BackForwardInstrument:  MIRAS 

Instrument details
Acronym MIRAS
Full name Microwave Imaging Radiometer using Aperture Synthesis
Purpose Ocean salinity, soil moisture, space weather
Short description Frequency: 1.413 GHz with synthetic-aperture antenna.  Several polarimetric modes.
Background New development
Scanning Technique Pushbroom.  Correlation interferometry is implemented among receiver arrays deployed on the three arms of an “Y” shaped antenna.  A swath of 1000 km is implemented
Resolution 50 km basic, to be degraded depending on the desired accuracy for salinity measurements
Coverage / Cycle Global coverage in 3 days (soil moisture).  Average over more weeks is needed depending on the desired accuracy for salinity measurements
Mass 355 kg Power 511 W Data Rate 89 kbps


Providing Agency ESA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 2010 to 2025
Last update: 2023-12-18
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
  • Passive microwave radiometer
  • Cross-track, special or non-scanning microwave radiometer
WIGOS Subcomponents
  • Subcomponent 1
  • Low-frequency MW imagery
  • Low-frequency MW imager
Mission objectives
Primary mission objectives
  • Sea surface salinity
  • Soil moisture (in the roots region)
  • Soil moisture at surface
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
Sea surface salinity*2 - very highNo specific limitation.MW L-band radiometer (1.4 GHz)
Soil moisture (in the roots region)*1 - primaryCoarse spatial resolution.MW channels around 1.4 GHz
Soil moisture at surface*1 - primaryCoarse spatial resolution.MW channels around 1.4 GHz