Synchronized Spoofing Attack Detection Using Galileo OSNMA and an Antenna Array

This paper presents an over-the-air GPS C/A and Galileo E1 spoofing attack. Two different lines of defense mechanisms, Galileo Open Service Navigation Message Authentication (OSNMA) and multi-antenna angle of arrival (AOA), have been used to identify the spoofing attack occurrence. Their specific responses to the spoofing attack are shown and are discussed. It has been found that angle-of-arrival indicators quickly indicate the presence of a disturbance, but are partly difficult to interpret in a conclusive manner. On the other hand, OSNMA provides a solid means to identify the attack, but has a much higher latency. The response of the OSNMA detector to the time-synchronized spoofing attack shows a complex pattern, as the spoofer partly predicts the OSNMA fields.