ESRIN is ESA's site located in Frascati, near Rome, Italy. It was created in 1966 and since 2004, it has been the headquarters for ESA's Earth Observation activities. One of its main tasks is managing the operation and exploitation of ESA's Earth Observation satellites. In cooperation with other space agencies, it also manages the acquisition, distribution and exploitation of data from non-ESA satellites. ESRIN is also responsible for the development operations regarding the Envisat satellite’s Payload Data System (PDS). This mission, with its load of complex, advanced instruments on board, transmits earthwards an enormous quantity of data that must be processed for their various fields of application. A special building in ESRIN is dedicated to housing the infrastructure control and management equipment for the ground segment of Envisat.