BackForwardInstrument:  AMI-SAR 

Instrument details
Acronym AMI-SAR
Full name Active Microwave Instrument - Synthetic Aperture Antenna
Purpose High-resolution all-weather multi-purpose imager for ocean, land and ice. Also wave spectra.
Short description C-band SAR, frequency 5.3 GHz, polarisation VV. Transmitter-receiver shared with scatterometer /AMI-Scat). Wave spectra achieved by processing SAR imagettes within the SAR swath. The AMI wave mode can be operated at the same time as the AMI-Scat mode [see detailed characteristics below]
Background One operating mode of AMI (Active Microwave Instrument) flown on ERS-1 and ERS-2
Scanning Technique Side-looking, 23° off-nadir, swath 100 km
Resolution 30 m
Coverage / Cycle Imagery: global coverage in 9 months average, depending on operation mode (duty cycle 12 %). Wave: global coverage in 1.5 months (duty cycle 70 %)
Mass 325.8 kg Power 4800 W Data Rate 105 Mbps

 

Providing Agency ESA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 1991 to 2011-07-06
Last update: 2012-09-05
Detailed characteristics

Operation mode

Resolution

Swath

Field of regard

Polarisation

Imaging

30 m

100 km

100 km

VV

Scatterometer (see AMI-Scat)

 

 

 

 

Wave

30 m

5 x 5 km2 imagettes sampled at 200-300 km intervals

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)
Mission objectives
Primary mission objectives
  • Glacier cover
  • Glacier motion
  • Glacier topography
  • Ice sheet topography
  • Land surface topography
Show allShow fewer
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
Biomass4 - fairIndex 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 cover2 - very highInfrequent coverage.C-band SAR. High resolution, for fire boundary detection
Fraction of vegetated land2 - very highNo specific limitation.C-band SAR
Glacier cover2 - very highLong time for mapping.C-band SAR for accurate boundary detection
Glacier motion3 - highInfrequent coverage.C-band SAR for interferometry between images taken at time intervals
Glacier topography3 - highLong time for mapping.C-band SAR for interferometry between images taken at time intervals
Ice sheet topography3 - highLong time for mapping.C-band SAR for interferometry between images taken at time intervals
Land cover3 - highNo specific limitation.C-band SAR
Land surface topography2 - very highLong time for mapping.C-band SAR for interferometry between images taken at time intervals
Oil spill cover2 - very highInfrequent coverage.C-band SAR
Sea-ice cover1 - primaryNo specific limitation.C-band SAR
Sea-ice elevation4 - fairNo specific limitation.C-band SAR. Sea ice elevation measured by interferometry
Sea-ice thickness5 - marginalChange detection only.C-band SAR. Sea ice elevation measured by interferometry. Thickness inferred by ice model
Sea-ice type3 - highNo specific limitation.C-band SAR. Type interpreted as age/roughness
Significant wave height5 - marginalHighly indirect.. Infrequent coverage.C-band SAR. Retrieved by spectral analysis of "imagettes". Boundary condition necessary for the retrieval
Snow cover4 - fairThick snow only.. Infrequent coverage.C-band SAR
Snow status (wet/dry)4 - fairThick snow only.. Infrequent coverage.C-band SAR
Snow water equivalent4 - fairChange 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 surface4 - fairAffected by vegetation.. Infrequent coverage.C-band SAR
Soil type4 - fairNo specific limitation.C-band SAR
Vegetation type4 - fairNo specific limitation.C-band SAR
Wave directional energy frequency spectrum3 - highInfrequent coverage.C-band SAR. Variable measured by spectral analysis of "imagettes"