BackForwardInstrument:  XRP 

Instrument details
Acronym XRP
Full name Soft X-Ray Polychromator
Purpose Investigation of those aspects of solar activity that lead to the production of plasma temperatures in the 1.5 to 50 million degree range
Short description Assemblage of two instruments: 1) BCS (Bent-Crystal Spectrometer), to obtain spectra in the range 2-3 Å, at a resolving power λ/Δλ of about 10,000 with eight position-sensitive proportional counters; and 2) FCS (Flat-Crystal Spectrometer), able to rotate its crystals to provide its seven detectors with access to the spectral range 1.40-22.43 Å.
Background New development
Scanning Technique Sun pointing from a low-inclination LEO. BCS with imaging capability by a collimator field of view of 6 arcsec
Resolution BCS: 4400 km at Sun surface
Coverage / Cycle FCS: full solar disk, BCS: selected areas; at 10 s intervals
Mass Power Data Rate


Providing Agency UKSA
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 magnetograph, solar EUV/X-ray imagery and EUV/X-ray irradiance, both on the Earth-Sun line and off the Earth-Sun line
  • Solar X-ray imager [from L1, GEO, LEO]
Mission objectives
Primary mission objectives
  • Solar X-ray flux spectrum
  • Solar X-ray 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
Solar X-ray flux spectrum*2 - very highNo specific limitation.High spectral resolution, moderate dynamic range
Solar X-ray image*2 - very highNo specific limitation.Spectrometry with coarse spatial resolution