The method used to extract sea-ice thickness from radar altimetry data is based on the pioneering work of Peacock and Laxon, 2004; Laxon et al., 2003 for the ERS-2 mission. The method involves separating the radar echoes returning from the ice floes from those returning from the sea surface in the leads between the floes. This step of a surface-type classification is crucial and allows for a separate determination of the ice floe and sea-surface heights. The freeboard that is the elevation of the ice upper side (or ice/snow interface) above the sea level can then be computed by deducting the interpolated sea-surface height at the floe location from the height of the floe. Using the freeboard and additional snow load information, sea-ice thickness is then computed along the satellite track. To account for sea-ice motion, the along-track thickness estimates are combined with drift data from passive microwave sensors (Lavergne & Down, 2023). Individual measurement parcels are advected daily over a one-month period, resulting in drift-aware sea-ice thickness maps that reflect the evolving distribution of the ice.