Year: 2025
Type: article
Abstract: Since the 2010 launch of Cryosat‐2, a new generation of altimeters, referred to as SAR altimetry, has emerged and partially replaced the previous conventional altimeters known as Low Resolution Mode (LRM) altimetry. A surface slope correction has been previously developed for LRM altimetry. However, the differences in the way the two altimeters work, and in particular their radar footprint, make LRM altimeter slope correction inapplicable to SAR altimetry. Thus, in this paper, a slope correction model is provided for SAR altimetry, derived from the LRM‐based approach. The shape of the SAR footprint induces that height correction depends on each satellite mission. Consequently, a generic method allowing to generate global maps of height correction for distinct missions is provided. The maps are computed for the Sentinel‐6A mission and the importance of correcting this effect for SAR altimetry is highlighted by studying the sea surface height anomaly biases between Sentinel‐6A SAR and LRM measurements. Finally, it is shown that applying the slope correction to Sentinel‐6A SAR mode sea surface height anomaly measurements enhances their consistency with the latest Mean Sea Surface (MSS) model, reducing the root mean square error between the sea surface height anomaly and the MSS model by up to 1 cm.
Source: Earth and Space Science
DOI: 10.1029/2025ea004294
Authors: Juliette Gamot, Marie‐Isabelle Pujol, Philippe Schaeffer, François Bignalet‐Cazalet, Emeline Cadier, Thomas Moreau
Language: English
Subfield: Oceanography
Field: Earth and Planetary Sciences
Domain: Physical Sciences
SDG: Climate action
Open Access status: gold
Estimated APC paid: $2,650
OpenAlex ID: W4416416858