What is GPS spoofing?
GPS spoofing is an attack that broadcasts counterfeit GNSS signals — precisely timed to mimic authentic GPS satellite transmissions — to overwhelm a victim receiver's signal and cause it to compute an incorrect position, velocity, or time. Unlike jamming (which simply blocks the signal), spoofing is deceptive: the receiver continues to function normally and reports a plausible but false location. Sophisticated spoofing attacks gradually shift the false position to avoid triggering receiver consistency checks.
Why GPS is vulnerable
GPS signals are extremely weak at Earth's surface (approximately −130 dBm, or 0.1 picowatts) because they travel 20,200 km from the satellite. A spoofing transmitter nearby can easily overpower the genuine signal with a hundred-watt amplifier. GPS signals are unencrypted for civilian use — anyone can generate a mathematically valid GPS signal with commercially available SDR hardware. The military GPS signal (M-code) uses cryptographic authentication, but civilian L1/L2 signals do not.
Documented incidents
GPS spoofing has been documented extensively in: the Black Sea and Eastern Mediterranean (ships reporting positions inland or at airports rather than at sea); GPS positions near the Kremlin being spoofed to show aircraft at Vnukovo Airport in Moscow; drone spoofing in Iraq and Syria redirecting UAVs; and widespread civilian aviation GPS anomalies across the Eastern Mediterranean, Baltic Sea, and Middle East from 2022 onwards correlating with conflict operations. In 2023, aviation regulators issued advisories warning pilots to expect GNSS anomalies in the region covering Israel, Lebanon, Iraq, and Turkey.
Countermeasures
Anti-spoofing measures include: multi-constellation receivers (GPS+Galileo+GLONASS — harder to spoof all simultaneously), inertial navigation integration (detecting position jumps inconsistent with measured accelerations), cryptographically authenticated signals (Galileo's Open Service Navigation Message Authentication, OSNMA, launched 2023), and receiver autonomous integrity monitoring (RAIM) algorithms that detect inconsistency between satellite signals.