From Military to Civil: How CRPA Antennas Counter GNSS Jamming and Spoofing

From Military to Civil: How CRPA Antennas Counter GNSS Jamming and Spoofing

Global navigation satellite system (GNSS) signals face an escalating threat from radio-frequency interference (RFI) — both intentional (jamming, spoofing, meaconing) and unintentional. One technology once reserved for authorized military users is now moving into the civil market: the controlled reception pattern antenna (CRPA).

What CRPA does

CRPA is a multi-element “smart antenna.” Its individual elements are independently controlled, allowing the system to detect interference and reshape its reception pattern in real time — forming nulls toward jammers while beam-steering gain toward genuine satellite signals. Minimum variance distortionless response (MVDR) is among the processing techniques commonly used.

Since entering the civil market around 2015, CRPA has been seen as a key way to strengthen GNSS resiliency in aviation, critical infrastructure, autonomous vehicles and drones, and heavy-duty freight monitoring. Receivers in sensitive roles — such as Galileo Public Regulated Service (PRS) receivers and Open Service (OS) receivers aboard autonomous platforms — are expected to adopt such interference-rejecting capability.

Testing is the bottleneck

CRPA systems must be thoroughly validated before deployment. Key test parameters include antenna element characterization, system power and carrier-phase calibration, the number of frequencies and constellations, and signal fidelity. Phase alignment across the test bench must hold below 5 picoseconds for the antenna to reject undesired signals effectively.

Testing methods also carry trade-offs: over-the-air (OTA) testing in anechoic chambers is limited to tens of minutes of scenario validity, while controlled-environment simulation offers longer, more flexible scenarios. Record-and-playback testing must handle extreme power differences between jammer and receiver, and multi-channel hybrid tests demand tight phase coherence across antenna channels.

What’s next

Future GNSS receiver architectures will integrate antennas and receivers more deeply, alongside broader PNT sensor fusion — driving miniaturization and system-on-chip (SoC) innovation. CRPA implementations are emerging in three forms — RF-layer, pre-correlation-layer, and post-correlation-layer — with next-generation designs likely combining them. Meanwhile, new signal authentication schemes, from Galileo’s OSNMA to the proposed GPS CHIMERA on NTS-3, will add further demands on testing.

With its dynamic adaptability to interference, CRPA is positioned as a practical and effective anti-jamming, anti-spoofing solution for the future of GNSS.