Ch 24. Interference: Origins, Effects, and Mitigation

Overview:

GNSS has been described as the stealth utility. When interference to GNSS occurs, as you might expect GNSS receiver performance becomes degraded but unexpected effects are also commonly seen. Among them, medical paging systems have turned themselves off, and cellular base stations have lost their ability to perform handoffs and so drop calls. Marine radar displays have shown dire warnings to the effect that position has been lost, and shipboard satellite communications systems have completely failed. GNSS is deeply integrated into diverse systems, often to the point where it almost becomes invisible, that is, until it fails.

GNSS is a critical part of international infrastructure. Not only does it provide low‐cost methods for obtaining precise position, it is also the world’s backbone system for precise time and frequency dissemination. In the United States, 14 of 16 critical infrastructure (CI) sectors have been identified as having critical dependencies on GNSS. These sectors include transportation, emergency services, energy distribution, financial services, agriculture, and information technology.

Widespread reliance on GNSS has a darker side, though: GNSS has become part of the attack surface for adversaries seeking to damage and/or exploit systems reliant on GNSS.

Attacks on GNSS follow a continuum but can be broadly divided into two categories: jamming and spoofing.