Scattering from arbitrarily‐shaped lossy dielectric bodies of revolution

Abstract

A surface integral equation (SIE) technique is developed to analyze the scattering properties of arbitrarily-shaped 1ossy dielectric bodies of revolution. Two coupled vector integral equations formulated via Maxwell's equations, Green's theorem, and the boundary conditions are used. The unknown surface currents (both electric and magnetic) are calculated by, first, Fourier decomposition, and then, the moment method, Galerkin's procedure. The far scattered field and radar cross section (RCS) are then readily determined from the reciprocity theorem and the measurement matrix concept. For a dielectric sphere good agreement is obtained between the SIE and exact solutions. Solutions of a thick dielectric cylinder are next used to demonstrate the arbitrary geometry capability of the SIE method. This method is suitable for homogeneous dielectric bodies and only the axially incident plane wave is considered here. The method also applies for a wide range of dielectric parameters (with E r from 1.44 to 80 and conductivity •r from 0 to 10 3 mho/m).

On the low-frequency natural response of conducting and permeable targets

“…The resulting sets of simultaneous equations may be represented in matrix form as (17) where is the moment matrix, is a column vector containing the unknown basis function coefficients, and is the driving vector for the th Fourier mode [21]- [23], [25]- [26]. Details regarding the calculation of the impedance matrix or the driving vector can be found in the literature.…”

“…After using circuit theory to explain the basic wave phenomenology, numerical damping coefficients and currents are computed for the special case of conducting, permeable BOR's. While such analyses have been applied to the case of scattering from perfectly conducting and lowloss dielectric BOR's [21]- [24], [25]- [30], its application to calculation of natural modes for highly (but not perfectly) conducting, permeable targets is new. To validate the accuracy of the numerical data, comparisons are made with measured data [31]- [32] for several variations in material properties.…”

The Complex Refractive Index of Yellow Sand Inferred from the Brightness Temperature Difference in the Infrared Split Window

“…Median radius of particles are assumed to be 0.6 µm or 0.3 µm. Single scattering characteristics are calculated by the combined field integral equation method (Wu and Tsai 1977;Mano 2000). Spheroids with semi-major axis between 0.1 µm and 15 µm and with between 0.2 and 0.9 are treated in the calculations.…”

Finite element-boundary integral formulation for electromagnetic scattering

“…Before showing how the informed bases can be generated (using the finite element method), it may be interesting to compare the boundary integral method with the method of moments solution [13,14]. The two methods follow somewhat different concepts in their origination, but possess similar mathematics in many respects.…”