This award would support the continued development of the technique of computerized ionospheric tomography through application of this technique to the analysis of phase observations of radio signals from the TRANSIT satellites by a network of radio receivers. The results of this analysis would be a collection of 2-dimensional images of the low latitude distribution of ionospheric electron density over a latitudinal swath of about 20 degrees. About 15 such images are available for each 24 hour period. These results would be examined to study the average daily behavior for a typical day in each season to establish a baseline behavior during solar minimum conditions. Images corresponding to atypical behavior relating to special events such as solar eclipses, earthquakes, volcanic eruptions would be examined and interpreted to improve the understanding of ionospheric behavior under these circumstances. All images constructed with applications of this technique would be made available through the means of Web access.
