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 Sentinel 2 and Sentinel 3. This encompasses the next generation of the Multi Spectral Imager (MSI), Ocean and Land Color Imager (OLCI) and Sea and Land Surface Temperature Radiometer (SLSTR) observations. 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 in the 2032 time horizon, considering user needs, addressing mainly the Copernicus Marine and Land services, starting from user requirements for Copernicus Next Generation derived from EC studies and related workshops. It also did draw from the experience and lessons learned regarding the current generation of Sentinel 2 and Sentinel 3, to ensure continuity of services and further enhancement as identified, necessary to meet new and emerging user needs. The study investigated also trends both in terms of other spaceborne optical missions by national agencies in Europe and worldwide, as well as commercial missions e.g. with the advent of “New Space” constellations of small satellites. Observation gaps and potential synergies were identified to avoid duplication when establishing the architecture of the next generation of the Copernicus Space Component optical imaging family for land and ocean applications. A wide range of scenarios have been analysed for possible combination of several observation capabilities within the same instrument, on the same platform or on satellites flying in formation, assessing pros and cons with respect to scenarios with free-flyer satellites for each observation capability. Based on the above analysis of user needs, gap/synergy analysis and architectural concept trade-offs, high level mission assumptions and technical requirements are being established for the continuity of the MSI, OLCI and SLSTR observations, including any additional elements, as identified, to meet user requirements in the respective Copernicus services and application areas.