Mining Publication: A Spatial/Spectral Domain Microwave Coal Seam Imaging Sensor-Progress in Signal Processing

The paper, An Electromagnetic Roof and Rib Thickness Sensor presented at the 12th WVU International Mining Electrotechnology Conference in 1992, presented the results of roof coal thickness measurements in underground mines and rib coal thickness measurements in highwall mines. The microwave sensor described uses a unique spatial modulation scheme created by antenna motion, along with frequency domain signal processing, to solve the problem of media, target, and antenna dispersion. This paper further describes the advantages of the unique frequency domain signal processing technology chosen by the U.S. Bureau of Mines in extending previously reported one dimensional thickness measurement technology to the generation of a full three-dimensional underground image of the underground environment.