Results 31 - 34 of 34

• Detection of Trapped Miner Electromagnetic Signals Above Coal Mines
  7/1/1980 - Contract reports
  This report assesses the expected detectability, on the surface above mines, of electromagnetic signals produced in the 630- to 3,030-hz frequency band by a rescue transmitter activated by miners trapped underground. The implications of the results and ...
• Survey of Electromagnetic and Seismic Noise Related to Mine Rescue Communications: Volume I - Emergency and Operational Mine Communications
  9/1/1974 - Contract reports
  Volume I of this report deals with theoretical, experimental, and practical implementation aspects of the federal Bureau of Mines programs related to present and planned, emergency and operational, mine communications and miner location systems for unde...
• Survey of Electromagnetic and Seismic Noise Related To Mine Rescue Communications: Volume II - Seismic Detection and Location of Isolated Miners
  7/1/1974 - Contract reports
  Volume II of this report (Contract No. H0122026) presents the findings of a short intensive assessment performed during the fall of 1972. This assessment provided the federal Bureau of Mines with independent technical judgments regarding the potentials ...
• Preliminary Performance Predictions For Electromagnetic Through-The-Earth Mine Communications: A Collection of Working Memoranda
  3/1/1972 - Contract reports, Open File Reports
  This report comprises three working memoranda that present preliminary performance estimates for baseband voice and narrowband through-the-earth electromagnetic communications systems of principal interest to the Bureau of Mines for operational/emergenc...