BackForwardInstrument:  CP 

Instrument details
Acronym CP
Full name Coronagraph/Polarimeter
Purpose Corona change monitoring over time; observation of the corona's large-scale magnetic structures and their evolution
Short description Externally occulted Lyot coronagraph with a vidicon detector. Images of the corona are built up in four quadrants by means of sector mirrors (spectral range: 4465-6385 Å in 7 bands). In addition, with seven filters and three polaroids with principal axes 60º apart, the CP is able to obtain measurements of coronal electron densities and distinguish ejected material from coronal features at chromospheric temperatures
Background New development
Scanning Technique Sun pointing from a low-inclination LEO drifting orbit. Corona view included
Resolution 7300 km at Sun surface
Coverage / Cycle Full solar corona in about 10 s
Mass Power Data Rate


Providing Agency NASA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 1980 to 1989
Last update: 2017-05-19
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
  • Solar activity monitor
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)
  • Solar coronographic imager [from L1, GEO, LEO]
Mission objectives
Primary mission objectives
  • Solar electric field
  • Solar magnetic field
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
Solar VIS flux1 - primaryLimited to the solar corona.Wide dynamic range, solar disc occulted, polarisation capability
Solar magnetic field*4 - fairLimited to the solar corona.Fluxmetry with coarse spatial resolution, polarimetry exploited, solar disc occulted
Solar electric field*3 - highLimited to the solar corona.Fluxmetry with coarse spatial resolution, polarimetry exploited, corona view included
Solar coronagraphic image2 - very highNo specific limitation.VIS (400-700 nm), observed with occultation