Mode Interferences of VLF Waves in an Anisotropic Waveguide Due to Sunrise and Sunset

作者：Gu, Ting Ting; Xu, Hong Lei^*; Li, Kai

来源：IEEE Transactions on Antennas and Propagation, 2018, 66(12): 7255-7264.

DOI：10.1109/TAP.2018.2870347

• Diurnal behavior
• inhomogeneous waveguide
• mode-conversion coefficient

It is found that for very low-frequency (VLF) signals, the mode-conversion interference produces a cycle slip during the sunrise or sunset transition at certain distances far away from the transmitter. In this paper, an anisotropic terrestrial waveguide with abrupt effective height change of 20 km geometry has been adopted to investigate the diurnal behaviors of amplitude and phase caused by the night-to-day transition. At the waveguide junction, sequential determinations of transmission and reflection coefficients are determined by the resulting linear equations from field matching. Field calculations across the day-to-night transition are carried out by using a reciprocity theorem correspondingly. This paper illustrates that VLF wave propagation experiences multimode interference in periodic variations in amplitude during sunrise and sunset over a long propagation path.

• 出版日期2018-12
• 单位浙江大学