Results 21 - 30 of 30

• A Spatial/Spectral Domain Microwave Coal Seam Imaging Sensor-Progress in Signal Processing
  7/1/1994 - Conference papers
  The paper, presents 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 ...
• Advances in Mine Emergency Communications
  4/1/1994 - Conference papers
  To address communicating while wearing an SCSR, two-way, FM radios were built in and improved mouthpieces were added to the SCSR to improve the ability to communicate. Prototypes we built and tested. Leaky feeder systems are also described.
• A Multiplexed Phone System for Small Mines
  7/1/1982 - Conference papers
  A new phone system was developed that provides eight full duplex communications channels over a single twisted shielded phone line, with no central switching station or line amplifiers. This system greatly simplifies installation and maintenance over th...
• Improved Rail Haulage Communications
  10/1/1978 - Conference papers
  An analysis is made of the trolley line as a communications line, and methods of improving its characteristics are discussed.
• Medium-Frequency Propagation in Coal Mines
  8/1/1978 - Conference papers
  Medium-frequency (MF) waves can propagate in a coal seam, bounded above and below by conducting rock, in an approximate transverse electro-magnetic (TEM) transmission-line mode with the electric field vertical and the magnetic field horizontal. The theo...
• Propagation of EM Signals in Underground Mines
  1/1/1977 - Conference papers
  This report is a comprehensive summary of the results of the propagation measurements program conducted for the Bureau of Mines.
• U.S. Bureau of Mines New Developments in Mine Communications
  8/1/1976 - Conference papers
  A brief description is given of various Bureau of Mines research activities that have begun since July 1974 and are not being reported on by others at the Third West Virginia University (WW) Conference on Coal Mine Electrotechnology.
• Experience with an Integrated, Computer-Controlled Communications and Monitoring System at the Robena Mine
  8/1/1976 - Conference papers
  A whole mine, computer-controlled communication and monitoring system for both normal and emergency use is installed and operating in the U.S. Steel Robena Mine complex near Uniontown, Pa. Experience with the system is reviewed.
• Mine Communications: An Overview of the Bureau of Mines Communications Research
  6/1/1974 - Conference papers
  Since 1969, the Department of Interior, Bureau of Mines, has carried out communications research. Research has been directed toward developing emergency and nonemergency mine communications. This paper gives an overview of the progress made in the last ...
• Communication Systems Research At Bruceton Safety Research Mine
  1/1/1972 - Conference papers
  An environment monitoring and communication system has been installed in the Bruceton Mine, and research is under way to improve mine safety. Standard day-to-day mine communications are available, along with additional systems installed to permit experi...