Propagation of Electromagnetic Fields Along the Sea/Sea-Bed Interface.
Final technical rept. 15 Aug 79-15 Apr 83,
STANFORD UNIV CA SPACE TELECOMMUNICATIONS AND RADIOSCIENCE LAB
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The propagation of electromagnetic fields along the seasea-bed interface is considered for frequencies in the ULFELF range frequencies less than 3 kHz and for three different sources a vertical magnetic dipole, a horizontal electric dipole, and an infinite cable, all located on the interface. The interface is assumed to be a plane boundary separating the two semi-infinite conducting media representing the sea and the material comprising the sea bed this assumption enables use to be made of field expressions derived previously for harmonically-varying current sources located at a plane boundary. The field components are calculated numerically and compared with those that would be produced under the same conditions in sea water of infinite extent. It is found that 1 the fields can propagate no longer distances along the sea floor because of the lower sea-bed conductivities, and 2 new field components are produced as a result of the presence of the seasea-bed interface. Some of these new components are larger at longer distances than the other field components they are also more sensitive to the conductivity of the sea bed at low frequencies.
- Physical and Dynamic Oceanography
- Radiofrequency Wave Propagation
- Radio Communications