Real-time evaluation method for multi-parameter GNSS interference based on factor analysis

The Global Navigation Satellite System is widely applied in the civil aviation sector, making the reliability of its service performance a major concern for users. However, various types of interference, such as multipath interference, jamming, and spoofing, severely degrade system service quality and may pose safety risks. Traditional navigation performance evaluation methods primarily rely on post-event analysis, which fails to provide timely interference monitoring and alerts. To address this issue, this paper proposes a real-time interference assessment method based on factor analysis. Key real-time evaluation indicators, including Carrier-to-Noise Ratio, Code Tracking Error Standard Deviation, Carrier Tracking Error Standard Deviation, Geometric Dilution of Precision, and Pseudo Range Residuals, are selected for assessment. The proposed method evaluates GNSS performance under different interference conditions, employs factor analysis to fuse the evaluation indicators, and computes factor scores. Based on civil aviation standards, the assessment results are categorized into five alert levels. Finally, real-time interference warning messages are sent to users according to the severity level, providing instant interference monitoring and risk alerts for GNSS services.