大气折射对甚高频闪电定位的影响分析  

Effect of atmospheric refraction on VHF lightning location

作　　者：杨长业[1] 李云[1] 高太长[1] 江志东[1] 

机构地区：[1]解放军理工大学气象海洋学院,南京211101

出　　处：《气象科学》2015年第5期574-580,共7页Journal of the Meteorological Sciences

基　　金：国家自然科学基金资助项目(61301063)

摘　　要：利用GPS探空仪实测数据计算大气折射率的高度廓线,建立大气折射误差模型。并分析大气折射效应对方向交汇、到达时间差以及综合法3种甚高频闪电定位方法测量精度的影响。结果表明,对于定位距离,大气折射对方向交汇法的影响最大,误差最大值可达到116.52 m,平均误差为30.18 m;大气折射对时间差法的影响最小,误差最大值约为44.70 m,平均值为12.32 m;对综合法的影响介于二者之间,误差最大值约为58.90 m,平均值为16.74 m。在综合法中,选取离闪电源较远测站进行方向交汇的定位误差是选取较近站点的定位误差的1.6倍,因此应当选取近站点。考虑到GPS授时误差,要保证大气折射对闪电定位造成定位误差小于GPS时间同步带来的误差,3种闪电定位方法的站间距应分别不大于28 km、60 km、45 km。By using the vertical profile of atmospheric refraction calculated by GPS sonde data, theerror model induced by atmospheric refraction was proposed. Moreover, the effect of atmospheric refrac-tion on lightning location methods（Direction Finder（DF）, Time-Of-Arrival（TOA） and Improved Ac-curacy using Combined Technology（IMPACT）） were also analyzed. Results show that for the locationprecision, the atmospheric refraction has the greatest impact on the DF method with the maximum errorvalue of 116 52 m and the mean error of 30 18 m; whereas it has the least impact on the TOA methodwith the maximum error of 44 70 m and the mean error of 12 32 m; the maximum error and the mean er-ror of the IMPACT method are 58 90 m and 16 74 m, respectively. For the IMPACT method, the loca-tion error of far station is 1. 6 times of the location error of more nearby station, hence, the nearby stationshould be chosen to locate the lightning. To ensure the error induced by the atmospheric refraction lessthan that induced by timing error of GPS, the station distances of the DF, TOA and IMPACT systemshould be less than 28 km, 60 km and 45 km, respectively.

关 键 词：雷电 大气折射效应 闪电定位 大气折射率 定位误差模型 

分 类 号：P457.9[天文地球—大气科学及气象学]