Sea Ice Detection Based on Unambiguous Retrieval of Scattering Coefficient from GNSS-R Delay-Doppler Maps

In this paper, a method is proposed for detecting sea ice based on the scattering coefficient $(\sigma^{0})$ retrieved from Global Navigation Satellite System-Reflectometry (GNSS-R) delay-Doppler maps (DDMs). First, a strategy for unambiguously retrieving the surface scattering coefficients is illustrated, by employing the spatial integration approach (SIA) and the multi-scan technique. Next, the application of this proposed scheme for sea ice remote sensing is demonstrated using DDMs acquired from the U.K. TechDemoSat-l (TDS-l) mission and verified with the collocated reference sea ice concentration (SIC) data obtained by Nimbus-7 SMMR and DMSP SSM/I-SSMIS sensors. The test results show that the proposed method offers a new solution to sea ice detection and a feasible aspect for resolving the ambiguity in the retrieval of $\sigma^{0}$ from GNSS-R DDMs.