Anders Tjulin, The k-filtering technique applied to Cluster EFW and STAFF data Abstract: The k-filtering technique is a method that can be used to characterise stationary electromagnetic fluctuations in space plasmas 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 provides good data for this kind of analysis. The combined data from the EFW and STAFF-SC instruments on Cluster have for the first time been used in k-filtering. The adjustments of the method that has been needed to perform this analysis, and the first results of it, are discussed.