BackForwardInstrument:  FUV/GEO 

Instrument details
Acronym FUV/GEO
Full name Far Ultraviolet Imager / Geocorona Photometer
Purpose To measure the hydrogen Lyman-alpha emission of the neutral atmosphere
Short description Three photometers operating over the H Lyman-alpha wavelength (121.6 nm), with an additional O2 gas cell providing an excellent throughput of the hydrogen radiation and simultaneously rejecting the photons at 130.4 nm from excited neutral oxygen. The temporal resolution between two complete measurements around 360º is 120 s.
Background Associated to FUV / WCI (Wideband Imaging Camera and FUV / SI (Spectrographic Imager)
Scanning Technique Volumetric exploration of the magnetosphere as the satellite moves along the polar Highly Eliptical Orbit. The three photometers have fields of view of 1º x 1º looking into three different directions perpendicular to the spin axis of the satellite and tilted by ±28º.
Coverage / Cycle Full interplanetary space including the magnetosphere at 2-min intervals
Mass Power Data Rate


Providing Agency NASA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 2000 to 2005-12-15
Last update: 2016-03-10
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 No WIGOS subcomponents have been defined.
Mission objectives
Secondary mission objectives
  • Heliospheric image
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Tentative 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
VariableRelevance for measuring this variableOperational limitationsExplanation
Heliospheric image3 - highNo specific limitation.Interplanetary space viewing in the H-Lyman-alpha line (121.6 nm)