一次人工触发闪电回击过程的光辐射色散特性分析  

Analysis of optical radiation dispersion characteristics of an artificially triggered lightning return stroke process

作　　者：罗小军 石立华 张琪 邱实 李云 刘毅诚 段艳涛 Luo Xiao-Jun;Shi Li-Hua;Zhang Qi;Qiu Shi;Li Yun;Liu Yi-Cheng;Duan Yan-Tao(National Key Laboratory on Electromagnetic Environment Effects and Electro-optical Engineering,PLA Army Engineering University,Nanjing 210007,China)

机构地区：[1]陆军工程大学,电磁环境效应与光电工程国家级重点实验室,南京210007

出　　处：《物理学报》2022年第17期419-426,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:51977219);中国博士后科学基金(批准号:2019M663978);江苏省自然科学基金(批准号:BK20200584);国防基础科学研究计划(批准号:JCKYS2021LD1)资助的课题.

摘　　要：采用改进的连续小波变换对一组人工触发闪电的回击过程光学辐射信号进行了色散特性分析,并与经典R-L-C传输线模型的计算结果进行了对比.结果表明,回击过程光学辐射信号不同频率分量的到达时间随频率的增加具有非线性变化;在不同频率分量的到达时间曲线上,低频段均出现了一个转折频率,并且转折频率的大小通常在10-25 kHz之间.该转折频率的存在为评估回击通道特性和电导率提供了一类新的参数化依据,据此估算了此次触发闪电六次回击过程的通道电导率,平均变化范围为(0.59-0.96)×10^(4) S/m,总体平均值约为0.77×10^(4) S/m,与经典评估结果相似.In this paper,improved continuous wavelet transform is used to analyze the dispersion characteristics of a group of optical radiation signals of return stroke in an artificially triggered lightning,and the analysis results are compared with the results calculated by the classical R-L-C transmission line model.The analysis results show that the arrival time of different frequency components of the optical radiation of return stroke presents nonlinear variation with frequency.Moreover,a turning point always appears in the low frequency band on the arrival time curves of different frequency components,and the turning frequency is usually between 10 kHz and 25 kHz.The existence of this turning frequency provides a new kind of parameterization basis for evaluating the characteristic and conductivity of the return stroke channel.Based on this,the channel conductivities of the six return strokes of this triggered lightning are estimated.The average variation ranges from 0.59×10^(4) S/m to 0.96×10^(4) S/m,and the overall average value is about 0.77×10^(4) S/m,which are similar to the classical evaluation results.

关 键 词：时频分析 回击 色散 通道电导率 

分 类 号：P427.3[天文地球—大气科学及气象学]