最新研究发现窄偶极脉冲(NBPs)由快速正击穿引起，随后在其起始点激发反向发展的负先导。发生在闪电起始阶段的这种快速正击穿强度变化范围很广，被认为是多数甚至可能是所有闪电放电的起因，但目前对这种快速正击穿过程的了解非常有限，它们在闪电始发过程中的作用机理及如何转变为负先导的方式尚不清楚。本项目以长存储8通道宽带干涉仪系统、宽带dE/dt和快电场变化仪为基础观测手段，结合多站VLF/VHF双频段闪电探测阵列，获取一些快速正击穿放电过程（NBPs、先兆放电(PCs)和屏蔽层放电）和完整闪电宽带辐射波形的同步观测资料。发展干涉法和时差法相结合的闪电宽带干涉仪3D定位技术，根据近距离快速正击穿放电事件的通道发展和宽带电场变化波形，建立物理模型，估算其放电参量。对比分析不同放电事件中快速正击穿的通道发展速度、尺度、峰值电流、辐射强度及辐射频谱特征，研究快速正击穿放电在闪电始发过程中的作用机理。

The new study found that the narrow pulse pulses (NBPs) are caused by fast positive breakdown, then stimulate the development of the reverse negative leader in its starting point. The fast positive breakdown occurring in the initial stage of the lightning with intensity changes in a wide range, is considered to be the most possible cause of all lightning discharge. But at present there is very limited understanding of such fast positive breakdown, including its mechanism during the initiation of lightning and the way how to transform into the negative leader. This project is based on the eight-channel broadband interferometer system which has a long time of storage, broadband dE/dt and fast electric field change waveforms. They are also combined with the observation results of VLF/VHF dual band multi-station lightning detection array. The purpose is to get synchronous observation data of radiation wave of some fast positive breakdown ( NBPs, short duration discharge precursor events (PCs) and discharge events occurring in the shielding layer) and complete lightning. Base on the development of interferometric method and different time of arrival method combined with the lightning broadband interferometer 3D positioning technology, and according to the fast positive breakdown discharge event channel development and changes in the broadband field waveform, a reasonable physical model can be established to estimate the discharge parameters. Base on comparative analysis of development speed, breakdown scale, peak current, radiation intensity and radiation spectrum characteristics of different kinds of fast positive breakdown, their mechanism in the initial stage of the lightning can be further explored.