TNT bomb timed to explode at about feet,This was the surface channel, not the deeper SOFAR channel. the explosion's sound wave is registered by a hydrophone aboard and hydrophones at two or more known shore locations that then send a radio signal of arrival time back to the vessel for range calculation, to better establish positions beyond shore signal visibility. Pioneer personnel successfully used the hydrophone to a depth of off the coast of southern California in the work establishing the velocity and path of sound in the sea.
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Many vector sensor signal processing algorithms have been designed.K. T. Wong & H. Chi, "Beam Patterns of an Underwater Acoustic Vector Hydrophone Located Away from any Reflecting Boundary," IEEE Journal of Oceanic Engineering, vol. 27, no. 3, pp. 628-637, July 2002.
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A hydrophone being lowered into the North Atlantic The first hydrophones consisted of a tube with a thin membrane covering the submerged end and the observer's ear on the other end. The design of effective hydrophones must take into account the acoustic resistance of water, which is 3750 times that of air; hence the pressure exerted by a wave of the same intensity in air is increased by a factor of 3750 in water. The American Submarine Signaling Company developed a hydrophone to detect underwater bells rung from lighthouses and lightships. The case was a thick, hollow brass disc in diameter.
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SOSUS grew out of tasking in 1949 to scientists and engineers to study the problem of antisubmarine warfare. It was implemented as a chain of underwater hydrophone arrays linked by cable, based on commercial telephone technology, to shore stations located around the western Atlantic Ocean from Nova Scotia to Barbados. The first experimental array was a six-element test array laid at Eleuthera in the Bahamas in 1951, followed, after successful experiments with a target submarine, in 1952 by a fully-functional , forty- hydrophone array. At that time the order for stations was increased from six to nine.
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Identifying the vocalizer on underwater video by localizing with a hydrophone array. Animal Behavior and Cognition. 3(4): 288-298. Herzing has described a method for unbiased quantification of nonhuman intelligence which can be applied to other animals as well as dolphins.
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WASP personnel acknowledge commands with the phrase "P.W.O.R." – short for "Proceeding With Orders Received". Stingray is piloted by the square-jawed Captain Troy Tempest. He is paired with Southern navigator Lieutenant George Lee Sheridan, nicknamed "Phones" for his secondary role as Stingrays hydrophone operator.
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The torpedo armament consisted of two tube racks with a total of eight torpedo tubes. Regarding anti-submarine warfare, there was a hydrophone housed in a dome under the forebody which could be retracted into the hull when the hydrophone was not used. When a submarine was discovered, eight Bofors 375 mm rocket launchers each with a 100 kg charge and a range of 300 - 1,200 meters could be fired in a pattern around, above and below the target from two directable four-barrelled launchers. In the stern there was also a mounting with two launchrails for firing the Robot 08 anti-ship missile.
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The Directional Hydrophone Command Activated Sonobuoy system (DICASS) both generate sound and listen for it. A typical modern active sonobuoy, such as the AN/SSQ 963D, generates multiple acoustic frequencies . Other active sonobuoys, such as the AN/SSQ 110B, generate small explosions as acoustic energy sources.
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Hydrophone Listening is still one of the main methods used in bioacoustical research. Little is known about neurophysiological processes that play a role in production, detection and interpretation of sounds in animals, so animal behaviour and the signals themselves are used for gaining insight into these processes.
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A Type 93 passive hydrophone system would have been fitted in the bow. The ships were designed to carry three aircraft on a platform between the funnel and the mainmast. These would have consisted of one three-seat Aichi E13A and two two- seat Yokosuka E14Y floatplanes.
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Sound pressure or acoustic pressure is the local pressure deviation from the ambient (average or equilibrium) atmospheric pressure, caused by a sound wave. In air, sound pressure can be measured using a microphone, and in water with a hydrophone. The SI unit of sound pressure is the pascal (Pa).
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X-ray sources, for example, must be in very close proximity to the target, while lasers can illuminate a target from a high satellite orbit. While this discussion has emphasized the electromagnetic spectrum, there are also both active (e.g., sonar) and passive (e.g., hydrophone and microbarograph) acoustic sensors.
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Spectrogram of the Whistle sound According to NOAA, the Whistle is similar to volcanogenic sounds previously recorded in the Mariana volcanic arc of the Pacific Ocean, but since it was only recorded on one hydrophone rather than the three required to triangulate a location, it is considered "unidentified".
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Two AMAR G4s being deployed near Kitimat, BC, each with a hydrophone surrounded by a yellow shroud to reduce flow-induced noise over the hydrophone The successor of the AMAR G3, the AMAR G4 (Autonomous Multichannel Acoustic Recorder Generation 4) is an underwater acoustic and oceanographic data recorder with 10 TB of removable SD memory cards and Wi-Fi communications. It consists of recording electronics housed inside a watertight pressure housing. The AMAR can be connected to up to 4 hydrophones sampled at 24-bit resolution at rates up to 512 kHz Up to 7 oceanographic sensors (e.g., dissolved oxygen, salinity, acidity, temperature) can be connected, allowing the system to be used as a mini ocean observatory.
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The name was given because the sound slowly decreases in frequency over about seven minutes. It was recorded using an autonomous hydrophone array.NOAA page The sound has been picked up several times each year since 1997. One of the hypotheses on the origin of the sound is moving ice in Antarctica.
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From 1951 to 1952 Nordenskjöld was converted to frigate, with the torpedo armament and the aft gun removed and replaced by four 40 mm automatic guns m/36. Furthermore, she was equipped with equipment such as hydrophone and depth charges for anti- submarine warfare. Command center was set up and radar was installed.
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Skulski, pp. 20–21 Musashi was built with a Type 0 hydrophone system in her bow, usable only while stationary or at low speed.Skulski, p. 21 In September 1942 a Type 21 air-search radar was installed on the roof of the 15-metre rangefinder at the top of the forward superstructure.
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From 1951 to 1952 Ehrensköld was converted to frigate, with the torpedo armament and the aft gun removed and replaced by four 40 mm automatic guns m/36. Furthermore, she was equipped with equipment such as hydrophone and depth charges for anti-submarine warfare. Command center was set up and radar was installed.
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More recently a variety of techniques have been used to study these eruptions with significant developments being made since 1990. These include the use of remote controlled submersibles which can conduct surveys of the ocean floor. The use of hydrophone networks allows volcanic eruptions to be detected., NOAA (2013) Recent Submarine Volcanic Eruptions.
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In November, he shared the Nobel Prize in Physics with elder son William Lawrence. The Navy was struggling to prevent sinkings by unseen, submerged U boats. The scientists recommended that the best tactic was to listen for the submarines. The Navy had a hydrophone research establishment at Aberdour Scotland, staffed with navy men.
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At 0132 Snowflake approached a hydrophone contact, and U-532 was detected visually and on radar at a range of . U-532 launched six torpedoes. The closest one missed Snowflake by about . After U-532 dived, Snowflake dropped three depth charges on the initial ASDIC contact and ten depth charges when contact was regained at .
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Lacroix & Wells, pp. 571–72, 579–580 The first two vessels in the class (Agano and Noshiro) had a larger catapult, while the later Yahagi and Sakawa had a shorter 19-meter catapult. To detect submarines, the Aganos were equipped with a Type 93 Model 2 hydrophone installation and a Type 93 Model 3 sonar.
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By the end of the war, the British had 38 hydrophone officers and 200 qualified listeners, paid an addition 4d per day.Van der Kloot 2014, p. 125. From late in World War I until the introduction of active sonar in the early 1920s, hydrophones were the sole method for submarines to detect targets while submerged; they remain useful today.
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Researchers have studied sea hares from the lagoon of Moorea Island, French Polynesia. In the study, recordings of boat noise were made by using a hydrophone. In addition, recordings of ambient noise were made that did not contain boat noise. In contrast to ambient noise playbacks, mollusks exposed to boat noise playbacks had a 21% reduction in embryonic development.
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Newbolt 1928, pp. 361–365. On 4 April 1917 Ambuscade left the 6th Flotilla, rejoining the 4th Flotilla, now based at Devonport and employed on convoy escort duties. On 14 May 1918, Ambuscade, on patrol with and , detected a possible submarine contact with her hydrophone. She and Cockatrice attacked with depth charges with no apparent result.
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An official cover story was written that described their mission of oceanographic research. Locally, the sign at the NAVFAC Point Sur entrance indicated the station was engaged in oceanographic research. LOFARgram writers on watch floor. NAVFAC Point Sur was part of a worldwide network of shore stations connected to undersea hydrophone arrays that tracked the movement of Soviet submarines.
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Radio acoustic ranging had its origins in a growing understanding of underwater acoustics and their practical application during the early decades of the 20th century, and developed in parallel with echo sounding. The first step took place in the early 1900s, when the Submarine Signal Company invented a submarine bell signalling device and a hydrophone that could serve as a receiver of the underwater sounds the bells generated. The crew of a ship equipped with the receiving hydrophone could plot their ship's distance from the submarine bell mechanism and plot intersecting lines from two or more bells to determine the ship's position. The bells were installed at lighthouses, aboard lightvessels, and on buoys along the coasts of North America and Europe, and receiving hydrophones were mounted aboard hundreds of ships.
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Spectrogram of the train sound The Train is the name given to a sound recorded on March 5, 1997 on the Equatorial Pacific Ocean autonomous hydrophone array. The sound rises to a quasi-steady frequency. According to the NOAA, the origin of the sound is most likely generated by a very large iceberg grounded in the Ross Sea, near Cape Adare.
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Compared to a scalar pressure sensor, such as a hydrophone, which measures the scalar acoustic field component, a vector sensor measures the vector field components such as acoustic particle velocities. Vector sensors can be categorized into inertial and gradient sensors.T. B. Gabrielson, “Design problems and limitations in vector sensors,” in Proc. workshop Directional Acoustic Sensors (CD-ROM), New Port, RI, 2001.
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It is highly likely he had, in fact, spotted the U-boats snorkel. The snorkel was still a new device at that time and probably unknown to Launders and his crew. The snorkel limited the U-boat's speed and depth. For Launders' hydrophone operator to hear diesel noises from a submerged U-boat, the snorkel would have had to be in operation.
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U-864 had already left the area recommended to Launders. Unfortunately for the U-boat, U-864's commander had decided once again to return to Bergen to repair an engine noise problem. The decision would bring U-864 right back past Fedje, where HMS Venturer was lurking. Venturers hydrophone operator noticed a strange sound which he could not identify.
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Each sensor is equipped with one or more acoustic transducers depending on its specific function. Data is transmitted from the sensors using wireless acoustic telemetry and is received by a hull mounted hydrophone. The analog signals are decoded and converted by a digital acoustic receiver into data which is transmitted to a bridge computer for graphical display on a high resolution monitor.
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UC-42 sailed on her last patrol on 1 September 1917. On 31 October 1917 Torpedo Boat TB 055 was accompanying minesweepers operating at the entrance to Cork harbour. At 1500 hours an oil track was seen floating on the surface of the water. Following it to its source, TB 055 used its hydrophone to see if the oil was coming from a submarine.
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Despite being over the age for compulsory military service at the start of World War I, Mason volunteered in 1917 for service in the Royal Naval Volunteer Reserve (RNVR).Lewis Op. cit. p.262–263. He was commissioned as a sub-lieutenant in the Hydrophone Service and posted first to HMS Tarlair, the service's main research and training base at Aberdour in Fife.Maxwell D (2014) Listen Up!.
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On 15 May 1917, TB 81 was directed by a seaplane towards a submarine which the aircraft had spotted and attacked in the English Channel. TB 81 detected a possible submarine contact on her hydrophone, and waited until a submarine (possibly or ) surfaced. TB 81 gave chase, and the submarine dived. The torpedo boat dropped a depth-charge and brought up a patch of oil.
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Stille, pp. 37–38 For defense against submarines, the carrier was fitted with six depth charge throwers and carried between six and ten depth charges for them. A Type 3 sonar and a Type 93 hydrophone were fitted to detect any submarines. Two Type 94 high-angle fire-control directors, one on each side of the ship, were fitted to control the Type 89 guns.
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The deep sound channel was discovered and described independently by Maurice Ewing and J. Lamar Worzel at Columbia University and Leonid Brekhovskikh at the Lebedev Physics Institute in the 1940s. In testing the concept in 1944 Ewing and Worzel hung a hydrophone from Saluda, a sailing vessel assigned to the Underwater Sound Laboratory, with a second ship setting off explosive charges up to miles away.
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She was struck by seven shells, which caused her to catch fire, damaged the hydrophone compartment and torpedo transmitting stations and destroyed her forward gun turret. Z31s speed was not affected, but casualties were heavy, with 55 sailors killed and another 24 wounded.O'Hara (2004), pp. 255–256 After Z31 was damaged, Commander Karl Hetz on board Z34 assumed command of the 4th Destroyer Flotilla.
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Noise suppression is particularly important when assessing populations of whales as the researchers can listen to their sounds up to 20 miles away using hydrophone arrays, not relying solely on surface sightings. Research undertaken is focused on the conservation of threatened species and habitats and includes work on the problems of underwater noise, whales becoming entangled in fishing gear or in collisions with ships.
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A spectrogram of "Julia". Julia is a sound recorded on March 1, 1999 by the U.S. National Oceanic and Atmospheric Administration (NOAA). NOAA said the source of the sound was most likely a large iceberg that had run aground off Antarctica. It was loud enough to be heard over the entire Equatorial Pacific Ocean autonomous hydrophone array, with a duration of about 15 seconds.
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Seismic waves are studied by geophysicists called seismologists. Seismic wave fields are recorded by a seismometer, hydrophone (in water), or accelerometer. The propagation velocity of seismic waves depends on density and elasticity of the medium as well as the type of wave. Velocity tends to increase with depth through Earth's crust and mantle, but drops sharply going from the mantle to the outer core.
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The explosions were taken to be premature explosions of mines caught in the nets. As dark fell more explosions were heard, two green rockets were spotted at the east end of the net line and more explosions were heard. On 3 October, hydrophones detected a submarine at the west end of the nets, an explosion and then silence. Other boats' hydrophone sets gave similar indications.
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Stretched between the towers would be improved anti-submarine nets; each tower would be equipped with two 4-inch guns, searchlights and hydrophone detection equipment. Gibb had worked with T G Menzies and Colonel William McLellan on a submarine detection system based on a galvanometer, which was also to be incorporated.Engineering Timelines: Guy Maunsell There would be accommodation for 100 men on each of the towers.
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Early in the war, French President Raymond Poincaré, himself a physicist, provided Paul Langevin with the facilities needed to work on a method to locate submarines by the echos from sound pulses. They developed a piezoelectric hydrophone by increasing the power of the signal with a vacuum tube amplifier; the high acoustic impedance of piezoelectric materials facilitated their use as underwater transducers. The same piezoelectric plate could be vibrated by an electrical oscillator to produce the sound pulses.Van der Kloot, 2014, pp. 110-112. The first submarine to be detected and sunk using a primitive hydrophone was the German submarine UC-3 on 23 April 1916. UC-3 was detected by the anti-submarine trawler Cheerio as the Cheerio was directly over the UC-3, the UC-3 was then caught in a steel net dragged by the trawler, and sank after a large underwater explosion.
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At the distances involved – generally less than – each of these radio signals arrived at the ship at essentially the same instant that each of the remote hydrophones detected the sound of the explosion. The ship's chronograph automatically recorded the time each radio signal arrived at the ship. By subtracting the time of the explosion from the time of radio signal reception, the ship's crew could determine the length of time the sound wave required to travel from the point of the explosion to each remote hydrophone and, knowing the speed of sound in the surrounding sea water, could multiply the sound's travel time by the velocity of sound in sea water to determine the distance between the explosion and the hydrophone. By determining the distance to at least two remote hydrophones in known locations, the ship's crew could use true range multilateration to fix the ship's position.
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Although snorkels allowed submarines to use their diesel engines while submerged, their use had limitations and problems. U-boats with their snorkels raised were limited to six knots to avoid damaging or breaking the tube. The Gruppenhorchgerät (the boat's hydrophone array) was useless while running diesel engines submerged. However, the most dramatic effect caused by the use of snorkels was their ability to create partial vacuums within the submarine.
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The fatigue crack had grown over time from a hydrophone port in the bracing tube. Judging by paint on part of the fractured surface the crack was probably due to improper labour at the plant in Dunkirk, France, where the rig was built in 1976. Other major structural elements then failed in sequence, destabilising the entire structure. The design of the rig was flawed owing to the absence of structural redundancy.
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The AMAR G3 (Autonomous Multichannel Acoustic Recorder Generation 3) is an underwater acoustic and oceanographic data recorder. It consists of recording electronics housed inside a watertight pressure housing. The AMAR can be connected to up to 8 hydrophones sampled at 24-bit resolution at rates up to 128 kHz, and another high-frequency hydrophone sampled at 16-bit resolution at rates up to 687.5 kHz. Oceanographic sensors (e.g.
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Spectrogram of the Upsweep sound Upsweep is an unidentified sound detected on the American NOAA's equatorial autonomous hydrophone arrays. This sound was present when the Pacific Marine Environmental Laboratory began recording its sound surveillance system SOSUS in August, 1991. It consists of a long train of narrow-band upsweeping sounds of several seconds in duration each. The source level is high enough to be recorded throughout the Pacific.
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Although multiple hydrophones are used, signature identification uses a single hydrophone and allows better identification. Variation between signature whistles can be tested by examining the whistle contours frequency modulation pattern. A frequency modulation pattern differs between dolphins, which is usually identified by using standard acoustic parameter measurements, such as beginning, end, maximum or minimum frequency. Combining the measurements of the frequencies will show the modulation pattern of the individuals signature whistle.
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At some points the hydrographic equipment aboard Tautog registered zero distance between the submarines. At another point "Tautog's" hydrophone operators assumed the K-108 had risen to near the surface, placing the Soviet submarine directly above Tautog. Then the operators determined the Soviet vessel was descending. The trace on the oscilloscope, that gave the American submariners at visual reference as to the distance of the K-108, disappeared.
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As Venturer continued her patrol of the waters around Fedje, her hydrophone operator noticed a strange sound which he could not identify. He thought that the noise sounded as though some local fisherman had started up a boat's diesel engine. Launders decided to track the strange noise. Then the officer of the watch on Venturer's periscope noticed what they thought was another periscope above the surface of the water.
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The floats consist of 8 cm by 1.5 to 2.2 m long glass pipe that contain a hydrophone, signal processing circuits, a microprocessor, a clock and a battery. A float weighs about 10 kg. The lower end is sealed with a flat aluminium endplate where all electrical and mechanical penetrators are located. The glass thickness is about 5 mm, giving the float a theoretical maximum depth of about 2700 m.
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One torpedo had found its mark on the battleship's bow, which caused flooding of the hydrophone compartment and 18 casualties. Toward sunset, the submarine lost contact with the formation. Later that night, she encountered what she thought to be the same force and was held down for two hours by one of the escorting ships. Hits by two of Tunnys torpedoes had damaged but failed to slow the powerful battleship.
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Such radio navigation systems were easier to maintain than hydrophone stations and did not require the handling of explosives and, as the new systems matured, the Coast and Geodetic Survey began to apply them to maritime navigation. Radio acoustic ranging appears not to have been used after 1944, and by 1946, Coast and Geodetic Survey ships had switched over to the new SHORAN electronic navigation technology to fix their positions.
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In deep waters, such as those that prevailed in the Pacific Ocean along the United States West Coast, the Coast and Geodetic Survey could rely upon shore stations to support radio acoustic ranging because the deep water allowed sound to travel to the coast. Along the United States East Coast, where shallower waters prevailed, sound had greater difficulty in reaching the coast, and the Coast and Geodetic Survey relied more heavily on anchored station ships, and later moored buoys, to support radio acoustic ranging. Chronographs recorded times to the hundredth of a second, and the crew of a ship using radio acoustic ranging could determine their ship's distance from the remote hydrophone stations to within , allowing them to plot their ship's position with great accuracy for the time. With sound waves traveling from the point of the explosion to the distant hydrophones at about , ships occasionally used radio acoustic ranging at distances of over between ship and hydrophone station, and distances of were common.
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At 13:05 the U-boat estimated that it was now about eight miles ahead of the convoy and submerged to use her hydrophones, proceeding dead slow at a depth of . On detecting propeller noise, the U-boat altered course to approach the convoy. After half an hour the hydrophone operator heard faint propeller noises approaching. The U-boat altered course again and after 15 minutes the operator again reported oncoming propeller noises.
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248, 545 Early warning would have been provided by a Type 2, Mark 2, Model 1 radar mounted at the top of the foremast. A Type 93 passive hydrophone system was intended be fitted in the bow. The cruisers were designed to carry three aircraft on a platform between the funnel and the mainmast. These would have consisted of a single three-seat Aichi E13A and a pair of two-seat Yokosuka E14Y floatplanes.
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Purely from the standpoint of detection, towed hydrophone arrays offer a long baseline and exceptional measurement capability. Towed arrays, however, are not always feasible, because when deployed, their performance can suffer, or they can suffer outright damage, from fast speeds or radical turns. Steerable sonar arrays on the hull or bow usually have a passive as well as active mode, as do variable- depth sonars Surface ships may have warning receivers to detect hostile sonar.
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Cavitation numbers of 0.5 (minimum) to 23 (maximum) can be accommodated for. Measurements can be taken using a 3 Watt, water-cooled, Argon-ion laser, a hydrophone, and two dynamometers. A high-speed video camera is also attached with an imaging frequency of 1–10,000 frames per second. Funding for the tunnel's equipment is raised by numerous organisations, including the Engineering and Physical Sciences Research Council (EPSRC) and the Scottish Universities of Glasgow and Strathclyde.
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The biggest challenge FSK faces in the UAC is multi-path reflections. With multi-path (particularly in UAC) several strong reflections can be present at the receiving hydrophone and the threshold detectors become confused, thus severely limiting the use of this type of UAC to vertical channels. Adaptive equalization methods have been tried with limited success. Adaptive equalization tries to model the highly reflective UAC channel and subtract the effects from the received signal.
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The piece addresses the issues of the sexual needs of people who have a physical, social and/or mental disability or handicap. Together with her husband Jonathan Loyche (né Gröger), she made Sonic Shanty, one of the Art Shanty Projects on White Bear Lake, Minnesota, in 2016. It is a hexagonal hut on the ice with a speaker connected to a hydrophone under the ice, reproducing the surrounding sounds. Piano wires resonate at the center.
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Launders tracked U-864 by hydrophone (in itself a difficult feat), hoping it would surface and allow a clear shot. However, U-864 detected the presence of the British submarine and remained submerged and started to zig-zag. This made U-864 quite safe according to the assumptions of the time. After several hours, it became clear that the U-boat was not going to surface, but Launders decided to attack anyway.
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In November 1915, two young physicists were added to its staff. Bowing to outside pressure for using science, in July 1916, the Admiralty appointed Bragg as scientific director at Aberdour, assisted by three additional young physicists. They developed an improved directional hydrophone, which convinced the Admiralty of their usefulness. Late in 1916, Bragg with his small group moved to Harwich, where the staff was enlarged and they had access to a submarine for tests.
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The Poles thought they were attacking an enemy submarine, but luckily the torpedoes missed their target. Unshaken captured the Italian submarine Menolti on the night that Italy ceased hostilities and escorted her to Malta. Lieutenant Commander Jack Whitton, Unshakens commander, ordered the boat to surface after her hydrophone operator reported 'high speed revs'. He then decided to board the Italian vessel as her bridge was crowded with people and could not dive quickly.
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The ships were forced to zigzag to avoid ice floes. At 19:22, hydrophone and radar operators aboard the German warships detected the cruiser at a range of approximately . Prinz Eugens radio- intercept team decrypted the radio signals being sent by Suffolk and learned that their location had been reported. Lütjens gave permission for Prinz Eugen to engage Suffolk, but the captain of the German cruiser could not clearly make out his target and so held fire.
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Asama Maru was placed back in served as a troopship and transport, shuttling men and supplies from Japan to various points in Southeast Asia. On 10 October, she was assigned to carry 1000 Allied prisoners of war from Makassar to Nagasaki. This was the first of several voyages to transport Allied prisoners, which would later earn Asama Maru the epithet of "hell ship." In February 1943, Asama Maru was fitted with a hydrophone and rack for 16 depth charges.
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In 2000 he played with Matthew McConaughey and Jon Bon Jovi in the movie U-571 as the German Hydrophone Operator. He also appeared in the German movie Hitlerkantate in 2005. While in international productions he has only been cast in supporting roles, in his German films he has played leading characters, too. Klawitter is often chosen to play in historical films because of his slightly old fashioned appearance that can be compared to that of Ralph Fiennes.
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The sound appears to be seasonal, generally reaching peaks in spring and autumn, but it is unclear whether this is due to changes in the source or seasonal changes in the propagation environment. The source can be roughly located at , near the location of inferred volcanic seismicity, but the origin of the sound is unresolved. The overall source level has been declining since 1991, but the sounds can still be detected on NOAA's equatorial autonomous hydrophone arrays.
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Approximate map of the 52-hertz whale's migration range The 52-hertz whale was discovered by a team from the Woods Hole Oceanographic Institution. Its call was first detected in 1989, then again in 1990 and 1991. In 1992, following the end of the Cold War, the U.S. Navy partially declassified the recordings and technical specifications of its SOSUS anti- submarine hydrophone arrays, and made SOSUS available for oceanographic research. , the whale had been detected every year since.
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Each hydrophone records 250 samples per second, while the tethering cable supplies power and carries information to the shore. This information is converted to a usable form and transmitted via secure satellite link to other facilities for analysis. T-phase monitoring stations record seismic signals generate from sound waves that have coupled with the ocean floor or shoreline. T-phase stations are generally located on steep-sloped islands in order to gather the cleanest possible seismic readings.
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Halpern p424-427 In 1918 the USN embarked on a mammoth scheme to create a barrage across the routes exiting the North Sea. The North Sea Mine Barrage saw the laying of over 70,000 mines during the summer of 1918. From September to November 1918 6 U-boats were sunk by this measure.Halpern p438-441 The RN also developed the R-class submarine, designed as a hunter-killer vessel, with a high underwater speed and sophisticated hydrophone system.
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Signature whistles are difficult to identify because bottlenose dolphins emit non-signature whistles as well. However, there is a distinct amount of time in between each signature whistle that helps researchers distinguish them from the rest of dolphin noises. Signature whistles are emitted within 1 to 10 milliseconds of each other, while non-signature whistles occur with longer or shorter intervals between each whistle. This distinction can be used to identify signature whistles in hydrophone recordings.
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AUVs carry sensors to navigate autonomously and map features of the ocean. Typical sensors include compasses, depth sensors, sidescan and other sonars, magnetometers, thermistors and conductivity probes. Some AUVs are outfitted with biological sensors including fluorometers (also known as chlorophyll sensors), turbidity sensors, and sensors to measure pH, and amounts of dissolved oxygen. A demonstration at Monterey Bay, in California, in September 2006, showed that a diameter AUV can tow a -long hydrophone array while maintaining a cruising speed.
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Although Jenssen never regretted his approval for use of the track, he also never sought this kind of fame and subsequently turned down various requests by his record company and peers to collaborate with well-known techno and drum 'n bass artists or to create a follow-up album in the same style. During that same year, Biosphere contributed the song "The Seal and the Hydrophone" exclusively to Apollo 2 – The Divine Compilation released by Apollo Records.
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The ships also had two rotating quadruple torpedo launchers on the upper deck for Type 93 (Long Lance) torpedoes on the centerline and had a reload system with eight spare torpedoes. The Agano-class ships were also fitted with a pair of Aichi E13A floatplanes and a catapult.Lacroix & Wells, pp. 571–72, 579–580 To detect submarines, the Aganos were equipped with a Type 93 Model 2 hydrophone installation and a Type 93 Model 3 sonar.
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A 1936 U.S. Coast and Geodetic Survey illustration of a "radio-sonobuoy." The buoys entered service in July of that year. USC&GS; Pratt putting to sea to serve as a hydrophone station ship for the survey ship USC&GS; Hydrographer during radio acoustic ranging operations in the Gulf of Mexico sometime between 1933 and 1937. She flies the United States Coast and Geodetic Survey flag from her mast and the national ensign at her stern.
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The ship collected gravity and magnetics data on the seafloor; created seismic images of rock layers below the ocean floor; dredged rock samples; took ocean-floor sediment cores (creating what is now a collection of over 13,000 cores); mapped the ocean floor with sonar; and collected water samples to explore ocean currents, temperature, salinity, marine life and other data for a wide range of oceanographic research. During the spring and summer of 1963 the ship worked with Submarine Development Group 2 as that group searched the ocean floor for traces of the submarine . In 1974 the ship was equipped with four airguns and a 24-channel hydrophone array for multichannel seismic surveying with upgrades to ten airguns and a , 160-channel hydrophone array by retirement in 1989 at which time the ship had logged over one million nautical research miles. A primary mission of the ship was collection of seismic profiles showing geological features below the ocean floor sediments as part of the laboratory's Marine Geology and Geophysics program initiated by Maurice Ewing with the R/V Vema in 1949.
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The term tonpilz or "acoustic mushroom" may refer to a certain type of underwater electro-acoustic transducer. By sandwiching active (i.e. piezoelectric or magnetostrictive) materials between a light, stiff radiating head mass and a heavy tail mass, the transducer can effectively operate as either a projector (source) or a hydrophone (underwater acoustic receiver). The transducer's size, odd shape, and acoustic projection capabilities have earned it the moniker "tonpilz", from the German words Ton (tone) and Pilz (mushroom) and from the figurative similarity.
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These were dual-purpose guns capable of attacking both surface and aircraft targets. Anti-aircraft protection was by four Type 96 anti-aircraft guns in two twin-gun mounts abreast the bridge. The Mikura class was initially armed with 120 Type 95 depth charges with two Type 94 depth charge launchers and had a Model 93 sonar and a Type 93 hydrophone. Later in the war, a third Type 94 depth charge launcher was added on the stern and the paravanes were removed.
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Surveys by the submersible Alvin in 1966 and 1967 found multiple float failures with collapsed modules and other damage to standing modules. The major technological limitation was found to be computing capability, particularly speed, that forced use of analog devices for beam steering and signal processing. Results in acoustics formed the basis for extensive ocean acoustics research going forward after the project's termination in the mid 1960s. The project successfully proved techniques for developing and deploying high powered, phased active hydrophone arrays.
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The captain ordered the U-boat to rise to periscope depth. Unknown to U-353, this was the destroyer , about two miles ahead of Convoy SC 104, which had gained a firm Asdic (sonar) contact, and increased speed to 15 knots to intercept the U-boat. Suddenly there was a series of ear-splitting explosions, as Fame dropped a pattern of 10 depth charges. The lights in U-353 went out and water entered forward and aft through the hydrophone shafts.
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There, he could cover enemy movements from Palermo. On 24 July he spotted and engaged a transport with a single destroyer escort. He dived and fired three torpedoes at 5,000 yards, one of which struck and his victim, the 5,000-ton Dandolo sank. The destroyer dropped 17 depth charges over two hours and attempted a hydrophone hunt, but Wanklyn dived to 150 feet and retired to the north-west. His score now stood at 67,000 tons of enemy shipping sunk.
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Loud mechanical sounds, of "hammering" and "turbine-like noises" were reported and, believing this to be a U-boat, a marker buoy was dropped, followed shortly after by a depth charge. Following detonation of the charge, TB 055 returned to the area and found that the volume of floating oil had increased, and there were bubbles rising to the surface. TB 055 signalled the nearby armed minesweeper HMT Sarba for assistance. Sarba used her hydrophone but detected no sounds from the presumed submarine.
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80 Additional torpedo tubes and hydrophone installation was ordered. As a result of the design changes placed on the ship mid-construction, the vessel that entered the water in 1920, was a badly overloaded design that, even at the beginning, had been rather tight. The ships were insufficiently insulated, too hot in the tropics and too cold in the north. Sacrifices in weight savings in the name of increased speed led to severe compromise in the habitability of the ship.
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A hydrophone is a seismic receiver that is typically used in marine seismic acquisition, and it is sensitive to changes in pressure caused by acoustic pulses in its surrounding environment. Typical hydrophones utilise piezoelectric transducers that, when subjected to changes in pressure, produce an electric potential which is directly indicative of pressure changes. As is the case with air- guns, hydrophones are often also employed in groups or arrays which comprise of multiple hydrophones wired collectively to ensure maximum signal-to-noise ratio.
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At 19:22, hydrophone and radar operators aboard the German warships detected the cruiser at a range of approximately . Prinz Eugens radio-intercept team decrypted the radio signals being sent by Suffolk and learned that their location had indeed been reported. Admiral Lütjens gave permission for Prinz Eugen to engage Suffolk, though the captain of the German cruiser could not clearly make out his target and so held fire. Suffolk quickly retreated to a safe distance and shadowed the German ships.
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Damage to USS Hartfords rudder. Navy divers from USS Emory S. Land inspected Hartford the next day and found large areas of the hull scraped down to bare metal. Sound damping anechoic tiles had been ripped away, metal grates over the ballast tanks had been badly distorted and the passive sonar hydrophone system damaged in three separate locations. The worst damage was at the aft end of the boat, where the rocks had torn off the bottom part of the rudder.
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The U-boat threat lessened in 1917, when merchant ships began travelling in convoys, escorted by destroyers. This tactic made it difficult for U-boats to find targets, which significantly lessened losses; after the hydrophone and depth charges were introduced, accompanying destroyers could attack a submerged submarine with some hope of success. Convoys slowed the flow of supplies, since ships had to wait as convoys were assembled. The solution to the delays was an extensive program of building new freighters.
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Once located, the beacon and its attached recorders can be retrieved by divers, submersibles or remotely operated vehicle (ROV), depending on depth. A model currently used by the United States Navy is the TPL-25, which has a weight of and a length of ; it is generally towed at . Most beacons transmit a pulse once a second at 37.5 kHz. The hydrophone must be positioned below the thermocline layer which reflects sounds, either back to the surface or back to the ocean floor.
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Additional eruptions at Macdonald occurred between June 1987 – December 1988, and a seismic swarm probably unassociated with eruptions occurred in 2007. Eruptions at Macdonald include phreatic and phreatomagmatic activity which led to the formation of lapilli and lava bombs and also to the hydrophone signals, but also effusive eruptions forming lava flows. Volcanic activity is not steady, with prolonged pauses observed between eruptions. Macdonald seamount is among the most active submarine volcanoes in the world, and the most active on the floor of the Pacific Ocean.
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The Leningrads were given a square stern with ramps to facilitate minelaying. They could carry 68 Model KB, 84 Model 1926 or 115 Model 1912 mines. Although no sonar was initially fitted, just the Arktur hydrophone system that was useless at speeds above three knots, they carried 20 B-1 and 32 Model 1931 depth charges. At some point during the war Baku, Minsk, Leningrad and Tbilisi were fitted with British Lend-Lease ASDIC (sonar), Type 285 fire control radars and American SG air search radars.
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The sensitivity of a microphone is usually expressed as the sound field strength in decibels (dB) relative to 1 V/Pa (Pa = N/m2) or as the transfer factor in millivolts per pascal (mV/Pa) into an open circuit or into a 1 kilohm load. The sensitivity of a loudspeaker is usually expressed as dB / 2.83 VRMS at 1 metre. This is not the same as the electrical efficiency; see Efficiency vs sensitivity. The sensitivity of a hydrophone is usually expressed as dB re 1 V/µPa.
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Western Electric and ONR representatives met on 29 October 1950 to draft a contract that was signed as a letter contract on 13 November to build a demonstration system. The contract was managed by Bureau of Ships (BuShips) with then Ensign Joseph P. Kelly, later Captain and termed "Father of SOSUS," assigned. An experimental six-element hydrophone array was installed on the island of Eleuthera in the Bahamas during 1951. Meanwhile, Project Jezebel and Project Michael focused on studying long range acoustics in the ocean.
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Within a few moments of these changes, a third group of U-boats was formed to swing out to the southeast of the Neptun-Ritter line and cut off any southerly diversion of the convoy. s hydrophone made contact with the convoy's screws. Convoy ON 166 had received three diversions by 17–18 February 1943, sent by the Admiralty using Naval Cypher No. 3 (recyphered using table S), and attempted to proceed in south. That Tranow had known about the convoy was unquestioned in the Admiralty.
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The submarines saw the convoy but were unable to maneuver to attack position. In December 1941, after the Soviets had evacuated Hanko, Iku-Turso was docked for the winter. Though Iku-Turso had not had much chance of using its torpedoes, the experiences from other Finnish subs were that the Italian torpedoes used (Finnish designation T/40) were unreliable. During 1942, Iku-Turso was upgraded with new 12-hydrophone listening arrays and equipped with a depth charge rack capable of carrying 4 depth charges.
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A mere 15 minutes later the submarine sighted another Soviet convoy, this time headed due West, but had no loaded tubes and was unable to engage it. During 1942 Vetehinen was upgraded with new 12-hydrophone listening arrays and equipped with a depth charge rack capable of carrying four depth charges. The submarine was further modified by streamlining the tower and moving the 20 mm gun up to the tower. On 5 November 1942, Vetehinen rammed the in the Sea of Åland and sank it.
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In operation, an electrical impulse from a transmitter is converted into a sound wave by an underwater transducer, called a hydrophone, and sent into the water. When the wave strikes something such as a fish, it is reflected back and displays size, composition, and shape of the object. The exact extent of what can be discerned depends on the frequency and power of the pulse transmitted. Knowing the speed of the wave in the water, the distance to the object that reflected the wave can be determined.
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Foxhound remained based at Buncrana in April 1918, but by June, Foxhound had joined the 4th Destroyer Flotilla, based at Devonport, Plymouth. In July 1918, Foxhound took part in an operation to intercept a German cruiser submarine reported by intelligence to be returning to Germany. Foxhound led one of five divisions of hydrophone-equipped trawlers deployed between the Faroe Islands and Shetland. While two of the other divisions detected signs of a submarine, and the destroyer dropped several depth charges, the submarine escaped the hunting force.
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The company has sold autonomous and weatherproof battery operated recorders called Song Meters for monitoring birds, frogs and other wildlife since 2007. The device can record for up to 230 hours spread out over months and can be programmed to record at specific times of day.About Us section at official website. In addition to the standard omnidirectional microphone, the company also sells a directional microphone for recording night flight calls of migrating birds as well a hydrophone that can be attached for monitoring underwater.
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She narrowly escaped four torpedoes fired at her by on 10 March off of Takao (now Kaohsiung), but was alerted in time by her hydrophone operator and was able to take evasive action. On 23 February 1944, she was slightly damaged in an attack by in the South China Sea 20 miles east of Taiwan. The oiler Nanpo Maru was sunk by Grayback in the same attack. In October 1944, Asama Maru was one of the ships in a major convoy transporting elements of the Imperial Japanese Army’s 1st Division from China to the Philippines.
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As a measure against submarine attack, the battleship HMS Hood was scuttled across the harbour's southern entrance in 1914. In 1917 the RNAS seaplane base at Portland was commissioned as HMS Sarepta. It was decommissioned two years later, but not before the establishment under its command of a 'listening school' to help develop hydrophone underwater listening devices and other anti-submarine measures, and to train personnel in their use. Its shore-based activities continued, moving from temporary accommodation in Weymouth to accommodation in East Weare, just south of the Dockyard.
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At the top of the island, Ibuki was planned to have a rangefinder and a Type 21 radar. In 1944, the radar was moved to a retractable mount in the flight deck near the bow and a Type 22 surface search and a Type 13 early-warning radar were going to be installed on the island. The ship retained the Type 93 hydrophone system. The ship's air group was intended to consist of 27 aircraft, 15 Mitsubishi A7M Reppū (Allied codename: "Sam") fighters and a dozen Aichi B7A Ryusei ("Grace") dive/torpedo bombers.
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Modern submarines have multiple passive hydrophone systems, such as a steerable array in a bow dome, fixed sensors along the sides of the submarines, and towed arrays. They also have specialized acoustic receivers, analogous to radar warning receivers, to alert the crew to the use of active sonar against their submarine. US submarines made extensive clandestine patrols to measure the signatures of Soviet submarines and surface vessels. This acoustic MASINT mission included both routine patrols of attack submarines, and submarines sent to capture the signature of a specific vessel.
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By early 1944 the Shipping Artillery Regiment had been reorganised into two units, the 1st and 2nd Shipping Artillery Regiments. The 1st Shipping Artillery Regiment was based in Japan. The 2nd Shipping Artillery Regiment was initially based in Singapore, but moved to Manila in the Philippines in July 1944. Each regiment's table of organisation strength was 15 anti-aircraft batteries, three light anti- aircraft batteries, three surface gun batteries, two sea watch companies, a mortar company, a machine gun company, a depth charge company, a hydrophone company and an air watch company.
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SOSUS systems consisted of bottom-mounted hydrophone arrays connected by underwater cables to facilities ashore. The individual arrays were installed primarily on continental slopes and seamounts at the axis of the deep sound channel and normal to the direction in which they were to cover. The combination of location within the ocean and the sensitivity of arrays allowed the system to detect acoustic power of less than a single watt at ranges of several hundred kilometres. SOSUS shore terminal processing stations were designated with the vague, generic name of Naval Facility (NAVFAC).
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24 hours later U-889 was turned over to the frigates and who escorted her to Shelburne Harbour where she was boarded and Braeucker, her commanding officer, made a formal surrender. On 14 May 1945, U-889 was commissioned into the RCN and decommissioned in December 1945. U-889 was one of ten U-boats allocated to the United States as part of the Tripartite Naval Commission sitting in Berlin in November 1945. She sailed to Portsmouth, New Hampshire on 11 January 1946 and experiments were conducted on her special hydrophone gear.
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The Centre started testing the first experimental hydrophone linear array built by Hughes Aircraft Corporation, on loan from the U.S. Office of Naval Research. Noise generated by the towing vessel proved to be the ultimate limiting factor. However the directionality (due to its length) and the possibility of positioning it at the optimal depth, as well as its passive and active capabilities, were the main advantages highlighted by tests. Based on studies carried out in 1976, two years later the Bistatic Active Towed Array (BITOW) sonar programme was launched.
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The Italian cruisers were heard first by hydrophone and then seen through the periscope at 07:25, heading north between the islands of Filicudi and Panarea. The ships were making with eight destroyer escorts and two CANT Z.506 aircraft overhead. Her commander raised the periscope for only short periods, to avoid being seen by the destroyers and the Cants, while manoeuvring into an attack position. At 08:05, the cruisers slowed to for Gorizia to fly off a seaplane and then the destroyer Fuciliere machine-gunned a periscope seen at .
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Herbert returned to duty on Q-ships, commanding a flotilla of four trawlers – the Sea King, Sea Sweeper, Nelly Dodds and W. H. Hastie. These were equipped with the recently introduced hydrophone technology and, while patrolling off the coast of The Lizard in Cornwall, they were the first that were thus equipped to have success. That success, however, was not due to the hydrophones: on 12 June 1917, Sea King sighted on the surface and in moving towards it caused the submarine to dive. The flotilla then let loose their depth charges.
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He at first thought that it sounded as though some local fisherman had started up a boat's diesel engine. Launders decided to track the strange noise. Then, due to poor adherence to proper periscope usage protocol on the part of the German crew, the officer of the watch on Venturers periscope noticed another periscope poking up above the surface of the water. Combined with the hydrophone reports of the strange noise, which he determined to be coming from a submerged vessel, Launders surmised that they had found U-864.
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Each process generates different rock; mid-ocean ridge volcanics are primarily basaltic, whereas subduction flows are mostly calc- alkaline, and more explosive and viscous. Spreading rates along mid-ocean ridges vary widely, from per year at the Mid-Atlantic Ridge, to up to along the East Pacific Rise. Higher spreading rates are a probable cause for higher levels of volcanism. The technology for studying seamount eruptions did not exist until advancements in hydrophone technology made it possible to "listen" to acoustic waves, known as T-waves, released by submarine earthquakes associated with submarine volcanic eruptions.
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Towed array systems are also used by the oil and gas industry for seismic exploration of geological formations under the sea bed. The systems used are similar in concept to the naval ones, but are typically longer and with more streamers in a given array (6 or more in some cases). Typical hydrophone spacing along each streamer is on the order of two meters, and each streamer may be up to 10 km long. Sometimes streamers are flown at different heights, to give a so-called 3D array.
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Captain Gilbert Roberts, p. 129: "It was obvious that the U-boat did not fire its acoustic torpedo until it was sure the escort was attacking. [..] As soon as it was certain it had been spotted, probably by Radar, or star shell, or even by a sudden increase in hydrophone noise, that would be the moment to dive and the T.5 torpedo would then be fired." The escort ship was to then turn 150 degrees away from the convoy and sail for one mile at a speed of 15 knots (1).
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During this time, she was fitted with a number of license-built Hotchkiss 25 mm Type 96 light AA guns, depth charges and a hydrophone. During the U.S. Navy carrier air attack on Kure on 24 July 1945, Settsu was attacked by 30 Grumman F6F Hellcat fighters near Etajima. She was struck by one bomb that killed two men and wounded another two; five near misses started a serious leak in the starboard engine room. Captain Masanano Ofuji decided to run his ship aground on Etajima to prevent her from sinking.
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At around 12:00, a second Kaibōkan arrived in the area to hunt for Torsk; the latter fired a second Mark 28 torpedo and then dove deep to evade any depth charge attacks. After reaching a depth of , she launched a Mark 27 torpedo, a passive acoustic torpedo. Shortly thereafter, the hydrophone operator detected a large explosion; this was the Mark 28 striking the Kaibōkan, and a minute later the Mark 27 struck the vessel as well. This proved to be the last Japanese warship to be sunk in World War II, as the Japanese government announced it would surrender the next day.
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With German U-boats reported off the coast in June 1918, the submarine spent two four-day periscope and listening patrols off Nantucket, Massachusetts, as a defense screen for shipping. Following the end of the war, G-1 conducted daily operations with enlisted students in connection with the Listener and Hydrophone School at New London. In August 1919, after a failed inspection by the Board of Inspection and Survey, the boat was laid up at New London in preparation for disposal. Towed to the Philadelphia Navy Yard on 30 January 1920 she was stripped of useful material and decommissioned on 6 March.
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The Ukuru-class was equipped with the Type 22 and Type 13 radar. The Ukuru class was initially armed with 120 depth charges with two Type 94 depth charge projectors, sixteen Type 3 depth charge throwers and two depth charge chutes at the stern. The ships were provided with a Model 93 sonar and a Type 93 hydrophone; later units received the Type 3 Model 2 sonar, and some would later receive an trench mortar. Initially, the class retained capacity as a minesweeper, and was equipped with two paravanes; however, this was removed soon after completion.
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Anti- aircraft protection was by four Type 96 anti-aircraft guns in two twin-gun mounts abreast the bridge. However, for a ship supposedly designed for convoy escort, only one Model 94 depth charge launcher was installed on the quarterdeck along with a Model 3 loading frame. The number of depth charges was initially 36, but this was increased to 60 while the ships were still in production, which necessitated the deletion of the two paravanes initially in the design for minesweeping. The ships were also equipped with a Model 93 sonar and a Type 93 hydrophone.
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The temperature in the cabin was 7 °C (45 °F) at the time. While at maximum depth, Piccard and Walsh unexpectedly regained the ability to communicate with the support ship, USS Wandank (ATA-204), using a sonar/hydrophone voice communications system. At a speed of almost - about five times the speed of sound in air - it took about seven seconds for a voice message to travel from the craft to the support ship and another seven seconds for answers to return. While at the bottom, Piccard and Walsh reported observing a number of small sole and flounder (both flatfish).
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The first commander of K-3 Leninskiy Komsomol was Captain 1st Rank L.G. Osipenko (future admiral and Hero of the Soviet Union). All other Novembers except K-3 Leninskiy Komsomol belonged to modified project – project 627A. The main visual differences of project 627A were a bow sonar dome in the keel and a hydrophone antenna over the torpedo tubes. The Project P627A design armed with nuclear cruise missile system P-20 was developed in 1956–1957 but not finished, equipment and mechanisms were used for building the usual attack submarine of project 627A (submarine K-50).
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Spectrogram (above) and oscillogram (below) of the humpback whale's calls An experienced observer can use animal sounds to recognize a "singing" animal species, its location and condition in nature. Investigation of animal sounds also includes signal recording with electronic recording equipment. Due to the wide range of signal properties and media they propagate through, specialized equipment may be required instead of the usual microphone, such as a hydrophone (for underwater sounds), detectors of ultrasound (very high-frequency sounds) or infrasound (very low-frequency sounds), or a laser vibrometer (substrate-borne vibrational signals). Computers are used for storing and analysis of recorded sounds.
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On 9 February, Venturers hydrophone operator detected a noise that sounded like a diesel engine. Launders raised periscope and surveyed the horizon, he spotted what he believed to be another periscope (in fact now thought to be the U-boat's snorkel) and began stalking it, assuming that it was U-864. As Venturer followed the German U-boat, it became apparent that they knew they had been spotted due to the erratic, zigzag course U-864 began to take. After following the German submarine for three more hours, Venturer's crew made a calculated decision based on U-864's movements.
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Three hydroacoustic stations were built before the adoption of the Comprehensive Nuclear-Test-Ban Treaty. Two hydrophone stations were built in the North Pacific Ocean and Mid-Atlantic Ocean, and a T-phase station was built off the west coast of Canada. When the CTBT was adopted, 8 more hydroacoustic stations were constructed to create a comprehensive network capable of identifying underwater nuclear detonations anywhere in the world. These 11 hydroacoustic stations, in addition to 326 monitoring stations and laboratories, comprise the International Monitoring System (IMS), which is monitored by the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO).
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The British cruisers tracked Prinz Eugen and Bismarck through the night, continually relaying the location and bearing of the German ships. The harsh weather broke on the morning of 24 May, revealing a clear sky. At 05:07 that morning, hydrophone operators aboard Prinz Eugen detected a pair of unidentified vessels approaching the German formation at a range of , reporting "Noise of two fast-moving turbine ships at 280° relative bearing!". At 05:45, lookouts on the German ships spotted smoke on the horizon; these turned out to be from and , under the command of Vice Admiral Lancelot Holland.
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Their source remained a mystery for decades. By the early 1980s they were thought to come from whales, but it wasn't known what species. In the early 2000s, it was suggested these sounds might originate from minke whales, based on their similarities to vocalizations produced by Southern Hemisphere forms. Finally, during a 2002 HICEAS (Hawaiian Islands Cetacean and Ecosystem Assessment Survey) survey, the R/V David Starr Jordan, using a towed hydrophone array, detected boings off the northwestern Hawaiian Islands on 7 November 2002 and discovered they came from a minke whale, which they photographed and biopsied.
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Neither of the torpedoes exploded and the escorts forced Vesihiisi to dive to the depth of . Though the submarine did not suffer severe damage from the depth charges the repairs on the dock lasted for a week. In December 1941 after the Soviets had evacuated Hanko the Finnish submarines were docked for the winter. During the sailing season of 1941 the Italian torpedoes Vesihiisi used (Finnish designation T/40) proved to be unreliable. During 1942 Vesihiisi was upgraded with new 12-hydrophone listening arrays and equipped with depth charge rack capable of carrying 4 depth charges.
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Wilson, pp. 74–75 B1 remained at Portsmouth for local defence and training duties through 1916 before being paid off. B3 and B4 were transferred to Ardrossan by the end of 1915 to relieve two even more obsolescent A-class boats on local defence duties in the Firth of Clyde. B3 was transferred to Leith during mid-1916 where she was fitted with an experimental hull-mounted directional hydrophone system and later sent to Rosyth in 1917 where she was used as either a target to train anti-submarine forces or experimental work for the rest of the war.
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Within each Lehrkommando were subordinate K-Flotilla; K-Flottille 311 was specifically designated to oversee deployment of the Hecht miniature submarine while the Seehund submarines were dispersed between K-Flottille 312, 313, and 314.Kemp, p. From the Allied point of view, the Seehunds small size made it almost impossible for Asdic to get a return from her hull, while her very quiet slow-speed running made her almost immune to detection by hydrophone. As Admiral Sir Charles Little, Commander-in-Chief, Portsmouth put it, "Fortunately for us these damn things arrived too late in the war to do any damage".
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In 1917, the US Navy acquired J. Warren Horton's services for the first time. On leave from Bell Labs, he served the government as a technical expert, first at the experimental station at Nahant, Massachusetts, and later at US Naval Headquarters, in London, England. At Nahant he applied the newly developed vacuum tube, then associated with the formative stages of the field of applied science now known as electronics, to the detection of underwater signals. As a result, the carbon button microphone, which had been used in earlier detection equipment, was replaced by the precursor of the modern hydrophone.
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On August 5, 2005 AS-28, under the command of Lieutenant Vyacheslav Milashevskiy, became entangled with the aerial of a hydrophone array off the coast of the Kamchatka Peninsula, in Berezovaya Bay, 70 km southeast of Petropavlovsk-Kamchatskiy, Kamchatka Oblast. The aerial, anchored by 60-tonne concrete blocks, snared the propeller of the submarine, and the submarine then sank to the seafloor at a depth of 190 m (600 ft). This was too deep for the ship's complement of seven to leave the submarine and swim to the surface. British rescuers and Russian officials stated that fishing nets also had entangled the vessel.
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Hydrophone gear aboard Wandank was still able to communicate with the craft once on the bottom, although the sound waves took seven seconds to make a one-way journey from ship to bathyscaphe, which was nearly seven miles deep. On occasion, Wandanks operations nonetheless assumed a dangerous character during tropical storms. During one of these storms, which occurred October 19, 1963, Wandank was trapped between two typhoons while en route to her annual buoy maintenance duty at Chichi Jima in the Bonin Islands. In the heavy seas, her tow line parted, leaving USS YCV-18 adrift.
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After eight war patrols under the command of Kapitänleutnant Claus Korth, command of of the 1st U-boat Flotilla was passed to Topp on 5 June 1940. Topp's fifth war patrol began in Kiel on 11 July 1940 and was destined for the North Atlantic, into the North Channel, and The Minch. Because the Gruppenhorchgerät, a hydrophone array, was experiencing technical difficulties, Topp took U-57 to port for repairs. U-57 arrived in Bergen on 15 July, departed again that day only to return to Bergen on 20 July. Two days later, U-57 was able to begin its patrol.
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Like echosounding, this method required an accurate calculation of the speed of sound through water.Anonymous, "Ocean's Depth Measured By Radio Robot," Popular Mechanics, December 1938, pp. 828-830. Heck oversaw tests at Coast and Geodetic Survey headquarters in Washington, D.C., that demonstrated that shipboard recording of the time of an explosion could be performed accurately enough for his concept to work. He worked with Dr. E. A. Eckhardt, a physicist, and M. Keiser, an electrical engineer, of the National Bureau of Standards to develop a hydrophone system that could automatically send a radio signal when it detected the sound of an underwater explosion.
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Semple was brought into the company as general manager to manufacture and market the company's model D-104 Crystal Microphone as well as other crystal microphones, crystal phonograph pickups and recording heads. In early 1944, Astatic moved operations to Conneaut, Ohio and supplied microphones, pickups and crystal cartridges as well as hydrophone and sonar devices to the military during World War II. After World War II, Astatic Microphone Laboratory became The Astatic Corporation. The commercial audio product division of Astatic became CAD Professional Microphones in 1988. After a merger with Omnitronics LLC in 2000, CAD, Astatic and Omnitronics combined under the CAD Audio brand.
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Full frequency range recording (ffrr) was a spin-off devised by Arthur HaddyArthur Haddy, English electronics engineer, 1970s – Science Museum, Science and Society Picture Library of British Decca's development, during the Second World War, of a high fidelity hydrophone capable of detecting and cataloguing individual German submarines by each one's signature engine noise, and enabled a greatly enhanced frequency range (high and low notes) to be captured on recordings.Millard, Andre J., "America on record: a history of recorded sound", Cambridge; New York: Cambridge University Press, 1995. . Cf. page 198 for material on ffrr. Critics regularly commented on the startling realism of the new Decca recordings.
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One of Massa's former colleagues from RCA-Victor had recently been named the commanding officer of the Naval Gun Factory and he commissioned Massa to develop systems that could counter the devastating effects of the German U-boats. Their first tactic was to protect individual, slow-moving ships from the U-boats' torpedo attacks. The plan was to tow streamers along the sides of U.S. ships with small charges of TNT explosives at fixed points. By developing a hydrophone that was placed at each TNT location, Massa created a device that could pick up noise from the approaching torpedo and automatically fire a counter charge before the torpedo reached the ship.
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The transducer, also called the "dome", a term borrowed from ship-board sonars, is lowered or "dipped" from the helicopter on a cable by means of the hydraulic reeling machine. The dip depth of the transducer is selected by the operator to achieve the maximum detection probability at the dip location on that particular day as determined by the study of ocean conditions (see Underwater Acoustics). During active search, the acoustic pulse is emitted from the projector assembly. Echos or "returns" are received by the hydrophone, routed through the sonar cable, processed in the aircraft and displayed on a cathode ray tube (CRT) in a plan position indicator (PPI) format.
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The first practical application for piezoelectric devices was sonar, first developed during World War I. In France in 1917, Paul Langevin and his coworkers developed an ultrasonic submarine detector. The detector consisted of a transducer, made of thin quartz crystals carefully glued between two steel plates, and a hydrophone to detect the returned echo. By emitting a high-frequency pulse from the transducer, and measuring the amount of time it takes to hear an echo from the sound waves bouncing off an object, one can calculate the distance to that object. The use of piezoelectricity in sonar, and the success of that project, created intense development interest in piezoelectric devices.
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A hydrophone was hung from Saluda to detect signals from a second ship setting off explosive charges up to miles away. Proof of the theory led to a development to use the SOFAR channel to locate downed air crews by detecting the explosion of a small charge close to the channel axis for detection and computation of location by shore stations. The long distance travel of low frequency sound in the channel was applied to the Sound Surveillance System (SOSUS) implemented in 1952 and continuing as a classified undersea surveillance system until 1991 when the mission and nature of the system was declassified. Elements of the system remain in operation.
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In this case there has to be the provision of a cable drum on which to haul, shoot and stow the cable during the different phases of the operation. The second type is the cable-less net-sounder – such as Marport's Trawl Explorer – in which the signals are sent acoustically between the net and hull mounted receiver-hydrophone on the vessel. In this case no cable drum is required but sophisticated electronics are needed at the transducer and receiver. The display on a net sounder shows the distance of the net from the bottom (or the surface), rather than the depth of water as with the echo- sounder's hull-mounted transducer.
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Admiral Richard Henry Leigh (August 12, 1870 – February 4, 1946) was a United States Navy officer who served during the late 19th and early 20th century. His service included active duty in the Spanish–American War, Philippine–American War, American Intervention in China, World War I, as well as numerous smaller actions in South America. His service during World War I led to the further development of hydrophone technology to hunt submarines. Following World War I Leigh rose to the rank of four-star admiral and served as Commander, Battle Force, U.S. Fleet (COMBATFOR) from 1931 to 1932 and as Commander in Chief, U.S. Fleet (CINCUS) from 1932 to 1933.
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A pump is a device that moves fluids (liquids or gases), or sometimes slurries, by mechanical action. A marine pump is an important auxiliary equipment in marine industry and ship building industry. It is widely used in all kinds of marine vessels, such as barges, tug boats, containers, carriers, ships, vessels, fixed offshore structure, drilling jack-up rigs and so on. These marine pumps can be serviced for cooling, circulating, ballast, general service(G/S), fire- fighting, boiler feed water, condensate water, fresh(drinking) water, sanitary water, bilge & sludge, F.O. transfer, L.O. transfer, F.O. and F.S. cargo pumping, cargo stripping, hydrophone tank unit, sewage treatment unit, oil water separator, incinerator, fresh water generator, and so on.
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With VE in 1945, Argentia saw a drop in personnel but by the start of the Cold War in 1947–1948, personnel numbers rose to 7,000. By the end of the Korean War in 1953, Argentia saw a total of 8,500 personnel posted in the area. In 1955 McAndrew AFB was deactivated and turned over to the US Navy as the US Air Force moved its personnel to more remote and northern locations along the coast of Newfoundland and Labrador to build radar stations which would become part of the Pinetree Line and DEW Line systems. In the 1960s Naval Station Argentia became a key "node" in the US Navy's SOSUS underwater hydrophone system.
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The temperature in the cabin was a mere at the time. While on the bottom at maximum depth, Piccard and Walsh unexpectedly regained the ability to communicate with Wandank using a sonar/hydrophone voice communications system. At a speed of almost (about five times the speed of sound in air), it took about seven seconds for a voice message to travel from the craft to the surface ship and another seven seconds for answers to return. While on the bottom, Piccard and Walsh reported they observed a number of small sole and flounder swimming away, indicating that at least some vertebrate life might withstand the extremes of pressure in any of the Earth's oceans.
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Launders received a brief message from Royal Navy Submarine Command as to the estimated whereabouts of U-864 (with reasonable precision, somewhere near the island of Fedje, off Norway's southwest coast, just north of the pens at Bergen), along with instructions to destroy her. Launders set about the task, making one risky but calculated decision: he decided to switch off Venturers ASDIC (a then-advanced form of sonar), which would severely limit their ability to detect other submarines, but would greatly reduce the chance of being detected themselves. They would rely purely on Venturer's hydrophone (a common, long-used, and far less sophisticated underwater acoustic detection device) to try to detect U-864. It was a huge gamble.
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I-8 left Brest on 5 October, with a cargo of German equipment, such as: machine guns, bomb sights, a Daimler-Benz torpedo boat engine, marine chronometers, radars, sonar equipment, anti-aircraft gunsights, electric torpedoes, and penicillin. The submarine also transported Rear Admiral Yokoi, naval attaché to Berlin since 1940; Captain Hosoya, naval attaché to France since December 1939; three German officers and four radar and hydrophone technicians. I-8 hit rough seas in the South Atlantic off the Cape of Good Hope, which delayed her arrival in Singapore. She radioed her position to Germany, but the message was intercepted by the Allies, prompting an attack by anti-submarine aircraft, which failed.
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As of July 2014, Flight 370 remains missing with no known crash site or confirmed debris. Since the only evidence for Flight 370's final resting site comes from an analysis of its satellite transmissions, which has resulted in an imprecise and very large search area, hydroacoustic recordings from CTBTO were analyzed to potentially determine and locate its impact with the Indian Ocean. Analysis of available hydroacoustic recordings (including those made by a CTBTO hydrophone located off Cape Leeuwin, Western Australia) identified one event which may be associated with Flight 370. Other potential civil and scientific applications include the use of CTBTO data and technologies in civil aviation and shipping and in climate change research.
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US submarines did not sink any U-boats in World War I. The class was generally under-powered, but they enjoyed good endurance for patrols in the North Atlantic and in British waters. After the war, the L class were involved in trials of new torpedoes and hydrophone equipment on both the east and west coasts before decommissioning in 1922 and 1923. At least L-3, L-9, and L-11 were re-engined with Busch-Sulzer diesels removed from Lake-built N-boats in 1921.NavSource Naval History N-class page Three Group 1 boats were scrapped in 1922, the four Group 2 Lake boats were scrapped in 1925, and the remainder were scrapped in 1933 under the London Naval Treaty limiting naval armament.
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It was considered possible, but highly unlikely, that a U-boat commander might attempt to race through undetected before the boom was closed. Two submarines unsuccessfully attempted infiltration during the First World War: on 23 November 1914 was rammed twice before running aground with the capture of her crew, and was detected by hydrophone and destroyed with the loss of all hands on 28 October 1918. Scapa Flow provided the main anchorage for the British Grand Fleet throughout most of the First World War, but in the interwar period this passed to Rosyth, further south in the Firth of Forth. Scapa Flow was reactivated with the advent of the Second World War, becoming a base for the British Home Fleet.
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After completing trials under the command of Lieutenant Commander E.D. Norman, Graph was placed under the command of Lieutenant Peter Barnsley Marriott, who had assisted in the trials. She departed from Holy Loch for her first Royal Navy war patrol on 8 October 1942, with the intention of patrolling the Bay of Biscay. Graph at Holy Loch, Scotland, after she had ceased active service and been reassigned for training use (20 April 1943) On the afternoon of 21 October 1942, about north-north-east of Cape Ortegal (), Graph dived to evade a German Focke-Wulf Fw 200 long-range patrol aircraft. A loud hydrophone contact made Marriott believe a nearby submarine had likewise dived and, 12 minutes later, he observed its conning-tower against the setting sun.
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The sound's source was roughly triangulated to , a remote point in the south Pacific Ocean west of the southern tip of South America. The sound was detected by the Equatorial Pacific Ocean autonomous hydrophone array, a system of hydrophones primarily used to monitor undersea seismicity, ice noise, and marine mammal population and migration. This is a stand-alone system designed and built by NOAA's Pacific Marine Environmental Laboratory (PMEL) to augment NOAA's use of the U.S. Navy Sound Surveillance System (SOSUS), which was equipment originally designed to detect Soviet submarines. According to the NOAA description, the sound "rose" in frequency over about one minute and was of sufficient amplitude to be heard on multiple sensors, at a range of over .
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After weeks of search, the Soviets were unable to locate the sunken boat, and Soviet Pacific Fleet operations gradually returned to normal. The American SOSUS hydrophone network in the northern Pacific was tasked with reviewing its recordings in the hope of detecting an implosion (or explosion) related to such a loss. The Navy analyzed acoustic data from four AFTAC sites and the Adak, Alaska SOSUS array, locating the wreck of the submarine to within 5 nautical miles. The site was hundreds of miles away from the Soviet Navy search area. Naval Facility (NAVFAC) Point Sur, south of Monterey, California, was able to isolate a sonic signature on its low frequency array recordings of an implosion event that had occurred on March 8, 1968.
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The French ship can deploy an ROV that can dive up to and that is able to detect signals from ULBs but with limited depth range. On 26 May, Italian and French companies capable of executing deep-sea searches, including ALSEAMAR and the Mauritius-based Deep Ocean Search, were asked by Egypt to help locate the flight recorders. A more specialized French Navy ship, the oceanographic research ship Laplace, left the Corsican port of Porto-Vecchio for the search area on 27 May, according to French aircraft accident investigation body the Bureau d'Enquêtes et d'Analyses pour la Sécurité de l'Aviation Civile (BEA). The vessel can deploy three towed Alseamar hydrophone arrays that are designed to detect a ULB from a distance of up to nearly .
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In fact, the opposite proved true: Among other problems, the relatively shallow water along the U.S. East Coast attenuated the sound of ranging explosions and shoals often blocked the sound from reaching shore at all. To overcome these difficulties, the Coast and Geodetic Survey anchored vessels well offshore along the U.S. East Coast to serve as hydrophone stations. In 1931, the Coast and Geodetic Survey proposed replacing the manned station ships with "radio- sonobuoys", and in July 1936 it began to place radio-sonobuoys in service. The 700-pound (317.5-kg) buoys – equipped with subsurface hydrophones, batteries, and radio transmitters that automatically sent a radio signal when their hydrophones detected the sound of a ranging explosion – could be deployed or recovered by Coast and Geodetic Survey ships in five minutes.
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On 4 April, the search was refocused to three more northerly areas from west of Learmonth, spanning over . ADV Ocean Shield, fitted with a TPL-25 towed pinger locator, together with HMS Echo – which carried a "similar device", began searching for pings along a seabed line believed to be the Flight 370 impact area. Operators considered it a shot in the dark, when comparing the vast search area with the fact that TPL-25 could only search up to per day. The Chinese vessel Haixun 01 made a possible ULB detection at The Operational Search for MH370 (Final) using a handheld hydrophone; the following day, Haixun 01 made another possible ULB detection about 3 km (1.9 mi) further west. HMS Echo and a submarine were later tasked to the location of the Haixun 01's detections, but unable to make any detections.
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The sound's source was roughly triangulated to a remote point in the south Pacific Ocean west of the southern tip of South America, and the sound was detected several times by the Equatorial Pacific Ocean autonomous hydrophone array. According to the NOAA description, it "rises rapidly in frequency over about one minute and was of sufficient amplitude to be heard on multiple sensors, at a range of over ." The NOAA's Dr. Christopher Fox did not believe its origin was man-made, such as a submarine or bomb, nor familiar geological events such as volcanoes or earthquakes. While the audio profile of Bloop does resemble that of a living creature, the source was a mystery both because it was different from known sounds and because it was several times louder than the loudest recorded animal, the blue whale.
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In March 1968, a Soviet Golf class submarine imploded – generally believed to be while on the surface recharging its batteries – and sank in about of ocean some northwest of Hawaii. The Soviet Fleet immediately started a major effort to locate the sub, but gave up in a few weeks, The U.S. Navy’s Sound Surveillance System (SOSUS) – a network of hydrophone arrays – had initially tracked the sub, and triangulation had been used to identify the general location where the accident occurred. The Office of Naval Intelligence (ONI) then arranged for a spy submarine, the USS Halibut, to search for the missing sub. During the summer of 1968, long cables lowered lights and cameras, and in August found the sub broken into several large pieces. The forward section contained the sub’s three missile launch tubes, one with an apparently intact nuclear-tipped missile.
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Anonymous, "Ocean's Depth Measured By Radio Robot," Popular Mechanics, December 1938, pp. 828-830. Heck oversaw tests at Coast and Geodetic Survey headquarters in Washington, D.C., that demonstrated that shipboard recording of the time of an explosion could be performed accurately enough for his concept to work. He worked with Dr. E. A. Eckhardt, a physicist, and M. Keiser, an electrical engineer, of the National Bureau of Standards to develop a hydrophone system that could automatically send a radio signal when it detected the sound of an underwater explosion. When Guide was commissioned in 1923, Heck had her based at New London, Connecticut, and arranged for her under his direction both to test her new echo sounder's ability to make accurate depth soundings and to conduct radio acoustic ranging experiments in cooperation with the U.S. Army Coast Artillery Corps.
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The British torpedo attack came when the Italian battlefleet was passing through the area of the 10th Submarine Flotilla, after the plan to form a line north of the track of the convoy had been overtaken by events after the Italian battleships sailed and the convoy turned back. (Lieutenant S. L. C. Maydon) picked up the Italian ships on hydrophone and steered towards the fleet as the torpedo-bombers dropped illumination flares. Maydon found that Umbra was Trento was circled by the battleships, which then resumed their southward course, leaving it behind with the destroyer Antonio Pigafetta; at Maydon fired torpedoes at Vittorio Veneto, with no hits. The Italian ships had also been seen at by (Lieutenant P. R. H. Harrison), the heavy cruisers to the west of the battleships and at Ultimatum attacked through the destroyer screen, only to be frustrated by the cruisers zig-zagging and passing overhead.
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In a study on three populations of Indo-Pacific bottlenose dolphins in Japan, the characteristics of acoustic signals are believed to be affected by the acoustic environments among habitats, and geographical variation in animal acoustic signals can result from differences in acoustic environments; therefore, the characteristics of the ambient noise in the dolphins' habitats and the whistles produced were compared. Ambient noise was recorded using a hydrophone located 10 m below the surface and whistles were recorded by using an underwater video system. The results showed dolphins produced whistles at varying frequencies with greater modulations when in habitats with less ambient noise, whereas habitats with greater ambient noise seem to cause dolphins to produce whistles of lower frequencies and fewer frequency modulations. Examination of the results suggest communication signals are adaptive and are selected to avoid the masking of signals and the decrease of higher-frequency signals.
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Local peculiarities in the propagation of acoustic waves in the water column could degrade its accuracy, there were problems with maintaining hydrophone stations, and handling explosive charges posed a considerable danger to personnel and ships.hydro-international.com Theberge, Albert E., "First Developments of Electronic Navigation Systems," 27 March 2009. On one occasion a Coast and Geodetic Survey Corps ensign on board the survey ship USC&GS; Hydrographer inserted a radio acoustic ranging bomb in the mouth of a shark and released the shark, only to watch in horror as it swam back to the ship and exploded next to Hydrographer′s hull; the explosion rocked the ship.history.noaa.gov "A Letter From the Front" Aboard Guide in 1927, tragedy almost struck when a petty officer handling a bomb lit its fuse and then fell when the ship lurched; he dropped the bomb, which rolled into a gutter.
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Lind, The Royal Australian Navy, p. 297 The Squadron, which included HMA Ships , , , , and spent two months in the Indian Ocean as part of a flag-showing cruise; the largest RAN deployment since World War II. In July 1983, Otama was docked for modernisation.Gillett, Australian and New Zealand Warships since 1946, p. 76 The Submarine Weapon Update Program refit lasted until 1985. Commemorative plaque at Rockingham Naval Memorial Park for the three sailors killed on board of Australian Oberons On 3 August 1987, two sailors were killed aboard Otama. At 09:00, the submarine left HMAS Platypus to test a new towed hydrophone array.Waller, Suddenly Dead, p. 6 Extreme weather forced the cancellation of the test, and two sailors were sent into the fin at around 10:20 to retrieve and stow the array. At 10:35, the submarine was prepared for diving, and she submerged four minutes later, with the two men still in the fin.
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In 2015 her work titled In the darkness of the world was commissioned to be premiered as a broadcast and as a performance by the CTM Festival 2015 for Adventurous Music and Art 2015 in the Radio Lab call, co-commissioned by Deutschlandradio Kultur – Hörspiel, ECAS – European Cities of Advanced Sound / ICAS – International Cities of Advanced Sound/ Klangkunst. The Wire's Frances Morgan commented on Rezza's project: > The project is imaginative and playful, drawing on classic radiophonic > drama, and its spatial aspect should make the installation inviting and > accessible In The Darkness Of The World was an experimental radio broadcast/performance. Through sound design, experimental sound work, hydrophone and traditional recordings and soundscape manipulation, the artwork aims to reread the ambient, motifs and intricate geographies of the 19th-century classic Vingt mille lieues sous les mers by Jules Verne. The work received favorable reviews in The Crack magazine, Gonzo (circus), Mondo Magazin and M/Magazyn.
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A working model of the Low Frequency Analyzer and Recorder was delivered in May 1951 which operated with real time analysis of a frequency band of 1 to 1/2 Hz. Along with the working model was a proposal for hydrophones, cables, processing systems and beamforming so that a hydrophone array could present multiple azimuthal beams to be displayed. Lofargram writers, one for each array beam, on a NAVFAC watch floor. Each system, from shore facility to the transducer array was a sonar set with the signal processing beginning as the array's signals were amplified, processed into beams by time delay and each beam processed by an electromechanical spectrum analyzer with the display being a sweep of the frequency spectrum's intensity burned across electrostatic recording paper moving on the time axis. The sweeps of the stylus recording the intensity of sound along the frequency axis formed a time record of background noise and specific frequency receptions that formed lines.
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Marine survey acquisition is not just limited to seismic vessels; it is also possible to lay cables of geophones and hydrophones on the sea bed in a similar way to how cables are used in a land seismic survey, and use a separate source vessel. This method was originally developed out of operational necessity in order to enable seismic surveys to be conducted in areas with obstructions, such as production platforms, without having the compromise the resultant image quality. Ocean bottom cables (OBC) are also extensively used in other areas that a seismic vessel cannot be used, for example in shallow marine (water depth <300m) and transition zone environments, and can be deployed by remotely operated underwater vehicles (ROVs) in deep water when repeatability is valued (see 4D, below). Conventional OBC surveys use dual-component receivers, combining a pressure sensor (hydrophone) and a vertical particle velocity sensor (vertical geophone), but more recent developments have expanded the method to use four- component sensors i.e.
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The Frank's embarked crew was, in Army terminology implemented November 1942, designated the 19th Coast Artillery Mine Planter Battery stationed at Fort Miles, Delaware. The 19th Coast Artillery Mine Planter Battery was activated 28 November 1942 at Fort Hancock, New York and was directed to Point Pleasant, West Virginia to man the USAMP Brigadier General Royal T. Frank (MP-12) which on 1 April 1943 was assigned to Fort Miles guarding the entrance to Delaware Bay. There the ship and battery joined the 12th Coast Artillery Mine Planter Battery embarked in USAMP 1st Lt. William G. Sylvester (MP-5) for the maintenance of the mine fields which during that year were being changed from the M3 Buoyant Mines to 455 mines of the much more powerful M4 Ground Mine type carrying a 3000-pound TNT charge planted in thirty-five groups of thirteen mines each. The ship's cable capability was to be used not only to maintain the mine control cables but the three hydrophone sets and the indicator loops acting as sensors in the approaches to the mine field.
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By dropping the array's 'tail' below the layer, a surface ASW platform can better detect a quiet, submerged contact hiding in cold water below a warm upper layer. A submarine can likewise monitor surface combatants by floating the tail of its array above a thermal layer while lurking below. Akula's towed array is stored in a teardrop shaped container mounted on top of the vertical fin The array's hydrophones can be used to detect sound sources, but the real value of the array is that the signal processing technique of beamforming and Fourier analysis can be used not only to calculate the distance and the direction of a sound source, but also to identify the type of ship by the distinctive, acoustic signature of its machinery noises. For this, the relative positions of the hydrophones need to be known, usually possible only when the cable is in a straight line (stable), or when a self-sensing system (see strain gauges) or GPS or other methods embedded in the cable, and reporting relative position of hydrophone elements, is used to monitor the shape of the array and correct for curvature.
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