Analysis of spherical particle distributions observed on the
WIND spacecraft

Abstract: WIND is a NASA spacecraft built to observe the solar wind. Since many
phenomena like auroras are related to the solar wind and it has also an
influence on all the spectra measured on Earth, therefore it is important to
explore its behaviour. On board the spacecraft the SST, EESA and PESA
instruments measure the electron and ion flux of the solar wind. These data
have been further investigated.

Access to existing data sets from the database of the WIND mission provided
by University of Berkeley, USA, has been gained through some IDL library
functions that have been specifically programmed for the purpose of
preprocessing and presenting data.

A statistical analysis of the present data is conducted using mostly
Mathematica. After examining the data for false measurements and general
characteristic attributes, like minima, maxima, mean value and variance,
more sophisticated statistical derivations have been computed for gaining
the knowledge about the spherical statistical behaviour which is thought to
be describable by the von Mises-Fisher distribution or similar functional
distributions. Therefore the data were examined first for the mean direction
which defines one major part of the simulating, theoretical distribution
expectation. It was found out that in the main solar events can be modelled
by distributions defined on a sphere and therefore missing or wrong data can
be reconstructed.