The Derivation and Evaluation of Algorithm of Anti-spoofing Attack on Loosely/Tightly Coupled GNSS/INS Integration System

The format of spoofing signal in Global Navigation Satellite System (GNSS) is identical to that of real navigation. Therefore, the spoofing has been a severe threat to GNSS. In loosely coupled GNSS/INS integration system, velocity and position are selected as the measurement innovations in Kalman filter (KF). In tightly coupled GNSS/INS integration system, inertial navigation system (INS) assists GNSS, with measurement innovations of pseudo-range and pseudo-range rate. In this paper, a spoofing attack test is performed by tightly coupled GNSS/INS integration system and loosely coupled GNSS/INS integration system respectively and the comparison between the capabilities of the two are made. The loosely or tightly coupled integrated system identifies the spoofing attack signals, by monitoring GNSS and INS. The inconsistency between velocity and position in loosely coupled integrated system, pseudo-range and pseudo-range rate in tightly coupled integrated system, which makes it possible to detect the spoofing attack signals. This paper presents the performance test on loosely/tightly coupled GNSS/INS integration system for anti-spoofing, by the trajectory generated by Spirent SimGen. The simulation result indicates that the algorithm of spoofing detection based on tightly coupled system outperforms that on the loosely coupled system.