Two-Step Trajectory Spoofing Algorithm for Loosely Coupled GNSS/IMU and NIS Sequence Detection

Yangjun Gao,Lundong Zhang,Zhiwei Lv

doi:10.1109/access.2019.2927539

Abstract

Satellite navigation spoofing has become a central issue of jamming technology research because of its serious threat and ability to conceal itself. Increasingly, targets are equipped with more robust GNSS/IMU systems and normalized innovation squared (NIS) is used to detect interference. Therefore, it is harder to implement covert trajectory spoofing on a GNSS/IMU system than a GNSS-only target. In practice, spoofing is needed to control unknown targets. Therefore, covert trajectory spoofing for GNSS/IMU targets is an important issue. Hence, using the information fusion of a GNSS/IMU system, the influence of spoofing on loosely coupled GNSS/IMU positioning is derived. To avoid ill-posed equations when introducing a measurement deviation, a Kalman gain matrix local regularization method is proposed to accurately determine the measurement deviation. To avoid triggering the NIS detection alarm, the range that enables the introduced measurement deviation to remain concealed is calculated. Then, a two-step trajectory guidance algorithm is proposed to quickly guide the target onto the spoofing trajectory. The simulation results show that the proposed trajectory spoofing algorithm can guide a loosely coupled GNSS/IMU target along a spoofing trajectory without triggering the NIS detection alarm. The proposed method can remain concealed and has good theoretical and practical application value.

Highlights

Satellite navigation spoofing technology has become a central issue of jamming technology research because of its serious threat and potential for concealment [1]
In 2017, a trajectory fusion strategy proposed by Li and Wang was shown to avoid the normalized innovation squared (NIS) sequence detection of UAV navigation system, it is assumed that the spoofing device is equipped with a position tracker to obtain the position information of UAV in real time, and acceleration value of the broadcast GPS spoofing signal matches the real acceleration of UAV, but the influence of spoofing on GNSS/IMU positioning results is not analyzed [19]
These results demonstrate that, during the process of GNSS spoofing, the Kalman filter output from the target navigation system is stable and there is no abnormality, which means that the alarm of the navigation system is unlikely to be triggered

Summary

INTRODUCTION

Satellite navigation spoofing technology has become a central issue of jamming technology research because of its serious threat and potential for concealment [1]. In 2017, a trajectory fusion strategy proposed by Li and Wang was shown to avoid the NIS sequence detection of UAV navigation system, it is assumed that the spoofing device is equipped with a position tracker to obtain the position information of UAV in real time, and acceleration value of the broadcast GPS spoofing signal matches the real acceleration of UAV, but the influence of spoofing on GNSS/IMU positioning results is not analyzed [19]. To avoid alerting the NIS detection of the target’s navigation system, the range that the introduced measurement deviation should satisfy is calculated, which strongly conceals the spoofing process; a two-step trajectory guidance algorithm is proposed to quickly induce the target to follow a spoofing trajectory. The spatial region satisfying yZ of formula (16) can be represented as the inner region of the sphere in Figure 3, where yZ is indicated by the black threedimensional vector

TWO-STEP TRAJECTORY GUIDANCE ALGORITHM

EXPERIMENTAL EVALUATION

Findings

CONCLUSIONS