通过对比分析2008年北京及其周边地区SAFIR(Surveillance et Alerte Foudre par Interferometrie Radiometrique)和ADTD(Advanced TOA and Direction system)两套闪电定位系统观测的地闪资料,结果显示:SAFIR系统探测的正地闪次数、负地闪次数均比ADTD系统偏少,但二者探测到正地闪和负地闪的日变化、月变化特征基本一致。SAFIR系统探测的正地闪百分比ADTD高。SAFIR系统的地闪高值区主要在偏南部,而ADTD系统的正地闪电流强度高值区流高值区主要在偏北部,地闪低值区分布基本一致。SAFIR系统探测的正地闪、负地闪电流强度小于ADTD系统的观测值,前者探测的正地闪电流强度日分布中整体比后者小约25 k A,负地闪电流强度日分布则小约10 k A。二者观测的电流强度日变化、月变化变化特征基本一致。ADTD负地闪电流累积概率分布整体和IEEE工作组给出范围较为接近。SAFIR系统探测的正地闪电流强度高值区空间分布较集中,而ADTD系统的空间分布相对较均匀分散。整体而言,两者探测的闪电时间分布特征较为接近,而闪电次数和强度分布特征有差别,对于出现差别的原因有待进一步研究。
The data of lightning location system is very important in scientific research and business of lightning protection. The characteristics of temporal,spatial and current distribution could be analyzed from the lightning location system and the characteristics could provide some guidance for the rational design of lightning protection project or lightning physics research.However,there are some differences in detection results between the different systems. The detection performances of the lightning location system are well known by comparing and analyzing the results of the different systems. Therefore the observation data of SAFIR system and ADTD system were compared and analyzed over Beijing and its surrounding areas in 2008. The results showed: The frequency of positive and negative CG( Cloud-to-Ground) lightning detected by SAFIR were both less than those detected by ADTD. However,the characteristics of the daily variation,the monthly variation of positive CG lightning and negative CG lightning were essentially similar respectively. The percentage of positive CG lightning frequency accounting for total lightning detected by SAFIR was higher than that detected by ADTD. The high value area of CG lightning of the SAFIR system was mainly distributed in the south,while the ADTD system 's was mainly distributed in the north. The distributions of lowvalue area of CG lightning were basically the same. The positive and negative CG lightning current intensity of SAFIR system was less than that of ADTD system. More concretely,the positive CG lightning current intensity of the former was 25 k A less than the latter,and meanwhile the negative CG lightning of the former was 10 k A less than the latter. The diurnal variation and the monthly variation characteristics of the current intensity of the two systems were basically similar. The cumulative probability distribution of negative CG lightning current by ADTD was consistent with that of the IEEE working group. The spatial distribution of current intensity of the