The first Progress Review of the St3TART project was held by videoconference on 7 February 2022. The thematic leaders for each surface (hydrology, sea ice and land ice) presented the status of the work performed by the thematic teams: the formalisation of the FRM protocols and procedures for the validation of the Copernicus Sentinel-3 STM data, including the work on the definition of the uncertainties associated with the ground measurements, the evaluation of the suitability and FRM-compliance of existing measurements and in-situ networks, and a specific focus on the first version of the project roadmap. This document contains recommendations and plans for the organisation of dedicated field campaigns and for the implementation and maintenance of permanent sites at various scales (super sites vs light/secondary sites).

The plans for the Arctic sea-ice joint campaign with CryoVex, expected end of March 2022, were presented, as well as the on-going preparatory work for the installation and deployment of several micro-stations at inland-water calibration sites in France, Germany and Italy, and for three drone campaigns to measure the Garonne river topography at the Marmande French super site.