Vertical ionosonde net and its data application in southwestern China

In order to monitor the ionospheric change in southwestern China, two stations were established in Pu'er City of Yunnan Province and Leshan Normal University of Sichuan Province jointly by Institute of Earthquake Science, China Earthquake Administration and Wuhan University. Based on the vertical ionosonde data from the two stations and space weather events, we used the moving average method with different threshold to extract ionospheric perturbation, and selected median±1.5Std and median±IQR as the threshold at the stations Pu'er and Leshan, respectively. Furthermore, using this method, we analyzed the data before Nepal M_S8.1 earthquake occurred at 14:11 on 25 April 2015. The results showed that there were positive anomalies in April 24 at the two stations Pu'er and Leshan, and negative anomalies lasting for three hours at Leshan station before the Nepal earthquake. According to our plan, besides the two stations, one or two vertical ionosonde stations and several oblique ionosondes will be set up in southwestern China, which will monitor the ionosphere over the region, and provide data for analyzing seismo-ionospheric disturbance.