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Georeferencing: Difference between revisions
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→Geographic Concepts Related to Georeferencing
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::A model of the earth used for geodetic calculations. A geodetic datum describes the size, shape, origin, and orientation of a coordinate system for mapping the surface of the earth.<br> | ::A model of the earth used for geodetic calculations. A geodetic datum describes the size, shape, origin, and orientation of a coordinate system for mapping the surface of the earth.<br> | ||
=== Coordinate System === | === Coordinate System === | ||
::A system used to denote direct or relative positions by coordinates; Examples of two-dimensional coordinate systems are <u>Latitude/Longitude</u> and <u>Universal Transverse Mercator (UTM)</u><br> | ::A system used to denote direct or relative positions by coordinates; Examples of two-dimensional coordinate systems are <u>Latitude/Longitude</u> and <u>Universal Transverse Mercator (UTM)</u><br> | ||
=== Geographic Coordinate System === | === Geographic Coordinate System === | ||
::The net or graticule of lines of latitude (parallels) numbered 0° to 90° north and south of the equator, and lines of longitude (meridians) numbered 0° to180° east and west of the international zero meridian of Greenwich, used to define locations on the Earth's surface (disregarding elevation) with the aid of angular measure (degrees, minutes and seconds of arc).<br> | ::The net or graticule of lines of latitude (parallels) numbered 0° to 90° north and south of the equator, and lines of longitude (meridians) numbered 0° to180° east and west of the international zero meridian of Greenwich, used to define locations on the Earth's surface (disregarding elevation) with the aid of angular measure (degrees, minutes and seconds of arc).<br> | ||
=== Projection === | === Projection === | ||
::A projection is a representation of the earth's three-dimensional surface as a flat two-dimensional surface. This normally involves a mathematical model (of which there are many) that transforms the locations of features on the earth's surface to locations on a two- dimensional surface. Such representations distort one or more parameters of the earth's surface such as distance, area, shape, or direction. <br> | ::A projection is a representation of the earth's three-dimensional surface as a flat two-dimensional surface. This normally involves a mathematical model (of which there are many) that transforms the locations of features on the earth's surface to locations on a two- dimensional surface. Such representations distort one or more parameters of the earth's surface such as distance, area, shape, or direction. <br> | ||
= Georeference Best Practices = | = Georeference Best Practices = | ||