Radio propagation measurements in coal mines at UHF and VLF.
Proceedings of Thru-the-Earth Electromagnetics Workshop, August 15-17, 1973, Colorado School of Mines, Golden, Colorado. Geyer RG, ed., Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, Grant G0133023, 1973 Dec; :54-61
Radio propagation measurements were conducted in a coal mine at UHF (200 to 1000 MHz) and VLF (1 to 50 kHz) to characterize the transmission loss of intra-mine paths. The basic experimental parameters included frequency, polarization, path orientation and distance. Further tests evaluated the performance of roof-bolt vs. loop antennas at VLF and parasitic reflectors at UHF. Measurement results are summarized in a series of transmission loss curves. Examples are presented to show the use of these curves in predicting the performance of radio communication systems in mines.
Mining-industry; Mining-equipment; Underground-mining; Radio-waves; Coal-mining
Proceedings of Thru-the-Earth Electromagnetics Workshop, August 15-17, 1973, Colorado School of Mines, Golden, Colorado
Collins Radio Company