闪电快电场信号时频特性的小波分析

应用小波变换方法将具有短时非平稳特点的闪电快电场时域波形信号转换到二维的时频平面,从时间和频率上同时描述闪电快电场信号的电场强度或相对能量分布,揭示其所包含的不同频率分量及其随时间变化的特性.分析结果表明,基于小波变换的闪电快电场信号时频特性分析可以挖掘闪电电场更深层次的变化规律和特征;也为闪电放电类型的识别研究提供了新的思路.

Analysis on Time-Frequency Characteristic of Lightning Rapid Electric Field Signals Based on Wavelet Transform

By using wavelet transform,one-dimensional short-time non-stationary lightning rapid electric field time series are transformed into two-dimensional time-frequency plane.Thus,the electric field intensity or the distribution of relative energy of the lightning rapid electric field signals can be expressed by time and frequency simultaneously,which can better reveal the relative energy distribution characteristics in different frequency bands and the regularity of the lighting electric field intensity varying with time.The results show that the time-frequency characteristic analysis based on wavelet transform yields more comprehensive and accurate information details of lightning rapid electric field signals.The suggested method provides a new approach for identifying the type of lightning discharges.