BackForwardInstrument:  SWAN 

Instrument details
Acronym SWAN
Full name Solar Wind Anisotropies
Purpose Observation of solar wind mass flux anisotropies
Short description Lyman photometer (spectral range: 115-180 nm) which maps the sky's interplanetary hydrogen emission almost entirely every other day. From these sky maps, the latitude distribution of the solar wind mass flux from the equator to the pole can be measured, as well as the variation of this distribution on a time scale of one month
Background Part of a package of instruments to observe the solar atmosphere
Scanning Technique Scanning the whole solid angle (by two back-to-back units) except the Sun, from the L1 Lagrange libration point
Coverage / Cycle Full sky except Sun, every other day
Mass 13.25 kg Power 11 W Data Rate 200 bps


Providing Agency CNES
Instrument Maturity Flown on an R&D satellite
Utilization Period: 1996 to ≥2025
Last update: 2021-09-29
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 coronagraph and heliospheric imagery both on the Earth-Sun line and off the Earth-Sun line (e.g. L5 point)
  • Heliospheric imager [from L1, GEO, LEO]
Mission objectives
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
Heliospheric image3 - highNo specific limitation.Interplanetary space viewing in the H-Lyman-alpha line (121.6 nm)