Quantitative Assessment of Urban Air Collision Risks

The increasing adoption of remotely piloted aircraft systems in urban areas will require a quantitative assessment of collision risks with other air traffic. Current approaches for assessing the effectiveness of detect and avoid systems may have limitations in both accounting for the influence of traffic coordination in controlled urban airspaces and understanding how strategic and tactical mitigations can reduce risks. By quantifying and combining the effect of these factors with a traffic density analysis, this paper proposes a new methodology to quantify collision risk and improve mitigation capability estimates by calculating a metric called the weighted risk ratio. The authors' findings indicate that short-range noncooperative detect and avoid systems, when used as the only means of tactical mitigation, have minimal effect on decreasing the collision risks in urban scenarios. Consequently, achieving adequate mitigation for future urban air mobility flights necessitates a combination of long-range noncooperative and cooperative sensors, along with strategic mitigations and traffic coordination. Finally, the developed methodology is demonstrated through a case study to highlight the quantitative and variable impact of various mitigation strategies to ease the integration of emerging technologies into the shared airspace with traditional aviation.