Abstract: A method of controlling an unmanned aerial vehicle executing a mission in a defined mission area including a first observation area within a Visual Line of Sight (VLOS) of a First Observer (FO), a second observation area within a VLOS of a second observer (SO), and a transition area within the VLOS of both the FO and the SO, the method including: the vehicle moving into the transition area after completing part of the mission within the first observation area, in sight of the FO; and in response to the vehicle moving into the transition area, determining whether the vehicle is in sight of the SO. The vehicle is including multiple processing systems in wireless communication with multiple remote user interfaces and a radar sensor mounted on the vehicle using a moveable mount for moving the radar sensor between different radar orientations, the radar sensor generating a range signal.