ASeLSU will study the feasibility for the Sentinel-6 Next Generation space component to address new requirements by a full assessment of the Sentinel-6 Sea Level Rise Uncertainty Stability Budget using metrological best practices and procedures.
The enhanced goals for Sentinel-6NG requested by the Copernicus Climate Service (C3S) requirements are: EC-REQ-010, 0.1 mm/yr for the global mean sea level trend; EC-REQ-020, 0.5 mm/yr for the regional mean sea level trends; EC-REQ-030, 05 mm/yr for the global mean sea acceleration. These requirements must be specified together with a suitable validation approach and appropriate apportionment to individual components to the Sentinel-6NG system to determine if the most appropriate approach to address the requirements is to improve the satellite system or to improve the elements associated with a sea level rise estimate. Specific aspects including regional/global differences and the uncertainty of the SSH field itself (as known from multi-mission altimetry and other means) must be included. As these goals (e.g. drift of 0.1 mm/yr) are very challenging, they must be apportioned based on evidence from sea level rise uncertainty budgets and apportionment of uncertainty components of relevant elements in the end-to-end sea level rise measurement system using a comprehensive uncertainty budget assessment.