O. Santolik et M. Parrot, Application of wave distribution function methods to an ELF hiss event at high latitudes, J GEO R-S P, 105(A8), 2000, pp. 18885-18894
Multicomponent waveform data are used to calculate wave polarization and pr
opagation characteristics, with both simple plane wave methods and more gen
eral wave distribution function (WDF) techniques. The WDF techniques allow
us to estimate a continuous distribution of wave energy with respect to the
wave vector directions. We describe several newly developed analysis metho
ds, and we compare their results with existing techniques. This comparison
allows us to reach a common interpretation of propagation properties and to
exclude possible artifacts. The methods are applied to an electromagnetic
ELF hiss event observed by the low-altitude satellite Freja. A part of the
emission can be described by simple plane wave methods. WDF techniques are,
however, needed to fully characterize the wave propagation when the compon
ents of the wave magnetic field vector are not mutually coherent and the po
larization degree is low. In this case we observe large peaks on the WDF sh
ape or simultaneous propagation of downgoing and reflected upgoing waves. T
he WDF techniques also confirm that experimental polarization properties ar
e consistent with their predictions by the cold plasma theory.