Analysis of the ionosphere wave-motion with GPS

Precise vertical total electron contents (VTEC) and its time variation have been obtained by using GPS dual-frequency observations collected by the continuously operating GPS tracking stations distributed over China. Using VTEC data, the wave-motion appearing in the ionosphere on November 3, 2003 is monitored and analyzed when a small solar flare happened. Detailed discussion with the VTEC and its change rate series, which are derived from the observations (data) from PRN23 satellite, indicates that the wave-motion mainly contains two dominant frequencies and propagates almost along the meridian line toward south. Additionally, the fluctuation of the mean VTEC has been calculated in a regional Single Layer Model (SLM) ionospheric shell in the range of N28.0 ° – 34.0 ° and E118.0 ° – 123.0 °. The spectral analysis and the multi-resolution analysis of mean VTEC time series show that the periods of these two components of the wave-motion at middle altitude are around 60 and 25 min separately, and the amplitudes can be up to 1.0–2.0 TECU and 0.4–0.7 TECU respectively. Meanwhile, the relative motion between the wave-motion and the Ionosphere Pierce Points (IPPs), which are defined as the cross points between the line-of-sight of the GPS signals and the SLM thin shell, reveals that the traveling speeds of the two components are about 120–150 m/s and 30–40 m/s respectively.