Simulation-Based Embedded-Pattern Calibration for Array-Aided GNSS Spoofing Detection: A NavIC L5 Study

Abstract

Global Navigation Satellite Systems (GNSS) are vulnerable to spoofing attacks that can manipulate receiver positioning while remaining difficult to distinguish from legitimate signals using conventional signal-quality checks alone. This study investigates a simulation-based approach to improving NavIC L5 spoofing detection through electromagnetic array calibration. Embedded element patterns for a four-element antenna array are obtained using electromagnetic simulation and incorporated into a spatial-signature-based detection framework with a four-state hidden Markov model. The approach is evaluated across 48 simulated spoofer geometries, with scenarios involving one to four transmitters and benign propagation conditions. In the evaluated power-matched attack case, the study reports a 3.9 dB carrier-to-noise density change and a detection latency of 63 s. In the simulated mitigation assessment, horizontal position error decreases from 2,400 m without mitigation to 6 m with mitigation. The detector identifies spoofing in all 48 tested geometries. However, the nominal false-alarm rate of 0.00% does not generalize to all propagation transitions: abrupt canyon entry produces a mean false-alarm rate of 1.50%, with a worst-run value of 11.97%. These results indicate the potential of electromagnetic array calibration to support spatially informed spoofing detection and mitigation in NavIC receivers. The findings are limited to simulation and require validation using physical antenna arrays and real receiver measurements.