South American Datum

The South American Datum (SAD) is a regional historical geodetic datum for South America. The most common version was established in 1969 (SAD69), as adopted by the Pan American Institute of Geography and History.^[1]

It uses as reference ellipsoid the Geodetic Reference System 1967 (GRS-67), recommended by the International Union of Geodesy and Geophysics in Lucerne in 1967.^[2] This ellipsoid acquired topocentric orientation defined at the astrogeodetic vertex Chuá, in the municipality of Uberaba, Brazil.^[3][4]

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.^[5]