In mid-January 1998 Dr. Miguel Juan from the Polytechnical University of Catalonia in Barcelona, Spain, arrived at Goddard Space Flight Center (GSFC) to begin his half-year fellowship at NSSDC. He and his colleague Dr. Manuel Hernandez-Pajares have both received a half-year Senior Scientist Fellowship from the Spanish government to work with Dr. Dieter Bilitza at NSSDC on incorporating Global Positioning System (GPS) data into the International Reference Ionosphere (IRI).
The two Spanish scientists have developed their own method for deducing global maps of ionospheric electron content from the measurements of the 23 satellites that are part of the U.S. Air Force's GPS. Their method and results are described in articles published in the Geophysical Research Letters and in Radio Science. During their stay at NSSDC, they will explore ways in which the GPS data and the IRI predictions could benefit each other. On one hand the IRI a priori information about the global density distribution can help to optimize the GPS data analysis algorithm. GPS-derived electron content data, on the other hand, can be used to update the full IRI electron density profile and thus contribute to a more reliable and accurate prediction of ionospheric space weather.
Dr. Miguel Juan, right, begins his fellowship with Dr. Dieter Bilitza of NSSDC.
With his arrival Dr. Juan is taking over from Dr. Hernandez, who went back to Spain after his first three months at NSSDC; Dr. Hernandez will be back for the last part of his fellowship in July 1998. Such an arrangement was worked out with the granting organization because of the teaching obligations of the two Spanish scientists at their alma mater.
Before returning to Spain Dr. Hernandez presented the first results of the GPS/IRI project at the Jet Propulsion Laboratory (JPL) Workshop on Ionospheric Determination and Specification for Ocean Altimetry, at the American Geophysical Union (AGU) fall meeting, and at the U.S. National Union of Radio Science (URSI) Meeting. First comparisons with incoherent scatter data and possibly also TOPEX data will be presented at the European Geophysical Meeting this April.
Erin D. Gardner, email@example.com, (301) 286-0163
Raytheon STX, Code 633, NASA Goddard Space Flight Center
Greenbelt, MD 20771, U.S.A.