BackForwardInstrument:  SAR-C (Sentinel-1) 

Instrument details
Acronym SAR-C (Sentinel-1)
Full name Synthetic Aperture Radar (C-band)
Purpose High-resolution all-weather multi-purpose imager for ocean, land and ice
Short description C-band SAR, frequency 5.405 GHz, multi-polarisation and variable swath/resolution [see detailed characteristics below]
Background New development
Scanning Technique Side-looking, 15-45° off-nadir, swath 80 to 400 km, depending on operation mode - See table
Resolution 4 m to 80 m, depending on operation mode - See table
Coverage / Cycle Global coverage in 5 day for the ‘Extra-wide swath’ mode (duty cycle 70 %); in longer periods for other operation modes (duty cycle 30 %), up to 3 months
Mass 880 kg Power 4400 W Data Rate 600 Mbps

 

Providing Agency ESA
Instrument Maturity Backed by strong heritage
Utilization Period: 2014 to 2035
Last update: 2021-06-15
Detailed characteristics
Operation mode Resolution Swath Polarisation

Stripmap (SM)

 4 x 5 m2 80 km VV + VH or HH + HV

ScanSAR - Interferometric wide-swath (IW)

 5 x 20 m2 240 km VV + VH or HH + HV

ScanSAR - Extra-wide swath (EW)

 25 x 80 m2 400 km VV + VH or HH + HV

Wave (WV)

 20 x 5 m2 20 x 20 km2 every 100 km HH or VV
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
  • Imaging radar (SAR)
WIGOS Subcomponents
  • Subcomponent 1
  • SAR imagers and altimeters
  • SAR imager
Mission objectives
Primary mission objectives
  • Glacier cover
  • Glacier motion
  • Glacier topography
  • Ice sheet topography
  • Land surface topography
  • Sea-ice cover
  • Sea-ice type
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
Biomass3 - highIndex only.. Infrequent coverage.C-band sensitive to total biomass
Dominant wave direction3 - highInfrequent coverage.C-band SAR. Variable measured by spectral analysis of "imagettes"
Dominant wave period3 - highInfrequent coverage.C-band SAR. Variable measured by spectral analysis of "imagettes"
Fire fractional cover3 - highInfrequent coverage.C-band SAR. High resolution, for fire boundary detection
Fraction of vegetated land4 - fairNo specific limitation.C-band SAR
Glacier cover*2 - very highLong time for mapping.C-band SAR for accurate boundary detection
Glacier motion*3 - highInfrequent coverage.C-band SAR for interferometry between images taken at time intervals
Glacier topography*3 - highLong time for mapping.C-band SAR for interferometry between images taken at time intervals
Ice sheet topography*3 - highLong time for mapping.C-band SAR for interferometry between images taken at time intervals
Land cover4 - fairNo specific limitation.C-band SAR
Land surface topography*3 - highLong time for mapping.C-band SAR for interferometry between images taken at time intervals
Oil spill cover1 - primaryInfrequent coverage.C-band SAR
Significant wave height4 - fairHighly indirect.. Infrequent coverage.C-band SAR. Retrieved by spectral analysis of "imagettes". Boundary condition necessary for the retrieval
Snow cover3 - highThick snow only.. Infrequent coverage.C-band SAR
Snow status (wet/dry)5 - marginalThick snow only.. Infrequent coverage.C-band SAR
Snow water equivalent3 - highChange detection only.. Infrequent coverage.C-band SAR. SWE is retrieved by grigging with data from ground networks
Soil moisture (in the roots region)5 - marginalAffected by vegetation.. Infrequent coverage.C-band SAR. Assimilation process required
Soil moisture at surface3 - highAffected by vegetation.. Infrequent coverage.C-band SAR
Soil type4 - fairNo specific limitation.C-band SAR
Vegetation type5 - marginalNo specific limitation.C-band SAR
Wave directional energy frequency spectrum3 - highInfrequent coverage.C-band SAR. Variable measured by spectral analysis of "imagettes"
Sea-ice cover*1 - primaryNo specific limitation.C-band SAR
Sea-ice elevation4 - fairNo specific limitation.C-band SAR. Sea ice elevation measured by interferometry
Sea-ice thickness4 - fairChange detection only.C-band SAR. Sea ice elevation measured by interferometry. Thickness inferred by ice model
Sea-ice type*2 - very highNo specific limitation.C-band SAR. Type interpreted as age/roughness