Vertical magnetic noise in the voice frequency band within and above coal mines
Advanced Search
Select up to three search categories and corresponding keywords using the fields to the right. Refer to the Help section for more detailed instructions.

Search our Collections & Repository

For very narrow results

When looking for a specific result

Best used for discovery & interchangable words

Recommended to be used in conjunction with other fields

Dates

to

Document Data
Library
People
Clear All
Clear All

For additional assistance using the Custom Query please check out our Help Page

i

Vertical magnetic noise in the voice frequency band within and above coal mines

Filetype[PDF-1.41 MB]


English
Details You May Also Like

Details:

  • Personal Author:
    Durkin, John
  • Corporate Authors:
    United States. Bureau of Mines.
  • Description:
    "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." - NIOSHTIC-2

    NIOSH no. 10003224

  • Subjects:
  • Series:
    Report of investigations (United States. Bureau of Mines) ; 8828
  • Document Type:
    Report
  • Collection(s):
  • Main Document Checksum:
  • Download URL:
  • File Type:

Supporting Files

  • No Additional Files
More +

You May Also Like

Checkout today's featured content at stacks.cdc.gov