What term describes the height measured above the geoid?

The term that describes the height measured above the geoid is known as orthometric height. Orthometric height represents the vertical distance between a point on the Earth's surface and the geoid, which is an equipotential surface of the Earth's gravity field. It is an important measurement in surveying and geodesy because it reflects the height that corresponds to mean sea level, providing a more intuitive understanding of elevation as it relates to the Earth's gravitational field.

In practice, orthometric height allows surveyors to convey information about how high a location is in relation to sea level, which is essential for construction, navigation, and various engineering applications. This measurement considers both the physical surface of the Earth and the gravitational variations that might affect how we perceive height.

Contrastingly, geoidal separation measures the difference between the height of the geoid and another reference surface, such as an ellipsoid, but does not specify height in relation to the Earth's surface directly. Elevation determination generally refers to the overall process of finding an elevation value, which may involve various standards and methodologies that are not strictly about the relationship to the geoid. Geodetic height measures the height above the reference ellipsoid rather than the geoid, using the ellipsoid as a geometric approximation of the