DocumentCode :
3604978
Title :
RF Propagation in Mines and Tunnels: Extensive measurements for vertically, horizontally, and cross-polarized signals in mines and tunnels.
Author :
Chenming Zhou ; Plass, Timothy ; Jacksha, Ronald ; Waynert, Joseph A.
Volume :
57
Issue :
4
fYear :
2015
Firstpage :
88
Lastpage :
102
Abstract :
This article reports measurement results on radiofrequency (RF) propagation in tunnels and mines for vertically, horizontally, and cross-polarized signals. Extensive measurements have been made in concrete tunnels, coal mines with rock dust and shotcrete, with and without conductive mesh, and hard-rock mines. The measurements include power attenuation over distances with and without line of sight (LOS) at four frequencies (455, 915, 2,450, and 5,800 MHz) that are common to underground radios, as well as swept wideband-frequency measurements from 30 MHz to 1 GHz at fixed separation distances to investigate the attenuation behavior as the waveguide cutoff frequency is approached. In addition, power loss associated with radio propagation around a 90? corner was measured for the four frequencies and two polarizations in an operational coal mine.
Keywords :
UHF radio propagation; VHF radio propagation; coal; concrete; dust; mining; rocks; tunnels; underground communication; LOS; RF propagation; coal mine; concrete tunnel; cross-polarized signals; frequency 30 MHz to 1 GHz; hard-rock mine; horizontally-polarized signals; line of sight; power attenuation measurement; power loss; radiofrequency propagation; rock dust; shotcrete; swept wideband-frequency measurement; underground radio; vertically-polarized signals; waveguide cutoff frequency; Antenna measurements; Attenuation; Frequency measurement; Propagation losses; Radio frequency; Transmitting antennas;
fLanguage :
English
Journal_Title :
Antennas and Propagation Magazine, IEEE
Publisher :
ieee
ISSN :
1045-9243
Type :
jour
DOI :
10.1109/MAP.2015.2453881
Filename :
7225146
Link To Document :
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