Mining Publication: Development of a Phase Difference of Arrival Technique for Location of Trapped Miners

The development of systems for location of miners who have become entrapped following a mine disaster is one of the major research goals in the Bureau of Mines. Current technologies for locating trapped miners from the surface are either simple direction finders or time difference pulse systems that have accuracy limitations. Developing technologies using full-vector field measurements at several receiving points are currently being studied. The necessity of measuring field strength with great accuracy can be a drawback in these systems. However, a system that operates with continuous-wave radio signals, with phase differences that can be measured accurately even in weak signal conditions, would greatly improve the location accuracy. Comparison of this system with existing technology indicates a favorable accuracy-complexity ratio for the phase difference of arrival technique.