Method of GNSS Security Augmentation Based on LEO Satellite

Abstract

In order to improve the service performance of the global navigation satellite system (GNSS), a variety of augmentation systems have been developed, including satellite-based and ground-based augmentation methods. The purpose of augmentation systems usually includes integrity augmentation, accuracy augmentation and availability augmentation. With the emerging user fields, especially those related to life safety or economic debt, more dependence on GNSS, leads to a high demand for the robustness and security of GNSS civil signals. The received power of GNSS signal on ground is weak and the civil signal structure is open, which is easy to become the target of jamming and spoofing. Therefore, it has become a trend to enhance the security of GNSS civil signals. At present, there are two ways to enhance the security. One is to introduce security authentication features into civil signals, including navigation message authentication and spread spectrum code authentication. This method has little effect on non-authenticated users, but the security authentication is not real time. The other method is based on the location authentication of LEO satellite multi spot-beam features represented by iridium next satellite. The method has high real-time performance, but the accuracy is limited by the beam pattern. In this paper, a GNSS security augmentation method based on LEO satellite is proposed. Using the credible ranging signal broadcasted by LEO satellite, the positioning result of GNSS civil signal is authenticated to achieve security augmentation. This proposed method has the advantages of high real-time performance and high precision. Theoretical analysis shows the effectiveness and feasibility of this method.