Thin saline ice thickness retrieval using time-series C-band polarimetric radar measurements

摘要

The application of time-series radar measurements to accurately invert the thickness of saline ice is presented in this study. The authors describe briefly some experimental observations from the United States Army Cold Regions Research and Engineering Laboratory, Hanover, NH, 1993 (CRRELEX'93) campaign of microwave scattering from sea ice. They demonstrate that volume scattering from brine inclusions is an important contribution to the backscatter response of saline ice in this case. From the experimental findings and the thermophysics of ice growth, they develop an inversion algorithm for the ice thickness based on a dynamic electromagnetic scattering model of saline ice. This inversion algorithm uses a parametric estimation approach in which the radiative transfer equation is used as the direct scattering model to calculate the backscattering signatures from ice medium and the Levenberg-Marquardt method is employed to retrieve ice thickness iteratively. Additional information provided by the saline ice thermodynamics is applied to constrain the electromagnetic inverse problem to achieve a reasonably accurate reconstruction. The inversion results using this algorithm and the data from CRRELEX'93 experiment are compared. The accurate thickness retrieval suggests the potential use of this algorithm for retrieving geophysical parameters from satellite remote-sensing data.