Using the GPS observations to reconstruct the ionosphere three-dimensionally with an ionospheric data assimilation and analysis system (IDAAS)

Using an international reference ionosphere (IRI) model as a background ionosphere and applying the Kalman filter to update the state with observations, we develop an ionosphere data assimilation analysis system (IDAAS) to reconstruct a three-dimensional (3D) ionosphere with the GPS slant TEC and ionosonde data over east-south Asia. The preliminary results with the GPS data collected over east-south Asia on 30 June 2005 showed that inversed slant TEC has very good correlation with the observations both for the GPS sites being and not being involved in reconstruction. The inversed NmF2 and vertical TEC both demonstrate great improvement of agreement with those observed from ionosondes and TOPEX satellite independently.