Cory, Terry S.

"This report is a comprehensive summary of the results of the propagation measurements program conducted for the Bureau of Mines. Data were gathered in the medium frequency (mf) range from a cross sample of six mines representative of the industry having typical wireless requirements. From the data that were gathered, a logical method of data reduction is presented that culminates in a set of average attenuation characteristics for all mines visited. These characteristics define a typical mf wireless system when the communication range requirements are known. Direct through-the- earth propagation and the range enhancement mechanism due to coupling on-and-off conductors are evaluated and related to the planning of a typical wireless mf communications system." - NIOSHTIC-2

NIOSHTIC no. 19770901

National Institute for Occupational Safety and Health

H00366028