A New Signal Quality Monitoring Method for Anti-spoofing

Abstract

Intermediate spoofing, identified as an efficient spoofing attack method, can launch a spoofing attack without interrupting the regular functioning of Global Navigation Satellite System (GNSS) receivers. GNSS is vulnerable and easily interfered by spoofing because of its opening signal structure and low signal power, and this threatens the security and integrity of GNSS, especially for the safety critical applications such as maritime and aviation. Signal Quality Monitoring (SQM) techniques, originally designed for multipath detection, are recently found to be useful to identify the deformation on the correlation function of a GNSS signal due to an intermediate spoofing attack. Conventional SQM-based methods directly employ the values of the SQM metric to detect spoofing attacks. In this paper, we develop an enhanced SQM technique for spoofing detection. It is known that the value of SQM metric fluctuates significantly during the interaction between the counterfeit signal and authentic signal. As the variance of metric can better reflect this fluctuation of metric, we choose the moving variance (MV) of the SQM metric as a new “metric” to detect the occurrence of spoofing. The basic principle of the proposed method is well introduced and tested on four different SQM metrics. Its ability to detect spoofing has been validated using the dataset collected using our SPIRENT simulators. The results show that the proposed moving variance-based SQM method is advantageous in the detection of spoofing attacks.