Monitoring and Mitigating Ionosphere threats in GNSS Space Environment Science

The ionosphere is an important part of geospatial environment, in the community of GNSS-based safety-critical systems, the GNSS error caused by the ionosphere is the error source second only to the satellite ephemeris error. To ensure that the difference between the unknown real position and the system-derived position estimate has a very high degree of confidence, it is necessary to determine the error caused by the ionosphere or the discontinuity of the GNSS signal. We sorted out the existing ionospheric threat model and confirmed the effectiveness of the threat model. In addition, the research status and progress of the existing GNSS space environment technology to deal with this ionospheric threat are also pointed out, including the basic assumptions and delay corrections of the 2D and 3D simulations of the ionosphere. We hope that the relevant description of this article can promote the comparison of ionospheric monitoring and mitigation technologies in GNSS space environment science.