THIN SALINE ICE THICKNESS RETRIEVAL USING TIME-SERIES C-BAND POLARIMETRIC RADAR MEASUREMENTS

The application of time-series radar measurements to accurately invert the thickness of saline ice is presented in this study. We describe b riefly some experimental observations from the United States Army Cold Regions Research and Engineering Laboratory, Hanover, NEI, 1993 (CRRE LEX'93) campaign of microwave scattering from sea ice. We demonstrate that volume scattering from brine inclusions is an important contribut ion to the backscatter response of saline ice in this case. From the e xperimental findings and the thermophysics of ice growth, we develop a n inversion algorithm for the ice thickness based on a dynamic electro magnetic scattering model of saline ice. This inversion algorithm uses a parametric estimation approach in which the radiative transfer equa tion is used as the direct scattering model to calculate the backscatt ering signatures from ice medium and the Levenberg-Marquardt method is employed to retrieve ice thickness iteratively, Additional informatio n provided by the saline ice thermodynamics is applied to constrain th e electromagnetic inverse problem to achieve a reasonably accurate rec onstruction. The inversion results using this algorithm and the data f rom CRRELEX'93 experiment are compared. The accurate thickness retriev al suggests the potential use of this algorithm for retrieving geophys ical parameters from satellite remote-sensing data.