EVALUATION OF GROUND STROKE DENSITY DISTRIBUTION AND LIGHTNING DETECTION EFFICIENCY IN BEIJING-TIANJIN-HEBEI AREA

It is possible to understand the lightning activities in a specific region and compare test results of different apparatus only when a reliable evaluation of detection efficiency distribution pertaining to a particular lightning location system(LLS) is available.Based on the data in 1992.an approximate evaluation of detection efficiency spatial distribution for single-station lightning location system(M-LDARS) and LLP three-station lightning location system in Beijing-Tianjin-Hebei area is presented in the paper,showing that the average detection efficiencies are smaller than 48% and 46% respectively.In addition,the article offers an evaluation of spatial distribution of ground stroke density(Dg) and positive stroke percentage,indicating that six high stroke density zones exist along the southeastern sides of the Taihang and Yan-shan Mountains.The stroke density of mountainous region is higher than that of the plain region,in contrast to the case of positive stroke percentage.Also,it is shown that within a radius of 250km,the average of Dg is 1.2(km-2 a-1) while the average positive stroke percentage is 10.9%.Finally,the paper proposes a possible test method of accurately evaluating the spatial distribution of detection efficiency(A).