Airspace Geometry and 4D Flight Proximity Detection for Simulation of the National Airspace System

The authors present uncomplicated and well established equations that can be used in simulation or real-world applications to determine key crossing points and aircraft proximity when the trajectory and speed of aircraft pairs are known. These equations, in closed form, were developed for computing the minimum distance between two aircraft within the four-dimensional (4D) space-time domain. The 4D flight proximity information can be used in simulation to evaluate large numbers of scheduled routes over a limited airspace for controller workload assessment. Also, it can be used to detect potential separation violations and impacts of traffic flow management (TFM) strategies. An example of computing the distance between two flights in 4D is presented. Sample aircraft proximity landscape in 4D space-time simulation with MATLAB code is also provided.