Evaluation of U-Plan Representation Impact on Uspace Capacity and Computational Needs

Flight plan (also known as u-plan) declaration prior to unmanned air operations is one of the safety pillars of Unmanned Traffic Management systems and particularly of the U-Space ecosystem. In this sense, European regulation dictates to represent operations as a set of 4 D volumes (i.e.: polygonal area, height limits and duration). However, the size of these 4D volumes is not limited, and may generate an unnecessary airspace allocation and congestion problems. In this sense, this paper compares 4 different alternative flight representations: one based on a single 4D volume, one based on the construction a 4D volume per each flight segment, one based on the declaration of numerous 4 D points and one based on the definition of line strings. To evaluate the efficiency of each representation and its associated computational requirements in conflict detection, an accelerated-time simulator of the strategic authorization flow is used. Results demonstrate an inverse dependence between 4D volumes size and an efficient use of airspace, at the expense of higher computational costs. Alternatively, it is proved that a linestring-based definition achieves the best efficiency values without an increase in computational load.