BackForwardInstrument:  DIFOS 

Instrument details
Acronym DIFOS
Full name Solar Flux Optical Photometer
Purpose Observation of global solar irradiance oscillations
Short description Three-channel radiometer: one for total irradiance (0.4-1.0 μm), one around 0.55 μm with bandwidth 0.1 μm, one around 0.75 μm with bandwidth 0.1 μm. Time resolution 16 s
Background Consolidated technology
Scanning Technique Sun pointing
Resolution N/A
Coverage / Cycle Full Sun disk
Mass 6 kg Power 18 W Data Rate


Providing Agency Roscosmos
Instrument Maturity Flown on an R&D satellite
Utilization Period: 1994 to 2005
Last update: 2016-11-07
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
  • Earth observation instrument
  • Passive optical radiometer or spectrometer
  • Solar irradiance monitor
WIGOS Subcomponents
  • Subcomponent 1
  • Absolutely calibrated broadband radiometers, and TSI and SSI radiometers
  • TSI and SSI radiometers (for solar irradiance)
Mission objectives
Primary mission objectives
  • Downward short-wave irradiance at TOA
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
Downward short-wave irradiance at TOA*4 - fairNo specific limitation.TSI over the range UV, VIS and part of NIR