NIOSHTIC-2 Publications Search

A Radar Coal Thickness Sensor.

Authors
Chufo-RL; Johnson-WJ
Source
Paper in 1991 II:1182-1191
Link
NIOSHTIC No.
10011362
Abstract
A radar coal thickness sensor is being developed by the U.S. 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 coefficient of the coal-shale interface to resolve the coal thickness to subwavelength accuracies. The technique uses a monostatic antenna configuration. Transfer function errors are identified by using spacial 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- to 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 a physical measurement.
Publication Date
19910101
Document Type
OP;
Fiscal Year
1991
Identifying No.
OP 82-92
NIOSH Division
PRC;
Source Name
Paper in 1991 IEEE Ind. Appl. Soc. Annual Mtg., Vol. II. IEEE Service Center, PP. 1182-1191
State
IN;
Page last reviewed: April 12, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division