BackForwardInstrument:  MUSI 

Instrument details
Acronym MUSI
Full name Multiband Ionospheric Ultra-Violet Spectrum Imager
Purpose To measure the daytime atomic–molecular ratio and the nightime ionospheric density altitude distribution
Short description Detailed description not yet available. The instrument collects spectral images of Earth’s UV emission from 132 to 162 nm, with resolution <2 nm
Background New development
Scanning Technique Earth's disk scanning with the field of view 14°× 0.08° at a 66.7(night) or 6.7 (day) minute cadence.
Resolution 14°× 0.08° at the s.s.p.
Coverage / Cycle Earth's disk sampling at 66.7 min rate in nightime and 6.7 min rate in daytime
Mass Power Data Rate


Providing Agency CMA
Instrument Maturity Flown on operational programme
Utilization Period: 2025 to 2040
Last update: 2021-12-09
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
  • Space radiometer or spectrometer
WIGOS Subcomponents
  • Subcomponent 3
  • UV spectral imagery (e.g. GEO, HEO, MEO, LEO)
  • UV spectral imager [from GEO, HEO, MEO, LEO]
Mission objectives
Primary mission objectives
  • Ionospheric plasma density
  • UV 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
UV flux*2 - very highNo specific limitation.Earth's limb and surface observed, moderate dynamic range
UV sky image2 - very highNo specific limitation.Earth's limb observed, coarse spatial resolution
Ionospheric plasma density*5 - marginalNo specific limitation.UV imaging spectrometer measuring ionospheric plasma density in the Earth's limb
Electron Density5 - marginalNo specific limitation.UV spectrometry of the Earth's limb