BackForwardInstrument:  MDI 

Instrument details
Acronym MDI
Full name Michelson Doppler Imager
Purpose High resolution imaging of velocity oscillations, indicators of Sun's internal processes
Short description Imaging spectrometer to measure line-of-sight velocity by Doppler shift of Ni I 6768 Å line profile, transverse velocity by local correlation tracking, line and continuum intensity, and line-of-sight magnetic fields
Background Part of a package of instruments to observe the solar atmosphere
Scanning Technique Sun pointing from the L1 Lagrange libration point
Resolution 1000 km at Sun surface
Coverage / Cycle Full solar disk at 1 min intervals
Mass Power Data Rate 40 kbps

 

Providing Agency NASA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 1996 to ≥2025
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
  • Solar activity monitor
WIGOS Subcomponents
  • 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 VIS spectrometer [from L1, GEO, LEO]
  • Solar VIS imager [from L1, GEO, LEO]
  • Solar magnetic field sensor [from L1, GEO, LEO]
  • Solar electric field sensor [from L1, GEO, LEO]
  • Solar velocity field sensor [from L1, GEO, LEO]
Mission objectives
Primary mission objectives
  • Solar electric field
  • Solar magnetic field
  • Solar velocity fields
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 VIS flux spectrum1 - primaryNo specific limitation.High spectral resolution, moderate dynamic range, polarimetry and Doppler shift exploited
Solar VIS image1 - primaryNo specific limitation.Spectrometry with high spatial resolution, polarimetry and Doppler shift exploited
Solar magnetic field*1 - primaryNo specific limitation.Spectrometry with high spatial resolution, polarimetry and Doppler shift exploited
Solar electric field*1 - primaryNo specific limitation.Spectrometry with high spatial resolution, polarimetry and Doppler shift exploited
Solar velocity fields*1 - primaryNo specific limitation.Spectrometry with high spatial resolution, polarimetry and Doppler shift exploited