What is AGL an abbreviation for?

AGL stands for "Above Ground Level." This term is crucial in aviation, particularly when discussing altitude and flight operations. When an aircraft's altitude is described in AGL, it refers to the height of the aircraft relative to the surface of the ground directly beneath it. This measurement is important for several reasons, including ensuring safe clearance over obstacles, complying with airspace regulations, and assessing terrain avoidance.

Understanding AGL is essential for unmanned aircraft operators to maintain safe flight operations during missions, especially in urban or congested environments where ground features may vary significantly. The other options do not accurately represent this term or its context in aviation, making A the clearly defined and correct choice.