Detection and Orientation of GNSS Spoofing Based on Positioning Solutions of Three Receivers

Spoofing poses a serious security threat to the satellite navigation system. Most of the current spoofing detection methods are based on the information in the receiver-solving process. Applying the above spoofing detection algorithm on the receiver requires a redesign of the original receiver, which limits the application of the deceptive detection method on the ex-factory receiver. In the case of single-station spoofing, the positions of the successfully spoofed multiple receivers are the same according to the deception signal, but the clock offset is different. The single-difference clock offset is positively correlated with the distance between the two receivers. Based on the above principles, this paper proposes a spoofing detection and spoofing direction method based on the positioning solutions of three receivers. The observation value of the baseline length is calculated from the position information in the positioning solution, and spoofing detection is realized by hypothesis testing. The clocks of the three receivers are synchronized. The Adaptive Delta Gradient Descent(ADGD) method is adopted to calculate the spoofing direction according to the single-difference clock offset in the positioning solution. The direction angle is optimized through the Interacting Multiple Model based on the volume Kalman Filter. The relationship between several parameters and the direction accuracy of spoofing is analyzed through simulation tests. Experimental results show that this method can effectively detect and orient spoofing. In addition, the detection and orientation method of spoofing has the advantage of fast response speed, which can realize fast spoofing detection and direction finding in a deception environment.