Detecting airport surface movement events using ground surveillance

The availability of high-quality multi-sensor surveillance for the airport enables new forms of surface movement analysis. The Airport Surface Detection Equipment, Model X (ASDE-X) system provides precise time-stamped position and velocity reports associated with aircraft identification codes, as required for its primary mission of improving situation awareness in the air traffic control (ATC) tower. Many additional trajectory properties can be estimated from the same source. ASDE-X has no requirements for estimating and reporting acceleration in real time. However, the ability to estimate acceleration improves the ability to detect maneuvers. For the purpose of this paper, a maneuver is defined to be any acceleration of sufficient magnitude and duration to affect operational decisions. The focus of this paper is on the feasibility of estimating acceleration as part of non-real-time analysis, the ability to relate those acceleration estimates to maneuver recognition, and the operational applications of such a capability. Deeper understanding of surface activity can be obtained by re-processing surveillance data for precise trajectory reconstruction. Changes in velocity, including starts, turns, and stops, are particularly significant for operational analysis; the timing of such events in relation to airport geometry and the movement of other traffic can indicate the reasons for the observed behavior. For example, slowing can be explained by the need to yield to converging traffic at an intersection, and stopping can be explained by proximity to a hold line or joining the end of a queue. This paper shows results on the sensitivity and precision with which these surface movement events can be detected and measured. In addition, examples of the potential use of these events in studies of operational efficiency and safety will be given. Particular examples include relating speed changes to fuel use and emissions metrics, and relating acceleration from a stop to the recognition of runway entry and start of take-off roll.