ortometría

Ortometría is a term used in surveying and geodesy to refer to the process of calculating the orthometric height of a point. Orthometric height, also known as height above sea level or mean sea level, is a measure of the vertical distance from a reference geoid surface to a point. This is distinct from ellipsoidal height, which is the vertical distance from a reference ellipsoid.

The calculation of orthometric height typically involves gravity measurements. A common method is to use the normal gravity formula to approximate the geoid undulation, which is the difference between the geoid and the reference ellipsoid. By subtracting the geoid undulation from the ellipsoidal height, one can obtain the orthometric height. This process is crucial for many applications, including mapping, engineering, and hydrological studies, where consistent vertical datums are essential.

The accuracy of ortometría depends heavily on the quality and density of gravity data available and the precision of the geodetic control network. Modern techniques often combine GPS measurements for ellipsoidal heights with terrestrial gravity surveys to achieve high-accuracy orthometric heights. The concept of ortometría is fundamental to establishing a unified and physically meaningful vertical reference system for the Earth.