Search results
Results From The WOW.Com Content Network
The WGS 84 datum surface is an oblate spheroid with equatorial radius a = 6 378 137 m at the equator and flattening f = 1 ⁄ 298.257 223 563. The refined value of the WGS 84 gravitational constant (mass of Earth's atmosphere included) is GM = 3.986 004 418 × 10 14 m 3 /s 2. The angular velocity of the Earth is defined to be ω = 72.921 15 × ...
The dataset was created in 1985 by Jean-Patrick Girbig of Elf, to "standardize, improve and share spatial data between members of the European Petroleum Survey Group". [5] It was made public in 1993. [6] In 2005, the EPSG organisation was merged into International Association of Oil & Gas Producers (IOGP), and became the Geomatics Committee ...
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]
The NAD83 map datum is sufficiently close to WGS84 for initial use. It is best to double check on a mapping site such as WikiMapia. Cordinates obtained in China from commercial sources (Google, Bing, Baidu, etc.) may be obfuscated with GCJ-02 or BD-09. Vector sources are more frequently affected than satellite sources.
The first EGM, EGM84, was defined as a part of WGS84 along with its reference ellipsoid.WGS84 combines the old GRS 80 with the then-latest data, namely available Doppler, satellite laser ranging, and Very Long Baseline Interferometry observations, and a new least squares method called collocation. [3]
Each projected coordinate system, such as "Universal Transverse Mercator WGS 84 Zone 26N," is defined by a choice of map projection (with specific parameters), a choice of geodetic datum to bind the coordinate system to real locations on the earth, an origin point, and a choice of unit of measure. [2]
For example, the WKT below describes a two-dimensional geographic coordinate reference system with a latitude axis first, then a longitude axis. The coordinate system is related to Earth by the WGS84 geodetic datum:
The National Spatial Framework for India uses Datum WGS84 with a LCC projection and is a recommended NNRMS standard. Each state has its own set of reference parameters given in the standard. [ 8 ]