RefElevation

RefElevation is a term used in geographic information systems (GIS) and surveying to denote a reference elevation. This is a specific vertical datum or a point of known elevation used as a basis for measuring other elevations. Without a reference elevation, it is impossible to accurately determine the height of other locations. Commonly used reference elevations include mean sea level (MSL), which represents the average height of the sea's surface, or a national geodetic vertical datum established by a country's surveying authority. Surveyors establish and use reference elevations to ensure consistency and accuracy in mapping, construction, and other land-based projects. In digital elevation models (DEMs), the elevation values are typically given relative to a defined vertical datum, which acts as the refElevation. Changes in ground elevation are measured as differences from this established reference point.