Global Navigation Satellite Systems (GNSS) reference receivers are an essential part of ground stations that make the operation of Satellite-Based Augmentation Systems (SBAS) possible. In the recent years, there has been an increasing concern on the presence of spoofing and interference events, which have been shown to seriously threaten the operation of GNSS receivers. While this concern is transversal to all GNSS receivers, it stands with particular emphasis in those deployed in the framework of liability- and safety-critical applications, as it is the case of GNSS reference receivers in SBAS ground stations. It is for this reason that dedicated countermeasures are needed in order to preserve the reliability of the observables provided by such receivers.

It is well-known, though, that no single countermeasure is capable of succeeding in the problem of detecting the abovementioned threats in all possible working conditions. Instead, a plurality of techniques is needed in order to cover all the different features and behaviors that can be experienced by a GNSS receiver under attack.

In this context, the goal of this paper is two-fold. On the one hand, it presents a set of spoofing and interference detection techniques that are specifically tailored to operate with the output observables provided by a NovAtel G-III reference receiver. On the other hand, these techniques are assessed using a conducted test with a Safran Skydel GSG-8 GNSS RF simulator in order to validate their implementation and effectiveness. To this end, a set of dedicated spoofing and interference scenarios have been implemented to specifically assess the goodness of the proposed detection techniques. The work concludes with the analysis of the obtained extensive results, as well as it provides insightful recommendations and guidelines.