Articles | Volume 3, issue 1
Geosci. Instrum. Method. Data Syst., 3, 49–58, 2014

Special issue: Calibration methods and results of the in-situ experiments...

Geosci. Instrum. Method. Data Syst., 3, 49–58, 2014

Research article 23 Apr 2014

Research article | 23 Apr 2014

In-flight calibration of the Hot Ion Analyser on board Cluster

A. Blagau1, I. Dandouras2,3, A. Barthe2,3,4, S. Brunato2,3,5, G. Facskó6,7,8, and V. Constantinescu1 A. Blagau et al.
  • 1Institute for Space Sciences, Bucharest, Romania
  • 2Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse, Toulouse, France
  • 3CNRS, Institut de Recherche en Astrophysique et Planétologie, Toulouse, France
  • 4AKKA Technologies, Toulouse, France
  • 5Noveltis, Toulouse, France
  • 6Laboratoire de Physique et Chimie de l'Environnement et de l'Espace, Orléans, France
  • 7Geodetic and Geophysical Institute, Research Centre for Astronomy and Earth Sciences, HAS, Sopron, Hungary
  • 8now at: Finnish Meteorological Institute, Helsinki, Finland

Abstract. The Hot Ion Analyser (HIA), part of the Cluster Ion Spectrometry experiment, has the objective to measure the three-dimensional velocity distributions of ions. Due to a variety of factors (exposure to radiation, detector fatigue and aging, changes in the operating parameters, etc.), the particles' detection efficiency changes over time, prompting for continuous in-flight calibration. This is achieved by comparing the HIA data with the data provided by the WHISPER (Waves of HIgh frequency and Sounder for Probing of Electron density by Relaxation) experiment on magnetosheath intervals, for the high-sensitivity section of the instrument, or solar wind intervals, for the low-sensitivity section. The paper presents in detail the in-flight calibration methodology, reports on the work carried out for calibrating HIA and discusses plans to extend this activity in order to ensure the instrument's highest data accuracy.