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Irish Transverse Mercator
Irish Transverse Mercator (ITM) is the geographic coordinate system for Ireland. It was implemented jointly by the Ordnance Survey Ireland (OSi) and the Ordnance Survey of Northern Ireland (OSNI) in 2001. The name is derived from the Transverse Mercator projection it uses and the fact that it is optimised for the island of Ireland. History The older Irish grid reference system required GPS measurements to be "translated" (using co-ordinate transformations). The more precise the GPS measurements were, the more the translation process introduced inaccuracies. While the existing UTM co-ordinate system partly fulfilled the requirement for direct GPS compatibility it had some drawbacks, including varying levels of distortion across the island due to the central meridian being at the west coast of Ireland. The new system needed to satisfy various criteria: GPS compatibility, map distortion for the whole island of Ireland had to be minimal, it was to be conformal and backward co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ITM Example 2007-06-05
ITM may stand for: Education * ITM Law School, one of the professional graduate schools of ITM University * ITM-IFM, Mumbai, India * Institut Teknologi Mara, a public university in Shah Alam, Selangor, Malaysia * Institute for Information, Telecommunication and Media Law, educational organization in Münster, Germany * Institute of Tropical Medicine Antwerp, research and training in tropical medicine, Belgium * Information technology management * International Tourism Management Music * In This Moment, a female-led metalcore band * Irish traditional music * ''In the Meantime'' (Alessia Cara album) Science and Engineering * Irregular Terrain Model, an algorithm to estimate radio frequency propagation pathloss (a.k.a. the "Longley-Rice" algorithm). Other * Independent Timber Merchants, a New Zealand building supplies and hardware retailer * ITM Cup, a rugby union professional competition for New Zealand unions * ITM Power, manufactures integrated hydrogen energy solutions * IT ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Y Axis
Y, or y, is the twenty-fifth and penultimate letter of the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. According to some authorities, it is the sixth (or seventh if including W) vowel letter of the English alphabet. Its name in English is ''wye'' (pronounced ), plural ''wyes''. In the English writing system, it mostly represents a vowel and seldom a consonant, and in other orthographies it may represent a vowel or a consonant. Name In Latin, Y was named ''I graeca'' ("Greek I"), since the classical Greek sound , similar to modern German ''ü'' or French ''u'', was not a native sound for Latin speakers, and the letter was initially only used to spell foreign words. This history has led to the standard modern names of the letter in Romance languages – ''i grego'' in Galician, ''i grega'' in Catalan, ''i grec'' in French and Romanian, and ''i greca'' in Italian – all meaning "Greek I". The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Land Surveying Systems
Land, also known as dry land, ground, or earth, is the solid terrestrial surface of Earth not submerged by the ocean or another body of water. It makes up 29.2% of Earth's surface and includes all continents and islands. Earth's land surface is almost entirely covered by regolith, a layer of Rock (geology), rock, soil, and minerals that forms the outer part of the Earth's crust, crust. Land plays an important role in Earth's climate system, being involved in the carbon cycle, nitrogen cycle, and water cycle. One-third of land is covered in trees, another third is used for agriculture, and one-tenth is covered in permanent snow and glaciers. The remainder consists of desert, savannah, and prairie. Land terrain varies greatly, consisting of mountains, deserts, plains, plateaus, glaciers, and other landforms. In physical geology, the land is divided into two major categories: Mountain ranges and relatively flat interiors called cratons. Both form over millions of years through p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geography Of Ireland
Ireland is an island in Northern Europe, in the north Atlantic Ocean. The island measures about north-south, and east-west, with a total area of . It lies about , near the western edge of the European continental shelf, part of the Eurasian Plate. Ireland is separated from the island of Great Britain by the Irish Sea to the east, and from mainland Europe by the Celtic Sea to the south. It is bounded to the north by the North Channel and to the south by St George's Channel. Ireland is the second-largest landmass in the British Isles, after Great Britain and before the Isle of Man. Its main geographical features include low central plains surrounded by coastal mountains. The highest peak is Carrauntoohil (), which is above sea level. The western coastline is rugged, with many islands, peninsulas, headlands and bays, while the southern and northern coasts have a smaller number of substantial sea inlets, such as Lough Foyle and Cork Harbour; no part of the land is more th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geographic Coordinate Systems
A geographic coordinate system (GCS) is a spherical or geodetic coordinate system for measuring and communicating positions directly on Earth as latitude and longitude. It is the simplest, oldest, and most widely used type of the various spatial reference systems that are in use, and forms the basis for most others. Although latitude and longitude form a coordinate tuple like a cartesian coordinate system, the geographic coordinate system is not cartesian because the measurements are angles and are not on a planar surface. A full GCS specification, such as those listed in the EPSG and ISO 19111 standards, also includes a choice of geodetic datum (including an Earth ellipsoid), as different datums will yield different latitude and longitude values for the same location. History The invention of a geographic coordinate system is generally credited to Eratosthenes of Cyrene, who composed his now-lost ''Geography'' at the Library of Alexandria in the 3rd century BC. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spatial Reference System
A spatial reference system (SRS) or coordinate reference system (CRS) is a framework used to precisely measure locations on the surface of Earth as coordinates. It is thus the application of the abstract mathematics of coordinate systems and analytic geometry to geographic space. A particular SRS specification (for example, "Universal Transverse Mercator WGS 84 Zone 16N") comprises a choice of Earth ellipsoid, Geodetic datum, horizontal datum, map projection (except in the geographic coordinate system), origin point, and unit of measure. Thousands of coordinate systems have been specified for use around the world or in specific regions and for various purposes, necessitating geographic coordinate conversion, transformations between different SRS. Although they date to the Hellenistic period, spatial reference systems are now a crucial basis for the sciences and technologies of Geoinformatics, including cartography, geographic information systems, surveying, remote sensing, and civ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ETRS89
The European Terrestrial Reference System 1989 (ETRS89) is an ECEF (Earth-Centered, Earth-Fixed) geodetic Cartesian reference frame, in which the Eurasian Plate as a whole is static. The coordinates and maps in Europe based on ETRS89 are not subject to change due to the continental drift. The development of ETRS89 is related to the global ITRS geodetic datum, in which the representation of the continental drift is balanced in such a way that the total apparent angular momentum of continental plates is about 0. ETRS89 was officially born at the 1990 Florence meeting of EUREF, following its Resolution 1, which recommends that the terrestrial reference system to be adopted by EUREF will be coincident with ITRS at the epoch 1989.0 and fixed to the stable part of the Eurasian Plate. According to the resolution, this system was named European Terrestrial Reference System 89 (ETRS89). Since then ETRS89 and ITRS diverge due to the continental drift at a speed about 2.5 cm pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EPSG
EPSG Geodetic Parameter Dataset (also EPSG registry) is a public registry of geodetic datums, spatial reference systems, Earth ellipsoids, coordinate transformations and related units of measurement, originated by a member of the European Petroleum Survey Group (EPSG) in 1985. Each entity is assigned an EPSG code between 1024 and 32767, along with a standard machine-readable well-known text (WKT) representation. The dataset is maintained by the IOGP Geomatics Committee. Most geographic information systems (GIS) and GIS libraries use EPSG codes as Spatial Reference System Identifiers (SRIDs) and EPSG definition data for identifying coordinate reference systems, projections, and performing transformations between these systems, while some also support SRIDs issued by other organizations (such as Esri). Common EPSG codes * EPSG:4326 - WGS 84 datum ensemble for 2D (latitude, longitude) coordinates with 2 meter accuracy, used by the Global Positioning System among others. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malin Head
Malin Head () is the Extreme points of Ireland, most northerly point of mainland Ireland, located in the townland of Ardmalin on the Inishowen peninsula in County Donegal. The head's northernmost point is called Dunalderagh at latitude 55.38ºN. It is about north of the village of Malin, County Donegal, Malin. The island of Inishtrahull is further north, about northeast of the headland. Malin Head gives its name to the Malin Shipping Forecast, sea area. There is a weather station on the head, which is one of List of coastal weather stations in the British Isles, 22 such stations whose reports are broadcast as part of the Shipping Forecast, BBC Shipping Forecast. A tower built in 1805 is on Altnadarrow, also known locally as the Tower Hill. Ptolemy's ''Geography (Ptolemy), Geography'' (2nd century AD) described a point called Βορειον (''Boreion'', "the northern") which probably referred to Malin Head. Locality To the northeast Inistrahull Island can be seen. The first ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordnance Datum
An ordnance datum (OD) is a vertical datum used by an ordnance survey as the basis for deriving altitudes on maps. A spot height may be expressed as above ordnance datum (AOD). Usually mean sea level (MSL) at a particular place is used for the datum. British Isles * In Great Britain, OD for the Ordnance Survey is Ordnance Datum Newlyn (ODN), defined as the MSL as recorded by the Newlyn Tidal Observatory between 1915 and 1921. **Prior to 1921, OD was Ordnance Datum Liverpool (ODL) defined as MSL as recorded in the Victoria Dock (Liverpool), Victoria Dock, Liverpool, during a short period in 1844. The first datum, in 1840 used a benchmark on St John's Church, Liverpool Central, St. John’s Church, . * In Northern Ireland, OD for the Ordnance Survey of Northern Ireland is Belfast Ordnance Datum: the MSL at Clarendon Dock, Belfast Harbour, between 1951 and 1956. * In Republic of Ireland, Ireland, OD for the Ordnance Survey of Ireland is Malin Ordnance Datum: the MSL at Portmoor Pie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scale (map)
The scale of a map is the ratio of a distance on the map to the corresponding distance on the ground. This simple concept is complicated by the curvature of the Earth's surface, which forces scale to vary across a map. Because of this variation, the concept of scale becomes meaningful in two distinct ways. The first way is the ratio of the size of the generating globe to the size of the Earth. The generating globe is a conceptual model to which the Earth is shrunk and from which the map is Map projection, projected. The ratio of the Earth's size to the generating globe's size is called the nominal scale (also called principal scale or representative fraction). Many maps state the nominal scale and may even display a bar scale (sometimes merely called a "scale") to represent it. The second distinct concept of scale applies to the variation in scale across a map. It is the ratio of the mapped point's scale to the nominal scale. In this case 'scale' means the scale factor (also ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GRS80
The Geodetic Reference System 1980 (GRS80) consists of a global reference ellipsoid and a normal gravity model. The GRS80 gravity model has been followed by the newer more accurate Earth Gravitational Models, but the GRS80 reference ellipsoid is still the most accurate in use for coordinate reference systems, e.g. for the international ITRS, the European ETRS89 and (with a 0,1 mm rounding error) for WGS 84 used for the American Global Navigation Satellite System (GPS). Background Geodesy is the scientific discipline that deals with the measurement and representation of the earth, its gravitational field and geodynamic phenomena (polar motion, earth tides, and crustal motion) in three-dimensional, time-varying space. The geoid is essentially the figure of the Earth abstracted from its topographic features. It is an idealized equilibrium surface of sea water, the mean sea level surface in the absence of currents, air pressure variations etc. and continued under the continental m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
