The 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.

中文翻译：

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由陆海过渡引起的极低频波传播的模式转换系数

研究模式转换系数以研究 ELF 波在混合陆地到海洋路径上的传播。作为考虑电离层反射影响的划分，我们假设在极低频远场和近场范围内的传播距离方面，可以将传播视为在混合路径上受到两种不同模型的影响， 分别。提到的两个分层模型都可以表示为陡峭连接处的级联传输网络。与先前将远场传播表述为具有突然高度和地面阻抗变化的级联地面波导的研究一致，本研究提出了一个等效的级联网络，以利用模式转换的概念进行近场传播跨越间断。相比之下，接地类型的代表性参数支持证明 ELF 频段阻抗突变的干扰。所提出的分析提供了计算方案以获得 ELF 波传播的合成场，该方案可以扩展到多段混合路径上更现实的模型。