The ESA St3TART-FO (Sentinel-3 Topography mission Assessment through Reference Techniques Follow On) project invites the submission of proposals for collaborative field campaigns focused on the provision of Fiducial Reference Measurements (FRMs) over Land Ice and Sea Ice surfaces, with emphasis on key regions including Svalbard and the Beaufort Gyre. This open call is issued within the framework of the St3TART-FO activities (https://sentinel3-st3tart.noveltis.fr/), which aims to support the Copernicus Sentinel-3 mission through the provision of high-quality in situ reference data.

St3TART-FO is designed to establish and maintain an operational framework for FRM provision to validate and enhance the exploitation of ESA’s Sentinel-3 Synthetic Aperture Radar L2 altimeter Hydro-Cryo Thematic data products, covering inland waters, sea ice, and land ice.

The activities carried out under this Announcement of Opportunity (AO) are intended to complement the core objectives of the St3TART-FO project by expanding the geographical and temporal scope of Fiducial Reference Measurements (FRMs) over polar regions, particularly in Svalbard and the Beaufort Gyre.

Selected proposals are expected to contribute directly to the generation of new FRMs over Land Ice and Sea Ice surfaces that meet the standards defined by St3TART-FO in terms of quality, format, documentation, and uncertainty traceability (see details in PDF document), thereby supporting the validation of Sentinel-3 STM Hydro-Cryo Thematic products.

FRM acquisition may be conducted through airborne campaigns, drone-based observations, ground-based measurement systems (e.g., fixed stations, buoys, moorings), kinematic GNSS campaigns, and other relevant methods. Proposals addressing both land ice and sea ice surfaces, as well as those integrating multiple measurement techniques simultaneously, are strongly encouraged.