Articles | Volume 22, issue 7
Ann. Geophys., 22, 2633–2641, 2004
https://doi.org/10.5194/angeo-22-2633-2004

Special issue: Spatio-temporal analysis and multipoint measurements in space...

Ann. Geophys., 22, 2633–2641, 2004
https://doi.org/10.5194/angeo-22-2633-2004

  14 Jul 2004

14 Jul 2004

Instantaneous local wave vector estimation from multi-spacecraft measurements using few spatial points

T. D. Carozzi, A. M. Buckley, and M. P. Gough T. D. Carozzi et al.
  • Space Science Centre, University of Sussex, Brighton, England

Abstract. We introduce a technique to determine instantaneous local properties of waves based on discrete-time sampled, real-valued measurements from 4 or more spatial points. The technique is a generalisation to the spatial domain of the notion of instantaneous frequency used in signal processing. The quantities derived by our technique are closely related to those used in geometrical optics, namely the local wave vector and instantaneous phase velocity. Thus, this experimental technique complements ray-tracing. We provide example applications of the technique to electric field and potential data from the EFW instrument on Cluster. Cluster is the first space mission for which direct determination of the full 3-dimensional local wave vector is possible, as described here.