méthode de tracé des rayons

CONT: Akebono satellite launched in Feb., 1989 has been used to observe the Omega signals. It was found that the Omega signals were continuously detected over more than 30 minutes and their time delay and wave normal direction can be determined. Then an idea came up that by using these wave data as well as the electron density along the satellite orbit, a global plasmaspheric electron density profile may be determined by a tomographic approach, i.e. by using ray tracing technique.