Abstract:
This thesis focuses on mapping and predicting ionospheric effects to communication systems in northern high latitude areas using GPS (Global Positioning System). The monitoring of ionospheric scintillation and TEC (Total Electron Content) over Fairbanks, Alaska has been achieved by using the GSV4004 GPS Ionospheric Scintillation and TEC Monitor (GISTM), which has been installed on the roof of Duckering Building at UAF since September 2001. The algorithm of acquiring equivalent vertical TEC above Fairbanks from various satellite measurements is given in detail. Both an empirical ionosphere model, IRI, and a physics-based ionosphere model, PIM, are used to verify the TEC real field measurement. Another signal estimation method, BP neural network, is used to forecast the TEC short-term variation, which can give better performance than the other two. The relationships among TEC, amplitude scintillation and phase scintillation are analyzed. Multipath effects and the impact to GPS performance from ionospheric scintillation are discussed. Lastly the TEC and scintillation index mapping around Fairbanks is presented.
