A unified approach to separation assurance and collision avoidance for UAS operations and traffic management

A unified approach to cooperative and non-cooperative Separation Assurance and Collision Avoidance (SA&CA) is presented addressing the technical and regulatory challenges of Unmanned Aircraft Systems (UAS) integration into all classes of airspace. Additionally, the emerging UAS Traffic Management (UTM) system requirements are captured and addressed in this novel unified framework. In a multiplatform UTM system implementation, the errors in navigation and tracking measurements associated to each manned/unmanned platform in a certain airspace region (as seen by all other platforms in that region), are combined statistically to generate a Position Uncertainty Volume (PUV). Successively, the PUV is inflated by considering the traffic relative dynamics, leading to the generation of avoidance volumes (dynamic geo-fences) at discrete time intervals. Case studies are presented for evaluating the feasibility of the approach in an urban environment. In this approach, real-time and off-line determination of the UAS safe-to-fly envelope is performed based on the installed avionics sensors and on the own/intruder platform dynamics. Additionally, the SA&CA models developed in this approach support an identification of the UAS sensors required to safely operate in specific portions of the host aircraft operational flight envelope. The resulting build-up of SA&CA design and operational requirements allows a detailed definition of the UAS safety case, thereby providing a pathway to certification