Last update: . More information about this Galileo/GPS/BeiDou/Glonass open source monitor can be found here. Live map here!. Contact me if you want access to the Grafana dashboard.

Stale:

This table shows live output from four Galileo/GPS/BeiDou/GLONASS receivers hosted in Nootdorp, The Netherlands and California, United States. It is very much a work in progress, and will not be available at all times. Extremely rough code is on GitHub. Some technical detail behind this setup can be found in this post. For updates, follow @GalileoSats on Twitter, or join us on our IRC channel (chat) via the web gateway. The meaning of the fields is as follows:

svSatellite Vehicle, an identifier for a Galileo satellite. Not the actual name of the satellite, other satellites could take over this number in case of failures
iodIssue of Data. Satellites periodically get sent updates on their orbit & other details, each update has a new IOD number. It is coincidence that all SVs currently receive the same IOD numbers, this is by no means guaranteed. Currently however, if an SV has a lower IOD, it has not received new updates recently.
eph‑age‑mAge of ephemeris in minutes. Denotes how old the current set of orbit data is. Could be very old if SV is out of sight (see below). An acceptable limit is 4 hours (240 minutes).
latest-disco"jump" of the orbit prediction at the latest ephemeris change. Centimeters are good.
sisaSignal In Space Accuracy, how well the position of an SV is known.
e1bhs, e1bdvs, e5bhs, e5bdvsHealth flags for E1 (common) and E5 (uncommon) frequencies.
a0, a1Offset of the Galileo Standard Time to UTC. a0 is (more or less) the offset in nanoseconds, a1 is a measure of the rate of change
elevElevation of an SV over my horizon (90 is straight up), reported by receiver
calc-elevElevation of an SV over or under my horizon (90 is straight up), calculated by this website
dbA measure of signal to noise ratio (in unknown units, 40 is good)
last‑seen‑sNumber of seconds since we've last received from this SV. A satellite can be out of sight for a long time

The official Galileo constellation status can be found on the European GNSS Service Centre page, which also lists "NAGUs", notifications about outages or changes.

Official GLONASS status can be found on this page from the Russian Information and Analysis Center for Positioning, Navigation and Timing.

Sadly reduced status updates on GPS can be found on this page from the US Department of Homeland Security.

Information on the status of BeiDou can be found on this page from the Chinese Test and Assessment Research Center of China Satellite Navigation Office.

Feedback is very welcome on bert@hubertnet.nl or @PowerDNS_Bert.