BackForwardInstrument:  UVCS 

Instrument details
Acronym UVCS
Full name UV Coronagraph and Spectrometer
Purpose Study of electron and ion temperatures, densities and velocities in the corona, for interpretation of coronal heating, solar wind acceleration, and solar wind composition
Short description Assemblage of an occultation telescope and a high resolution spectrometer. 3 sections: one in the 114.8-124.8 nm inclusive of the Lyman-alpha line at 121.6 nm; one for line intensity measurements in the range 49.9-106.8 nm. one is used to measure polarized radiance of the visible corona
Background Part of a package of instruments to observe the solar atmosphere
Scanning Technique Sun pointing from the L1 Lagrange libration point. Corona view included
Resolution 15000 km at the Sun surface for most of the EUV range, 7500 km for the Lyman-alpha range
Coverage / Cycle Full Sun disk in about 10 s
Mass Power Data Rate


Providing Agency NASA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 1996 to 2013
Last update: 2021-11-09
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
  • Solar coronagraph and radio- spectrograph, at L1
  • Solar coronographic imager at L1
  • 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 EUV spectrometer [from L1, GEO, LEO]
  • Solar coronagraph and heliospheric imagery both on the Earth-Sun line and off the Earth-Sun line (e.g. L5 point)
  • Solar coronographic imager [from L1, GEO, LEO]
Mission objectives
Primary mission objectives
  • Solar coronagraphic image
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 EUV flux spectrum3 - highLimited to the solar corona.Coarse spectral resolution EUV, solar disc occulted
Solar Lyman-alpha flux3 - highLimited to the solar corona.H-Ly-alpha at 121.6 nm (EUV/UV boundary), solar disc occulted
Solar coronagraphic image*1 - primaryNo specific limitation.H-Ly-alpha at 121.6 nm (EUV/UV boundary), observed with occultation