电离层虚高的高精度测量与分析

Measurement and Analysis of Ionospheric Virtual Height With High Precision

为了提高电离层虚高测量精度,介绍了利用电离层回波相位实现高精度虚高测量的方法,并以CADI (Canadian Advanced Digital Ionosonde)电离层数字测高仪为研究平台,进行组合脉冲控制和回波相位测量分析,开展了一系列虚高测量实验,并与传统的利用回波时间延迟的虚高测量方法进行了分析比较．实验结果表明,基于回波相位的测量分析方法与回波时延测量分析方法相比,其虚高测量精度高一个量级以上,这对精确反演电离层峰下电子浓度剖面及研究电离层精细结构具有重要意义．

In order to improve the spacial resolution of ionospheric virtual height in vertical ionospheric sounding, a high precision virtual height measurement experiment are carried out by means of ionospheric echo＇s phase measurement and corresponding data analysis processing arithmetic with modern digital ionosonde. When two radio frequency pulse signals, the frequency difference of which is a fixed value are transmitted and the echo＇s phase difference is measured, the ionospheric virtual height with high precision can be acquired. According to this ionospheric virtual height sounding principle, the observation mode of ionospheric virtual height with high precision is realized. In this mode, the measured height resolution of the ionospheric virtual height is increased by more than ten times, that is, from 6 km to about 200 m, which can entirely satisfy the observation research demand of the ionospheric fine structure and small scale disturbances. Through a series of virtual height measurement experiments by using combinational pulses control and echo＇s phase measurement analysis based on CADI ionosonde, some meaningful results are obtained and some comparisons are made with TOA （Time Of Arrival） method. Experimental results reveal that the height resolution of ionospheric virtual height measurement with echo＇s phase method is ten times higher than that of virtual height measurement with TOA method. This is very important in that electron density profile under ionospheric peak can be accurately inversed and ionospheric fine structure can be carefully studied.