![]() Since the 1st January 1999, the official co-ordinate system for South Africa is based on the World Geodetic System 1984 ellipsoid, commonly known as WGS84, with the International Terrestrial Reference Frame 1991 (ITRF91 (epoch 1994.0))coordinates of the Hartebeesthoek Radio Astronomy Observatory Telescope used as the origin of this system. The upgrading, recomputation and repositioning of the South African coordinate system was driven by the advancement of modern positioning technologies and the globalization of these techniques for navigation and surveying. In addition to these flaws and distortions, most national geodetic networks do not have the centre of their reference ellipsoids co-incident with the centre of the Earth, thus making them useful only to their area of application. The Cape Datum was based on the work of HM Astronomers: Sir Thomas Maclear, between 18, and Sir David Gill, between 18, whose initial geodetic objectives were to verify the size and shape of the Earth in the Southern Hemisphere and later to provide geodetic control for topographic maps and navigation charts.įrom these beginnings, the network was extended to eventually cover the entire country and now comprises approximately 29 000 highly visible trigonometrical beacons on mountains, high buildings and water towers, as well as approximately 20 000 easily accessible town survey marks.Īs with other national control survey networks throughout the world, which were established using traditional surveying techniques, flaws and distortions in these networks have become easily detectable using modern positioning techniques such as the Global Positioning System (GPS). This Datum was referenced to the Modified Clarke 1880 ellipsoid and had its origin point at Buffelsfontein, near Port Elizabeth. Prior to 1st January 1999, the co-ordinate reference system, used in South Africa as the foundation for all surveying, engineering and georeferenced projects and programmes, was the Cape Datum. The datum was implemented in 1999 when it replaced the Cape Datum. ![]() The Hartebeesthoek94 Datum is the official geodetic datum for South Africa.
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