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To establish the position of a geographic location on a map, a map projection is used to convert geodetic coordinates to plane coordinates on a map; it projects the datum ellipsoidal coordinates and height onto a flat surface of a map. The datum, along with a map projection applied to a grid of reference locations, establishes a grid system for ...
This WKT format was initially defined by the Open Geospatial Consortium (OGC) in 1999, then extended in 2001. This format, also defined in ISO 19125-1:2004, is sometime known as "WKT 1". [ 5 ] Later, evolution of the Coordinate Reference System conceptual model, new requirements and inconsistencies in implementation of WKT 1 format between ...
Conversion of coordinates and map positions among different map projections reference to the same datum may be accomplished either through direct translation formulas from one projection to another, or by first converting from a projection to an intermediate coordinate system, such as ECEF, then converting from ECEF to projection . The formulas ...
The straight-line distance between the central point on the map to any other point is the same as the straight-line 3D distance through the globe between the two points. c. 150 BC: Stereographic: Azimuthal Conformal Hipparchos* Map is infinite in extent with outer hemisphere inflating severely, so it is often used as two hemispheres.
/Locator maps: Blank area for creating Locator maps. Based on simplified Location maps. A province in the country (when the blank map is actually filled). /Area maps (en) Maps that highlight one subject area, primarily for species distributions. Locator maps: a country (red) in its region and in the world (corner map).
A datum is a formal description of the shape of the Earth along with an "anchor" point for the coordinate system. In surveying , cartography , and land-use planning , two North American Datums are in use for making lateral or "horizontal" measurements: the North American Datum of 1927 (NAD 27) and the North American Datum of 1983 (NAD 83).
A geodetic datum or geodetic system (also: geodetic reference datum, geodetic reference system, or geodetic reference frame, or terrestrial reference frame) is a global datum reference or reference frame for unambiguously representing the position of locations on Earth by means of either geodetic coordinates (and related vertical coordinates) or geocentric coordinates. [1]
Given that every projection gives deformations, each country's needs are different in order to reduce these distortions. These national projections, or national Coordinate Reference Systems are officially announced by the relevant national agencies. The list below is a collection of available official national projected Coordinate Reference ...