GNSS Spoofing
Kartavya Desk Staff
Source: TH
Subject: Science & Technology
Context: Aircraft flying near Delhi reported multiple cases of GNSS spoofing in early November 2025, triggering false cockpit alerts and misleading terrain warnings.
About GNSS Spoofing:
What is GNSS Spoofing?
• GNSS spoofing is the intentional transmission of fake satellite navigation signals to mislead receivers such as aircraft, drones, ships or vehicles into calculating an incorrect position, time or velocity.
Types of GNSS Interference:
• GNSS Spoofing (Deception): Fake signals are injected to mislead the aircraft about its location, altitude or direction. This is the most dangerous form.
• GNSS Jamming (Blocking): High-power noise disrupts genuine satellite signals, making the receiver unable to compute a location.
• Meaconing (Signal Re-broadcasting): Original signals are captured and rebroadcast with a delay, tricking receivers subtly without generating obvious alarms.
How GNSS Spoofing Works?
• A transmitter near the target emits counterfeit GNSS signals with slightly stronger power than genuine satellite signals.
• The aircraft receiver unintentionally locks onto the fake signal believing it to be legitimate.
• Gradually, the spoofer drifts the false signals to pull the computed aircraft position away from reality, creating false navigation, terrain, or proximity alerts.
• Weapon systems and drones can be misdirected, diverted or disabled using the same technique.
Characteristics of GNSS Spoofing:
• Covert and Hard to Detect: Signals mimic genuine GNSS codes, making cockpit warnings ambiguous.
• Localized in Range: Typically affects aircraft within a radius of a few kilometres from the source.
• Gradual Drift: Spoofing attempts often shift position slowly to avoid abrupt discrepancies.
• Can Trigger False Cockpit Alerts: E.g., fake terrain warnings, incorrect runway alignment, wrong altitude/position calculation.
• Bypasses Basic Anti-Jamming Measures: Because the receiver sees it as a “valid” signal—not just noise.
Threats from GNSS Spoofing:
• Loss of Navigation Accuracy: Aircraft may display incorrect position, wrong flight path, or misleading headings—forcing pilots to rely on manual navigation.
• False Terrain & Collision Warnings: Spoofed signals can trigger false terrain warnings, runway misalignment alerts or obstacle proximity alerts, distracting pilots during critical phases like takeoff/landing.
• Pilot Workload Spike & Situational Confusion: Crew workload increases sharply as they cross-check instruments, verify backup systems, and coordinate with ATC.
• Dependence on Backup Systems: Aircraft must switch to Inertial Reference Systems—safe for several hours—but not ideal for long stretches or high-traffic zones.