SmartNet North America, as well as other GNSS Network Service providers, have identified a GLONASS ephemeral issue that is affecting GNSS tracking characteristics of GNSS receivers on a global basis. We have confirmed our findings with our sister network, SmartNet Australia, as well as 2 other service providers and have reported the issue back to the Russian Federal Space Agency.
The issue, while primarily affecting GLONASS tracking, has also caused some makes and models of GNSS receivers to completely stop tracking both GPS and GLONASS rendering services in the immediate area offline. There are also certain firmware versions of certain GNSS receiver types that seem to be more sensitive to the issue as well.
Update #1 - 9:22 PM ET
The "illegal ephemeris" has been reported and is being displayed on the Russian Federal Space Agency website - http://snna.co/1dPuHSD
The "illegal ephemeris" that is being broadcast by the GLONASS constellation must be corrected and uploaded into each satellite to correct the issue by the Russian Federal Space Agency system. This cannot happen until the satellites pass back over the Agency's upload station so the upload link can take place. Each satellite passes the upload station on 12 hour orbits, so at the moment the only resolution to the issue is to wait until a healthy ephemeris can propagate completely thru the constellation.
Update - 9:25 AM ET, April 2, 2014
The health ephemeris has propagated thru the GLONASS constellation and operations seem to be have returned to normal.
6:00 PM ET, April 1, 2014 - GLONASS Tracking issues were noticed by SmartNet AUS and SmartNet NA
7:00 PM ET, April 1, 2014 - Issue began spreading to additional receivers (West to East) in NA