Impact of Meaconing and Spoofing on Galileo Receiver Performance

The vulnerability of GNSS to radio frequency interference and spoofing becomes more and more of concern for navigation applications which require a high level of accuracy and reliability, e.g. for safety of life applications in aviation, railway and maritime environments. Besides pure power jamming with CW, noise or chirp signals, intentional or unintentional spoofing with faked GNSS signals is considered as a potential threat. The simplest kind of spoofing, so- called meaconing, is the spoofing by repeaters, which retransmit received GPS signals. Cases of unintentional spoofing by airport repeaters have already been reported, where GPS repeaters used in airport hangars, had unintentionally transmitted their signals to outside and caused ground proximity warnings at aircrafts during take-off [1]. More advanced spoofing techniques try to force a target receiver to a wrong position by transmission of simulated GNSS-signals. In some experiments it was already demonstrated, that it is possible to take over the control of the receiver tracking loops with advanced spoofing techniques [2]. Hardware simulations with GNSS-signal generators allow investigating the impact of radio interference and spoofing on real GNSS receivers in a systematic, parameterized and repeatable way. The behaviour of different receivers and receiver algorithms for detection and mitigation can be analyzed in dependence of interference power, distance of spoofers and other parameters. In a previous study [1] the impact of repeaters on the measured GPS position was investigated by hardware simulations and field experiments. In this paper we concentrate on simulations of meaconing and spoofing and their impact on the Galileo receiver performance. The focus was to examine, analyse and explore the impact on the receiver raw observables in the E1 and E5a bands, in particular the C/N 0 and pseudorange measurements. The simulations were carried out within the frame of SESAR WP15.3.7 on multi-frequency/multi constellation GBAS. Disturbed or biased pseudorange measurements would cause the transmission of erroneous pseudorange corrections by the GBAS stations. The knowledge about the behaviour of the raw observables in dependence of different spoofing scenarios is also important for the development of monitors for spoofing detection at the ground stations. The paper describes different spoofing scenarios, the simulation setup and data processing and presents exemplary measurements for the results obtained. Three different spoofing scenarios are considered: meaconing, simplistic attack and intermediate up attack.