Geopotential Number (C)

The geopotential number is a physical quantity which is used physical geodesy to describe the (physical) height of a point in terms of the Earth’s gravity field rather than simple geometric distance like in levelling. It represents the difference in geopotential (W) between a point on the Earth’s surface and a reference potential at the geoid which approximates the sea level (Wo). In this way, it measures the amount of work required to move a unit mass from the geoid up to that specific point.