Avoiding Collisions Between Aircraft: State of the Art and Requirements for UAVs operating in Civilian Airspace

In this paper we consider the ability of Unmanned Aerial Vehicles (UAVs) to operate safely in civilian airspace. This ability is increasingly important as UAVs proliferate and their usage spreads to non-military applications. According to regulatory requirements by the FAA and others this capability must demonstrate a level of performance that meets or exceeds that of an equivalent human pilot without the use of cooperative communication with other aircraft or prior knowledge of the flight plans. We survey the state of the art in systems, sensors and algorithms that have been investigated for use in ‘Sense and Avoid’ applications and then examine both basic and derived requirements for systems suited for deployment on small UAVs.