What intentional interference can disrupt GNSS signals?

What intentional interference can disrupt GNSS signals?

• A. Jamming
• B. Doppler shift
• C. Multipath
• D. Selective availability

Answer: (A)

Intentional interference with GNSS is most effectively done through jamming. Jamming works by transmitting a strong signal on the same frequencies used by GNSS, raising the noise floor and drowning out the genuine satellite signals. When the received signal is overwhelmed, receivers can’t acquire or track satellites and navigation becomes unreliable or unavailable. Doppler shift is a natural frequency change caused by relative motion between satellite and receiver; receivers are designed to handle it, so it isn’t an interference tactic. Multipath occurs when signals reflect off surfaces and take multiple paths to the receiver, which can degrade accuracy but isn’t an intentional attack. Selective availability was a historical method of degrading GPS accuracy on purpose, but it is no longer active, so it isn’t a current method of disruption.

Intentional interference with GNSS is most effectively done through jamming. Jamming works by transmitting a strong signal on the same frequencies used by GNSS, raising the noise floor and drowning out the genuine satellite signals. When the received signal is overwhelmed, receivers can’t acquire or track satellites and navigation becomes unreliable or unavailable.

Doppler shift is a natural frequency change caused by relative motion between satellite and receiver; receivers are designed to handle it, so it isn’t an interference tactic. Multipath occurs when signals reflect off surfaces and take multiple paths to the receiver, which can degrade accuracy but isn’t an intentional attack. Selective availability was a historical method of degrading GPS accuracy on purpose, but it is no longer active, so it isn’t a current method of disruption.