BackForwardInstrument:  Altimeter (COMPIRA) 

Instrument details
Acronym Altimeter (COMPIRA)
Full name Altimeter
Purpose Ocean topography, significant wave height, wind speed on sea surface; specific to sea-surface height
Short description Two frequencies (around 5.3 and 13.5 GHz)
Background Consolidated technology. Associated with SHIOSAI to implement the COMPIRA mission
Scanning Technique Nadir-only viewing, continuous sampling along track
Resolution 20 km
Coverage / Cycle Global coverage in 2 weeks for 70-km cells
Mass Power Data Rate

 

Providing Agency JAXA
Instrument Maturity Backed by strong heritage
Utilization Period: ≥2020 to ≥2025
Last update: 2014-04-12
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
  • Active and radio-occultation sensor
  • Radar altimeter
Mission objectives
Primary mission objectives
  • Geoid
  • Ocean dynamic topography
  • Significant wave height
Secondary mission objectives
  • Coastal sea level (tide)
  • Gravity field
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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
Coastal sea level (tide)2 - very highAlong-track only.Dual-frequency radar altimeter: Ku-band and supporting S-band or C-band to correct for ionospheric rotation
Geoid2 - very highLong time series needed.. Along-track only.Geoid derived from multi-temporal analysis of radar altimetry data
Gravity field4 - fairPartial information (geoid).. Along-track only.Gravity field derived from multi-temporal analysis of radar altimetry data
Ocean dynamic topography2 - very highLong time for mapping.. Along-track only.Dual-freqency altimeter: Ku-band and supporting S-band or C-band to correct for ionospheric rotation
Significant wave height2 - very highAlong-track only.Ku-band radar altimeter
Wind speed (near surface)5 - marginalOver sea only.. Along-track only.Radar altimeter. Wind speed estimated from the intensity of the backscattered signals
Ionospheric Vertical Total Electron Content (VTEC)4 - fairAlong-track only.Dual-frequency altimeter: Ku-band and supporting S-band or C-band to correct for ionospheric rotation