The Electromagnetic Fields of a Subterranean Cylindrical Inhomogeneity Excited by a Line Source

Abstract

The anomalous fields from a buried cylindrical inhomogeneity in an otherwise uniform half‐space are analyzed. The problem is rendered two‐dimensional by assuming that the uniform line source of current is parallel to the subsurface cylinder. The multipole scattered field coefficients are obtained from the numerical solution to the associated singular Fredholm integral equation of the second kind. The horizontal magnetic field amplitude, the vertical magnetic field phase, and the amplitude and phase of the ratio of horizontal to vertical magnetic fields are shown to be diagnostic of the location of the inhomogeneity. The results have possible applications to electromagnetic location in mine rescue operations and to geophysical prospecting.

Analysis of Electromagnetic Interaction with Ships on the Ocean Surface

“…Previously, electromagnetic wave scattering by arbitrarily shaped objects in free space has been well developed using wire [8,9,10] and surface-patch model [11,12,13,14,15,16,17,18]. The theory and numerical approaches associated with object near flat interface of layered medium have also be studied extensively by many researchers [26,27,19,20,21,22,7,31,32,25]. However, the consideration of the interface to be rough surface is a new challenge, and little work has been reported.…”

“…It cannot be used near grazing incidence where the field distribution in the x-y plane becomes highly oscillatory. Its continued use is rooted in its close relation to a scalar tapered wave employed previously [26], [27]. The latter wave, on the other hand, goes back to a popular incident field introduced by E. I. Thorsos [28] who-for the 2-D case-derived it as an approximation to a summation of plane waves, accurate for sufficiently small angles of incidence 0 { (also employed in [29], [30], [15], [31], [32], [33].…”

Scattering of Electromagnetic Waves from a Deeply Buried Circular Cylinder

“…The exact analytic analysis of a buried circular cylinder was first undertaken by D'Yakonov [4] but the results of his analytic work are not suitable for numerical evaluation. This has been pointed out by Howard [5] and Ogunade [6]. Ogunade [6] extended D'Yakanov's exact analytic solution to obtain solution for the scattered field of an embedded circular cylinder using conventional eigenfunction expansion.…”

Electromagnetic Scattering From a Perfect Electromagnetic Conductor Cylinder Buried in a Dielectric Half-Space

“…Various analytical and numerical contributions are available in this direction. The analysis of a buried object below flat surface has been done analytically by D'Yakonov [1], and subsequently has been explained by Howard [2] and Ogunade [3], where the solution was obtained by the eigenfunction expansion of the total fields. A number of other analytical studies involving the scattering from buried objects below a flat interface have also been done [4][5][6][7][8][9][10][11][12][13][14][15].…”