C/N0 Analysis-Based GPS Spoofing Detection with Variable Antenna Orientations

2025-10-17

AI Summary

GPS spoofing poses a severe threat to aviation navigation safety; existing detection methods often rely on specialized hardware or complex signal processing. This paper proposes a lightweight, antenna-attitude-sensitive spoofing detection method that exploits the fundamental directional dependence disparity between authentic and spoofed GPS signals. By performing simple roll maneuvers—level flight, left bank, and right bank—and monitoring corresponding carrier-to-noise density ratio (C/N₀) variations, the approach identifies characteristic patterns: spoofed signals exhibit pronounced C/N₀ peaks when the antenna boresight aligns with the spoofer and show systematic, steep C/N₀ drops during banking; authentic signals yield stochastic fluctuations. Experiments using a u-blox EVK-M8U receiver and GPSG-1000 simulator under both open-sky and spoofed conditions validate this behavior. The method requires no additional hardware or signal demodulation, demonstrating a low-cost, highly feasible spoofing detection solution for general aviation and unmanned aerial systems.

Technology Category

• Planning, Routing, and Scheduling: Activity and Plan Recognition
• Intelligent Robots: Localization, Mapping, and Navigation
• Application Domains: Mobility, Driving & Flight

Application Category

• Security and Privacy: Large-scale security measurements
• Web Mining and Content Analysis: Web data provenance, reliability, and authenticity
• User Modeling, Personalization and Recommendation: Attacks and countermeasures in recommendation systems

Abstract

GPS spoofing poses a growing threat to aviation by falsifying satellite signals and misleading aircraft navigation systems. This paper demonstrates a proof-of-concept spoofing detection strategy based on analyzing satellite Carrier-to-Noise Density Ratio (C/N$_0$) variation during controlled static antenna orientations. Using a u-blox EVK-M8U receiver and a GPSG-1000 satellite simulator, C/N$_0$ data is collected under three antenna orientations flat, banked right, and banked left) in both real-sky (non-spoofed) and spoofed environments. Our findings reveal that under non-spoofed signals, C/N$_0$ values fluctuate naturally with orientation, reflecting true geometric dependencies. However, spoofed signals demonstrate a distinct pattern: the flat orientation, which directly faces the spoofing antenna, consistently yielded the highest C/N$_0$ values, while both banked orientations showed reduced C/N$_0$ due to misalignment with the spoofing source. These findings suggest that simple maneuvers such as brief banking to induce C/N$_0$ variations can provide early cues of GPS spoofing for general aviation and UAV systems.

Problem

• Detects GPS spoofing through C/N0 variation analysis
• Identifies spoofed signals using controlled antenna orientation changes
• Provides early spoofing cues for aviation via simple maneuvers

Innovation

• Detects spoofing via C/N0 variation analysis
• Uses controlled antenna orientations for signal comparison
• Identifies spoofing by highest C/N0 in flat orientation