Continued UK Contribution to the MicroCarb Mission – CO₂ Retrieval Algorithm Development and Programme Support

The MicroCarb mission is a Centre National d'Études Spatiales (CNES) led satellite mission designed to deliver high-precision measurements of atmospheric carbon dioxide (CO₂). The United Kingdom contributes to the mission through scientific, technical and validation activities coordinated by UK Space Agency (UKSA) and delivered via UK partners. This contract covers the continuation of activities required to support the UK contribution for the remainder of FY 2026–27, with a particular focus on continued CO₂ retrieval algorithm development, post-launch data exploitation, and ongoing programme-level technical engagement within the MicroCarb mission framework. The services under this contract will continue the development and application of CO₂ retrieval algorithms, preparation for the ingestion and processing of MicroCarb data products provided by CNES, and coordination of UK expertise through continued participation in the MicroCarb Advisory Group (MAG). The work builds upon progress delivered to date in providing mission-specific technical support, including adaptation of NASA-developed retrieval frameworks and preparatory activities supporting the transition of MicroCarb towards an operational data exploitation phase. Activities will place increased emphasis on algorithm robustness, data handling capability, validation readiness and sustained mission engagement. Activities under this contract would include: CO₂ Retrieval Algorithm Development and Assessment - Incorporation of prior information modules (ABO2 and GASBAG) and a meteorological pre-processor (GEOS-IT) into the CO₂ retrieval pipeline; adaptation of existing NASA-developed software to operate with synthetic MicroCarb data for the standard three spectral bands; Development of capability to ingest and utilise the fourth MicroCarb spectral band (1.27 µm) and assessment of its performance; Assessment of preliminary MicroCarb Level 2 retrieval performance, including preparation for comparison with CNES retrieval products. MicroCarb Advisory Group and Programme Support - Representation of UKSA/DSIT within the MicroCarb Advisory Group (MAG); Liaison with UK and French partners, including CNES; Provision of technical and programme-level updates and reporting; and submission of a summary report of activities undertaken.