SESAR investigates how real-time i4D data from aircraft can improve the accuracy of trajectory prediction

Apr. 5, 2019

SESAR members Airbus, NATS and Thales recently completed a study into the use of automatic dependent surveillance-contract extended projected profile (ADS-C–EPP) data, downlinked from aircraft via ATN baseline 2 datalink (Solution PJ.18-06b), to improve the trajectory predictions used by controller tactical decision support tools.

Today, tactical tools predict the near-term (<20 mins) progress of a flight based on standard values of aircraft performance parameters for each aircraft type, and support the tasks of the executive controller. These tools include medium-term conflict detection (MTCD) and conformance monitoring. Improvements to the accuracy and uncertainty of the underlying trajectory prediction can reduce the volume of airspace required to ensure the safety of a flight, leading to an increase in airspace capacity, improved flight efficiency and reduced controller workload.

NATS, Thales and Airbus investigated the possibility of improving the accuracy of this trajectory prediction by integrating predicted performance data that is specific to each flight, downlinked in real-time from the flight management system (FMS) via ADS-C datalink. NATS modified their iFACTS ground tactical trajectory predictor to enable integration of ADS-C data, whilst the data was generated for a number of test scenarios, derived from typical intra-Europe flights and North Atlantic arrivals and departures, by Thales using a flight management system test bench. The enhanced trajectory prediction was compared to baseline data. In addition, Airbus’ FMS emulator, PAS@ATM, was used to study the effects of FMS operating behaviours on downlinked ADS-C data.

These initial results indicated that trajectory prediction improvements could be realised in certain operational situations and phases of flight. These results will be further explored with the analysis of ADS-C data received from airline revenue flights under the SESAR very large-scale demonstration, PJ31 DIGITS. This study (PJ.18-06b) complements parallel work on the ATC planning trajectory in in SESAR within the framework of Solution PJ.18-06a. If this research continues to show promising results then NATS will consider it for operational deployment in the iFACTS system.

This project has received funding from the SESAR Joint Undertaking under the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 734161.