利用大功率高频( HF)电波对多个电离层区域进行调制加热，使电离层中的自然电流产生振荡，被调制的电流组成VLF磁流源，以此作为辐射VLF波的小环天线。利用全波解的方法对磁流源向下辐射的电磁波在电离层中的传播进行数值模拟，计算出在海面上的场强，分析在不同电离层参数和地磁场参数条件下对传播衰减的影响。结果表明：VLF磁流源的磁偶极矩与调制频率和加热功率有关，调制频率越低，加热功率越大，所产生的磁偶极矩越大。调制过程中所产生的电子温度变化对电磁波的传播衰减影响很小，而地磁场参数对传播衰减的影响较大。
Using powerful high-frequency (HF) radio waves to modulate and heat multiple ionospheric regions can make the natural current in the ionosphere oscillate, and the modulated currents form a VLF magnetic current source, which is used as a small loop antenna that radiates VLF waves. Using full-wave model simulate the propagation of the VLF wave radiated downward by the magnetic current source in the ionosphere, calculate the field strength on the sea surface, and analyze the influence the propagation attenuation under different ionospheric parameters and geomagnetic field parameters. It is shown show that the magnetic dipole moment of the VLF magnetic current source is related to the modulation frequency and heating power. The lower the modulation frequency and the greater the heating power, the greater the magnetic dipole moment produced. The variation of electron temperature generated in the modulation process has little effect on the propagation attenuation of VLF waves, while the geomagnetic field parameters have a greater impact on the propagation attenuation.
2023,45(9): 141-146 收稿日期：2022-04-24
DOI：10.3404/j.issn.1672-7649.2023.09.031
分类号：U666.14
基金项目：船舶振动噪声国家级重点实验室基金资助项目（6142204210710）
作者简介：王宁(1998-),男,硕士研究生,研究方向为电波传播
