Global Navigation Satellite System (GNSS) signal spoofing is an emerging threat to civilian GNSS receivers. Inertial Navigation Systems (INS) are often integrated with GNSS for accurate positioning and navigation, and to bridge GNSS outages in cases where GNSS-only navigation is not feasible. Inertial observations, being self-contained, are not easily spoofed and this redundant information can be used to authenticate GNSS observations.
This thesis presents a comparative study and analysis of the GNSS signal authentication limits using INS in terms of minimum detectable blunder while using different grades of GNSS/INS integrated systems to detect/identify a fault in GPS observation. Results show that for lower spoofing dynamics and longer spoofing duration, all sensor grades fail to detect the GNSS spoofing error immediately. When the spoofing dynamics are high, a high quality INS provides better GNSS signal authentication performance. GNSS/INS integration provides a marginal improvement in the detection/identification performance of spoofed GNSS observations.