Autonomous Signal-Situational-Awareness in a Terrestrial Radionavigation System

This paper aims to augment terrestrial radion-avigation systems (TRNS) with autonomous signal-situational-awareness capability, allowing TRNS operators to detect spoofing and meaconing attacks within their systems. Such a capability is necessary to address a vulnerability to certain replay attacks that remains even when TRNS signals are secured by navigation message encryption and authentication. Two signal authentication techniques are developed to detect a weak spoofing signal in the presence of static and dynamic multipath. Both are shown to be effective in simulations of the varied operating environments that TRNS will encounter. With autonomous signal-situational-awareness, TRNS gain a defensive capability that GNSS cannot easily match: a comprehensive defense against most man-in-the-middle attacks on position, navigation, and timing services.