service d'exploration de la Terre par satellite

OBS: In an Earth exploration-satellite service system, information relating to the characteristics of the Earth and its natural phenomena, including data relating to the state of the environment, is obtained from active or passive sensors located on Earth-orbiting satellites. Similar information is collected from airborne or Earth-based platforms. All information or data that is collected may be distributed to Earth stations within the system concerned. Platform interrogations may also be included, and the service may include feeder links that are necessary for its operation.