Air-ground trajectory synchronization — Metrics and simulation results

It has been established that Trajectory Based Operations are a key component of future Air Traffic Management systems as currently underway in the United States with NextGen and Europe with SESAR. One of the major goals of Trajectory Based Operations is to provide participants accurate 4- Dimensional Trajectories predicting the future location of the aircraft with a high level of certainty. This is not realizable without improving the coordination and interoperability of air and ground systems. By leveraging GE's Flight Management System and aircraft expertise with Lockheed Martin's Air Traffic Control domain expertise, including the En Route Automation Modernization system, a research initiative has been formed to explore and evaluate means of better integrating air and ground systems to bring airspace operations closer to the business-optimal goal in a safe and efficient manner. The two main components of this effort are trajectory synchronization and trajectory negotiation. Trajectory synchronization will essentially result in a more complete flight plan in the air and a more accurate trajectory representation on the ground, which is a prerequisite for trajectory negotiation. This paper briefly discusses the high-level trajectory synchronization algorithm and its implementation in a fast-time simulation environment that incorporates actual Flight Management and Air Traffic Control software. It then focuses on the analysis of metrics and simulation results from several case studies. The conclusion of these studies shows that implementation of the trajectory synchronization algorithm using Controller-Pilot Data Link Communications messages as well as the Automatic Dependent Surveillance-Contract service (including the Extended Projected Profile application) achieves consistent trajectory predictions between the air and ground systems.