BackForwardInstrument:  SEM/SSJ4 

Instrument details
Acronym SEM/SSJ4
Full name SEM / Special Sensor Precipitating Electron and Ion Spectrometer - 4
Purpose Measurement of transfer energy, mass, and momentum of charged particles through the magnetosphere-ionosphere in the Earth's magnetic field
Short description Electrostatic analyzer for electrons protons and alpha-particles in the energy range 0.03-30 keV
Background Part of the SEM (Space Environment Monitor) package
Scanning Technique N/A (in-situ in the platform environment)
Resolution N/A
Coverage / Cycle N/A
Mass Power Data Rate

 

Providing Agency DoD
Instrument Maturity Flown on operational programme
Utilization Period: 1976-12-11 to 2018
Last update: 2017-06-04
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
Mission objectives
Primary mission objectives
  • Alpha particles differential directional flux
  • Electron differential directional flux
  • Proton differential directional flux
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Tentative 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
VariableRelevance for measuring this variableOperational limitationsExplanation
Electron differential directional flux5 - marginalNo specific limitation.Platform environment, low energy (up to 40 keV)
Proton differential directional flux5 - marginalNo specific limitation.Platform environment, low energy (up to 40 keV)
Alpha particles differential directional flux5 - marginalNo specific limitation.Platform environment. Low-medium energy range (<10 up to 100 MeV/n)