摘要
利用麦克风阵列采集雷声信号,设计了一套由麦克风阵列和便携式数据采集存储设备组成的单站闪电通道三维定位系统,采用CCF相关函数法计算了雷声脉冲信号到达不同麦克风的时间差,通过最小二乘法获得声源的方向角和仰角信息,并结合声源与麦克风阵列的距离定位声源的三维位置。对一次包括8次回击的人工触发闪电过程进行了观测,得到多个声源点的三维定位信息。系统的定位结果与高速摄像的观测结果具有较好的一致性,定位方法合理、可行,为进一步研发便携式闪电通道三维定位系统奠定了基础。
Single-station-based three-dimensional lightning channel imaging system,which uses the differential time of arrival of thunder,has been developed.The system consists of a small-size microphone array,a data collection and storage system.The microphone array is consisted of four microphones which work at a frequency range from 15 to 20 kHz.Thunder signals recorded by different microphones are processed by the cross-correlation analysis to obtain the differential time of arrival at different microphones,and the direction the thunder propagation is calculated by using the least square method.The distance from the thunder source to the array is determined by the time interval between the arrival of the electromagnetic signal and the thunder.Then the three-dimensional thunder sources are obtained by combining the direction and distance of thunder.The thunder signal of a rocket-triggered lightning comparing with 8 return strokes was recorded by this system,and the lightning channel imaging results have been compared with the photographs observed by a high-speed camera.The thunder source and photograph are found to agree fairly well,which indicates that the system developed in this study is feasible and can be used as a convenient lightning channel 3D imaging tool.
出处
《高原气象》
CSCD
北大核心
2012年第1期209-217,共9页
Plateau Meteorology
基金
国家自然科学基金项目(41075003
41030960)
中国气象科学研究院基本科研业务费专项(2010Z004)共同资助
关键词
雷电
雷声
闪电三维定位
人工触发闪电
麦克风阵列
Lightning Thunder Three-dimensional lightning channel imaging Rocket-triggered lightning Microphone array
