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Instrument details
Acronym SEE
Full name Solar Extreme Ultraviolet Experiment
Purpose Solar-terrestrial interactions - observation of solar soft X-ray, Extreme UV, and Far UV irradiance from 0.1 to 200 nm
Short description Two sub-systems: EGS (Extreme UV Grating Spectrograph), range 25-200 nm [including Fe-XV at 28.4 nm, He-II at 30.4 nm and H-Lyman-alpha at 121.6 nm], resolution 0.4 nm; and XPS (XUV Photometer System), range 0.1-40 nm, 12 channels wide 2-5 nm each
Background New development
Scanning Technique Sun pointing from a high-inclination LEO
Resolution N/A (full disk)
Coverage / Cycle Full solar disk at 10 s intervals
Mass 27 kg Power 27 W Data Rate 210 bps


Providing Agency NASA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 2002 to 2024
Last update: 2021-12-16
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
  • Solar activity monitor
WIGOS Subcomponents
  • Subcomponent 1
  • X-ray spectrograph on GEO orbit
  • X-ray spectrometer at LEO
  • Subcomponent 2
  • Solar magnetograph, solar EUV/X-ray imagery and EUV/X-ray irradiance, both on the Earth-Sun line and off the Earth-Sun line
  • Solar X-ray spectrometer [from L1, GEO, LEO]
  • Solar EUV spectrometer [from L1, GEO, LEO]
  • Subcomponent 3
  • UV spectral imagery (e.g. GEO, HEO, MEO, LEO)
  • X-ray spectrometer [from GEO, HEO, MEO, LEO]
  • EUV spectrometer [from GEO, HEO, MEO, LEO]
Mission objectives
Primary mission objectives
  • Solar EUV flux spectrum
  • Solar X-ray flux spectrum
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
Solar X-ray flux spectrum*1 - primaryNo specific limitation.High spectral resolution, wide dynamic range
Solar EUV flux spectrum*3 - highNo specific limitation.Coarse spectral resolution, wide dynamic range
Solar Lyman-alpha flux2 - very highNo specific limitation.H-Ly-alpha at 121.6 nm (EUV/UV boundary)