基于闪电定位数据的地闪密度修订

摘要

利用湖北省闪电定位系统(Lightning Location System,LLS)资料,用网格地闪密度数据表征地闪的空间分布,测站距离因子表征探测站布局,对2015年地闪空间分布特征进行分析,结果表明,其密度与因子之间存在负相关,其中雷电流幅值5～30 kA的密度分量与因子之间存在显著性相关,大于30 kA的密度分量与因子相关不显著.同时发现探测站布局对地闪空间分布的疏密程度有一定的影响,因此有必要对密度进行修订,以消除测站布局的影响.运用线性回归方法及其残差理论,建立了网格地闪密度的修订模型和相对探测效率的统计模型.验证了密度分段修订和不分段修订结果的一致性.通过对理论探测效率和相对探测效率的对比分析,论证了地闪密度修订方法和相对探测效率统计方法的可行性.%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 Location in 2015,it is found that the layout of the detection station has influence on the spatial distribution of lightning.Using the grid CG flash density data to characterize the spatial distribution of the CG flashes and the station distance factor to characterize the detection station layout,the study shows that there exists negative correlation between density and factor,significant correlation between the density of the component and the factor for the lightning current amplitude of 5 to 30 kA,and insignificant correlation for the ＞30 kA the density of the component.So it is necessary to revise the density to eliminate the influence of the station layout.In this paper,the relative detection efficiency is defined as the ratio of the densities before and after the revision in percentage,setting the station distance factor as the minimum value that corresponds to the grid relative detection efficiency of 100％.On the basis of the theory of the linear regression method and its residual,the revision model of the grid CG flash density and the statistical model of relative detection efficiency are established.The consistency of the results of the density segment and the non-segmented revision is verified.Through the contrastive analysis of the theoretical detection efficiency and relative detection efficiency,the revision and statistical methods and the feasibility of relative detection efficiency are also verified.