L-3 and a partner are developing a TRU-TRACKER Precision Location System based on a “reverse” radio frequency identification (RFID) system. This system was generated under a competitively-awarded research and development contract from the National Institute for Occupational Safety and Health (NIOSH). The L-3 TRU-TRACKER Precision Location System is similar in nature to RFID inventory control systems that have been in use for many years in both the public and private sectors. However, unlike many of these systems which attach a tag on the moveable item to be tracked and utilize a fixed receiver to identify and locate the item, L-3 is “reversing” the concept.

In the L-3 TRU-TRACKER Precision Location System, it is the long endurance RFID tags that are dispersed throughout the mine at precise, fixed locations while each miner carries a portable tag reader/receiver. As a miner walks through the mine, an antenna integrated into his or her cap lamp receives an ultra wideband (UWB)-based signal from the fixed RFID tags in closest proximity to the miner’s current location.

By using UWB signals, the L-3 TRU-TRACKER Precision Location System is able to overcome the mine environment challenges (e.g., numerous reflective surfaces) that impede the effective use of standard narrowband communications systems. The tag signal strength and related location data are then recorded and stored by the tag reader attached to the miner’s belt. At predetermined intervals, the stored location data is then transmitted to the surface where it is displayed on a computer terminal allowing above-ground personnel to know the accurate, real-time location of all below-ground mine personnel.

System component development and mine testing for the L-3 TRU-TRACKER Precision Location System will take place in the summer of 2009, with large-scale deployments throughout the coal mining industry beginning later in 2009.