For several hours on April 1st and 2nd (GMT) the GLONASS constellation experienced reliability issues that were associated with the generation of incorrect or invalid ephemeris information. This system failure was global in nature, affecting all GPS+GLONASS receivers regardless of make or brand. Reported effects ranged from very slow RTK initialization times, to extreme cases where the computed GNSS position was significantly in error. Correct operation of the GLONASS constellation was successfully restored at approximately 7AM (GMT) on April 2nd. Since this time, all GPS+GLONASS receivers should again be functioning normally. Topcon is monitoring the situation closely, and will keep you aware of any changes as new information becomes available. In case of any immediate concerns regarding the current health of the GLONASS system, status information can be seen at the following site.