Results And Its Applications Of Studying And Monitoring Ionospheric Total Electron Content Based On Ground GPS Network

By means of GPS technique, a 0.5 hours by 0.1 degrees by 0.1 degrees (time by longitude by latitude) grid module of ionosphere has been established for real time monitoring precise ionospheric vertical total electron content (TEC) over the area of Shanghai Comprehensive GPS Application Network (SCGAN). In every 30 minutes, one TEC map which shows the detailed distribution of TEC over this area is acquired and used for real-time correction to ionosphere delay of GPS receiver with single frequency. Based on this module, two-year TEC time series of ionosphere over Shanghai is extracted from the observation data of SCGAN. The analyses of the TEC time series show that the some characters of TEC over Shanghai are similar to other areas in middle latitude district, and some are different for the local environment of Shanghai. Furthermore, the time sequences of TEC and TEC rate with sample spacing of 1 minute during all big geo-magnetic storms since the year of 2003 have been obtained together with TEC maps which used for demonstration of TEC distribution over SCGAN of each half an hour during geo-magnetic storms. The results show that both of the TEC value and rate are anomalous during geo-magnetic storms, and the amplitude of such anomaly in daytime is larger than in nighttime. TEC distribution is characterized by the fact that TEC values in the south part of SCGAN are larger than the north part especially during daytime. It is also shown that the TEC value increases during nighttime and then quickly decreases to normal value.