BackForwardInstrument:  GLOWS 

Instrument details
Acronym GLOWS
Full name GLObal solar Wind Structure
Purpose GLOWS measures hydrogen and helium using the heliospheric resonant backscatter glow of hydrogen (the Lyman-α line at 121.6 nm) and helium (at 58.4 nm).
Short description GLOWS consists of two separate detectors: LαD and HeD for the two spectral channels,with the lines of sight directed at different angles with respect to the IMAP rotation axis.
Background Similar to detectors on TWINS.
Scanning Technique Almost-full-sky map per 6 months for Lyman alpha ±20º x 360º; Belt around ecliptic for He I 58.4 nm per 6 months
Coverage / Cycle LαD: 2 hr for 4º Belt, almost great circle Sun-centered; HeD: 2 hr for 4º Belt, 40º in diameter Sun-centered
Mass Power Data Rate


Providing Agency NASA
Instrument Maturity Flown on operational programme
Utilization Period: TBD
Last update: 2023-02-20
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 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]
Mission objectives
Primary mission objectives
  • Solar Lyman-alpha 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
EUV flux4 - fairNo specific limitation.Interplanetary space viewing, moderate dynamic range