A GNSS Spoofing Detection Technique Based on Signal Spatial Correlation

The gain of a GNSS receiving antenna is a function of signal arrival angle which consists of azimuth and elevation. Thus, the antenna direction changing would make impact on the gain of the received signals, which would be reflected on the signal CNR estimated results. Since the spoofing signals are generally transmitted from a single source, they always have the same arrival angles. Therefore, the CNR variations of spoofing signals have high correlativity as the receiving antenna direction changing, which could be used to differentiate the authentic and spoofing signals. In this paper, the influence of receiving antenna direction changing on CNR estimations for authentic signals and spoofing signals is analyzed, and the relativity of CNR variations is studied to differentiate the authentic signals and the spoofing signals. Furthermore, the effectiveness of the spoofing detection technique is verified by a series of experiments, in which the CNR estimations with a rotating antenna are monitored and utilized to distinguish the spoofing signals.