EUMETSAT MICROWAVE SOUNDER CONSTELLATION: THE EPS-STERNA PROGRAMME

P. Colucci¹, V. Mattioli¹, C. Accadia¹, J. Ackermann¹, F. Bosco¹, S. Di Michele¹, I. Krizek¹, T. Hewison¹, G. Karsli Demirbas¹

¹EUMETSAT

The EUMETSAT Polar System (EPS) Sterna has been identified as a potential expansion of the EPS and EPS Second Generation (SG) programmes, to complement and expand the services provided by the Joint Polar System (JPS) operated by EUMETSAT and NOAA.

EPS-Sterna programme will be fully funded by EUMETSAT and will contribute to the realisation of the WMO Integrated Global Observing System (WIGOS) Vision 2040, in line with the objectives of the EUMETSAT Destination 2030 strategy.

The EPS-Sterna System encompasses the Space Segment, the Ground Segment and the Launcher Services. The EPS-Sterna Space Segment consists of a constellation of small polar-orbiting satellites, each equipped with a cross-track scanning microwave sounder, which will allow to retrieve atmospheric humidity and temperature profiles. The initial constellation will consist of six EPS-Sterna satellites and is planned to be deployed in 2029. The satellites of the constellation will be replaced with new satellites throughout the mission lifetime of thirteen years and a total of twenty satellites will be manufactured and launched. The complementarity to EPS-SG and JPS is reflected in the choice of constellation orbits, designed to optimize the overall global coverage of the constellation while keeping the mission affordable.

Level 1 products from the EPS-Sterna mission will be disseminated via EUMETCast to support operational meteorology and will enable the generation of higher-level products (e.g., Level 2) supported by the EUMETSAT Satellites Application Facilities (SAFs).

The EPS-Sterna programme will capitalise on the experience from the European Space Agency’s mission Arctic Weather Satellite (AWS) launched in August 2024, which served as technology demonstrator and protoflight model for the satellites to be used in the constellation. The MicroWave Radiometer (MWR) is the instrument embarked on the Sterna Satellites, which will be based on the AWS instrument, the technology of which has similarities with the EUMETSAT Polar System – Second Generation (EPS-SG) Microwave Sounder (MWS). The MWR is featuring 19 channels covering the millimetre-wave frequency range 50–325 GHz. Together with well-established frequencies in the 50 and 183 GHz bands and windows channel at 89 GHz, the instrument also include 4 channels at 325 GHz, comparable to those of the EPS-SG Ice Cloud Imager (ICI). The antenna system comprises 4 feedhorns, one for each group of channels without any quasi-optics and a more compact design than MWS.

This presentation will provide an overview of the EPS-Sterna programme and its status, outlining scientific goals and the operational objectives.