Last updated: 31.03.2021
Datum means a set of parameters specifying the reference surface or the reference co-ordinate system used for geodetic control in the calculation of co-ordinates of points on the earth. Commonly datums are defined as horizontal and vertical datums separately. For the practical use of the datum it is necessary to have one or more well distinctive points with co-ordinates given in that datum.
(Source: CCNR Inland ECDIS Standard; Edition 2.0/23/11/2006)