Emission Forward Modeling for Mountain Glacier With Basal Slope

In the passive remote sensing of mountain glaciers, the underlying basal slope may exist within the footprint of radiometric measurement. In such case, it is necessary to account for the basal slope effect for the correct interpretation of the mountain glacier emission features. In this letter, we develop an emission modeling approach to account for the basal slope effect based on the scattering operator framework. Through the equivalent boundary set above the basal slope region, the effective scattering operator and emission contribution on the equivalent boundary, including the basal slope effect, can be determined in the basal local coordinates, avoiding the coupling between polar and azimuthal angles in the observation coordinates. The effective scattering operator and emission contribution on the equivalent boundary are then transformed back into the observation coordinates, and incorporated into the comprehensive layer emission model (CLEM) for the full layered emission calculation. The basal slope equivalent boundary modeling approach is validated numerically using finite difference frequency domain (FDFD) solutions of Maxwell’s equations, and the model is used to analysis basal slope effects on emission features. Results show that the proposed model agree well with the FDFD approach and can be used to interpret the basal slope effect on emission features for mountain glaciers.