Uncovering GNSS Interference with Aerial Mapping UAV

Global Navigation Satellite System (GNSS) receivers provide ubiquitous and precise position, navigation, and time (PNT) to a wide gamut of civilian and tactical infrastructures and devices. Due to the low GNSS received signal power, even low-power radiofrequency interference (RFI) sources are a serious threat to the GNSS integrity and availability. Nonetheless, RFI source localization is paramount yet hard, especially over large areas. Methods based on multi-rotor unmanned aerial vehicles (UAV) exist but are often limited by hovering time, and require specific antenna and detectors. In comparison, fixed-wing planes allow longer missions but are more complex to operate and deploy. A vertical take-off and landing (VTOL) UAV combines the positive aspects of both platforms: high maneuverability, and long mission time and, jointly with highly integrated control systems, simple operation and deployment. Building upon the flexibility allowed by such a platform, we propose a method that combines advanced flight dynamics with high-performance consumer receivers to detect interference over large areas, with minimal interaction with the operator. The proposed system can detect multiple interference sources and map their area of influence, gaining situational awareness of poor GNSS quality or denied environments. Furthermore, it can estimate the relative heading and position of the interference source within tens of meters. The proposed method is validated with real-life measurements, successfully mapping two interference-affected areas and exposing radio equipment causing involuntary in-band interference.