"The Bureau of Mines electromagnetic trapped miner location and communications system requires a thorough understanding of through- the-earth electromagnetic wave propagation. An earth model incorporating a magnetic dipole buried in a three-layered earth has been developed. The dipole source is located in the second subsurface layer. By application of proper limiting values, the three-layered model is reduced to two different two-layered models and eventually to the homogeneous half-space model. The solutions are in the form of infinite integrals. A numerical analysis was carried out and a computer program written to evaluate the surface magnetic fields. Numerical values for the magnetic field at the point above the source are presented in a variety of models." - NIOSHTIC-2 NIOSHTIC no. 10002569

Stephen B. Thacker CDC Library collection
National Institute for Occupational Safety and Health