Airport reference point
An airport reference point is the centre point of an airport, located at the geometric centre of all the usable runways. The ARP is computed as a weighted average of the end of runway coordinates.
Internationally, the rules governing the establishment of an Airport reference point are defined by ICAO Annex 14, and include:
2.2.1 An aerodrome reference point shall be established for an aerodrome.
2.2.2 The aerodrome reference point shall be located near the initial or planned geometric centre of the aerodrome and shall normally remain where first established.
2.2.3 The position of the aerodrome reference point shall be measured and reported to the aeronautical information services authority in degrees, minutes and seconds.
