This is a discussion of the application of the zonal harmonic series to problems involving dipole sources in the vicinity of spherical boundaries. The application of a formal zonal-harmonic series solution to directly obtain numerical results involves two distinct problems: namely, the convergence of the series solution and the accurate calculation of the special functions involved in the series solution. Some interesting techniques will be introduced which help to improve the convergence properties of the series solution.
In 1969, new coal mine health and safety legislation was enacted in the United States. As a result of this legislation, the Department of Interior, Bu...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 62-72
Description:
The use of radio signals for underground communications was considered as early as the mid-1920's [1] - [4] . However, early experiments did not produ...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 38-48
Description:
This paper is concerned with the theoretical study of UHF radio communication in coal mines, with particular reference to the rate of loss of signal s...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 9-14
Description:
It is the purpose of this paper to review theoretical model concepts in through- the -earth transmission of electromagnetic waves. While the subject i...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 20-33
Description:
One aspect of a program to improve the chances of survival following coal mine disasters is the development of a communications system which will allo...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 48-53
Description:
So far as the propagation of electromagnetic waves is concerned, an underground tunnel behaves like a pipe or hollowed waveguide. Waves propagate in t...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 34-37
Description:
The Coal Mine Health and Safety Act of 1969, passed by Congress in the wake of the disaster at Farmington, West Virginia, led to an extensive study by...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 54-61
Description:
Radio propagation measurements were conducted in a coal mine at UHF (200 to 1000 MHz) and VLF (1 to 50 kHz) to characterize the transmission loss of i...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 15-19
Description:
Introduction The fields of an infinite line source in the presence of a conducting half-space have been examined by Wait and Spies (1971). In any real...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 73-80
Description:
An approximate solution to the electromagnetic boundary value problem consisting of a horizontal cylindrical conductor buried in a lossy half-space an...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 112-120
Description:
Considerable current interest is evident[l,2] in the use of transient electromagnetic methods for subsurface remote sensing. A transient method is dis...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 140-148
Description:
nvestigation into the expressions of the field produced by a loop over a conducting half space or in an infinite conducting half space are well docume...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 81-85
Description:
The feasibility of locating a buried vertical magnetic dipole source (horizontal loop) from surface measurements of the vertical and horizontal magnet...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 121-129
Description:
We present an electromagnetic method taken from the well known radiogoniometer that allows us to locate at the surface of the ground the vertical axis...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 92-94
Description:
Three -dimensional boundary value problems are difficult to solve. Indeed, while the separation of the scalar wave equation can be effected in 11 diff...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 95-97
Description:
I do not regard the criticism by Rankin of my work as valid or even meaningful. I strongly reject the assertion by Rankin that my results are invalid....
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 130-139
Description:
To realize a radiowave communication along mine galleries a few kilometers long without repeater, we show that it is possible to use a coaxial cable b...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 86-91
Description:
The perturbation of alternating electromagnetic fields by three-dimensional structures is considered. The general model is that of a semi-infinite con...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 178-201
Description:
The attention of this group was focussed on four through-the-earth communication systems that are presently of high interest to the U.S. Bureau of Min...
"This report (Grant No. G0133023) includes papers on current research in thru-the-earth communications. The papers presented herein summarize a worksh...
"This volume contains a summary of past analyses that are relevant to electromagnetic location in mine rescue situations. The analytical results indic...
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