Providing Continuity and Integrity in the Presence of GNSS Spoofing

In this paper we attempt to provide continuity and integrity guarantees despite the presence of a spoofing attack. Using a software defined radio (SDR), we assign two channels per PRN allowing us to track both the authentic and spoofed signal. We employ a Multi-Hypothesis Extended Kalman Filter (MHEKF) to coast on inertial sensors during signal outages and identify the authentic signals once they become available. We finally leverage and modify RAIM integrity equations to cast protection levels that encompass the authentic and spoofed position solution for a guarantee on the user's location. We present results both for highway driving data with artificially injected spoofing signals as well as results on the TEXBAT dataset. We demonstrate continuous navigation despite the presence of spoofing attacks and provide integrity through protection levels that account for the lift-off spoofing attacks in their threat model.