Environment Monitoring Unit


  • Mass: 3.5 kg
  • Volume: 3 litres
  • Power: 8 Watts
  • Reliability: 15 year MEO mission
  •  Sensors:
    • SURF: 8 stacked charge collection plates, 7 cm diameter,
    • 8 Proton Telescopes
    • Heavy ion LET sensor
    • RadFETS
  • GSAT0207 (Antoniaana) launched in Nov. 2016
  • GSAT0215 (Nicole) launched in Dec. 2017
  • Himawari-8 launched in Oct. 2014
Hands, A D P; Ryden, K A; Sandberg, I; Heynderickx, D; Provatas, G; Aminalragia-Giamini, S; Tsigkanos, A; Papadimitriou, C; Rodgers, D; Evans, H: An Update to MOBE-DIC Using Current Monitor Measurements From Galileo. In: IEEE Transactions on Nuclear Science, vol. 67, no. 1, pp. 181-190, 2020, ISSN: 1558-1578. (Type: Journal Article | Abstract | Links | BibTeX)
Sandberg, I.; Aminalragia-Giamini, S.; Provatas, G.; Hands, A.; Ryden, K.; Heynderickx, D.; Tsigkanos, A.; C.Papadimitriou,; Nagatsuma, T.; Evans, H.; Rodgers, D.: Data Exploitation of New Galileo Environmental Monitoring Units. In: IEEE Transactions on Nuclear Science, vol. 66, no. 7, pp. 1761-1769, 2019, ISSN: 0018-9499. (Type: Journal Article | Abstract | Links | BibTeX)

The Environment Monitoring Unit (EMU) is a radiation monitor designed and built for use in the Galileo orbit. Its design is based on the Giove-A MERLIN and the Cosmic Radiation Environment and Dosimetry (CREDO) instruments. It is manufactured by Thales-Alenia Space, Switzerland.

EMU consists of four separate sensors:

  • a set of 8 charge collection plates for measuring internal charging currents under shielding;
  • 8 Proton telescopes for measuring energetic proton fluxes;
  • an Linear Energy Transfer (LET) heavy ion sensor;
  • RadFETS for measuring internal doses inside the instrument.

Two instruments have been flown on the Galileo satellites GSAT207 and GSAT215.