An implicit enumeration algorithm for arrival aircraft

A novel scheduling algorithm has been designed and coded to optimize arrival aircraft sequences and schedules. This algorithm, called the implicit enumeration (IE) scheduling algorithm, has been adopted as the foundation of the Traffic Management Advisor which is part of the Center/Terminal Radar Approach Control (TRACON) Automation System (CTAS). Because of the dynamic nature of air traffic control, the IE scheduling algorithm has been developed to operate in a dynamic feedback environment. The algorithm structure which controls the scheduling feedback also provides the platform for other advances. The criteria to be optimized can be specified flexibly, and can be varied on-line. Another feature of the algorithm applies to the situation found at many high-density airports, where multiple runways are used for arrivals simultaneously. The approach taken in the algorithm allows the planning process to be expanded to include runway assignment. Initial results from using the IE algorithm for runway assignment indicate that significant performance enhancements are possible when both runway and sequence assignments are considered in the scheduling process. This algorithm was first used in early 1992 at the Denver Air Route Traffic Control Center for the first stages of the field evaluation of CTAS by the FAA.<
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