Emission of rough surfaces calculated by the integral equation method with comparison to three-dimensional moment method simulations

Extension and Validation of an Advanced Integral Equation Model for Bistatic Scattering From Rough Surfaces

“…Recalled from the preceding section that the complementary scattered field is contributed from the reradiated fields that may propagate through medium 1 and medium 2, represented by upwardly and downwardly waves, the physical mechanism may be graphically represented by the field coefficients or propagators, F qp , G qp , as illustrated in Figure 2. Further dealing with the phase term involving the surface height, the propagators may be decomposed into the upward components designated by F + qp , G + qp and the downward components by F − qp , G − qp , mathematically appearing as the absolute terms in (14), physically denoting the change of propagation velocity at different media. In the original IEM model [3,7], the reradiated fields propagating through the lower medium is ignored, and also in calculating the coefficient F ± qp , a simplified phase term,…”

“…Driven by the need of predicting bistatic scattering and microwave emissivity, much effort has been devoted to further improving the IEM accuracy [9][10][11][12][13][14][15][16][17][18][19] by removing some of the assumptions originally imposed for the purpose of mathematical simplicity during the course of derivation. Another leap forward step was the introduction of a transition function into the Fresnel reflection coefficients to take spatial dependence into account, removing the restrictions on the limits of surface roughness and permittivity [3,11].…”

“…Another leap forward step was the introduction of a transition function into the Fresnel reflection coefficients to take spatial dependence into account, removing the restrictions on the limits of surface roughness and permittivity [3,11]. Though the approach is of heuristic but self-consistent, it proves to work well for a broad range of surface dielectric and geometric parameters [6,11,14].…”

Potential of X-Band TerraSAR-X and COSMO-SkyMed SAR Data for the Assessment of Physical Soil Parameters

“…Consequently, different radar backscattering models (physical, semi-empirical, and empirical) have been developed to improve scientific understanding of the relationship between the backscattering coefficient and the parameters used to characterize the soil. The most frequently used models are the Integral Equation Model IEM of Fung et al [13,14] and the Advanced Integrated Equation Model (AIEM) [15,16], which are applicable to a large range of soil roughness conditions, as well as semi-empirical models such those of Oh [17] and Dubois [18], which provide simple analytical relationships between the backscattered radar signal and physical soil parameters.…”

Evaluation of the Community Microwave Emission Model Coupled with the Community Land Model over East Asia

“…Several RTMs (Dobson et al, 1985;Weng et al, 2001;Drusch et al, 2001;Chen et al, 2003;Shi et al, 2005;Wigneron et al, 2007) have been proposed to simulate microwave brightness temperatures over various surface conditions. The Community Microwave Emission Model (CMEM) was developed by the European Centre for Medium-Range Weather Forecasts (ECMWF) as the forward operator for low frequency passive microwave brightness temperatures (from 1 GHz to 20 GHz) of the surface (Holmes et al, 2008;Drusch et al, 2009).…”