X and C-band SAR Signatures of Sea Ice in the Bohai Sea

Abstract

This study carried out an X and C-band spaceborne synthetic aperture radar (SAR) observation synchronized with the field experiment in the Bohai Sea of China in January 2024. Based on the co-located X and C band SAR multi-polarized data from TerraSAR-X/TanDEM-X, Gaofen-3, and Sentinel-1, we elucidated the signatures of thin ice and quantified their separability. Underlying the identified thin ice information, we further demonstrated the feasibility of separating thin ice and seawater from the ice-water mixture. Combining with the LiDAR-measured surface roughness, we investigated its correlation with different X- and C-band SAR signatures, of which the optimal parameter was used to develop the regression models for estimating thin-ice surface roughness. The comprehensive application of multi-band, multi-polarization SAR contributes to resolving the ambiguity of observed thin ice signatures. Our case study highlights the potential role of multi-polarized (or even fully polarized) X-band SAR for thin ice observations.