昆明地区连绵起伏山体对地闪回击定位精度影响的模拟研究  

Simulation study on the impact of rolling hills in Kunming area on the accuracy of cloud-to-ground return stroke location

作　　者：吉德志 张运龙 王磊[2] 张金波 戴炳哲 JI Dezhi;ZHANG Yunlong;WANG Lei;ZHANG Jinbo;DAI Bingzhe(Kunming Power Supply Bureau of Yunnan Power Grid Co.Ltd.,Kunming 650011,China;Yunnan Electric Power Test Institute(Group)Co.Ltd.,Kunming 650217,China;Key Laboratory of Meteorological Disaster,Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation ofMeteorological Disaster(CIC-FEMD)/Key Laboratory far Aerosol-Cloud-Precipitation of China Meteorological Administration,Nanjing University of Information Science and Technology,Nanjing 210044,China)

机构地区：[1]云南电网有限责任公司昆明供电局,昆明650011 [2]云南电力试验研究院(集团)有限公司,昆明650217 [3]南京信息工程大学气象灾害教育部重点实验室/气候与环境变化国际合作联合实验室/气象灾害预报预警与评估协同创新中心/中国气象局气溶胶与云降水重点开放实验室,南京210044

出　　处：《电波科学学报》2021年第2期179-186,312,共9页Chinese Journal of Radio Science

基　　金：配电网综合防雷体系研究与工程示范(YNKJQQ00000274)。

摘　　要：为了探讨真实地形对雷电定位精度的影响,利用二维时域有限差分(two-dimensional finitedifference time-domain,2D FDTD)算法,采取共形网格剖分技术,通过与平坦地面相比,首先研究了云南昆明地区复杂地形地貌对雷电电磁场传播的影响,然后利用时差定位算法,进一步探讨了该地区复杂地形地貌对雷电定位精度的可能影响.结果表明:1)由于复杂山体对雷电高频信号的优先衰减作用,传播路径上的山体越高大,相应的雷电电磁波波头时间越长,即信号到达时间(time of arrival,TOA)可能会延迟.从本文选取的昆明研究区域看,脉冲波形峰值到达滞后时间大概分布在4~5μs.2)根据脉冲信号TOA的不同定义方式,无论是平坦地面还是考虑复杂地形地貌的真实地表,峰值到达法的误差最大.对假定的平坦地面而言,除了峰值到达法,绝大多数TOA时差定位偏差在200 m以内,甚至重合.但对真实传播路径而言,不同雷击点对应不同的传播路径,有的偏差在100~200 m左右,有的偏差在2000 m左右.In this paper,two-dimensional finite-difference time-domain algorithm(2 D FDTD)and conformal meshing technology are adopted.By comparing with the flat ground,the influence of complex topography and geomorphology on the electromagnetic field propagation in Kunming,Yunnan is firstly studied.Then we further analyze the possible influence of the complex topography of the area on the accuracy of lightning location by time of arrival(TOA)method.The results shows that:1)Due to the preferential attenuation of high-frequency lightning signals by the complex mountains,the larger the mountain on the propagation path,the longer the wave risetime of thecorresponding lightning electromagnetic field,that is,the signal arrival time may be delayed.For the selected area of Kunming,it can be seen that the delay time of the peak value of the pulse waveform is distributed within 4-5 gs.2)According to the different definitions of the pulse signal arrival time,for the flat ground or the real surface considering complex terrain,the 10%peak arrival method has smaller delay time.According to the lightning location technique by TOA method,when the ground is flat,the positioning result of the 10%peak method basically coincides with the assumed lightning strike position.For the complex real ground,the positioning error of the 10%peak method is basically about 2000 m and the location errors are different for different propagation paths.

关 键 词：山体 雷电电磁场 辐射场强度 信号到达 时差定位 

分 类 号：TN957[电子电信—信号与信息处理]