Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

The IMPACT Solar Wind Electron Analyzer (SWEA): Reconstruction of the SWEA Transmission Function by Numerical Simulation and Data Analysis


The IMPACT SWEA instruments on board the twin STEREO spacecraft detect the solar wind electrons with energies between 1 and 2000 eV. The instruments provide 3-dimensional velocity distributions, pitch angle distributions and solar wind properties at two vantage points in the ecliptic at 1 AU. A few days after launch suppression of the low energy solar wind electrons was detected, which makes data analysis challenging and causes a significant loss of information below 50 eV. This paper describes the methods used to both understand the nature of the problem and to recover the most information about the low energy solar wind electrons from the measured datasets. These include numerical simulations, in-flight calibration results, and data reconstruction methods that allow the calculation of solar wind parameter proxies with minor limitations.


  1. C.W. Carlson, J.P. McFaden, Design and application of imaging plasma instruments, in Measurements Techniques in Space Plasmas: Particles. Geophysical Monograph, vol. 102 (1998)

  2. M.A. Furman, M.T.F. Pivi, Probabilistic model for the simulation of secondary electron emission. Phys. Rev. Spec. Top., Accel. Beams 5, 124404 (2002)

  3. M.L. Kaiser, T.A. Kucera, J.M. Davila, O.C. St. Cyr, M. Guhathakurta, E. Christian, Space Sci. Rev. 136(1–4), 5–16 (2008)

  4. J.G. Luhmann, D.W. Curtis, P. Schroeder, J. McCauley, R.P. Lin, D.E. Larson et al., Space Sci. Rev. 136(1–4), 117–184 (2008)

  5. H. Rosenbauer, R. Schwenn, E. Marsch, B. Meyer, H. Miggenrieder, M.D. Montgomery, K.H. Muehlhaeuser, W. Pilipp, W. Voges, S.M. Zink, A survey on initial results of the HELIOS plasma experiment. J. Geophys. 42, 561–580 (1997)

  6. J.-A. Sauvaud, D. Larson, C. Aoustin, D. Curtis, J.-L. Medale, A. Fedorov et al., Space Sci. Rev. 136(1–4), 227–239 (2008)

  7. R. Ullrich, J. McCauley, P. Turin, K. McKee, B. Donokowski, The STEREO IMPACT boom. Space Sci. Rev. 136, 185–201 (2008). doi:10.1007/s11214-008-9334-3

Download references

Author information

Correspondence to A. Fedorov.

Rights and permissions

Open Access This is an open access article distributed under the terms of the Creative Commons Attribution Noncommercial License (, which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.

Reprints and Permissions

About this article

Cite this article

Fedorov, A., Opitz, A., Sauvaud, J. et al. The IMPACT Solar Wind Electron Analyzer (SWEA): Reconstruction of the SWEA Transmission Function by Numerical Simulation and Data Analysis. Space Sci Rev 161, 49–62 (2011).

Download citation


  • Solar wind
  • Space instrumentation