An introduction to a medium frequency propagation characteristic measurement method of a transmission line in underground coal mines.
Li-J; Waynert-JA; Whisner-BG
Prog Electromagn Res B 2013 Nov; 55:131-149
An underground coal mine medium frequency (MF) communication system generally couples its electromagnetic signals to a long conductor in a tunnel, which acts as a transmission line, and exchanges signals with transceivers along the line. The propagation characteristics of the transmission line, which is usually the longest signal path for an MF communication system, play a major role in determining the system performance. To measure the MF propagation characteristics of transmission lines in coal mine tunnels, a method was developed based on a basic transmission line model. The method will be presented in this paper along with the propagation measurements on a transmission line system in a coal mine using the method. The measurements con»rmed a low MF signal power loss rate, and showed the infuence of the electrical properties of surrounding coal and rock on the MF propagation characteristics of the line.
Underground-mining; Coal-mining; Electromagnetic-fields; Electromagnetic-wave-transmission; Electrical-fields; Electric-power-transmission-lines; Electrical-transmission; Communication-systems
Jingcheng Li, National Institute for Occupational Safety and Health, 626 Cochran's Mill Road, Pittsburgh, PA 15236
Progress in Electromagnetics Research B