Trajectory Specification for Automation of Terminal Air Traffic Control

Abstract

Trajectory specification" is the explicit bounding and control of aircraft trajectories such that the position at each point in time is constrained to a precisely defined volume of space. The bounding space is defined by cross-track, along-track, and vertical tolerances relative to a reference trajectory that specifies position as a function of time. The tolerances are dynamic and will be based on the aircraft navigation capabilities and the current traffic situation. A standard language will be developed to represent these specifications and to communicate them by datalink. Assuming conformance, trajectory specification can guarantee safe separation for an arbitrary period of time even in the event of an air traffic control (ATC) system or datalink failure, hence it can help to achieve the high level of safety and reliability needed for ATC automation. As a more proactive form of ATC, it can also maximize airspace capacity and reduce the reliance on tactical backup systems during normal operation. It applies to both enroute airspace and the terminal area around airports, but this paper focuses on arrival spacing in the terminal area and presents ATC algorithms and software for achieving a specified delay of runway arrival time.

Trajectory Specification for Terminal Airspace: Conflict Detection and Resolution

“…Trajectory Specification is a proposed far-term enhancement of the Advanced Airspace Concept project being developed by NASA for automating ATC in both en route airspace [4][5][6] and the terminal airspace around major airports [7,8]. The Trajectory Specification concept was first published in 2005 [9] and has been updated in more recent publications [10][11][12] (and issued a U.S. patent). A similar proposal by others [13] with a more airborne focus followed several years after the first publication on the concept.…”

Trajectory Specification Language for Air Traffic Control

“…Trajectory Specification is a proposed far-term enhancement of the Advanced Airspace Concept (AAC) being developed by NASA for automating ATC in both enroute airspace [4][5][6] and the terminal airspace around major airports [7,8]. The Trajectory Specification concept was first published in 2005 [9] and has been updated in more recent publications [10][11][12] (and issued a US patent). A similar proposal by others [13] followed several years after the first publication on the concept.…”