由于探测技术手段的局限，当前对于电离层D层的探测研究还相当不充分。利用强烈闪电VLF/LF信号探测和诊断电离层D层是当前电离层探测技术的新领域。本申请研究基于江淮地区闪电站网系统记录的闪电VLF/LF信号波形以及广州从化站同步记录的远场VLF闪电信号波形，开展中国东部地区电离层D层平均电子密度廓线反演及其时空变化研究，同时基于站网系统记录的地闪回击和NBE波形开展局地电离层D层特性不均匀性研究，以及电离层D层与雷暴放电相互作用研究。这一研究将扩展当前国内对于电离层D层的探测手段，研究结果也将丰富对于电离层D层特性的认识。

Due to the great difficulty in detecting technique，knowledge on ionospheric D region is quite inadequate.However,a novel method is currently proposed to measure and diagnose the lower ionosphere by using intense lightning signals. In this project, a GPS-based 6-station network in Jianghuai area as well as one remote sensor in Conghua(Guangzhou) will be setup to synchronously record VLF/LF radiation waveforms from lightning discharges.The sources of lightning signals will be obtained by time of arrival locating technique.For those located sources,their remote VLF waveforms as recorded in Conghua will be used to remote sense the electron density profile along the VLF-propagating path.Time-domain waveforms of return strokes and NBEs will be also used to probe the high temporal and spatial-resolution detection of D-layer fluctions as well as the response of ionospheric D region to lightning discharges.The results of this project is sure to enrich the knowledge on ionospheric D region.