Sometimes GNSS spoofing seems a bit like UFOs: much speculation, occasional alarms at suspected instances, but little real-world evidence of its existence.

As far back as 2001, a U.S. Department of Transportation Volpe Center report suggested that as GPS further penetrates into the civil infrastructure, “it becomes a tempting target that could be exploited by individuals, groups or countries”.

A recent Department of Home Security (DHS) National Risk Estimate (NRE) of GPS signals that, although jamming disruptions were more likely than spoofing incidents, spoofing is typically of higher consequence than jamming due to the potential duration of time before users or devices would detect spoofing.

Nonetheless, such incidents remain rare.

Iran has claimed to have taken control of U.S. surveillance drones operating along its border. A now well-known demonstration of the same by University of Texas researchers stimulated a Congressional hearing. Last year, Carnegie Mellon University computer science students performed security penetration tests against numerous receiver types and demonstrated not only RF spoofing vulnerabilities but also cyber vulnerabilities and a sensitivity to malformed 50 bps data messages.

So, how great is the risk that spoofing will become a major problem for the GNSS community, and what can we do about it?

To learn more on this subject, we turned to Logan Scott, a consultant specializing in radio frequency (RF) signal processing and waveform design for communications, navigation, radar, and emitter location. Scott has more than 30 years of military and civil GPS systems engineering experience.