BackForwardInstrument:  SAR 

Instrument details
Acronym SAR
Full name Synthetic Aperture Radar
Purpose High-resolution all-weather multi-purpose imager for ocean, land and ice
Short description L-band SAR, frequency 1.275 GHz, polarisation HH
Background First SAR in space
Scanning Technique Pushbroom, side-looking, 20 to 26 degrees, swath 100 km, 290 km off-nadir
Resolution 25 m
Coverage / Cycle Global in 4 months (duty cycle 10 %) or less by strategic activation
Mass 147 kg Power 216 W Data Rate 20 MHz (analogue, S-band at 2.265 GHz)

 

Providing Agency NASA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 1978 to 1978-10-10
Last update: 2012-09-12
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
  • Imaging radar (SAR)
Mission objectives
Primary mission objectives
  • Biomass
  • Fraction of vegetated land
  • Land cover
  • Land surface topography
  • Oil spill cover
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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
Biomass3 - highIndex only.. Infrequent coverage.L-band sensitive to total biomass
Dominant wave direction3 - highInfrequent coverage.L-band SAR. Variable measured by spectral analysis of "imagettes"
Dominant wave period3 - highInfrequent coverage.L-band SAR. Variable measured by spectral analysis of "imagettes"
Fire fractional cover3 - highInfrequent coverage.L-band SAR. High resolution, for fire boundary detection
Fraction of vegetated land3 - highNo specific limitation.L-band SAR
Glacier cover3 - highLong time for mapping.L-band SAR for accurate boundary detection
Glacier motion3 - highInfrequent coverage.L-band SAR for interferometry between images taken at time intervals
Glacier topography3 - highLong time for mapping.L-band SAR for interferometry between images taken at time intervals
Ice sheet topography3 - highLong time for mapping.L-band SAR for interferometry between images taken at time intervals
Land cover4 - fairNo specific limitation.L-band SAR
Land surface topography2 - very highLong time for mapping.L-band SAR for interferometry between images taken at time intervals
Oil spill cover3 - highInfrequent coverage.L-band SAR
Sea-ice cover1 - primaryNo specific limitation.L-band SAR
Sea-ice elevation4 - fairNo specific limitation.L-band SAR. Sea ice elevation measured by interferometry
Sea-ice thickness5 - marginalChange detection only.L-band SAR. Sea ice elevation measured by interferometry. Thickness inferred by ice model
Sea-ice type3 - highNo specific limitation.L-band SAR. Type interpreted as age/roughness
Significant wave height5 - marginalHighly indirect.. Infrequent coverage.L-band SAR. Retrieved by spectral analysis of "imagettes". Boundary condition necessary for the retrieval
Snow water equivalent4 - fairChange detection only.. Infrequent coverage.L-band SAR. SWE is retrieved by grigging with data from ground networks
Soil moisture (in the roots region)4 - fairInfrequent coverage.L-band SAR
Soil moisture at surface3 - highInfrequent coverage.L-band SAR
Soil type5 - marginalNo specific limitation.L-band SAR
Vegetation type5 - marginalNo specific limitation.L-band SAR
Wave directional energy frequency spectrum3 - highInfrequent coverage.L-band SAR. Variable measured by spectral analysis of "imagettes"