Apparatus and methods for emergency mine communications using acoustic waves, time synchronization, and digital signal processing

摘要

Apparatus and methods to implement post accident communications in a coal mine, in compliance with the MINER Act and MSHA regulations, are disclosed. Acoustic waves are transmitted bidirectionally through-the-earth in a simple robust half-duplex architecture in combination with signal-to-noise reduction techniques which ensure the ability to communicate using simple tools available in a mine. A personal electronics device, designed to be carried by each miner, automatically decodes acoustically transmitted text messages sent by rescue operations, and automatically encodes text messages by a miner to synchronized impulses manually produced by the miner. Signals are synchronized, in time of day protocol, between the miner and rescue operations. Digital signal processing techniques are disclosed.