JAMMING AND SPOOFING
GPS/GNSS jamming and spoofing are increasing worldwide and are no longer a niche risk: they disrupt navigation and timing services that modern shipping, energy grids, telecoms and military systems depend on, causing safety, financial and national-security consequences. Regulators and operators are accelerating mitigation, but many organizations remain exposed.
Jamming is the deliberate transmission of radio-frequency (RF) energy to disrupt or deny legitimate signals. In the context of satellite navigation (GNSS/GPS), jamming overwhelms the very weak signals received from satellites with stronger noise or interference, making receivers unable to calculate position, velocity, or time.
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How it works:
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GNSS satellites transmit extremely low-power signals by the time they reach Earth.
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A jammer transmits noise or a competing signal on the same frequencies (for example, the L1 band).
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The receiver’s signal-to-noise ratio collapses.
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Result: the receiver either loses lock, reports no position, or switches into degraded or fallback modes.
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Importantly, jamming does not fake data—it simply prevents the receiver from working. This distinguishes it from spoofing, which manipulates the receiver with false but believable signals.
Spoofing is the deliberate transmission of false but valid-looking GNSS signals that deceive a receiver into calculating an incorrect position, velocity, or time—while the receiver believes everything is normal. Unlike jamming, spoofing does not deny service; it corrupts it silently.
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How spoofing works:
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A spoofer generates GNSS-like signals that mimic real satellites (same frequencies, codes, and structure).
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These counterfeit signals are transmitted at slightly higher power than the genuine satellite signals.
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The receiver locks onto the stronger, fake signals.
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The spoofer gradually shifts the false solution—moving position, altering time, or changing velocity—without triggering alarms.
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This “carry-off” approach is particularly dangerous because it avoids sudden jumps that operators or systems might notice.
In professional practice, spoofing is widely regarded as the more serious threat.
