GNSS Interference Detection and Geolocalization for Aviation Applications

GNSS is the primary enabler for Performance Based Navigation (PBN) and Automatic Dependent Surveillance Broadcast (ADS-B) applications and is becoming an increasingly essential technology used in air navigation. GNSS outputs are also used in various other Communication, Navigation and Surveillance (CNS) applications. Unfortunately, in some regions, Radio Frequency Interferences (RFI) affecting aviation has become a widespread challenge. EUROCONTROL monitors GNSS RFI impact through a number of means, including pilot reports and ADS-B data. Thanks to alternative CNS capabilities, these situations can generally be managed. Nonetheless, EUROCONTROL is investigating how GNSS RFI impact zones can be detected and how this information can be used by operational centres to improve the management of air traffic when subject to GNSS RFI. EUROCONTROL has conducted a GNSS Receiver Interference Testing (GRIT) study with a GMV-led consortium to better understand the behavior of currently fielded aircraft GNSS receivers when subject to RFI. The test campaign used three commonly used aviation receivers. The objective of the testing was to see how receiver observables could be used to help detect RFI. Based on the simulation results, a set of RFI detection techniques have been defined and tested against different types of RFI, including CW, chirp and Noise-like jammers. The proposed techniques focused on the use of C/N0 derived metrics: detection of RFI based on the entropy of the C/N0 mean, Classification of RFI versus non-RFI events using Support Vector Machine method and Random Sample Consensus method applied to C/N0 versus elevation. These methods will be further explained in the paper and their performances will be discussed in terms of detection, complexity and possible ways of improvement. Finally, a dataset was generated to obtain receiver tracking profiles with a simulated RFI source to see how ADS-B data can be used to detect and localize the RFI source.