Robust and Secure UAV Navigation Using GNSS, Phased-Array Radio System and Inertial Sensor Fusion

Positioning using global navigation satellite systems (GNSS) has for several years been the de facto method for long-range navigation of ground, marine and aerial vehicles. With global coverage, high accuracy, and lightweight receivers, GNSS positioning has several desirable properties, especially on unmanned aerial systems (UAVs) with limited sensor payload capacity. However, due to the low signal-to-noise ratio (SNR) of the GNSS signals the navigation signal is prone to malicious attacks, such as jammig or spoofing. In the last few years, alternative solutions for absolute positioning of unmanned vehicles have emerged. One example of this is positioning using a phased array radio systems (PARS). PARS equipment has the potential to provide position measurements that are accurate within tens of meters. The PARS solutions typically have significantly higher SNR and strongly encrypted messages, which makes them robust towards malicious attacks. This paper presents a method for an inertial navigation system which is aided using redundant position sensors. The high-accuracy RTK solution is the primary position reference, when it is available. The PARS is used to detect if GNSS solution is being spoofed (or jammed), and is used as the fall-back positioning solution.