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In this paper, we report a new approach of modeling anisotropy snowpack using bicontinuous media [1, 2]. We then extract the uniaxial effective permittivity of the anisotropic bicontinuous media by numerical solving Maxwell's equation in 3D (NMM3D) over spherical samples of the media extending a few wavelengths. The effective permittivity is then extracted by comparing the coherent scattering field...
A partially coherent low frequency microwave emission model for polar ice sheet is developed to operate from 0.5GHz to 2.0GHz predicting brightness temperatures. The emission from polar ice sheet over the wide frequency band is shown to be correlated with its temperature profile and affected by its density fluctuations. The density fluctuations creating weakly reflective internal interfaces cause...
Snowpack consists of ice grains that are densely packed in the wavelength scale at microwave frequencies so that the coherent microwave interactions among the ice grains are important in microwave signatures. We have used Numerical Maxwell Model of 3D simulations (NMM3D) of random media / discrete scatterer to study such interactions. In the partial coherent model of Dense Media Radiative Transfer...
We apply computer generation of anisotropic bicontinuous media with different vertical and horizontal correlation functions. We then use NMM3D (Numerical solutions of Maxwell equations in 3-Dimensions) to calculate the uniaxial effective permittivities and the effective propagation constants of V and H polarizations. The co-polarization phase differences (CPD) between VV and HH backscattered signal...
A radar-based time-series algorithm is evaluated for retrieving soil moisture (from the surface down to 5 cm depth) and roughness using two co-polarized (HH and VV) backscatter cross-section measurements (σ0). The retrieval approach inverts a forward model for radar scattering from a bare surface using a pre-computed lookup-table representation of σ0 obtained from Numerical Maxwell Model in 3D simulations...
A hybrid UV/PBTG/SMCG method is developed based on the Numerical Solution of Maxwell Equation in 3D Simulations (NMM3D) of electromagnetic wave scattering by Gaussian dielectric random rough surfaces with exponential correlation functions. In 3D simulations, the height function z=f(x,y) of the rough surfaces vary in both two horizontal directions. The method inherits the advantages of the UV method,...
We consider a parallel plate waveguide model excited by a line source to address the rough surface effect in an environment more directly applicable to package substrates and PCBs. The problem is solved by the finite element method (FEM). The FEM is applied to the region between the metal plates of the waveguide. The excitation line source is outside the numerical modeling region. Modal basis functions...
In this paper, we report on the polarimetric active and passive microwave remote signatures for exponential correlation function surfaces. Applications are in soil moisture problems at the frequencies L, C and X band. We use the same physical parameters of rms heights and correlation lengths at the three frequencies. Results for 2D case with rms height up to 2 wavelengths at X band are shown. The...
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