The IGS MGEX experiment as a milestone for a comprehensive multi-GNSS service

The International GNSS Service (IGS), formerly the International GPS Service, is a voluntary federation of more than 200 worldwide agencies that pool resources and permanent GPS & GLONASS station data to generate precise GPS & GLONASS products. The IGS is committed to providing the highest quality data and products as the standard for Global Navigation Satellite Systems (GNSS) in support of Earth science research, multidisciplinary applications, and education. Currently the IGS includes two GNSSs: GPS and the Russian GLONASS. In view of the ongoing GPS modernisation and the buildup of new navigation systems such as BeiDou, Galileo and QZSS, the IGS has recently established the Multi- GNSS Experiment (MGEX). MGEX serves as a platform for early experimentation and familiarisation with the emerging new signals and constellations. Aside from collecting multi-GNSS tracking data from a global network implemented in parallel to the core IGS network, MGEX promotes the generation of dedicated multi-GNSS orbit and clock products and the development of advanced processing algorithms. The paper describes the current status of the MGEX project, discusses early achievements and presents the long-term vision for transitioning the IGS into a fully generic multi-GNSS service.