GNSS Spoofing Mitigation Using Multiple Receivers

GNSS receivers are vulnerable to spoofing attacks, where false satellite signals are transmitted to trick the receiver to provide false position and/or time estimates. Novel algorithms are proposed for spoofing mitigation by exchanging double differences of pseudorange, or carrier phase, measurements between multiple GNSS receivers. In scenarios where the spoofing system utilizes a single transmit antenna, the pseudorange, and carrier phase, measurements that are associated with the spoofing signal can be detected and removed. Simulated meaconing attacks generated with a Spirent hardware simulator and measurements obtained with a modified version of GNSS-SDR are used to evaluate the proposed algorithms. Spoofing mitigation using pseudorange measurements is possible, for receivers that are separated at least five meters apart. With a receiver separation of 20 meters, the pseudorange double difference algorithm is able to correctly authenticate at least six of seven pseudoranges within 30 seconds. The carrier phase approach enables mitigation of spoofing signals at shorter receiver distances. However, this approach requires a more accurate time synchronization between the receivers.