The Esa Sentinel Next-Generation Land & Ocean Optical Imaging Architectural Study, An Overview

ESA initiated in 2018 an architectural design study to prepare the development of the next generation of the optical component of the current Sentinel-2 and Sentinel-3 observation functions i.e. Sentinel-3 without the SAR altimeter and related payloads. The aim of this activity was to analyse and trade-off different architectural options for the next-generation of the Copernicus Space Component optical imaging missions, with an implementation in the 2032-time horizon. A holistic approach was taken to assess architectural option to secure the respective observation capabilities in future, not only extrapolating the current scenario, but to openly assess e.g. the merging of observation functions of different instruments as well as to consider potential data flows from third part missions and service providers, institutional as well as commercial. The outcome of the analysis, taking technological as well as programmatic aspects into account, resulted in the conclusion that Sentinel-2 MSI NG as well as Sentinel-3 OLCI NG together with SLSTR NG on the same platform, are most efficiently implemented as free flyers, with dedicated instruments. The data flow of these two missions will be ideally supplemented by the Land Surface Temperature Mission (LSTM) and the Hyperspectral Mission (CHIME), which are going to be implemented in the frame of the High Priority Candidate Missions (HPCMs) of Copernicus. Those operational data flows, building the backbone of the operational services, can benefit significantly by including the data flows of reliable sources e.g. as from the Landsat series of satellites. The needs for very high resolution (VHR) imaging data, can best be served by data from third party missions, as currently implemented in the Copernicus framework; a Sentinel VHR mission is currently not baselined.