U.S. flag An official website of the United States government.
Official websites use .gov

A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS

A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

i

Adaptive Noise-Cancellation Techniques for Through-the-Earth Electromagnetics: Volume II

Public Domain


Details

  • Personal Author:
  • Description:
    An electromagnetic (em) system to locate trapped miners at coal mine depths was investigated. The use of such a system in deep mines requires transmission at extremely low frequencies (elf) and a reduction in the effective noise level beyond that which can be obtained by acceptable integration times. Automatic-noise- cancellation (anc) techniques reduce the efective noise level by combining several received signals that contain correlated noise. The signals can be obtained from either a remote magnetic antenna or a local electric antenna. This report presents the results of a simulation of the use of anc techniques in a through-the-earth em system. A multicomponent elf noise model that incorporates impulsivity, direction of arrival, and ground characteristics was developed. Nonlinear processors (nlp) for elf noise were compared and the adaptive clipper was found to be preferable. Direct-matrix- inversion (dmi) and least-mean-square anc techniques were compared and the dmi algorithm was preferable. The performance of the combined nlp-anc system was evaluated. [Description provided by NIOSH]
  • Subjects:
  • Series:
  • Subseries:
  • Document Type:
  • Genre:
  • CIO:
  • Division:
  • Topic:
  • Location:
  • Pages in Document:
    1-121
  • NIOSHTIC Number:
    nn:10004200
  • NTIS Accession Number:
    PB85-111409
  • Citation:
    NTIS: PB/85-111409 Available for Reference At Bureau Libraries :121 pages
  • Federal Fiscal Year:
    1983
  • Performing Organization:
    Green Mountain Radio Res.
  • Peer Reviewed:
    False
  • Collection(s):
  • Main Document Checksum:
    urn:sha-512:cad5130387bda9ed8d11a3668de67f4cd4d3a761e6b45d0895b0eaf2e0a151e3906515bde835d2b086f1115b759f5f40a5fd33b29b6cf5b24e9a88f554feedae
  • Download URL:
  • File Type:
    Filetype[PDF - 3.62 MB ]
ON THIS PAGE

CDC STACKS serves as an archival repository of CDC-published products including scientific findings, journal articles, guidelines, recommendations, or other public health information authored or co-authored by CDC or funded partners.

As a repository, CDC STACKS retains documents in their original published format to ensure public access to scientific information.