Remote sensing backscattering model for sea ice: Theo-retical modelling and analysis

Abstract

Remote sensing has been used in Antarctic studies as an earth observation technique to study the polar region. A remote sensing forward model is an important tool in polar research to study and understand scattering mechanisms and sensitivity of physical parameters of snow and sea ice. In this paper, a reliable theoretical model to study sea ice is developed. The theoretical model in a prior work was improved by including multiple-surface scattering, based on an existing integral equation model and additional second-order surface-volume scattering. This model is applied to a desalinated ice layer above thick saline ice and analyzed using different frequencies, bottom surface roughness and sea-ice layer thickness. Improvement in calculation of the backscattering coefficient of the sea-ice layer is investigated for both co-polarized and cross-polarized returns. The effect on each scattering mechanism is also investigated, to understand in more detail the effect of surface multiple scattering and second-order surface-volume scattering. Comparisons are also made with field measurement results, to validate the theoretical model. Results show improvement in the total backscattering coefficient for cross-polarized return in the studied range, suggesting that multiple-surface scattering and surface-volume scattering up to second order are important scattering mechanisms in the sea-ice layer and should not be ignored in polar research.

Backscattering Analysis Utilizing Relaxed Hierarchical Equivalent Source Algorithm (RHESA) for Scatterers in Vegetation Medium

“…In future, this study can be extended to a layer or to layers of scatterers, as in real vegetation media, with the ability to model more realistic shapes of scatterers. By combining the RHESA with radiative transfer theory solution and DMPACT, the total backscattering return from layers of dense media can be modelled as in previous studies [2,5,7,8,11], but with more accurate results for vegetation media.…”

“…Theoretical models in microwave remote sensing research have been developed using analytical methods that employ approximation models [1][2][3][4][5][6][7][8][9][10][11][12], especially for vegetation media [9][10][11][12]. Analytical method models can provide some physical insight into media, and allow the study of scattering behaviour for variations in parameters; however, their accuracy is limited, as this is carried out by approximating the scatterers into limited shapes such as spheres, cylinders, needles, ellipsoids, and elliptic discs.…”