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Trig Point
A triangulation station, also known as a trigonometrical point, and sometimes informally as a trig, is a fixed surveying station, used in geodetic surveying and other surveying projects in its vicinity. The nomenclature varies regionally: they are generally known as trigonometrical stations or triangulation stations in North America, trig points in the United Kingdom, trig pillars in Ireland, trig stations or trig points in Australia and New Zealand, and trig beacons in South Africa. Use The station is usually set up by a government with known coordinates and elevation published. Many stations are located on hilltops for the purposes of visibility. A graven metal plate on the top of a pillar may provide a mounting point for a theodolite or reflector, often using some form of kinematic coupling to ensure reproducible positioning. Trigonometrical stations are grouped together to form a network of triangulation. Positions of all land boundaries, roads, railways, bridges and other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trigonometrical Station
A triangulation station, also known as a trigonometrical point, and sometimes informally as a trig, is a fixed surveying station, used in geodetic surveying and other surveying projects in its vicinity. The nomenclature varies regionally: they are generally known as trigonometrical stations or triangulation stations in North America, trig points in the United Kingdom, trig pillars in Ireland, trig stations or trig points in Australia and New Zealand, and trig beacons in South Africa. Use The station is usually set up by a government with known coordinates and elevation published. Many stations are located on hilltops for the purposes of visibility. A graven metal plate on the top of a pillar may provide a mounting point for a theodolite or reflector, often using some form of kinematic coupling to ensure reproducible positioning. Trigonometrical stations are grouped together to form a network of triangulation. Positions of all land boundaries, roads, railways, bridges and other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordnance Survey
, nativename_a = , nativename_r = , logo = Ordnance Survey 2015 Logo.svg , logo_width = 240px , logo_caption = , seal = , seal_width = , seal_caption = , picture = , picture_width = , picture_caption = , formed = , preceding1 = , dissolved = , superseding = , jurisdiction = Great BritainThe Ordnance Survey deals only with maps of Great Britain, and, to an extent, the Isle of Man, but not Northern Ireland, which has its own, separate government agency, the Ordnance Survey of Northern Ireland. , headquarters = Southampton, England, UK , region_code = GB , coordinates = , employees = 1,244 , budget = , minister1_name = , minister1_pfo = , chief1_name = Steve Blair , chief1_position = CEO , agency_type = , parent_agency = , child1_agency = , keydocument1 = , website = , footnotes = , map = , map_width = , map_caption = Ordnance Survey (OS) is the national mapping agency for Great Britain. The agency's name indicates its original military purpose (se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Mapping
Digital mapping (also called digital or computer cartography) is the process by which a collection of spatial data is compiled and formatted into a virtual image on a computer. The primary function of this technology is to produce maps that give accurate representations of a particular area, detailing major road arteries and other points of interest. The technology also allows the calculation of distances from one place to another. Although digital mapping can be found in a variety of computer applications the main use of these maps is with the Global Positioning System, or GPS satellite network, used in standard automotive navigation systems. History From paper to paperless The roots of digital mapping lie within traditional paper maps such as the Thomas Guide and Geographers' A–Z Street Atlas. Paper maps provide basic landscapes similar to digitized road maps, yet are often cumbersome, cover only a designated area, and lack many specific details such as road blocks. In additio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerial Photography
Aerial photography (or airborne imagery) is the taking of photographs from an aircraft or other airborne platforms. When taking motion pictures, it is also known as aerial videography. Platforms for aerial photography include fixed-wing aircraft, helicopters, unmanned aerial vehicles (UAVs or "drones"), balloons, blimps and dirigibles, rockets, pigeons, kites, or using action cameras while skydiving or wingsuiting. Handheld cameras may be manually operated by the photographer, while mounted cameras are usually remotely operated or triggered automatically. Aerial photography typically refers specifically to bird's-eye view images that focus on landscapes and surface objects, and should not be confused with air-to-air photography, where one or more aircraft are used as chase planes that "chase" and photograph other aircraft in flight. Elevated photography can also produce bird's-eye images closely resembling aerial photography (despite not actually being aerial shots) when ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Daily Telegraph
''The Daily Telegraph'', known online and elsewhere as ''The Telegraph'', is a national British daily broadsheet newspaper published in London by Telegraph Media Group and distributed across the United Kingdom and internationally. It was founded by Arthur B. Sleigh in 1855 as ''The Daily Telegraph & Courier''. Considered a newspaper of record over ''The Times'' in the UK in the years up to 1997, ''The Telegraph'' generally has a reputation for high-quality journalism, and has been described as being "one of the world's great titles". The paper's motto, "Was, is, and will be", appears in the editorial pages and has featured in every edition of the newspaper since 19 April 1858. The paper had a circulation of 363,183 in December 2018, descending further until it withdrew from newspaper circulation audits in 2019, having declined almost 80%, from 1.4 million in 1980.United Newspapers PLC and Fleet Holdings PLC', Monopolies and Mergers Commission (1985), pp. 5–16. Its si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Levelling
Levelling or leveling (American English; American and British English spelling differences#Doubled in British English, see spelling differences) is a branch of surveying, the object of which is to establish or verify or measure the height of specified points relative to a datum. It is widely used in geodesy and cartography to measure vertical position with respect to a vertical datum, and in construction to measure height differences of construction artifacts. Optical levelling Optical levelling, also known as spirit levelling and differential levelling, employs an ''optical level'', which consists of a precision telescope with crosshairs and stadia marks. The cross hairs are used to establish the level point on the target, and the stadia allow range-finding; stadia are usually at ratios of 100:1, in which case one metre between the stadia marks on the levelling staff represents 100metres from the target. The complete unit is normally mounted on a Tripod (surveying), tripod, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trigonometric
Trigonometry () is a branch of mathematics that studies relationships between side lengths and angles of triangles. The field emerged in the Hellenistic world during the 3rd century BC from applications of geometry to astronomical studies. The Greeks focused on the calculation of chords, while mathematicians in India created the earliest-known tables of values for trigonometric ratios (also called trigonometric functions) such as sine. Throughout history, trigonometry has been applied in areas such as geodesy, surveying, celestial mechanics, and navigation. Trigonometry is known for its many identities. These trigonometric identities are commonly used for rewriting trigonometrical expressions with the aim to simplify an expression, to find a more useful form of an expression, or to solve an equation. History Sumerian astronomers studied angle measure, using a division of circles into 360 degrees. They, and later the Babylonians, studied the ratios of the sides o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Martin Hotine
Brigadier Martin Hotine CMG CBE (17 June 1898 – 12 November 1968) was the head of the Trigonometrical and Levelling Division of the Ordnance Survey responsible for the 26-year-long retriangulation of Great Britain (1936–1962) and was the first Director General of the Directorate of Overseas Surveys (1946–1955). He served on the North-West Frontier during the First World War and later in the Persian and Mesopotamian campaigns. He has been described as "decisive, ingenious and tough". Cartography Hotine was responsible for the design of the triangulation pillars constructed during the Geodetic resurvey of Britain. 6,173 of these were built. They provided a solid base for the theodolites used by the survey teams during the survey, thereby improving the accuracy of the readings obtained. They are sometimes referred to as "Hotine Pillars". In the 1940s, Hotine developed a map projection for the Malay Peninsula and Borneo that is known as the Hotine oblique Mercator project ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benchmark (surveying)
The term benchmark, bench mark, or survey benchmark originates from the chiseled horizontal marks that surveyors made in stone structures, into which an angle-iron could be placed to form a "bench" for a leveling rod, thus ensuring that a leveling rod could be accurately repositioned in the same place in the future. These marks were usually indicated with a chiseled arrow below the horizontal line. The term is generally applied to any item used to mark a point as an elevation reference. Frequently, bronze or aluminum disks are set in stone or concrete, or on rods driven deeply into the earth to provide a stable elevation point. If an elevation is marked on a map, but there is no physical mark on the ground, it is a spot height. Purpose The height of a benchmark is calculated relative to the heights of nearby benchmarks in a network extending from a ''fundamental benchmark''. A fundamental benchmark is a point with a precisely known relationship to the vertical datum of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Obelisk
An obelisk (; from grc, ὀβελίσκος ; diminutive of ''obelos'', " spit, nail, pointed pillar") is a tall, four-sided, narrow tapering monument which ends in a pyramid-like shape or pyramidion at the top. Originally constructed by Ancient Egyptians and called ''tekhenu'', the Greeks used the Greek term to describe them, and this word passed into Latin and ultimately English. Ancient obelisks are monolithic; they consist of a single stone. Most modern obelisks are made of several stones. Ancient obelisks Egyptian Obelisks were prominent in the architecture of the ancient Egyptians, and played a vital role in their religion placing them in pairs at the entrance of the temples. The word "obelisk" as used in English today is of Greek rather than Egyptian origin because Herodotus, the Greek traveler, was one of the first classical writers to describe the objects. A number of ancient Egyptian obelisks are known to have survived, plus the " Unfinished Obelisk" found part ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyramid
A pyramid (from el, πυραμίς ') is a structure whose outer surfaces are triangular and converge to a single step at the top, making the shape roughly a pyramid in the geometric sense. The base of a pyramid can be trilateral, quadrilateral, or of any polygon shape. As such, a pyramid has at least three outer triangular surfaces (at least four faces including the base). The square pyramid, with a square base and four triangular outer surfaces, is a common version. A pyramid's design, with the majority of the weight closer to the ground and with the pyramidion at the apex, means that less material higher up on the pyramid will be pushing down from above. This distribution of weight allowed early civilizations to create stable monumental structures. Civilizations in many parts of the world have built pyramids. The largest pyramid by volume is the Great Pyramid of Cholula, in the Mexican state of Puebla. For thousands of years, the largest structures on Earth were pyrami ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trig Point
A triangulation station, also known as a trigonometrical point, and sometimes informally as a trig, is a fixed surveying station, used in geodetic surveying and other surveying projects in its vicinity. The nomenclature varies regionally: they are generally known as trigonometrical stations or triangulation stations in North America, trig points in the United Kingdom, trig pillars in Ireland, trig stations or trig points in Australia and New Zealand, and trig beacons in South Africa. Use The station is usually set up by a government with known coordinates and elevation published. Many stations are located on hilltops for the purposes of visibility. A graven metal plate on the top of a pillar may provide a mounting point for a theodolite or reflector, often using some form of kinematic coupling to ensure reproducible positioning. Trigonometrical stations are grouped together to form a network of triangulation. Positions of all land boundaries, roads, railways, bridges and other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
