LLSDA: Design and Implementation of Lightning Location Data Analysis and Visualization

Visualizing lightning location data is necessary in analyzing and researching lightning activity patterns.This article uses C#and the cross-platform.NET framework to develop a lightning location data analysis class library and the data-driven client to help lightning researchers improve work efficiency by avoiding repeated wheel invention.Lightning Location System Data Analyzer(LLSDA)is a suite of software tools that includes a.NET class library for software developers and a desktop application for end users.It supports a wide range of lightning location data formats,such as the University of Washington Global Lightning Location System(WWLLN)and Beijing Huayun Dongfang ADTD Lightning Location System data format,and maintains scalability.The class library can easily read,parse,and analyze lightning location data,and combined with third-party frameworks can realize grid analysis.The desktop application can be combined with MeteoInfo(a GIS open-source project)for secondary development.

Estimation of Lightning-Generated NO_(x) in the Mainland of China Based on Cloud-to-Ground Lightning Location Data

Lightning-generated nitrogen oxides(LNO_(x))have a major influence on the atmosphere and global climate change.Therefore,it is of great importance to obtain a more accurate estimation of LNO_(x).The aim of this study is to provide a reference for the accurate estimation of the total LNO_(x) in the mainland of China based on cloud-to-ground lightning(CG)location data from 2014 to 2018.The energy of each CG flash was based on the number of return strokes per CG flash,the peak current of each return stroke,and the assumed CG breakdown voltage.The energy of intracloud lightning(IC)was based on the estimated frequencies of IC and the assumed energy of each IC flash.Combining the energy of lightning and the number of nitric oxide(NO)molecules produced by unit energy(ρno),the total LNO_(x) production in the mainland of China was determined.The LNO_(x) in the mainland of China estimated in this study is in the range(0.157-0.321)×10^(9) kg per year[Tg(N)yr-1],which is on the high end of other scholars’works.Negative cloud-to-ground lightning(NCG)flashes produce the most moles of NO_(x),while positive cloud-to-ground lightning(PCG)flashes produce the least total moles of NO_(x).The breakdown voltage of PCG is greater than that of IC or NCG,while the latter has a greater output of LNO_(x).

Development of a low-frequency magnetic lightning mapping system(LFM-LMS)in North China:validation and preliminary results

A low-frequency magnetic lightning mapping system(LFM-LMS)was built during the SHAndong Triggered Lightning Experiment(SHATLE),based on continuous measurements of magnetic field radiation from lightning.The hardware and source-mapping techniques used by the LFM-LMS were introduced;both Monte Carlo simulations and the observation of rocket-triggered lightning examples were employed to examine the location accuracy and detection effectiveness of the LFM-LMS.We estimated that the system’s location accuracy about 100−200 m horizontally and~200 m vertically.A natural intra-cloud lightning flash and a rocket-triggered lightning flash,both with intricate structures and discharging processes,were examined using the three-dimensional mapping results.The progressing path of negative lightning leaders is usually well-defined,and its propagation speed is estimated to be(0.5−1.4)×10^(6)m/s.In summary,the LFM-LMS can reconstruct the three-dimensional morphology of lightning flashes;this technology provides a efficient method for investigating the characteristics of lightning development,as well as the overall electrical strucuture of thunderstorms.

Power Network Lightning Accident Quick Inquiry with the Lightning Location System

目前，闪电是 10 自然灾难之一，并且它也是力量打断的最高的环境因素。它经常引起巨大的损失到电的系统。自从 1980 年代末，中国和科技的 Huazhong 大学的州的格子公司的武汉高电压研究所一直在研究并且发展中闪电地点系统(LLS ) 。在 mid-1990s，一个闪电察觉网络在中国在 29 个省和城市被创造。很快发现闪电事故首先被使用，还原剂它极大地驱动打断。另外，它保证高效率和电系统的安全操作。显著利益被完成。中国的 LLS 通过了一“放的取向 - 放的时差 - 综合的放”开发过程。放的精确，察觉效率，自动化的学位，有实行可能和应用范围被改进。另外，国家网络的一个闪电信息系统计划被实现了，它满足整个协会。

Application of Data from a Lightning Location System in Huai'an Region

Based on data of cloud-to-ground lightning detected by a lightning location system in Jiangsu Province from 2007 to 2012and data of thunderstorm days from seven meteorological observation stations in Huai'an during 1961-2012,the spatial and temporal distribution characteristics of cloud-to-ground lightning in Huai'an were analyzed.The results show that the total frequency of cloud-to-ground lightning in one day was closely related to the intensity and frequency of thunder and lightning.The seasonal variations in the total frequency of cloud-to-ground lightning in Huai'an.The total frequency was shown in unimodal distribution,and the extreme values always appeared in July or August.Most cloud-to-ground lightning was negative,and its frequency accounted for about95.3% of the total frequency.Cloud-to-ground lightning density was high in the south of Huai'an and low in the north,and the serious and very serious ground flash zones concentrated in the south of Hongze County,and most parts of Xuyi and Jinhu County,so lightning protection should be an important task particularly in these regions.

Design and Implementation of Lightning Analysis Software Based on Lightning Location System Data

This paper discusses the steps about how to design and implement software based on lightning location system data and its localization map.The system contains four major modules such as real-time lightning monitoring,historical query,lightning intensity zoning,lightning disaster statistics,etc.The system is able to automatically generate real-time lightning monitoring image,lightning animation,and lightning intensity zoning image,which contributes to the high accuracy of the calculation results and the efficiency of data analysis.The paper also points out the deficiencies of software life cycle management and proposes actionable solutions.

Lightning Nowcasting with an Algorithm of Thunderstorm Tracking Based on Lightning Location Data over the Beijing Area

A thunderstorm tracking algorithm is proposed to nowcast the possibility of lightning activity over an area of concern by using the total lightning data and neighborhood technique.The lightning radiation sources observed from the Beijing Lightning Network(BLNET)were used to obtain information about the thunderstorm cells,which are significantly valuable in real-time.The boundaries of thunderstorm cells were obtained through the neighborhood technique.After smoothing,these boundaries were used to track the movement of thunderstorms and then extrapolated to nowcast the lightning approaching in an area of concern.The algorithm can deliver creditable results prior to a thunderstorm arriving at the area of concern,with accuracies of 63%,80%,and 91%for lead times of 30,15,and 5 minutes,respectively.The real-time observations of total lightning appear to be significant for thunderstorm tracking and lightning nowcasting,as total lightning tracking could help to fill the observational gaps in radar reflectivity due to the attenuation by hills or other obstacles.The lightning data used in the algorithm performs well in tracking the active thunderstorm cells associated with lightning activities.

Revision of CG Flash Density Based on Lightning Location Data

Using the data of the Lightning Location System( LLS) over Hubei Province,through the analysis of the distribution characteristics of CG( Cloud-to-Ground) flash density in 2015,it was found that the layout of the detection station had influence on the spatial distribution of lightning.Grid CG flash density data were used to characterize the spatial distribution of the CG flash,and station distance factor was used to characterize the detection station layout. The result showed that there existed negative correlation between density and factor,significant correlation between the density component and the factor for the lightning current amplitude of 5 to 30 kA,and insignificant correlation between >30 kA of density component and factor. So it is necessary to revise the density to eliminate the influence of the station layout. On the basis of the linear regression method and its residual theory,the revision model of the grid CG flash density and the statistical model of relative detection efficiency were established. The result consistency of segment and non-segmented revision of the density was verified. Through the contrastive analysis of theoretical detection efficiency and relative detection efficiency,the feasibility for revision method of CG flash density and the statistical method of relative detection efficiency was also verified.

Error Correction of Lightning Location Data

[ Objective] The study aimed to correct error of lightning location data with small amplitude. [ Method] Using the curve fitting toolbox of matlab mathematical software, the distribution of lightning location data in Chongqing during 1999 -2008 was fitted based on logarithmic normal distribution function, and the specific characters of lightning data with current amplitude from -10 to 10 kA were analyzed. [ Result] During 1999 - 2008, the frequency of lightning with current amplitude from -10 to 10 kA in Chongqing City accounted for 4.93% of total frequency, while the fre- quency of lightning with current amplitude from -5 to 5 kA accounted for only 1.27%, lower than 2%, according with the conventional deletion proportion in China. Lightning data with current amplitude from -5 to 5 kA caused a great disturbance to the fitting effect, so the fitting effect was the best after these lightning data was deleted. After the lightning location system of Chongqing City was upgraded in 2005, the frequency of lightning with current amplitude from -10 to 10 kA decreased, and there were obvious changes in the frequency of lightning with current amplitude from -10 to -5 kA and from 5 to 10 kA, while the frequency of lightning with current amplitude from -5 to 5 kA was small and stable, so these data could be deleted. [Conclusion] The research could provide theoretical references for error correction of lightning location data with small amplitude in Chongqing City.

Temporal and Spatial Distribution of Lightning Activity in Ulanqab City

From January 2020 to December 2021,Ulanqab Meteorological Bureau of Inner Mongolia used VLF/LF lightning locator to carry out three-dimensional lightning monitoring in Ulanqab City,and compared with ADTD lightning location data in the same period.The results show that both VLF/LF lightning locator and ADTD lightning locator had excellent monitoring ability for lightning during flood season in Ulanqab.VLF/LF lightning locator was slightly superior to ADTD lightning locator in observation accuracy,the observation ability of low-current cloud-to-ground lightning,intracloud lightning observation and so on.There were obvious temporal and spatial characteristics of cloud-to-ground lightning during flood season in Ulanqab,and there was a certain correlation between the areas where lightning appeared frequently and surface water.Intracloud lightning was mainly concentrated at a height of 1-7 km.Negative cloud-to-ground lightning accounted for about 75%of total cloud-to-ground lightning,and negative intracloud lightning accounted for 39%of total intracloud lightning.

应用脉冲回波的避雷线断线检测系统研究

为高效率、低成本地检测风力发电机组桨叶避雷线断线位置,设计基于脉冲回波的避雷线断线检测系统。该系统以单端行波法为原理,由信号发生模块,传感器模块,信号采集模块、控制器模块四部分构成。信号发生模块负责产生行波脉冲信号,传感器模块负责采集回波信号,信号采集模块负责将采集到的回波信号处理转化送给控制模块,控制模块负责分析回波信号,判断故障类型和故障点位置。该文对各个模块的电路和性能参数进行设计,搭建整体的检测系统。经实验验证,该系统可以精准的实现断线判断,并获得断线位置,测量误差精确到0.5 m以内。

基于归闪的湖北省两套闪电定位系统对比分析

为研究湖北省两套闪电定位系统,在归闪的基础上研究分析了2015—2020年湖北地区地闪数据,对闪电频次、时空分布、电流强度月分布、雷电流幅值累积概率等主要参数进行了比对分析,研究结果表明:ADTD-2系统在定位正地闪强度存在局部异常值外,比ADTD-1系统具有更高的探测效率,其中正地闪的探测效率比负地闪提升幅度更高,探测负地闪回击的时间分辨率也比ADTD-1系统高,ADTD-2闪电数据整体优于ADTD-1数据。

基于LLS的雷电流波头陡度时间和概率分布特征

为研究雷电流波头陡度分布特征,以满足雷电防护工程设计、雷击事故分析等雷电灾害防御工作需要,根据湖北省2007-2013年雷电定位系统（Lightning Location System,LLS）监测的雷电流波头陡度资料,采用数理统计方法,对雷电流波头陡度的年、季、月、日变化及累积概率和概率密度分布进行了统计分析。结果表明,正闪、负闪和总闪电的年平均陡度分别为12.0、11.0和11.1 k A/μs;雷电流波头陡度夏季最大,冬季最小,秋季比春季大。1年中,正闪和负闪电波头陡度最大值分别出现在7月和6月,最小值均出现在12月。日中,正闪电陡度最小值与负闪电陡度最大值均出现在6-8时,正闪电陡度最大值和负闪电陡度最小值分别出现在23-0时和13-14时。95%的正闪和负闪电的波头陡度分别不大于31.4和21.1 k A/μs,正闪与负闪电波头陡度累积概率差异明显,负闪电波头陡度累积概率分布比正闪电更集中。雷电流波头陡度主要分布在2-20 k A/μs,正闪和负闪电陡度概率密度最大值出现在8 k A/μs左右。采用最小二乘法进行回归拟合,正闪、负闪和总闪电波头陡度累积概率实测曲线与拟合曲线基本一致,相关系数均在0.999 5以上。

基于LLS的雷电流波头时间分布特征

利用湖北省2007—2013年雷电定位系统（Lightning Location System,LLS）监测的雷电流相关参数资料,采用数理统计方法,对雷电流波头时间的年、季、月、日变化以及累积概率和概率密度分布进行了统计分析。结果表明,正闪电平均波头时间为4.8μs,负闪和总闪电为3.6μs;一年中,正闪电7月波头时间最短,月变化特征大致呈＂V＂形;负闪和总闪电5—7月波头时间比其他月份短,月变化特征大致呈＂U＂形。正闪电波头时间季节、日变化明显,负闪和总闪电季节、日变化不明显。波头时间小于等于10μs时,正闪、负闪和总闪电的波头时间累积概率分别为95.5%、99.7%和99.6%,总闪电95%的波头时间大于1.5μs,50%的大于3.1μs,5%的大于6.0μs。波头时间在2-3μs时,正闪、负闪和总闪电的概率密度最大。气温较低月份,波头时间相对较长,反之,波头时间相对较短,其原因可能与雷电流幅值大小有关,具体原因有待进一步研究。

全并联AT牵引供电系统雷击故障测距多路径行波算法研究

针对AT变压器和并联结构导致行波传播路径复杂,行波波头性质难以有效识别和行波色散现象,线路频变参数特性导致波速不稳定的问题,提出一种基于多路径行波测距方法。基于上下行电流行波传播的差异性,利用电流相似度识别故障区段。探讨全并联AT牵引网结构对行波传播特性的影响,并对电流、电压行波传播路径进行标定。基于多路径电流、电压行波极性分析,筛选出用于故障测距的多路径行波,以推导出消去波速的测距方程。仿真表明:所提测距方法可以有效识别波头性质,且计算故障距离基本与波速无关,不受牵引网区段长度、结构影响。

结合闪电定位数据分析北京市同时间点几起雷击事故

准确及时的灾害调查事故分析有助于人们更好地了解雷击途径和方式。结合闪电定位资料,分析某区域的雷电概率分布,可判断并认识雷电导致灾害的规律性,便于采取更有效的防护措施。通过对2022年5月24日北京市东城区同时间节点的三起雷击事故的详细分析,还原雷击过程,探究导致雷击的原因,提出相关解决方案,从而减少或避免以后类似雷电灾害事故的发生。对北京市东城区和西城区近年来的雷击数据统计分析发现,总的落雷走向大多在古河道或大致水位线,因潮湿或水位高,其建筑物下的土壤电阻率较小。尤其在北侧护城河一带每年都会或多或少地发生雷击事故。以上这些雷击规律虽是北京城区的,但颇具普遍性,因而对防雷、防火很有参考价值。城区周边的现代建筑和各古建筑物的雷电灾害防护要引起足够重视,对其进行定期全面的防雷检测是必要的。

青岛沿海地区雷暴过程闪电始发位置的微物理参量特征分析

本文通过低频磁脉冲闪电探测系统和双偏振雷达联合观测结果,针对2019—2020年青岛沿海地区发生的5次雷电灾害天气,研究了雷暴的闪电始发位置与微物理参数之间的关系,结果如下:(1)闪电主要始发于组合反射率大于45 dBz的强回波区,地闪的接闪位置距离主雷暴云系可达10~30 km左右。闪电始发区域组合反射率的中位数为55 dBz,液态水含量的中位数为37 kg/m^(2)。(2)闪电始发位置的双偏振雷达水平反射率主要集中于35~45 dBz,差分反射率主要集中在1.5~2.5 dB,相关系数集中于0.97~0.99。大部分雷电始发于0℃等温线和–10℃等温线之间,位于液态水、湿霰和干霰混合相态粒子区。部分雷电过程发生于湿霰区的中上部,这种情况一般差分反射率值很大。(3)在–10~0℃等温层之间存在相关系数大值区且相态粒子为湿霰粒子,说明为过冷水区。过冷水区中极易产生大直径的霰粒,在强上升气流的作用下,大直径霰粒与冰晶碰撞从而极易发生闪电过程。

DDW1型闪电定位仪数据质量分析评估

文章分析了DDW1型闪电定位仪的探测原理,通过分析江苏省DDW1型闪电定位仪试运行期间的雷电数据,并对比DDW1型与ADTD型闪电定位仪的雷电探测类别与数量。结果表明:除个别站点因网络问题导致传输数据到报率略低外,其余站点数据到报率均达到99%;与ADTD型闪电定位仪相比,DDW1型闪电定位仪灵敏度更高,所探测到的正闪数量是ADTD型闪电定位仪的5.8倍,负闪数量二者相差不大,DDW1型闪电定位仪正闪与负闪比为1∶1.8。研究结果为DDW1型闪电定位仪的推广应用奠定基础。

园区类项目区域雷击风险评估应用探讨

介绍区域雷击风险评估相关内容,包括项目前期勘测、闪电定位资料应用、评估子区域划定标准和区域雷击风险评估模型;以上海某化工园区为例,介绍项目基本情况、雷电环境特点、子区域划分,给出评价指标隶属度及区域雷击风险值的计算结果;提出在区域雷击风险评估时,应尽可能通过现场勘测、调研问卷等多种形式详细了解项目基本情况,并结合雷电分布特征详细划分子区域,开展区域雷击风险评估。

一次强对流天气的雷达和闪电特征分析

文章利用地面常规观测资料、ECMWF ERA5再分析资料、三维闪电定位资料及雷达资料对乌兰察布市2021-07-05出现的一次强对流天气进行了详细的分析和研究。文章主要分析了高低空环流形势、地面形势场和物理量场的演变特征,以及强对流天气发生时,雷达回波特征和闪电特征,为本地强对流天气的预报提供有利的依据。