GNSS Spoofing

Broadcasting counterfeit GNSS signals that a receiver accepts as genuine, causing it to compute a false position, velocity, or time rather than losing its fix outright. The FAA has issued public Safety Alerts For Operators (SAFOs) advising flight crews to expect and cross-check for spoofing in specific geographic areas.

Key facts

Field	Value
Threat type	Deception (false signal injection)
Primary target frequency	GPS L1 (1575.42 MHz)
Distinguishing trait vs. jamming	Receiver keeps a fix — but a false one
FAA guidance	SAFO 24002 — use analog NAVAIDs, cross-check position, report anomalies to ATC
Reported hotspots	Black Sea, parts of the Middle East, per public FAA/industry reporting

Why it matters operationally

DHS S&T’s public GPS Receiver Whitelist Development Guide and PNT Integrity Library are examples of publicly documented, generic (non-vendor-specific) approaches to spoofing resilience referenced in federal guidance.

Public examples

• Reported GNSS spoofing incidents affecting civil aviation near the Black Sea and Middle East conflict zones, per FAA SAFO 24002
• Publicly reported maritime AIS/GNSS spoofing incidents affecting vessel-reported positions in contested waters

Sources

• SAFO 24002 — Global Positioning System (GPS)/Global Navigation Satellite System (GNSS) Interference — Federal Aviation Administration
• Resilient PNT for Critical Infrastructure — U.S. Department of Homeland Security, Science and Technology Directorate
• Information About GPS Jamming (covers spoofing context) — GPS.gov (National Coordination Office for Space-Based PNT)