ICE SOLAR WIND PLASMA ELECTRON ANALYSER DATA V1.0

The instrument measures the 2-D electron distribution function in one spacecraft rotation (3 s) once every 24 s, by obtaining 16 evenly spaced energy spectra, each with 15 contiguous levels covering the energy range 8.5 eV to 1140 eV. From these 2-D distributions the density, velocity, and temperature of the electrons are then derived.

A 2-D temperature matrix is calculated which is subsequently diagonalized. Then nominally the maximum temperature corresponds to the parallel temperature and the minimum temperature corresponds to the perpendicular temperature. This is done independently of the magnetic field measurements however, the direction of maximum temperature determined in this manner is usually found to be within 15 degrees of the magnetic field direction inferred from the magnetometer measurements.