The mode‐conversion coefficient of ELF wave propagation due to land‐to‐sea transition

Abstract

AbstractThe mode‐conversion coefficient is studied to investigate the ELF wave propagation over a mixed land‐to‐sea path. As partition by the consideration of reflection influence from the ionosphere layer, we assume the propagation can be regarded as being subjected to two different models over mixed paths, in terms of the propagation distance in the range of ELF far‐field and near‐field regions, respectively. Both of the mentioned stratified models can be represented as cascaded transmission networks at the abrupt junctions. In conformity with previous study to formulate the far‐field propagation as a cascaded terrestrial waveguide with abrupt height and ground impedance changes, the presented study proposed an equivalent cascaded network to exploit the concept of mode‐conversion for near‐field propagation across discontinuity. Representative parameters of ground types in contrast are supportive to demonstrate the interference of abrupt impedance‐change at ELF band. The presented analysis provide with computational schemes to obtain synthetic fields of ELF wave propagation, which could be extended to more realistic model over multi‐segmental mixed paths.