BackForwardInstrument:  EMU 

Instrument details
Acronym EMU
Full name Environmental Monitor Unit
Purpose Monitoring fluxes of electrons and protons in the platform environment
Short description 8-channel particle counter to measure the fluxes of protons in the range 15-100 MeV and electrons in the range 0.2-5 MeV. Time resolution: 10 s
Background Also flown on Himawari 8 and 9 with the name SEDA (Space Environment Data Acquisition monitor)
Scanning Technique N/A (in-situ measurement in the platform environment)
Resolution N/A
Coverage / Cycle Field of view ± 39.35° for protons, ± 78.3° for electrons
Mass 3.5 kg Power 8 W Data Rate


Providing Agency ESA
Instrument Maturity Flown on operational programme
Utilization Period: 2012 to 2031
Last update: 2021-10-02
Detailed characteristics
Satellites this instrument is flying on

Note: a red tag indicates satellites no longer operational, a green tag indicates operational satellites, a blue tag indicates future satellites

Instrument classification
  • Solar and space environment monitors
  • Energetic particle spectrometer
WIGOS Subcomponents
  • Subcomponent 1
  • In-situ plasma probes, and energetic particle spectrometers and magnetometers at GEO and LEO, and magnetic field at GEO
  • Electron sensor at GEO
  • Proton sensor at GEO
Mission objectives
Primary mission objectives
  • Electron integral directional flux
  • Proton integral directional flux
Evaluation of Measurements

The following list indicates which measurements can typically be retrieved from this category of instrument. To see a full Gap Analysis by Variable, click on the respective variable.

Note: table can be sorted by clicking on the column headers
Note: * Primary mission objective.
VariableRelevance for measuring this variableOperational limitationsExplanation
Electron integral directional flux*5 - marginalNo specific limitation.Platform environment, medium and high energy (over 40 to over 400 keV)
Proton integral directional flux*5 - marginalNo specific limitation.Platform environment, high energy (over 1000 keV)