Research on Spoofing Detection of GNSS/INS Tightly Coupled System Based on Skewness Test

When GNSS is subjected to spoofing interference, the positioning errors of GNSS/INS integrated navigation system will increase, so it is necessary to study the effective algorithm of detecting GNSS spoofing interference. Existing spoofing detection algorithms, such as snapshot and sequential, can effectively detect some types of spoofing, but their performance in detecting slowly varying spoofing is not ideal. To address this issue, this paper proposes a spoofing detection algorithm based on skewness test. Firstly, this paper established GNSS spoofing model, and obtained the statistical characteristics that the innovation sequence no longer obeys normal distribution under spoofing interference. Based on this, the skewness of the innovation sequence is used to construct test statistics for spoofing detection. Monte Carlo simulations verify the correctness of theoretical analysis, which show that compared with sequential algorithms, the spoofing detection algorithm based on skewness test has prominent advantages of rapid detection and high detection probability, especially when detecting the slowly varying spoofing. This is of great significance for ensuring the reliability of the integrated navigation system positioning.