Measurement of Airport Operations Using a Low-Cost Transponder Data System

Abstract

Knowledge of the precise number of operations of aircraft occurring at general aviation airports is essential due to the application of that information in the process of allocating funds for airport development and improvement; however, fewer than 270 of these 2950 airports have personnel available to register the operation counts. Data from aircraft transponders, critical for the safe and efficient management of airspace, may also be used to accurately count airport operations when collected by a receiver and analyzed with appropriate algorithms. Whereas 91% of transponder data records do not include aircraft positions, 9% (extended mode S) contain position information. This information may be used to calibrate an adaptive digital filter that can subsequently estimate distances for the aircraft that do not report positions, a novel technical approach to the problem. Aircraft distance, altitude, and other parameters may then be used as inputs to decision heuristics that register airport operations. This study collected over 16 million data records from two receiver installations at a general aviation airport and used these data to evaluate the algorithms developed in the course of the research. These automated operation counts were compared with official air-traffic-control-tower counts obtained from the Air Traffic Activity Data System database provided by the Federal Aviation Administration. A 180-day evaluation found that the algorithm provided counts within 2.2% of 52,750 actual operations. It is evident, then, that this method is useful for determining operation counts at airports with limited personnel.