Geomatique
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GRS 80 , or Geodetic Reference System 1980 , is a geodetic reference system consisting of a global reference ellipsoid and a gravity field model .
GRS 80 - Wikipedia, the free encyclopedia
The World Geodetic System is a standard for use in cartography , geodesy , and navigation . It comprises a standard coordinate frame for the Earth , a standard spheroidal reference surface (the datum or reference ellipsoid ) for raw altitude data, and a gravitational equipotential surface (the geoid ) that defines the nominal sea level . The latest revision is WGS 84 (dating from 1984 and last revised in 2004), which was valid up to about 2010. [ 1 ] Earlier schemes included WGS 72 , WGS 66 , and WGS 60 .
World Geodetic System - Wikipedia, the free encyclopedia
Raster graphics - Wikipedia, the free encyclopedia
The smiley face in the top left corner is a bitmap image. When enlarged, individual pixels appear as squares.
