NIOSHTIC-2 Publications Search

A radar coal thickness sensor.

Authors
Chufo RL; Johnson WJ
Source
IEEE Trans Ind Appl 1993 Sep/Oct; 29(5):834-840
NIOSHTIC No.
10012293
Abstract
A radar coal thickness sensor is being developed by the Bureau of Mines to measure both the dielectric constant and thickness of a coal seam as part of a sensor array supporting a computer-assisted coal mining machine. The noncontacting stepped-CW radar sensor measures the complex reflection of coefficient of the coal-shale interface to resolve the coal thickness to sub-wavelength accuracies. The technique uses a monostatic antenna configuration. Transfer function errors are identified by using spatial modulation created by antenna motion. Synthetic range gating is used for clutter rejection. Finally, polarimetric scattering matrix techniques are used to calculate the dielectric constant and thickness of the multilayered coal/shale media. Data taken both in the laboratory and in an underground mine, in the 0.6-1.4 GHz range, with a network analyzer and dipole antenna, have validated the technique. Accurate in situ measurements were made of a coal seam 6 in (15.2 cm) thick with a dielectric constant of 4. The coal thickness was confirmed by physical measurement. An independent measurement of the coal dielectric constant confirmed the accuracy of the noncontacting dielectric measurement technique.
Keywords
dielectric measurement; frequency domain radar; industry applications; spatial spectral sensor
Contact
Robert L. Chufo, U.S. Bureau of Mines, Pittsburgh Research Center, P.O. Box 18070, Pittsburgh, PA 15236
CODEN
ITIACR
Publication Date
19930901
Document Type
Journal Article
Fiscal Year
1993
Identifying No.
OP 10-94
Issue of Publication
5
ISSN
0093-9994
NIOSH Division
PRC
Source Name
IEEE Transactions on Industry Applications
State
PA; WA
Page last reviewed: December 11, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division