基于自然雷电的甚低频传播特性分析

Evaluation of Propagation Characteristics of The VLF Channel With Lightning Pulse

雷电是自然界最重要的大气现象之一,典型情况下雷电电流强度可达几万安培,放电路径可达几千米,持续时间几十微秒,包含非常丰富的频率成分,雷电脉冲在甚低频地—电离层波导中经多次反射到达远处的接收点,接收到的雷电脉冲实际携带了甚低频地—电离层波导频率传播特性。首先对雷电脉冲进行分类与统计,在此基础上对雷电脉冲进行频谱分析,然后将研究结果与LWPC软件预测结果进行对比分析。结果表明,使用自然雷电脉冲的平均谱估计甚低频传播特性是可行的。此法与人工辐射源法相比,主要优势在于被动检测、应用成本低、可测频率范围宽、低端频率特性测量精度较高。

Lightning is one of the most important atmospheric phenomenon in nature,with tens of thousands of amperes of current,a few kilometers of the discharge distance,tens of microseconds of the duration time,abundant frequency components. Lightning pulses reach the distant receiver by multiple reflection in the VLF earth-ionosphere waveguide,so the received lightning pulses carry the propagation characteristics of the VLF channel in fact. In this work,we classify and count the lightning pulses firstly,then make spectrum analysis of the lightning pulses,finally make a comparison and analysis of the spectrum analysis and the prediction result of the LWPC. It shows that it＇s feasible to evaluate the propagation characteristics of the VLF channel with lightning pulse. Compared to the method of artificial radiation source,the main advantage is passive detection,low cost and wide frequency range,especially the measurement of the characteristics with high-precision in low frequency.