The Federal Aviation Administration (FAA) defines the Airport Elevation as the highest point of an airport’s usable runways and is measured in height above mean sea level.
AAL (Above Aerodrome Level) and AAE (Above Aerodrome Elevation) are European acronyms. These term are not used as often but it is referenced in the FAA’s Instrument Flying Handbook. You can reference the AFD, Sectional Charts, Terminal Charts, or the Airport Diagram to find the AFE (Above Field Elevation) for your airport.
1. “What is the difference between Above Ground Level and Above Field Elevation?” by CARLVALERI on JANUARY 8, 2014