Candidate scatterometer concepts for the Post-EPS mission

Post EUMETSAT Polar System (Post-EPS) is the next generation meteorological polar satellites system of EUMETSAT, a joint ESA-EUMETSAT development programme currently in phase 0, to replace MetOp system in the 2018-2020 time frame. Post-EPS is a mandatory programme addressing the need to continue EPS to provide, first of all, observations for operational meteorology and climate monitoring, and in addition, environmental services covering ocean, atmosphere, land and biosphere, and natural disasters. According to these objectives, the Scatterometry (SCA) mission has to provide ocean surface wind vectors, which are an important input to global and regional Numerical Weather Prediction (NWP) and also models of the ocean surface waves. The SCA instrument is conceived with the objectives of ensuring continuity of past spaceborne scatterometer missions. Their heritages (ASCAT, SeaWinds, etc.) have been fully exploited in SCA design and has directly led to the identification of the SCA candidate concepts. The direct comparison of the performance for past scatterometry missions and the SCA requirements shows that SCA performance would be in line with the ASCAT radiometric performance, while significantly exceeding ASCAT in terms of geometric parameters (horizontal resolution and accuracy). This paper presents the preliminary instrument concepts that have been investigated during the on-going phase 0 study.