Local Characterization of Homogeneous Turbulence in a Space Plasma from Simultaneous Measurements of Field Components at Several Points in Space

The best method was sought for defining locally an electrostatic or an electromagnetic turbulence in a space plasma, based on the simultaneous measurement of several wave field components at several points in space. The turbulent field is supposed to be stationary in time and homogeneous in space. An estimate of a local field energy distribution, denoted F(omega, k), which specifies how the field energy observed by a limited number of satellites is distributed with regard to the angular frequency omega and to the wave number k, is derived from a generalization of the Capon [1969] high-resolution method. The quality of this estimate is deemed sufficient, as shown by examples of application to synthetic data.