EGUsphere EGUsphere EGUsphere EGUsphere Copernicus Publications Göttingen, Germany 10.5194/egusphere-2026-5452 3-D characterization of Arctic lake ice with polarimetric SAR tomography at X- and C-band Saporta Paloma https://orcid.org/0009-0003-4084-630X 1 2 Pardini Matteo 1 Wilcox Evan J. 3 Boike Julia https://orcid.org/0000-0002-5875-2112 4 5 Hajnsek Irena 1 2 Microwaves and Radar Institute (HR), German Aerospace Center (DLR), Münchener Straße 20, 82234 Wessling, Germany Institute of Environmental Engineering (IFU), Swiss Federal Institute of Technology (ETH), Laura-Hezner-Weg 7, 8093 Zurich, Switzerland Department of Earth System Sciences, Earth and Society Research Hub (ESRAH), University of Hamburg, Allende-Platz 2, 20146 Hamburg, Germany Permafrost Research Section, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Telegrafenberg A45, 14473 Potsdam, Germany Geography Department, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099 Berlin, Germany 25 09 2026 2026 1 28 Copyright: © 2026 Paloma Saporta et al. 2026 This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/ This article is available from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-5452/ The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-5452/egusphere-2026-5452.pdf

This study investigates for the first time the three-dimensional structure of Arctic lake ice based on tomographic reconstruction from a polarimetric, multi-baseline airborne  Synthetic Aperture Radar (SAR) data set. The tomographic reconstruction indicates the presence of two strong interfaces at both X- and C-band, which can be attributed, based on field observations, to the air/ice and ice/liquid water interfaces. This means that the tomographic reconstruction is sensitive to the thickness of the ice layer of the investigated lakes. The reconstructed vertical reflectivity profiles are found to vary with polarization, therefore they can only be interpreted with a dedicated polarimetric analysis. In some lakes, we observe regions characterized by scattering with high entropy focused at the ice/water interface. We propose several hypotheses regarding the physical origin of these regions. Finally, requirements for the estimation of lake ice thickness from multi-baseline SAR are formulated to support the planning of future spaceborne SAR missions with tomographic capabilities.