Results 21 - 30 of 131

• Ray Tracing and Modal Methods for Modeling Radio Propagation in Tunnels With Rough Walls
  5/1/2017 - Peer reviewed journal articles
  An article that discusses how wall roughness affects radio propagation in tunnels, and presents a unified ray tracing and modal method for modeling radio propagation in tunnels with rough walls.
• Communications and Tracking Systems Modeling and Performance
  3/13/2017 - Research projects
  A project to enhance the understanding of underground mining communication and tracking system performance through the development and validation of radio signal propagation models.
• Time Domain and Frequency Domain Deterministic Channel Modeling for Tunnel/Mining Environments
  1/1/2017 - Peer reviewed journal articles
  An article that proposes two physics-based, deterministic ultra-wideband (UWB) channel models for characterizing wireless channels in mining/tunnel environments — one in the time domain and the other in the frequency domain.
• Low-Frequency Electromagnetic Noise Cancelling Antenna System
  11/22/2016 - Interagency agreements
  An interagency agreement to improve signal-to-noise in TTE receivers. The aim is to use existing transmitters that are not "intrinsically safe" to provide a reference signal from underground.
• Integration of Sensing Technologies for Post-Event Monitoring of Hazardous Conditions in the Mining Environment
  11/22/2016 - Contracts and cooperative agreements
  A contract to provide detection of ambient conditions in lesser traversed, remote areas of a mine by way of a repeater system with sensing modules capable of linking into the existing, hardened communications and tracking system.
• Simulation and Measurement of Medium-Frequency Signals Coupling From a Line to a Loop Antenna
  10/1/2016 - Peer reviewed journal articles
  An article which presents the simulation and measurement results of recent NIOSH research aimed at investigating medium frequency coupling between a transmission line and a loop antenna in an underground coal mine.
• Mobile Adaptable RF/IT Infrastructure - Experimental (MATRIX)
  7/19/2016 - Contracts and cooperative agreements
  A contract to test the efficacy of deploying a vehicular satellite communication system, augmented with rapidly deployable mesh networking nodes and other emerging telecommunications technologies, during mine rescue and other emergency events.
• Mine Communications Engineering and Compatibility Guidelines
  7/19/2016 - Contracts and cooperative agreements
  A contract to ensure that the limited useful spectrum is used efficiently, health and safety hazards are not introduced, and new systems do not interfere with each other or with older systems already in place.
• Medium Frequency Radio System Modifications for Refuge Chamber Situational Awareness
  7/19/2016 - Contracts and cooperative agreements
  A contract to modify medium frequency radio systems to improve refuge chamber situational awareness in an underground coal mine.
• Magneto-Inductive TTE Communications
  7/19/2016 - Contracts and cooperative agreements
  A contract to fabricate and test through-the-earth communication devices in an underground mine.