The South American Datum (SAD) is a regional historical

geodetic datum A geodetic datum or geodetic system (also: geodetic reference datum, geodetic reference system, or geodetic reference frame) is a global datum reference or reference frame for precisely representing the position of locations on Earth or other plan ...

for

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

. The most common version was established in 1969 (''SAD69''), as adopted by the

Pan American Institute of Geography and History {{Expand Spanish, date=June 2021 The Pan American Institute of Geography and History (PAIGH, es, Instituto Panamericano de Geografía e Historia - IPGH) is an international organisation dedicated to the generation and transference of knowledge spe ...

. It uses as

reference ellipsoid An Earth ellipsoid or Earth spheroid is a mathematical figure approximating the Earth's form, used as a reference frame for computations in geodesy, astronomy, and the geosciences. Various different ellipsoids have been used as approximations ...

the

Geodetic Reference System A geodetic datum or geodetic system (also: geodetic reference datum, geodetic reference system, or geodetic reference frame) is a global datum reference or reference frame for precisely representing the position of locations on Earth or other plan ...

1967 (GRS-67), recommended by the

International Union of Geodesy and Geophysics The International Union of Geodesy and Geophysics (IUGG; french: Union géodésique et géophysique internationale, UGGI) is an international non-governmental organization dedicated to the scientific study of Earth and its space environment usi ...

Lucerne Lucerne ( , ; High Alemannic German, High Alemannic: ''Lozärn'') or Luzern ()Other languages: gsw, Lozärn, label=Lucerne German; it, Lucerna ; rm, Lucerna . is a city in central Switzerland, in the Languages of Switzerland, German-speaking po ...

in 1967. This ellipsoid acquired topocentric orientation defined at the astrogeodetic

vertex Vertex, vertices or vertexes may refer to: Science and technology Mathematics and computer science *Vertex (geometry), a point where two or more curves, lines, or edges meet *Vertex (computer graphics), a data structure that describes the position ...

''Chuá'', in the municipality of

Uberaba Uberaba () is a city in the state of Minas Gerais, southeast Brazil. It is located in the Brazilian Highlands at above sea level on the Uberaba River, and away from the state capital, Belo Horizonte. The city status was granted in 1856, and i ...

, Brazil. This datum was subsequently adopted by many South American countries, including the earlier ''Brazilian Geodetic System'' (''Sistema Geodésico Brasileiro'' - ''SGB''). In most countries, SAD was recently replaced by SIRGAS; for example, in Brazil SIRGAS was adopted starting in 2005 and mandated since 2014.

References

Geodetic datums {{SouthAm-stub