The Advanced Data Collection System (A-DCS) (also known as ARGOS) is to provide a worldwide in-situ environmental data collection and Doppler-derived location service with the basic objective of studying and protecting the Earth's environment. The A-DCS is currently jointly operated by NOAA and CNES. However, with the instrument installed on the MetOp series, EUMETSAT will become the third agency to operate the system.
A-DCS collects data from platform transmitters (PTTs) located on land and ocean in UHF frequency. Over 5000 environmental platforms are located around the world. Marine PTTs located on buoys transmit oceanographic data and PTTs on ships transmit weather and oceanographic data. Land-based PTTs provided meteorological and hydrological data and those on balloons provide atmospheric information.