Phased Array Radio Navigation: UAV Field Tests During GNSS Jamming

Phased array radio systems (PARS) on the ground can determine the direction and range to uncrewed aerial vehicles (UAV) that it communicates with. By communicating the position back to the UAV, it can be used for navigation also in conditions when GNSS or other positioning systems are unavailable. In this paper we report field tests with fixed-wing UAV flights under actual GNSS jamming, where an inertial navigation system (INS) aided by both GNSS and PARS is tested. The experimental results show that uninterrupted stable flight is possible by switching between GNSS and PARS aiding. The results also show that reliable integrity monitoring of the GNSS and PARS are essential for resilient navigation when switching between GNSS and PARS, especially in conditions when the UAV fly outside the PARS frustum while GNSS is jammed.