GNSS Spoofing detector for GNSS aided Inertial System

Nowadays, GNSS signal spoofing has become an increasingly concrete threat. Low-cost consumer electronics, software defined radios and ADS-B are some of the keys that made GNSS spoofing technology accessible. A function for detecting, or even mitigating, the occurrence of a spoofing attack on GNSS signals has therefore become mandatory for civilian equipment such as the SkyNaute. Thus, the new standard for GNSS aided inertial equipment (RTCA DO384) includes a dedicated appendix specifying how to claim and evaluate the performance of such a function. The solution patented by Safran consists of analyzing the statistical behavior of the shifts computed by the hybridization filter. Several new detectors based on shift magnitude and direction have been tested. Under normal conditions, this shift direction is random with a relatively large standard deviation. In the event of GNSS signals coherent spoofing, the shift direction becomes constant; the standard deviation tends towards zero. This is the principle of the detector implemented by Safran. This article aims to present these new detectors, their reaction under spoofing condition and the results of the first evaluation campaign. Further evaluation campaigns and development will be presented in the conclusion.