BackForwardInstrument:  SEM (GMS) 

Instrument details
Acronym SEM (GMS)
Full name Space Environment Monitor
Purpose To measures solar particles: protons, alpha and electrons
Short description Spectral bands: 1-500 MeV (protons); 8-390 MeV (alpha particles); >2 MeV (electrons)
Background Consolidated technology
Scanning Technique N/A (in-situ in the platform environment)
Resolution N/A
Coverage / Cycle N/A
Mass Power Data Rate


Providing Agency JMA
Instrument Maturity Flown on operational programme
Utilization Period: 1977 to 2000
Last update: 2017-07-25
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
  • Alpha-particle sensor at GEO
Mission objectives
Primary mission objectives
  • Alpha particles integral directional flux
  • 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, high energy (over 400 keV)
Proton integral directional flux*5 - marginalNo specific limitation.Platform environment, medium and high energy (over 40 to over 1000 keV)
Alpha particles integral directional flux*5 - marginalNo specific limitation.Platform environment. Low-medium energy range (<10 up to 100 MeV/n)