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Project Sanguine
Project Sanguine was a U.S. Navy project, proposed in 1968 for communication with submerged submarines using extremely low frequency (ELF) radio waves. The originally proposed system, hardened to survive a nuclear attack, would have required a giant antenna covering two fifths of the state of Wisconsin. Because of protests and potential environmental impact, the proposed system was never implemented. A smaller, less hardened system called Project ELF consisting of two linked ELF transmitters located at Clam Lake, Wisconsin and Republic, Michigan was built beginning in 1982 and operated from 1989 until 2004. The system transmitted at a frequency of 76 Hz. At ELF frequencies the bandwidth of the transmission is very small, so the system could only send short coded text messages at a very low data rate. These signals were used to summon specific vessels to the surface to receive longer operational orders by ordinary radio or satellite communication. Proposed system The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clam Lake ELF
Clam is a common name for several kinds of bivalve molluscs. The word is often applied only to those that are edible and live as infauna, spending most of their lives halfway buried in the sand of the seafloor or riverbeds. Clams have two shells of equal size connected by two adductor muscles and have a powerful burrowing foot. They live in both freshwater and marine environments; in salt water they prefer to burrow down into the mud and the turbidity of the water required varies with species and location; the greatest diversity of these is in North America. Clams in the culinary sense do not live attached to a substrate (whereas oysters and mussels do) and do not live near the bottom (whereas scallops do). In culinary usage, clams are commonly eaten marine bivalves, as in clam digging and the resulting soup, clam chowder. Many edible clams such as palourde clams are ovoid or triangular; however, razor clams have an elongated parallel-sided shell, suggesting an old-fash ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground Dipole ELF Antenna
Ground may refer to: Geology * Land, the surface of the Earth not covered by water * Soil, a mixture of clay, sand and organic matter present on the surface of the Earth Electricity * Ground (electricity), the reference point in an electrical circuit from which voltages are measured * Earthing system, part of an electrical installation that connects with the Earth's conductive surface * Ground and neutral, closely related terms Law * Ground (often grounds), in law, a rational motive or basis for a belief, conviction, or action taken, such as a legal action or argument: * Grounds for divorce, regulations specifying the circumstances under which a person will be granted a divorce Music * ''Ground'' (album), the second album by the Nels Cline Trio * "Ground" (song), one of the songs in the debut album of the Filipino rock band Rivermaya * Ground bass, in music, a bass part that continually repeats, while the melody and harmony over it change * ''The Ground'', a 2005 album by Nor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Times Of India
''The Times of India'', also known by its abbreviation ''TOI'', is an Indian English-language daily newspaper and digital news media owned and managed by The Times Group. It is the third-largest newspaper in India by circulation and largest selling English-language daily in the world. It is the oldest English-language newspaper in India, and the second-oldest Indian newspaper still in circulation, with its first edition published in 1838. It is nicknamed as "The Old Lady of Bori Bunder", and is an Indian " newspaper of record". Near the beginning of the 20th century, Lord Curzon, the Viceroy of India, called ''TOI'' "the leading paper in Asia". In 1991, the BBC ranked ''TOI'' among the world's six best newspapers. It is owned and published by Bennett, Coleman & Co. Ltd. (B.C.C.L.), which is owned by the Sahu Jain family. In the Brand Trust Report India study 2019, ''TOI'' was rated as the most trusted English newspaper in India. Reuters rated ''TOI'' as India's most trus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Akula-class Submarine
The ''Akula'' class, Soviet designation Project 971 ''Shchuka-B'' (russian: Щука-Б, , Pike-B, NATO reporting name ''Akula'') are a series of fourth generation nuclear-powered attack submarines (SSNs) first deployed by the Soviet Navy in 1986. There are four sub-classes or flights of Shchuka-B, consisting of the original seven Project 971 boats (codenamed ''Akula I''), commissioned between 1984 and 1990; six Project 971Is (Improved ''Akula''s), commissioned between 1991 and 2009; one Project 971U (''Akula II''), commissioned in 1995; and one Project 971M (''Akula III''), commissioned in 2001. The Russians call all of the submarines ''Shchuka-B'', regardless of modifications. Some confusion may exist as the name ''Akula'' (russian: Акула, meaning "shark" in Russian) was used by the Soviets for a different class of submarines, the Project 941, which is known in the West as the . The Project 971 was named ''Shchuka-B'' by the Soviets but given the designation ''Akula'' b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arihant-class Submarine
The ''Arihant''-class ( in Sanskrit) is a class of Indian nuclear-powered ballistic missile submarines being built for the Indian Navy. They were developed under the ''Advanced Technology Vessel'' (ATV) project to design and build nuclear-powered submarines. These vessels are classified as 'strategic strike nuclear submarines' by India. The lead vessel of the class, was launched in 2009, and after extensive sea trials, was confirmed to be commissioned in August 2016. ''Arihant'' holds the distinction of being the first ballistic missile submarine to have been built by a country other than one of the five permanent members of the United Nations Security Council. History In December 1971, during the Indo-Pakistani War of 1971, US President Richard Nixon sent a carrier battle group named Task Force 74, led by the nuclear-powered into the international waters of the Bay of Bengal in a show of force. Task Force 74 remained in international waters, where it was legally entitled t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
INS Kattabomman
INS Kattabomman is the designation of the VLF-transmission facility of the Indian Navy situated at Vijayanarayanam near Tirunelveli in Tamil Nadu. The facility spread over 3,000 acres has 13 masts, which are arranged in two rings around the central mast. The centre mast has a height of 301 metres, the masts on the inner ring measure 276.4 metres, that on the outer ring measure 227.4 metres. Two further masts of the station carrying an umbrella antenna, the INS Kattabomman is 471 metres tall and the tallest structure in India. They are also the tallest military structure in the world. The facility opened an ELF transmission facility in 2014. History Development and construction of INS Kattabomman started in 1984 as Project Skylark and costed . It was commissioned into service by Indian President Ramaswamy Venkataraman on 20 October 1990. It is named after king Veera Pandya Kattabomman, who died during the Indian independence movement. After operationalising the base, India ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indian Navy
The Indian Navy is the maritime branch of the Indian Armed Forces. The President of India is the Supreme Commander of the Indian Navy. The Chief of Naval Staff, a four-star admiral, commands the navy. As a blue-water navy, it operates significantly in the Persian Gulf Region, the Horn of Africa, the Strait of Malacca, and routinely conducts anti-piracy operations and partners with other navies in the region. It also conducts routine two to three month-long deployments in the South and East China seas as well as the western Mediterranean sea simultaneously. The primary objective of the navy is to safeguard the nation's maritime borders, and in conjunction with other Armed Forces of the union, act to deter or defeat any threats or aggression against the territory, people or maritime interests of India, both in war and peace. Through joint exercises, goodwill visits and humanitarian missions, including disaster relief, the Indian Navy promotes bilateral relations between n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laurentian Shield
The Canadian Shield (french: Bouclier canadien ), also called the Laurentian Plateau, is a geologic shield, a large area of exposed Precambrian igneous and high-grade metamorphic rocks. It forms the North American Craton (or Laurentia), the ancient geologic core of the North American continent. Glaciation has left the area with only a thin layer of soil, through which exposures of igneous bedrock resulting from its long volcanic history are frequently visible. As a deep, common, joined bedrock region in eastern and central Canada, the Shield stretches north from the Great Lakes to the Arctic Ocean, covering over half of Canada and most of Greenland; it also extends south into the northern reaches of the United States. Geographical extent The Canadian Shield is a physiographic division comprising four smaller physiographic provinces: the Laurentian Upland, Kazan Region, Davis and James. The shield extends into the United States as the Adirondack Mountains (connected by the Fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Resistivity And Conductivity
Electrical resistivity (also called specific electrical resistance or volume resistivity) is a fundamental property of a material that measures how strongly it resists electric current. A low resistivity indicates a material that readily allows electric current. Resistivity is commonly represented by the Greek letter (rho). The SI unit of electrical resistivity is the ohm-meter (Ω⋅m). For example, if a solid cube of material has sheet contacts on two opposite faces, and the resistance between these contacts is , then the resistivity of the material is . Electrical conductivity or specific conductance is the reciprocal of electrical resistivity. It represents a material's ability to conduct electric current. It is commonly signified by the Greek letter ( sigma), but (kappa) (especially in electrical engineering) and (gamma) are sometimes used. The SI unit of electrical conductivity is siemens per metre (S/m). Resistivity and conductivity are intensi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antenna (radio)
In radio engineering, an antenna or aerial is the interface between radio waves propagating through space and electric currents moving in metal conductors, used with a transmitter or receiver. In transmission, a radio transmitter supplies an electric current to the antenna's terminals, and the antenna radiates the energy from the current as electromagnetic wave In physics, electromagnetic radiation (EMR) consists of waves of the electromagnetic (EM) field, which propagate through space and carry momentum and electromagnetic radiant energy. It includes radio waves, microwaves, infrared, (visib ...s (radio waves). In Receiver (radio), reception, an antenna intercepts some of the power of a radio wave in order to produce an electric current at its terminals, that is applied to a receiver to be Amplifier, amplified. Antennas are essential components of all radio equipment. An antenna is an array of conductor (material), conductors (Driven element, elements), elect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wavelength
In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats. It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, troughs, or zero crossings, and is a characteristic of both traveling waves and standing waves, as well as other spatial wave patterns. The inverse of the wavelength is called the spatial frequency. Wavelength is commonly designated by the Greek letter ''lambda'' (λ). The term ''wavelength'' is also sometimes applied to modulated waves, and to the sinusoidal envelopes of modulated waves or waves formed by interference of several sinusoids. Assuming a sinusoidal wave moving at a fixed wave speed, wavelength is inversely proportional to frequency of the wave: waves with higher frequencies have shorter wavelengths, and lower frequencies have longer wavelengths. Wavelength depends on the medium (for example, vacuum, air, or water) that a wav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
