BackForwardInstrument:  SRAL 

Instrument details
Acronym SRAL
Full name Synthetic aperture Radar Altimeter
Purpose Ocean and ice topography, significant wave height, wind speed on sea surface
Short description
  • Dual-frequency (5.4 and 13.58 GHz); SAR capability along-track for high spatial resolution
  • Monitoring and calibration information here
Background

Evolution of SIRAL flown on CryoSat-2
Scanning Technique

No scanning.  SAR mode possible to be activated, depending on the target area
Resolution 20 km IFOV.  When used in SAR mode, the along-track resolution is 300 m
Coverage / Cycle Global coverage in 1 month for 30 km average spacing, or in 10 days for 100 km average spacing
Mass 60 kg Power 90 W Data Rate 100 kbps, 12 Mbps (SAR)

 

Providing Agency ESA
Instrument Maturity Backed by strong heritage
Utilization Period: 2016 to 2038
Last update: 2024-09-23
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
WIGOS Subcomponents
  • Subcomponent 1
  • Wide-swath radar altimeters, and high altitude, inclined, high-precision orbit altimeters
  • Conventional radar altimeter
  • Subcomponent 2
  • Magnetospheric energetic particles and magnetometers
  • Ionospheric total electron content sensor [at LEO and cross magnetosphere]
Mission objectives
Primary mission objectives
  • Geoid
  • Ocean dynamic topography
  • Significant wave height
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
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
Geoid*2 - 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 topography*2 - 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
Sea-ice elevation2 - very highAlong-track only.Ku-band radar altimeter with supporting S- or C-band and along-track SAR capability for accurate ice border detection and differential ice-sea height measurement
Sea-ice thickness2 - very highChange detection only.. Along-track only.Ku-band radar altimeter with supporting S- or C-band and along-track SAR capability for accurate ice border detection and differential ice-sea height measurement. Thickness inferred by ice model
Significant wave height*2 - 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 Total Electron Content (TEC)4 - fairAlong-track only.Dual-frequency altimeter: Ku-band and supporting S-band or C-band to correct for ionospheric rotation