中文摘要：

雷电放电过程的研究是准确仿真模拟雷击过程的基础,高速摄像技术的快速发展为雷电放电过程观测研究提供了有力手段。利用最快帧速达6.5×10^5帧/s、最大分辨率达（1024×1024）像素,拍摄时长达秒级的摄像系统,结合覆盖全国电网的雷电监测网,对雷电放电过程进行了观测研究和分析。连续多次地闪的观测结果表明：高速摄像系统与雷电监测网观测到的地闪时间间隔完全吻合,监测到的电流大小和图像中回击通道亮度变化一致;地闪和云闪观测结果较好反映了先导发展过程,高速摄像系统的高时间分辨率及高图像分辨率可以获得地闪的多个先导的发展速度随时间变化的曲线,细致反映出梯级先导竞争放电的变化过程;观测到的地闪主先导发展速度约在2.7×10^5m/s～2.4×10^6m/s,平均为1.2×10^6m/s,与以往其它雷电研究结果一致。云地闪放电过程高速摄像观测为全面掌握雷击物理机理提供了详细的图像资料。

英文摘要：

Studies on lightning discharge processes are the foundation for the accurate simulation of lightning strike process, and the rapid development of high-speed video technology provides a good way to the observation studies on lightning discharge processes. Combining with the China Grid Lightning Detection Network （CGLDN}, this paper utilizes the latest high-speed video system with the maximum resolution of 1024 1024 pixels, the maximum frame rate of over 650,000fps, and the record time over one second to carry out the lightning discharge proeess observations. The observed return strokes of three continuous cloud-to-ground flashes show that the time intervals between every two return strokes observed by high-speed video system are well agreeable with those detected by CGLDN, and detected currents of these three return strokes accord with the luminosity＇s changes of lightning channel in ob- served images. The observed results of cloud-to-ground （CG） flashes and inter-cloud （IC） flashes well describe the propagation processes of leaders, and the variation curve of lead speeds with time is obtained according to the high resolution images and high frame rate of the video system. The speed of the primary stepped leader of CG flash is between 2.7 × 10^5 m/s and 2.4 ×10^6 m/s, averaged 1.2 × 10^6 m/s, which is consistent with other previous obtained results. The observations of discharge processes of CG and IC flashes provide detailed image materials for completely understand the lightning strike mechanism.