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Stereoscopic Rangefinder
A stereoscopic rangefinder or stereoscopic telemeter is an optical device that measures distance from the observer to a target, using the observer's capability of binocular vision. It looks similar to a coincidence rangefinder, which uses different principles and has only one eyepiece. German instruments tended to use the stereoscopic principle while British ones used coincidence. Technical Principle A stereoscopic rangefinder uses two eyepieces and relies on the operator's visual cortex to merge the two images into a single picture. A reference mark is separately inserted into each eyepiece. The operator first adjusts the direction of the range finder so that the fixed mark is centered on the target, and then the prisms are rotated until the mark appears to overlap in the operator's combined view. The range to the target is proportional to the degree of rotation of the prisms.FM 4-15, Coast Artillery Field ManualSeacoast Artillery Fire Control and Position Finding U.S. Government ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bundesarchiv Bild 183-J08361, Entfernungsmesser Einer Vierlings-Flak
The German Federal Archives or Bundesarchiv (BArch) (german: Bundesarchiv) are the National Archives of Germany. They were established at the current location in Koblenz in 1952. They are subordinated to the Federal Commissioner for Culture and the Media (Claudia Roth since 2021) under the German Chancellery, and before 1998, to the Federal Ministry of the Interior (Germany), Federal Ministry of the Interior. On 6 December 2008, the Archives donated 100,000 photos to the public, by making them accessible via Wikimedia Commons. History The federal archive for institutions and authorities in Germany, the first precursor to the present-day Federal Archives, was established in Potsdam, Brandenburg in 1919, a later date than in other European countries. This national archive documented German government dating from the founding of the North German Confederation in 1867. It also included material from the older German Confederation and the Imperial Chamber Court. The oldest documents i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binocular Vision
In biology, binocular vision is a type of vision in which an animal has two eyes capable of facing the same direction to perceive a single three-dimensional image of its surroundings. Binocular vision does not typically refer to vision where an animal has eyes on opposite sides of its head and shares no field of view between them, like in some animals. Neurological researcher Manfred Fahle has stated six specific advantages of having two eyes rather than just one: #It gives a creature a "spare eye" in case one is damaged. #It gives a wider field of view. For example, humans have a maximum horizontal field of view of approximately 190 degrees with two eyes, approximately 120 degrees of which makes up the binocular field of view (seen by both eyes) flanked by two uniocular fields (seen by only one eye) of approximately 40 degrees. #It can give stereopsis in which binocular disparity (or parallax) provided by the two eyes' different positions on the head gives precise depth perc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coincidence Rangefinder
A coincidence rangefinder or coincidence telemeter is a type of rangefinder that uses mechanical and optical principles to allow an operator to determine the distance to a visible object. There are subtypes split-image telemeter, inverted image, or double-image telemeter with different principles how two images in a single ocular are compared. Coincidence rangefinders were important elements of fire control systems for long-range naval guns and land-based coastal artillery circa 1890–1960. They were also used in rangefinder cameras. A stereoscopic telemeter looks similar, but has two eyepieces and uses a different principle, based on binocular vision. The two can normally be distinguished at a glance by the number of eyepieces. Design The device consists of a long tube with a forward-facing lens at each end and an operator eyepiece in the center. Two prism wedges which, when aligned result in no deviation of the light, are inserted into the light path of one of the two lense ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Defense Research Committee
The National Defense Research Committee (NDRC) was an organization created "to coordinate, supervise, and conduct scientific research on the problems underlying the development, production, and use of mechanisms and devices of warfare" in the United States from June 27, 1940, until June 28, 1941. Most of its work was done with the strictest secrecy, and it began research of what would become some of the most important technology during World War II, including radar and the atomic bomb. It was superseded by the Office of Scientific Research and Development in 1941, and reduced to merely an advisory organization until it was eventually terminated during 1947. Organization The NDRC was created by an order of President Franklin Delano Roosevelt on June 27, 1940. It was part of the Council of National Defense, which had been created during 1916 to coordinate industry and resources for national security purposes. Vannevar Bush, the director of the Carnegie Institution, had pressed for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bausch And Lomb
Bausch + Lomb is an eye health products company based in Vaughan, Ontario, Canada. It is one of the world's largest suppliers of contact lenses, lens care products, pharmaceuticals, intraocular lenses, and other eye surgery products. The company was founded in Rochester, New York, in 1853 by optician John Bausch and cabinet maker turned financial backer Henry Lomb. Until its sale in 2013, Bausch + Lomb was one of the oldest continually operating companies in the United States. Bausch + Lomb was a public company listed on the NYSE, until it was acquired by private equity firm Warburg Pincus in 2007. In May 2013, Canadian-based Valeant Pharmaceuticals announced that it would acquire Bausch + Lomb from Warburg Pincus for $4.5 billion in cash. The deal, which was approved by shareholders, closed on August 5, 2013. On May 6, 2022, the company completed an initial public offering and again became publicly traded. Today, the company employs about 21,000 people and manufactures and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barr And Stroud
Barr & Stroud Limited was a pioneering Glasgow optical engineering firm. They played a leading role in the development of modern optics, including rangefinders, for the Royal Navy and for other branches of British Armed Forces during the 20th century. There was a non-military arm of the company which made medical equipment, like photocoagulators and electronic filters, some of which were used by the BBC. The company and its intellectual property passed through Pilkington group to Thales Optronics. The Barr and Stroud name was sold on to an importer of optical equipment, who use the trademarked name for a line of binoculars and similar instruments. History Archibald Barr and William Stroud had been associated from as early as 1888 when the two men were professors of, respectively, engineering and physics at the Yorkshire College (now the University of Leeds). In 1891, they were approached by the Admiralty to submit a design for a short-base rangefinder for trial. By this time, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Defense Technical Information Center
The Defense Technical Information Center (DTIC, pronounced "Dee-tick") is the repository for research and engineering information for the United States Department of Defense (DoD). DTIC's services are available to DoD personnel, federal government personnel, federal contractors and selected academic institutions. The general public can access unclassified information through its public website. History The DTIC traces its history to the June 1945 formation of the Air Documents Research Center (ADRC), a joint effort of the US Army Air Force, US Navy and Royal Air Force to build a single collection of captured German aeronautical research, based in London. The ADRC was initially tasked with the sorting of the document collection into three broad groups; documents that would assist the war in the Pacific theater, documents of immediate intelligence interest to the United States or British forces and documents of interest for future research. With the ending of the war in 1945, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Marine Corps
The United States Marine Corps (USMC), also referred to as the United States Marines, is the maritime land force service branch of the United States Armed Forces responsible for conducting expeditionary and amphibious operations through combined arms, implementing its own infantry, artillery, aerial, and special operations forces. The U.S. Marine Corps is one of the eight uniformed services of the United States. The Marine Corps has been part of the U.S. Department of the Navy since 30 June 1834 with its sister service, the United States Navy. The USMC operates installations on land and aboard sea-going amphibious warfare ships around the world. Additionally, several of the Marines' tactical aviation squadrons, primarily Marine Fighter Attack squadrons, are also embedded in Navy carrier air wings and operate from the aircraft carriers. The history of the Marine Corps began when two battalions of Continental Marines were formed on 10 November 1775 in Philadelphia as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
17th Antiaircraft Artillery Battalion
The 17th Antiaircraft Artillery Battalion (17th AAA Bn) was an antiaircraft unit in the United States Marine Corps that served during World War II. The battalion was originally formed in 1942 as the 2d Airdrome Battalion and has the distinction of being the last defense battalion formed in the Marine Corps during the war. Its original mission was to provide air and coastal defense for advanced naval bases. During the war the battalion spent significant time defending Nukufetau and took part in combat operations at Tarawa and Tinian. The battalion was decommissioned on December 6, 1945. History Organization The 2d Airdrome Battalion was commissioned on October 28, 1942 at Camp Elliott, San Diego, California. It was one of two airdrome battalions formed by the Marine Corps specifically to defend airfields in the China Burma India Theater. Those airfields were overrun by the Japanese before the battalions deployed so the Marine Corps quickly changed their tasking to mission ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nukufetau
Nukufetau is an atoll that is part of the nation of Tuvalu. The atoll was claimed by the US under the Guano Islands Act some time in the 19th century and was ceded in a treaty of friendship concluded in 1979 and coming into force in 1983. It has a population of 597 who live on Savave islet (2017 Census). In 1951 the school that was located on Motumua islet was transferred to Savave and became the government primary school for Nukufetau. It was named the Tutasi Memorial School in honour of its predecessor. Geography Nukufetau is an atoll with passages through the reef that allow large ships to enter and anchor in the lagoon. Nukufetau consists of at least 33 islets: * Faiava Lasi * Fale * Funaota * Kongo Loto Lafanga * Lafanga * Matanukulaelae * Motufetau * Motulalo * Motuloa (north of Nukufetau) * Motuloa (south of Nukufetau) * Motumua * Niualuka * Niuatui * Oua * Sakalua * Savave * Teafatule * Teafuaniua * Teafuanonu * Teafuone * Temotuloto * and at least 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stadiametric Rangefinding
Stadiametric rangefinding, or the stadia method, is a technique of measuring distances with a telescopic instrument. The term stadia comes from a Greek unit of length '' Stadion'' (equal to 600 Greek feet, '' pous'') which was the typical length of a sports stadium of the time. Stadiametric rangefinding is used for surveying and in the telescopic sights of firearms, artillery pieces, or tank guns, as well as some binoculars and other optics. It is still widely used in long-range military sniping, but in many professional applications it is being replaced with microwave, infrared, or laser rangefinding methods. Although much easier to use, electronic rangefinders can give away the shooter's position to a well-equipped adversary, and the need for accurate range estimation existed for much longer than electronic rangefinders small and rugged enough to be suitable for military use. Principle The stadia method is based upon the principle of similar triangles. This means tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coincidence Rangefinder
A coincidence rangefinder or coincidence telemeter is a type of rangefinder that uses mechanical and optical principles to allow an operator to determine the distance to a visible object. There are subtypes split-image telemeter, inverted image, or double-image telemeter with different principles how two images in a single ocular are compared. Coincidence rangefinders were important elements of fire control systems for long-range naval guns and land-based coastal artillery circa 1890–1960. They were also used in rangefinder cameras. A stereoscopic telemeter looks similar, but has two eyepieces and uses a different principle, based on binocular vision. The two can normally be distinguished at a glance by the number of eyepieces. Design The device consists of a long tube with a forward-facing lens at each end and an operator eyepiece in the center. Two prism wedges which, when aligned result in no deviation of the light, are inserted into the light path of one of the two lense ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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