Design of a highly precise TID sounder network in China

This paper systematically introduces a highly precise TID sounder network in China, which is made up of 13 high-frequency Doppler detection devices in Manzhouli, Changchun, Urumchi, Lhasa, Lanzhou, Chongqing, Xinxiang, Qingdao, Suzhou, Kashi, Guangzhou, Haikou and Kunming stations. This network is used to monitor the ionospheric disturbances and their propagations. It can also measure and display real-time solar flare, magnetic storm, sporadic E, the dinural variation in the ionosphere which will cause the Doppler shift. Thus, it is very important to understand the process of energy propagation and dissipation in the ionosphere. Through receiving the signal of 5 MHz, 10 MHz and 15 MHz operator frequency transmitted by National Time Service Center and using digital signal processing technology, we transmit three way of I, Q signals after they are orthogonal sampled and filtered, and obtain the data of HF Doppler shift. In addition, we monitor the audio signal of time service and obtain HF signal strength. All raw data can be stored in the database for transferring and analyzing, which meets different demands of ionospheric investigation. Finally, several typical records of ionospheric disturbances are recognized as the manifestations of solar flare, sporadic, sunrise effect, and the influence of HF propagation are presented. Observational results demonstrate the TID sounder network can be used for the long term monitoring of the ionospheric disturbances.