133. Study of Physical and Dynamical Processes in the Ionosphere at Equatorial Anomaly Crest Region during Magnetic Storm for High and Low Solar Activity Period

The ionosphere represents one of the most important error sources that affecting GPS positioning. It is strongly related to solar activity and geomagnetic field. The GPS satellites and dual frequency receivers can be used to measure the Total Electron Content (TEC) of the Earth’s ionosphere. In this paper, the total electron content (TEC) profile features, have been utilized for extraction of parameters like profile factor, P and anomaly factor, PEA separately for three seasons (summer, winter and equinox) and the parameters are used for assertion of a certain day as quiet (Q) or disturbed (D). The ionospheric Total electron content (TEC) is used to examine the influence of solar activity by taking advantage of the dispersive nature of the ionospheric medium. The definitions of Q and D days are made through profile features and the threshold values of ∑Kp for each season are evaluated. The relations between Disturbed storm time (Dst) and P factor, ∑Kp and P factor are established after corrections for solar activity condition. The prediction and assertion of Q/D days are then made by examining IEC profiles for the cases where IEC data were not used for the parameter extraction. A few case studies using these methods are also presented in these papers. Work is based on TEC/IEC data collected from VHF Radio Beacon (RB) technique from geostationary satellite and GPS receiver at Guwahati (26.20N, 91.750E), an equatorial anomaly crest station.