To facilitate emergency rescue operations, the 2006 MINER Act mandates that all coal mines have electronic underground tracking systems. Surface personnel can use electronic underground tracking systems to identify workers in the mine, and where they are located.
Manual tracking is used by many mines to track underground miners and their locations. Manual tracking comes with a few limitations. There are many electronic underground tracing systems technologies available that can overcome the limitations of manual tracking.
One method uses reader-based radiofrequency identification (RFID technology). RFID technology is commonly used in retail stores to protect merchandise from theft. A small electronic circuit known as a tag attaches merchandise to this system. Two vertical gates emit an RF signal at the store’s exit.
If the tag on the merchandise has not been removed from the register, the circuit will emit a return signal. The vertical gates pick up the signal and sound a warning. These tags are extremely low-cost and have a very limited read range. The tag-and-reader method is used by many industries to track equipment and items. There are many tag-and-reader system types. Each system is optimized to balance read range, cost reliability, and robustness.
The second type of tracking technology, node-based electronic tracking, uses the communication link between a radio receiver and a node. To determine the location of the miner, the node analyses the radio signal strength coming from the radio.