Threat space reduction method for satellite navigation signal distortion model

The threat space of a satellite navigation signal distortion model describes the signal distortion range which causes a large differential error but is difficult to detect by receiver observations. The threat space may have disastrous consequences for civil aviation and other safety navigation services. A larger threat space increases the navigation services risk and the distortion detection requirements. Thus, satellite navigation systems need appropriate methods to minimize the threat space. This paper presents a method that reduces the range bias detection threshold to reduce the threat space. The effectiveness of this method is evaluated using the BeiDou Navigation Satellite System (BDS) B1C and B2a signals as examples. The results show that the threat space can be reduced by more than 40% compared to a space for a 20 m threshold when the ranging bias threshold is 5 m. This method should be implemented by using satellite onboard receivers to reduce the threat space. © 2021, Tsinghua University Press. All right reserved.