Collision Risk Model for High-Density Airspaces

This chapter describes a collision risk model (CRM) of airspace scenarios to describe their safety levels when populated by given air traffic. The model requires the use of representative data, containing a description of the flown aircraft trajectories. It is a combination of deterministic and probabilistic mathematical tools able to estimate the level of safety. Furthermore, the model captures the frequency and spatial distribution of the encounters and conflicts, the time in advance the conflict is identified and the overall reaction time of the Air Traffic Control ATC system, and finally, the effectiveness of the ATC as safety layer. The model considers that the risk of an air miss depends on two different factors: on the one hand, the frequency of exposure to risks and, on the other, the chance of collision associated to this exposure. The exposure to risk is captured following a deterministic datadriven approach, whereas the associated chance of collision is derived from a statistical mathematical model, fed by the kinematics of the encounter and the statistics associated to the accuracy of the aircraft state vector when following a planned trajectory.