How do you mitigate the emergent dynamics induced by the existing gap between the long-term predictive part of the ATM system, represented by the central flow management measures and the short-term adaptive actions locally performed by tactical controllers?
STREAM has explored innovative trajectory de-confliction algorithms supporting the concept of a rolling conflict management process that seamlessly bridges the gap between strategic pre-departure flow management and conflict detection, and resolution during flight execution. The STREAM concept of operations considered pre-departure and dynamic Conflict Management as part of a future, hypothetical, enhanced Network Management function. It assumes a seamless, periodic Conflict Detection and Resolution (CD&R) process is in effect from the pre-departure phase, this being the Conflict Management part of the collaborative design process of the Network Operations Plan (NOP), up to the execution of the flight, when conflicts are tactically resolved by controllers.
As part of the STREAM project, a performance assessment framework, a methodology and a set of metrics were developed to evaluate the potential impact of the operational implementation of the STREAM algorithms on airspace users and on the ATM system as a whole. A fast-time simulation environment was applied, which served as a test bed for the algorithms and allowed summarizing high fidelity representations of the trajectories that aircraft would fly in response to the amendments proposed by the STREAM algorithms.
The performance assessment methodology made it possible to study the sensitivity of the metrics to trajectory prediction performance. An analysis was performed in order to evaluate the robustness of the STREAM solution in terms of conflict resolution success with respect to the trajectory prediction error. Two types of perturbations were introduced to model the Estimated Time of Departure Error and Along Track Error, with realistic distributions. The results demonstrated the capability to perform a thorough sensitivity analysis and provide insight into the potential value of the STREAM solution not only for individual conflict management, but also to enable efficient flow management strategies.