Propagation of EM signals in underground mines.
Washington, DC: U.S. Department of the Interior, Bureau of Mines, Contract H00366028, 1977 Sep; :1-158
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.
propagation characteristics; conductors; overburden and underburden conductivities; communication range; MF frequencies
CP; Final Contract Report
NTIS Accession No.
Washington, DC: U.S. Department of the Interior, Bureau of Mines, Contract H00366028