How is Absolute Altitude defined?

Absolute altitude is specifically defined as the height of an object above the terrain or ground over which it is flying. This measurement gives a precise indication of how high the aircraft is in relation to the surface beneath it. It is essential for maintaining safe operation, avoiding obstacles, and conducting various types of missions where ground proximity is critical.

When flying a drone, understanding absolute altitude allows pilots to properly navigate and avoid potential hazards such as buildings, trees, or other obstacles that may exist at ground level. Absolute altitude can also differ significantly from other types of altitude measurements, like altitude above sea level or pressure altitude, which do not account for variations in topography.