Abstract
Electromagnetic Ion Cyclotron waves (EMIC) and Magnetosononic waves (MSW) observed in the equatorial regions of the plasmasphere by the four CLUSTER satellites are studied in the objective to improve wave models used in physical radiation-belt models. Data analyses are performed on each satellite. They include the production of power spectrograms of the magnetic wave fields and the estimation of propagation characteristics (degree of polarisation, sense of polarisation, wave normal direction, ellipticity). Several characteristics of prime importance for the development of wave models are pointed out. They concern : the lower cut-off frequencies of MSW and EMIC waves, the evolutions of the harmonic structure of MSW waves in the course of the propagation towards lower L values, the localisation and the amplitude of the R mode waves that may interact with energetic electrons, and the distribution in K vectors of these emissions. Comparisons are made with results obtained from the GEOS, CRRES and AKEBONO satellites.