Composite Metal Dielectric Formulation of Surface-Volume-Surface Electric Field Integral Equation in Layered Media for Scatterometry of Arctic Sea Ice

Microwave remote sensing is an established method for monitoring and evaluating sea ice throughout the Arctic. Microwave scattering signatures of sea ice can be measured using satellite and near-surface radar systems. From these types of measurements, information on the physical and thermodynamic state of the sea ice can be understood. However, given the wide variety of sea ice types, formation, and distribution within the Arctic, improved information on how the physical factors give rise to the microwave scattering signatures is required. This critical information can be obtained through field campaigns where remote sensing instruments are brought to the Arctic to measure the radar signatures and researchers can extract physical samples of the sea ice that was scanned. Previous studies have improved knowledge of the mechanisms of microwave interactions with sea ice (K. C. Jezek, et.al., “A broad spectral, interdisciplinary investigation of the electromagnetic properties of sea ice,” IEEE Trans. Geoscience and Remote Sensing, vol. 36, no. 5, pp. 1633–1641, 1998). Examples of sea ice remote sensing models include those based on analytic wave theory (AWT), with part of the model based on strong fluctuation theory to calculate the effective permittivities, radiative transfer theory (RT), and dense medium radiative transfer theory. Surface scattering models have been applied under the geometric optics approximation, perturbation theory (for example, the small perturbation model, and integral equation methods (IEMs)). Computational electromagnetic methods have been used as an alternative to the AWT and RT formulations in sea ice modeling. Numerical simulation techniques can potentially accommodate variations in complex media descriptions relatively easily. For example, utility of FDTD for scattering from sea ice was studied and found that one can simulate scattering for midrange incidence angles with some success. The finite-volume time domain (FVTD) method has the potential to provide new information on sea ice scattering mechanisms. FVTD uses an unstructured mesh that provides a better physical representation of a rough surface than the cubic lattice of FDTD. A universal modeling method does not exist, however, and formulations are selected based on the specific remote sensing problem. Considering that the applied problem of remote sensing of sea ice and potential contaminants within it reduces to electromagnetic analysis of scattering on irregularities embedded in multilayered media formed by the sea, ice layers, contaminant layers, snow layers, etc., in this work we utilize a Method of Moment (MoM) solutions of the Layered Media Surface-Volume-Surface Electric Field Integral Equation (SVS-EFIE) formulated for general 3D composite objects embedded in a layered medium (Okhmatovski, V.I., S. Zheng, Theory and Computation of Electromagnetic Fields in Layered Media, IEEE Press/Wiley, 2024). We will present a model comprising an accurate representation of the pencil beam incident field generated by a parabolic dish antenna with its properties close to those featured in the actual C-band scatterometers as the incident field in the full-wave solution of the SVS-EFIE describing scattering of such incident field on the rough surface of sea ice embedded in layered environment.