Mission requirements for GMES Sentinels 4 and 5
Joerg Langen(1) and Ellen Brinksma(1)
(1) ESA, POB 299, 2200AG Noordwijk, Netherlands
A large complement of satellites for observation of atmospheric composition is currently in orbit: Envisat, Aura, Odin, ACE, Mopitt, Gosat, Metop, plus other platforms with aerosol instruments onboard. These space missions provide a wealth of information for research. However, the continuity of data provision is not given, except for the operational meteorological platforms Metop and NPOESS. A reliable long-term space-based monitoring of atmospheric constituents, of quality adequate to serve atmospheric chemistry applications, still needs to be established.
A need for regular, reliable and comprehensive data addressing issues in relation with climate-chemistry interactions, air quality and stratospheric ozone / surface UV irradiance has been identified in the context of the GMES initiative. Applications have been identified and geophysical requirements established for each of them. Mission concepts have been identified. The requirements on atmospheric constituents have been mapped onto requirements for instruments and their radiometric, spectral and spatial performances. Comparative observation statistics accounting for the impact of cloud contamination have been established for several mission scenarios including geostationary and sun-synchronous as well as precessing low Earth orbits.
Following the decisions of last year’s Council meeting at Ministerial level, the space part of these requirements will now be implemented with instruments onboard the Meteosat Third Generation (Sentinel 4) and on a post-EPS platform (Sentinel 5). To bridge the gap between currently ongoing research missions such as Envisat and EOS-Aura and the launch of the post-EPS mission, a Sentinel 5 precursor with reduced payload will be flown with a planned launch in 2014.
The presentation will outline the derivation of the mission requirements and the status of the programme.