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Sonobuoy
A sonobuoy (a portmanteau of sonar and buoy) is a small expendable sonar buoy dropped from aircraft or ships for anti-submarine warfare or underwater acoustic research. Sonobuoys are typically around in diameter and long. When floating on the water, sonobuoys have both a radio transmitter above the surface and hydrophone sensors underwater. Sonobuoys are mission-critical platforms for enhancing Undersea Domain Awareness (UDA), providing an effective means to detect, locate, and track submarines and other underwater threats. Playing a key role in anti-submarine warfare (ASW) and other naval operations, they support in maintaining naval security and in protecting naval carrier strike groups. Theory of operation 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 be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sonobuoy Deployment
A sonobuoy (a portmanteau of sonar and buoy) is a small expendable sonar buoy dropped from aircraft or ships for anti-submarine warfare or underwater acoustics, underwater acoustic research. Sonobuoys are typically around in diameter and long. When floating on the water, sonobuoys have both a radio transmitter above the surface and hydrophone sensors underwater. Sonobuoys are mission-critical platforms for enhancing Undersea Domain Awareness (UDA), providing an effective means to detect, locate, and track submarines and other underwater threats. Playing a key role in anti-submarine warfare (ASW) and other naval operations, they support in maintaining naval security and in protecting naval carrier strike groups. Theory of operation 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 equip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buoy
A buoy (; ) is a buoyancy, floating device that can have many purposes. It can be anchored (stationary) or allowed to drift with ocean currents. History The ultimate origin of buoys is unknown, but by 1295 a seaman's manual referred to navigation buoys in the Guadalquivir River in Spain. To the north there are early medieval mentions of the French / Belgian River Meuse, Maas being buoyed. Such early buoys were probably just timber beams or rafts, but in 1358 there is a record of a barrel buoy in the Dutch Maasmond (also known as the Maas Sluis or Maasgat). The simple barrel was difficult to secure to the seabed, and so a conical ''tonne'' was developed. They had a solid plug at the narrow end through which a mooring ring could be attached. By 1790 the older conical tonne was being replaced by a ''nun'' buoy. This had the same conical section below the waterline as the tonne buoy, but at the waterline a barrel shape was used to allow a truncated cone to be above the water. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Acoustic Ranging
Radio acoustic ranging, occasionally written as "radio-acoustic ranging" and sometimes abbreviated RAR, was a method for determining a ship's precise location at sea by detonating an explosive charge underwater near the ship, detecting the arrival of the underwater sound waves at remote locations, and Radio transmission, radioing the time of arrival of the sound waves at the remote stations to the ship, allowing the ship's crew to use true range multilateration to determine the ship's position. Developed by the United States Coast and Geodetic Survey in 1923 and 1924 for use in accurately position fix, fixing the position of survey ships during hydrographic survey operations, it was the first navigation technique in human history other than dead reckoning that did not require visual observation of a landmark, marker, light, or celestial body, and the first non-visual means to provide precise positions. First employed operationally in 1924, radio acoustic ranging remained in use un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anti-submarine Warfare
Anti-submarine warfare (ASW, or in the older form A/S) is a branch of underwater warfare that uses surface warships, aircraft, submarines, or other platforms, to find, track, and deter, damage, or destroy enemy submarines. Such operations are typically carried out to protect friendly shipping and coastal facilities from submarine attacks and to overcome blockades. Successful ASW operations typically involve a combination of sensor and weapon technologies, along with effective deployment strategies and sufficiently trained personnel. Typically, sophisticated sonar equipment is used for first detecting, then classifying, locating, and tracking a target submarine. Sensors are therefore a key element of ASW. Common weapons for attacking submarines include torpedoes and naval mines, which can both be launched from an array of air, surface, and underwater platforms. ASW capabilities are often considered of significant strategic importance, particularly following provocative instanc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triangulation
In trigonometry and geometry, triangulation is the process of determining the location of a point by forming triangles to the point from known points. Applications In surveying Specifically in surveying, triangulation involves only angle measurements at known points, rather than measuring distances to the point directly as in trilateration; the use of both angles and distance measurements is referred to as triangulateration. In computer vision Computer stereo vision and optical 3D measuring systems use this principle to determine the spatial dimensions and the geometry of an item. Basically, the configuration consists of two sensors observing the item. One of the sensors is typically a digital camera device, and the other one can also be a camera or a light projector. The projection centers of the sensors and the considered point on the object's surface define a (spatial) triangle. Within this triangle, the distance between the sensors is the base ''b'' and must be kn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War II
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the world's countries participated, with many nations mobilising all resources in pursuit of total war. Tanks in World War II, Tanks and Air warfare of World War II, aircraft played major roles, enabling the strategic bombing of cities and delivery of the Atomic bombings of Hiroshima and Nagasaki, first and only nuclear weapons ever used in war. World War II is the List of wars by death toll, deadliest conflict in history, causing World War II casualties, the death of 70 to 85 million people, more than half of whom were civilians. Millions died in genocides, including the Holocaust, and by massacres, starvation, and disease. After the Allied victory, Allied-occupied Germany, Germany, Allied-occupied Austria, Austria, Occupation of Japan, Japan, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Coast And Geodetic Survey
The United States Coast and Geodetic Survey ( USC&GS; known as the Survey of the Coast from 1807 to 1836, and as the United States Coast Survey from 1836 until 1878) was the first scientific agency of the Federal government of the United States, United States Government. It existed from 1807 to 1970, and throughout its history was responsible for mapping and charting the coast of the United States, and later the coasts of Territories of the United States, U.S. territories. In 1871, it gained the additional responsibility of surveying the interior of the United States and geodesy became a more important part of its work, leading to it being renamed the U.S. Coast and Geodetic Survey in 1878. Long the U.S. government's only scientific agency, the Survey accumulated other scientific and technical responsibilities as well, including astronomy, cartography, metrology, meteorology, geology, geophysics, hydrography, navigation, oceanography, exploration, Piloting, pilotage, tides, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Survey Ship
A survey vessel is any type of ship or boat that is used for underwater surveys, usually to collect data for mapping or planning underwater construction or mineral extraction. It is a type of research vessel, and may be designed for the purpose, modified for the purpose or temporarily put into the service as a vessel of opportunity, and may be crewed, remotely operated, or autonomous. The size and equipment vary to suit the task and availability. Role The task of survey vessels is to map the bottom, and measure the characteristics of the benthic zone, full water column, and surface for the purpose of: * hydrography, the measurement and description of the physical features of oceans and other natural bodies of water, and the prediction of their change over time, for the primary purpose of safety of navigation and in support of other activities associated with those bodies of water, * general oceanography, the scientific study of the oceans, * mapping of marine habitats as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrographic Survey
Hydrographic survey is the science of measurement and description of features which affect maritime navigation, marine construction, dredging, offshore wind farms, offshore oil exploration and drilling and related activities. Surveys may also be conducted to determine the route of subsea cables such as telecommunications cables, cables associated with wind farms, and HVDC power cables. Strong emphasis is placed on soundings, shorelines, tides, currents, seabed and submerged obstructions that relate to the previously mentioned activities. The term ''hydrography'' is used synonymously to describe ''maritime cartography'', which in the final stages of the hydrographic process uses the raw data collected through hydrographic survey into information usable by the end user. Hydrography is collected under rules which vary depending on the acceptance authority. Traditionally conducted by ships with a sounding line or echo sounding, surveys are increasingly conducted with the aid o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
U-boat
U-boats are Submarine#Military, naval submarines operated by Germany, including during the World War I, First and Second World Wars. The term is an Anglicization#Loanwords, anglicized form of the German word , a shortening of (), though the German term refers to any submarine. Austro-Hungarian Navy submarines were also known as U-boats. U-boats are most known for their unrestricted submarine warfare in both world wars, trying to Commerce raiding, disrupt merchant traffic towards the UK and force the UK out of the war. In World War I, Germany intermittently waged unrestricted submarine warfare against the United Kingdom, UK: a first campaign in 1915 was abandoned after strong protests from the US but in 1917 the Germans, facing deadlock on the continent, saw no other option than to resume the campaign in February 1917. The renewed campaign failed to achieve its goal mainly because of the introduction of Convoys in World War I, convoys. Instead the campaign ensured final defeat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atlantic Ocean
The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for separating the New World of the Americas (North America and South America) from the Old World of Afro-Eurasia (Africa, Asia, and Europe). Through its separation of Afro-Eurasia from the Americas, the Atlantic Ocean has played a central role in the development of human society, globalization, and the histories of many nations. While the Norse colonization of North America, Norse were the first known humans to cross the Atlantic, it was the expedition of Christopher Columbus in 1492 that proved to be the most consequential. Columbus's expedition ushered in an Age of Discovery, age of exploration and colonization of the Americas by European powers, most notably Portuguese Empire, Portugal, Spanish Empire, Sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
