GLONASS april: What went wrong

The GLONASS event was one that we might have described by the phrase "such a thing can never happen." For the user community, the situation was aggravated by the fact that the event was not reported through the official Russian channel by issuing a Notice Advisory to GLONASS Users (NAGU). This definitely should have happened in the interest of transparency. The above analysis was based on information available through the IGS. It was performed weeks after the event. It is worth noting, however, that the information needed for the analysis was available in real time. The reference orbit used in the analyses could have been replaced by the IGS predicted orbits generated in the ultra-rapid series. In view of the importance of BM for all users and in particular for the users of IGS real-time products, the IGS might consider monitoring the quality of BM for all GNSS.