LF Sky Wave Propagation Excited by a Horizontal Electric Dipole Towards Understanding of Its Radiation Mechanism.

In this paper, the electromagnetic pulses have been investigated based on the theory of wave-hop propagation. The approximate formulas are obtained for the electromagnetic field of a vertical magnetic dipole in the presence of an Earth-ionosphere waveguide. Based on the results obtained, the approximate formulas are derived readily for the ground wave and sky waves due to horizontal electric dipole excitation by using a reciprocity theorem. The corresponding computations and discussions are carried out specifically by analogy with those generated by a vertical electric dipole with the formulas in CCIR's recommendation. It is shown that the sky wave pulses would interfere at certain distances and occur by different time-delays. [ABSTRACT FROM AUTHOR]