Argos is the only global satellite-based data collection and location system of its kind dedicated to studying and preserving the environment. Created in 1978 on the initiative of the French national space agency, the Centre national d'études spatiales (CNES) and the U.S. National Oceanic and Atmospheric Administration (NOAA), it is today operated by CLS (Collecte Localisation Satellite), a subsidiary of CNES. Since Argos entered service, three generations of instruments have succeeded one another. Eumetsat and the Indian Space Research Organization (ISRO) joined the programme in 1997 and 2007 respectively.