Determination of global plasmaspheric electron density profile by tomographic approach using omega signals and ray tracing

It has been necessary requirements to determine the global electron density distribution in the plasmasphere with time resolutions, of less than a day . We have provided solutions to this requirement using the wave normal dire ctions, delay time of Omega signals and the in situ electron density observ ed on-board the Japanese satellite Akebono (Sawada et al., Journal of Geoph ysical Research 98(11) (1993) 267, Kimura et al., Advance Space Research 15 (2) (1995) 103, Advance Space Research 18(6) (1996) 279. Journal of Atmosph eric and Solar-Terrestrial Physics 59 (1997) 1569). The present paper is in tended to review our earlier studies. (C) 2001 Elsevier Science Ltd. All ri ghts reserved.