The k-filtering technique applied to Cluster EFW and STAFF data.
Résumé
The k-filtering technique is a method to characterize stationary electromagnetic fluctuations in a space plasma in terms of the field-energy distribution in both the angular frequency and wave vector space. The method is based on simultaneous multi-point measurements of the electromagnetic field components, where a filter bank is used to enhance the spatial resolution. The Cluster mission consists of four identical satellites that are flying in formation, so it provides good data for this kind of analysis. We have for the first time combined electric field data from the Electric Field and Wave (EFW) instrument and magnetic field data from the Spatio-Temporal Analysis of Field Fluctuation (STAFF) instrument on the four Cluster spacecraft in order to determine the localization of the electromagnetic energy in the (ω, k)-domain. The first results are presented and discussed.