Geometric altitude, also referred to as orthometric altitude or height above mean sea level (MSL), is a measure of an object’s elevation above a specified reference surface, typically the Earth’s mean sea level. It is measured along a straight line from a point on or above the Earth’s surface to a defined reference point, usually using geometric principles. The formula to calculate geopotential altitude as follows:
Where:
- : Geometric height in m.
- : Absolute Altitude in m.
- : Mean radius of the Earth in m.