Chapter 2: ENVISAT - SCIAMACHY's Host

ENVISAT is Europe’s ambitious Earth Observation enterprise to study the many facets of the Earth system. It carries 10 remote sensing instruments with SCIAMACHY, MIPAS and GOMOS forming the atmospheric chemistry mission. SCIAMACHY, although provided by national space agencies to ESA, is an integral part of the payload. Orbit and attitude of ENVISAT determine the framework of SCIAMACHY’s observing capabilities. As a polar, sun-synchronous satellite, ENVISAT provides a stable platform for orbiting the Earth every 100 min. All instruments share the available on-board resources, particularly on-board data handling capabilities. The ENVISAT ground segment consists of the Flight Operation Segment for platform and instrument control and of the Payload Data Segment for measurement data acquisition, processing, archiving and dissemination. The SCIAMACHY data processing occurs at the LRAC and the D-PAC, depending on whether the data is of type level 0, 1b or 2. Access to SCIAMACHY data follows the general ENVISAT data policy with the exception that the instrument providing agencies receive a separate copy of such data.