Removing the electromagnetic field of a low-frequency dipole in rocks
Abstract
For short-ranges, transmission along rocks is cheaper and more reliable than competing methods. Signal attenuation, the basic drawback to this method, can be reduced by lowering transmission frequency. Theoretical and experimental studies have been carried out in the laboratory on the propagation of audio-frequency electromagnetic waves in the rocks of coal mines. The choice of an emitter has also been considered.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- September 1974
- Bibcode:
- 1974STIN...7525013O
- Keywords:
-
- Coal;
- Electromagnetic Wave Transmission;
- Low Frequencies;
- Mines (Excavations);
- Underground Communication;
- Audio Frequencies;
- Electromagnetic Fields;
- Signal Analysis;
- Very Low Frequencies;
- Communications and Radar