Uncovering GNSS Interference with Aerial Mapping UAV
Marco Spanghero, Filip Geib, Ronny Panier, Panos Papadimitratos
TL;DR
This work tackles the challenge of locating and characterizing GNSS interference over large areas by using a VTOL UAV that combines cruise efficiency with hover precision and reuses a consumer GNSS receiver for both navigation and RFI sensing. It introduces a horizon-scanning methodology that measures relative spectral power across antenna headings, compensates for antenna directivity, and fuses multiple scans into an expectation-density heatmap to localize multiple interference sources without requiring calibrated front-ends. Real-world experiments over rural and urban areas demonstrate the ability to detect, map, and roughly localize multiple transmitters (within tens of meters), including the identification of a TV-tower–related spur, while highlighting the influence of flight geometry and environmental conditions on localization accuracy. The approach offers a practical, low-SWaP solution for GNSS denial awareness and safe UAV operation, with future work aimed at testing with actual jammers, improving source classification, and enabling real-time adaptive missions.
Abstract
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.