Vertical Magnetic Noise in the Voice Frequency Band Within and Above Coal Mines

Vertical Magnetic Noise in the Voice Frequency Band Within and Above Coal Mines

by John Durkin
     
 

Information on vertical magnetic noise in the voice frequency band, both within and above coal mines, is needed for the evaluation of through-the-earth baseband electromagnetic communications at mines where horizontal loop antennas are used. This report discusses the theory of the source of electromagnetic noise, the propagation of this noise to an observation point… See more details below

Overview

Information on vertical magnetic noise in the voice frequency band, both within and above coal mines, is needed for the evaluation of through-the-earth baseband electromagnetic communications at mines where horizontal loop antennas are used. This report discusses the theory of the source of electromagnetic noise, the propagation of this noise to an observation point above a mine, and its interaction with the local earth conductivity structure, which gives rise to vertical magnetic noise. The relationship of surface noise to underground noise is also discussed. Bureau of Mines investigators made surface and underground vertical magnetic noise measurements at a number of coal mines located throughout the United States. These data were modeled through regression analysis to characterize expected noise levels. The results are presented, including results in one-third octaves for use in evaluating the expected performance of through-the-earth communication systems by articulation-index studies.

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Product Details

ISBN-13:
2940013223592
Publisher:
1001 Property Solutions LLC
Publication date:
10/27/2011
Sold by:
Barnes & Noble
Format:
NOOK Book
File size:
4 MB

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