päädatum

Päädatum is a Finnish term that refers to the main or primary datum used as a reference point or dataset in measurements, data processing, and archiving. The word combines Finnish pää (main or principal) with datum (from Latin). In Finnish technical literature, päädatum denotes the principal reference point or dataset that other measurements or data items relate to.

In geodesy and surveying, a datum is a mathematically defined surface or point system that provides the origin for coordinates. A päädatum in this sense is the organization’s or project’s main geodetic reference frame, often a national or local datum such as ETRS89. When multiple datums are involved, the päädatum serves as a canonical baseline for transformations and comparisons between datasets or coordinate systems.

In data management and information systems, päädatum can mean the canonical or “master” dataset that serves as the primary source of truth for a family of data. It defines baseline values from which derivatives, calibrations, or aggregations are produced, and is frequently managed within master data management (MDM) or data governance programs.

Usage and translation: the term is common in Finnish contexts but not standardized in English; translations include “principal datum” or “main reference datum,” depending on the field. The concept aligns with English terms such as datum (in geodesy) or master data (in data management).

See also: datum, reference frame, geodetic datum, master data, data governance.