The multi-scale analysis of spatial GPS TEC data using the time-frequency transformation

To analyze the various regulation of ionosphere and the relationship between the solar activity and the ionosphere characteristics, the time domain to the frequency domain transformation is used in this paper to deal with the main ionospheric parameters, especially to carry on the processing to the important ionosphere data, the GPS TEC data, to separate the periodic variety of TEC. To obtain this various regulation, the Fourier transformation and wavelet transformation are used to perform the GPS TEC data. The result shows that the variety of all-year GPS TEC data gets remarkable multi-scale variation frequencies which include the semidiurnal variation, the daily variation, the day-to-day variation, the 27-day variation, the semi-annual variation and the annual variation. The investigation of these TEC periodicity of variations shows a good relation to the geomagnetic disturbance and solar cycle variations.