GNSS such as GPS are vulnerable, largely due to the tiny signal strength and the geometry of satellites in urban environments. Drone regulatory frameworks are progressing to where autonomous flight and operations Beyond Visual Line-Of-Sight (BVLOS) are a possibility, thus driving the need for reliable navigation services to complement or act as a back-up to existing ones (chiefly GNSS). Trusted PNT solutions must be developed to help tackle the challenges that congested airspace brings, such as the safety of autonomous flight in populated areas or avoiding inflight collisions.

The Robust Navigation of Airborne Autonomous Systems with Carrier Phase of ARNS Signals (RAASPAS) project aims to develop innovative and reliable Alternative PNT (APNT) concepts based on the carrier phase of Aeronautical Radio Navigation System (ARNS) signals such as DME and telecommunication Signals Of Opportunity (SOOP), hybridised with dead-reckoning and vision-based navigation sensors, providing Drone users with a positioning solution and an integrity measure, complementary to GNSS.

The project will make use of the Centre for Autonomous and Cyber-Physical Systems, operating the unmanned autonomous vehicles laboratory.