The IGS was formed through a Call for Participation that was circulated in 1991 by the International Association of Geodesy (IAG). In 1993, a pilot scientific service based on the US Global Positioning System (GPS) led to the official establishment of the International GPS Service in 1994. The IGS has been operating ever since.
In 1998, the IGS circulated a Call for Participation in the International GLONASS Experiment – IGEX. This successful experiment led to the establishment of the International GLONASS Service Pilot Project within the IGS. By 2003, GLONASS was fully incorporated into the IGS.
This led to the IGS becoming a truly GNSS service, GPS plus GLONASS and hence, in 2005, the IGS was renamed to the International GNSS Service.
This Call for Participation for the IGS Multi-GNSS Experiment – IGS M-GEX – recognizes the availability of new additional GNSS signals and new constellations on the horizon. The IGS is preparing for this next phase in the evolution of the IGS to eventually generate products for all GNSS available.
The Call for Participation can be downloaded from the IGS website