Fully polarimetric dual-frequency radar monitoring of Arctic sea ice

The NASA–ISRO SAR (NISAR) mission will provide the first spaceborne dual-frequency (L- and S-band) radar observations of polar regions, which is capable of acquiring fully-polarimetric acquisitions. While L-band polarimetric capabilities are relatively well understood from previous missions and airborne campaigns, the S-band component represents a novel observational opportunity whose potential for sea ice characterization remains largely unexplored. Because of the fast changing sea ice regime in the Arctic, there is a growing need to understand what observational capabilities emerging synthetic aperture radar (SAR) system can offer for sea ice monitoring.

This study leverages very high resolution airborne UAVSAR imagery at fully-polarimetric mode from winter and summer seasons in the Beaufort Sea to investigate how dual-frequency SAR can provide separability of thinner sea ice classes over the annual thermodynamic cycle. We examine SAR backscatter and a range of parameters derivable from fully-polarimetric data to assess their utility in ice type discrimination.

Given S-band's intermediate wavelength between L-band and C-band, we anticipate distinct scattering behavior arising from its sensitivity to ice properties at scales different from those of established frequencies. This study aims to characterize how L- and S-band respond to varying ice conditions across seasons and to explore whether the two frequencies offer complementary information for ice classification. Also, we would like to develop a ranking for most efficient parameters from separability matrices. These findings will inform the development of sea ice monitoring frameworks for the imminent NISAR era.