A spoofing mitigation technique for dynamic applications

Global Navigation Satellite System (GNSS) is becoming pervasive technology, widely used in many fields, like aviation, railway, maritime and road navigation systems. As a consequence an increasing number of applications are being created and it has become necessary to protect the GNSS receiver from malicious attacks, in order to guarantee the reliability of the navigation solution. In this work, a novel algorithm for GNSS spoofing attack detection and mitigation is proposed. This algorithm is a combination of techniques at signal processing level aiming at improving continuity, availability and reliability of the positioning solution. The idea is to detect and raise a warning about the presence of a spoofer while continuing to provide trusted position obtained by using Doppler measurements. A correction process estimates the relative delay between the true signal and the spoofer and unlocks the receiver from the spoofer and re-locks it to the true signal. If the unlocking process is successful, the receiver computes the position using mitigated pseudorange measurements.