阐述了如何提高系统数据记录与波形显示速度,快速捕捉闪电快、慢电场、磁场或人工引发闪电的回击电流等参量的亚微秒变化,以实现对闪电多参量数据的高速大容量实时采集、显示和分析。基于NI公司的PCI-5105数据采集卡,采用Labview 8.5图形化编程软件在Windows XP平台上开发研制了闪电多参量高速大容量实时数据采集、显示和分析系统,并应用于闪电观测试验。该系统最大采样率可达60 MS.s-1,可8通道同时采集。程序设计采用多线程编程技术,文件记录格式采用TDMS格式。将该系统应用于快、慢电场多站定位观测,增加了高精度GPS同步时钟授时装置后,各子站记录的信号触发时间精度可达到50 ns。2008年和2009年夏季分别在北京、西藏羊八井地区和东北大兴安岭地区开展了野外观测试验,获得了大量的快、慢电场观测资料。观测试验采用快、慢天线闪电电场变化仪对该系统进行了测试,采样的时间长度达到1 s,能够完整地记录一次闪电过程,动态捕捉闪电引起的时域电场变化的精细特征。
The design of a multi-parameter of lightning flash recording system used for measuring electric field change, magnetic field change produced by nature lightning and current in the return stroke of a triggered lightning with fast recording in real-time and large capability are described. Using the NI PCI- 5105 digitizer, the software is developed using Labview 8.5 in Windows XP platform. The system works in high-speed with sample rate is 60 MS· s^-1 at most. There are 8 channels which could work simultane- ously and could measure 8 different parameters of a lightning flash. The data format is TDMS format. The GPS receiver was used to give 1 per second pulse from the accurate trigger time by frequency divider, the absolute accuracy of trigger time is about 50 ns. The experiment in Tibetan Plateau in the summer of 2008 and 2009 have been conducted. The multi-station measurements of electric field change in Beijing in the summer of 2008 and in Great Xing'an mountains in the summer of 2009 also have conducted. The time of record length is 1 s. The system is useful for recording and describing the details of electric field change.