Meteosat Third Generation: mission and system concepts

EUMETSAT and ESA initiated in 2000 joint preparatory activities for the formulation and definition of the Meteosat Third Generation (MTG) geostationary system, to ensure continuity and improvement of current Meteosat Second Generation (MSG) services. MTG will become the backbone of the European operational meteorological applications taking the relay from MSG by 2017, and warranting the continuation of the earth imagery mission supported by the Spin Enhanced Visible and Infrared Imager (SEVIRI). The early program definition phases were devoted to the discussion and consolidation of end user requirements and their priorities in meteorology fields as Nowcasting and Very Short Term Weather Forecasting (NWC), Medium/Short Range global and regional Numerical Weather Prediction (NWP), Climate and Air Composition Monitoring and the identification of the relevant observation techniques. In the system conceptualization process, the following missions have been analyzed: • Full Disc High Spectral resolution Imagery (FDHSI) • High Resolution and Fast Imagery (HRFI) • Lightning detection Mission (LI) • IR Sounding Mission (IRS) • UV-VIS-NIR Sounding Mission as a payload complement (UVN). After pre-phase A mission studies (2003-2006), where preliminary instrument concepts were investigated allowing the consolidation of the most critical and demanding technical requirements, phase A studies were launched at the beginning of February (2007-2008) addressing both the space segment system feasibility and ground and operations programmatic aspects. The space segment, phase A level, studies covered the entire suite of optical instruments identified in the preliminary assessments including: 1) a flexible combined imager for both FDHSI and HRFI missions; 2) a Fourier Transform Spectrometer for IRS observations; and 3) a lightning detector sensor. The study of concepts and implementation of the UVN mission are covered by the efforts of ESA and the European Union (EU) in the framework of the Global Monitoring for Environment and Security (GMES) Sentinel 4 program. This paper provides an overview of the outcome of the MTG System analyses at the end of phase A confirming its technical feasibility, the key characteristics of the intended missions, and the progress accomplished in the definition of the satellite optical payloads.