基于FDTD的振幅频谱法定位精度评估  

Assessment of location accuracy by amplitude-frequency ratio method based on FDTD

作　　者：李云[1] 高太长[1] 江志东[1] 胡帅[1] 李宛桐 

机构地区：[1]解放军理工大学气象海洋学院,江苏南京211101

出　　处：《解放军理工大学学报（自然科学版）》2016年第1期81-87,共7页Journal of PLA University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(61301063)

摘　　要：为提高单站雷电定位系统的探测范围及定位精度,利用时域有限差分法对数百千米内雷电辐射电磁场的传播特征进行分析,分别计算了传输线模型（TL）、电流线性衰减的传输线模型（MTLL）、电流指数衰减的传输线模型（MTLE）3种回击模型在有限导电情况时,不同距离处雷电通道的垂直电场与磁场的分布。利用数值计算得到雷电电磁场波形,定量评估了振幅频谱法适用的探测范围及定位精度。结果表明：对于TL、MTLL和MTLE 3种模型,振幅频谱法定位相对误差小于10%的范围应分别为19~43km,17~46km和9~38km;对于距离测站小于9km或大于46km的雷电辐射源,3种回击模型得到的振幅频谱法定位相对误差均大于10%。因此,雷电源距离测站太近或太远,振幅频谱法均不适用。The detection range and location accuracy of single-station lightning location method was studied.The errors of amplitude-frequency ratio method were analyzed with finite difference-time domain（FDTD）.Then,vertical electric fields and magnetic fields of lightning were calculated by the transmission line model（TL）,modified transmission line model with liner current decay（MTLL）and modified transmission line model with exponential current decay（MTLE）in different ranges from the lightning channel on the finite conductivity ground.The results of the three models are very similar.To ensure the location error less than10%,detection range of amplitude-frequency ratio method in the three models is 19~43km,17~46km and 9~38km.When the distance is less than 9km or larger than 46 km,the location error is larger than10%in the three models.Therefore,if the distance between the lightning source and the observation station is too close or too far away,amplitude-frequency ratio method of single-station lightning location technique is not applicable.

关 键 词：振幅频谱法 单站雷电定位 时域有限差分 

分 类 号：P412.292[天文地球—大气科学及气象学]