Question 1

What is constellation status?

Accepted Answer

Constellation status shows the health and availability of all GNSS satellites based on their broadcast ephemeris. A healthy satellite is usable for positioning; an unhealthy one has been flagged by the control segment and should be excluded.

Question 2

Where does the data come from?

Accepted Answer

The data is sourced from the IGS (International GNSS Service) real-time broadcast ephemeris stream BCEP00BKG0, which aggregates navigation messages from a global network of reference stations.

Question 3

How often is it updated?

Accepted Answer

The server collects fresh ephemeris data every 2 minutes from the IGS stream. Broadcast ephemeris update intervals vary by constellation: GPS every 2 hours, Galileo every 10 minutes, GLONASS every 30 minutes, and BeiDou every 1 hour.

Question 4

What do the health flags mean?

Accepted Answer

A health value of 0 means the satellite is healthy and usable. Any non-zero value indicates the satellite has been marked unhealthy by its control segment — it may be undergoing maintenance, orbit maneuvers, or experiencing clock issues.

Broadcast Ephemeris

GPS

Galileo

GLONASS

BeiDou

QZSS

SBAS

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