Within the RESIF-EPOS observation research infrastructure and the Action Spécifique RESIF-GNSS action, the Reseau National GNSS permanent (RENAG) is the network of GNSS observation stations of French universities and research organizations. It is currently composed of 85 GNSS stations (Global Navigation Satellite System such as GPS, GLONASS, Galileo). The scientific objectives of RESIF-RENAG range from the quantification of the slow deformation in France to the sounding of the atmosphere (troposphere and ionosphere), through the measurement of sea-level variations and the characterization of transient movements related to overloads.
Data production is carried out in a distributed way by the laboratories and organizations that manage the stations. 12 teams are specifically in charge of station maintenance and of accurately filling in the metadata files. A single data center, RENAG-DC, hosted at the Observatoire de la Côte d'Azur (OCA) within the Geoazur laboratory, is in charge of data management, from their collection to their distribution in the standard RINEX format (http://renag.resif.fr).