ELECTROMAGNETIC FIELD DISTORTIONS AND CURRENTS IN AND NEAR BURIED CABLES AND BUNKERS
Abstract
The first purpose of this report is to establish the electromagnetic properties of a land area containing numerous buried wires, cables, and other substerranean structures by measuring the deviations produced by these structures in the electric and magnetic fields from an electric monopole antenna of known characteristics. The second purpose of this report is to determine the currents induced in the buried conductors and to establish a practical method of predicting these currents for conductors near the surface of the earth. The portable system utilized in the experimental work is designed to perform the necessary field mapping (both CW and impulse) in the 0.5- to 510-kc frequency range. This system is described and evaluated. Field mapping accuracy is demonstrated to be 5 percent for magnitude, 5 degrees for phase relative to local vertical electric field, and 1 degree for the spatial orientation of the fields. A cable current theory based on a transmission line model is developed for isolated or widely separated cables. This theory and Wait's wave impedance theory for currents induced in closely spaced cables are experimentally confirmed by measurements of currents induced in conductors on or near the surface of the earth. For pulse field and current calculations, the transfer functions from the transmitter to the receiving location are obtained using a computer program for Fourier transforms.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1965
- Accession Number
- AD0470095
Entities
People
- Arthur L. Whitson
- Edward F. Vance
Organizations
- SRI International