一套双频段三维全闪电定位系统及其初步观测结果

Initial Results of a Dual Band 3-D Lightning Locating System

介绍了一套同时工作在甚高频(very high frequency,VHF)和甚低频/低频(very-low/low frequency,VLF/LF)频段的三维闪电定位系统,并给出了初步观测结果。系统使用到达时间差法对2个频段的闪电辐射源进行定位,能连续地给出雷暴过程中闪电活动空间位置,并详细给出单次闪电的发展路径,在使用2个频段辐射波形参数进行定位的同时还可以保存原始波形用于深入研究。VHF、VLF/LF 2个频段闪电定位结果的时间分辨率分别为100?s和1ms,定位精度在站网覆盖范围可优于200m。2个频段的定位结果都能很好地描述雷暴中的闪电活动,但表现出的特征有一定差异。两频段定位结果对单个闪电发生路径进行描绘时,VLF/LF频段的大部分定位结果能与VHF定位结果重叠。

A newly designed dual-band lightning locating system that works in very high frequency(VHF) and very-low/low frequency(VLF/LF) bands is used to locate lightning discharges by using differential time of arrival(DTOA) method. The system currently consists of 14 dual-band sensors deployed over an area of 100 km in diameter in Chongqing, China. The system can continuously give the location of lightning activity during thunderstorms, and give the development path of single lightning in detail. It can also save the original waveform for in-depth study while using waveform parameters of two frequency to locate. The time resolutions of the VHF and VLF/LF location results are 100?s and 1 ms respectively. The location accuracy is better than200 m within the coverage of the sensors according to a Monte Carlo simulation performed at an altitude of 7 km. Most of the VLF/LF sources overlapped with VHF sources. The combination of the two frequency band observations is helpful to describe the occurrence and development characteristics of lightning accurately.