BackForwardInstrument:  GeoSTAR 

Instrument details
Acronym GeoSTAR
Full name Geostationary Synthetic Thinned-Aperture Radiometer
Purpose Frequent MW temperature and humidity sounding. Also precipitation
Short description Synthetic aperture antenna, three arms in Y-shape configuration inscribed in 6-m diameter. Bands: 54 GHz for temperature and 183 GHz for humidity
Background Technological development. A reduced-scale model, called GeoSTAR-light, is now being studied for a "GeoStorm" mission
Scanning Technique Non-scanning. Full-disk image synthetised from arrays of 300 spectrometers (54 GHz) or 600 spectrometers (183 GHz)
Resolution 50 km s.s.p. at 54 GHz, 25 km s.s.p. at 183 GHz
Coverage / Cycle Full disk in 1 hour
Mass Power Data Rate

 

Providing Agency NASA
Instrument Maturity Demonstration pending
Utilization Period: TBD
Last update: 2012-09-04
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
Mission objectives
Primary mission objectives
  • Accumulated precipitation (over 24 h)
  • Atmospheric temperature
  • Precipitation intensity at surface (liquid or solid)
  • Specific humidity
Secondary mission objectives
  • Cloud ice Total Column
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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
Accumulated precipitation (over 24 h)1 - primaryNo specific limitation.MW channels in 54 and 183 GHz bands. Frequent sampling (GEO) is essential for accumulated precipitation
Atmospheric temperature1 - primaryCoarse vertical resolution.Many MW channels in the 54 GHz band. Nearly all-weather sounding. Frequent sampling (GEO) enables monitoring instability onset
Cloud drop effective radius2 - very highNo specific limitation.MW channels in 54 and 183 GHz bands. Frequent sampling (GEO) enables growth monitoring
Cloud ice3 - highNo specific limitation.MW channels in 54 and 183 GHz bands. Frequent sampling (GEO) enables growth monitoring
Cloud ice Total Column3 - highNo specific limitation.MW channels in 54 and 183 GHz bands. Frequent sampling (GEO) enables growth monitoring
Cloud ice effective radius2 - very highNo specific limitation.MW channels in bands 54 and 183 GHz. Frequent sampling (GEO) enables growth monitoring
Cloud liquid water (CLW)2 - very highNo specific limitation.MW channels in bands 54 and 183 GHz. Frequent sampling (GEO) enables growth monitoring
Cloud liquid water (CLW) total column2 - very highNo specific limitation.MW channels in bands 54 and 183 GHz. Frequent sampling (GEO) enables growth monitoring
Downward long-wave irradiance at Earth surface5 - marginalHighly indirect.MW channels in bands 54 and 183 GHz to account for downward cloud radiation
Freezing level height in clouds3 - highNo specific limitation.MW channels in the 54 GHz band. Inference from the temperature profile
Melting layer depth in clouds3 - highNo specific limitation.MW channels in the 54 GHz band. Inference from the temperature profile
Precipitation intensity at surface (liquid or solid)1 - primaryNo specific limitation.MW channels in the 54 and 183 GHz bands. Suitable for solid and liquid precipitation over sea and land, Insensitive to surface emissivity. Frequent sampling (GEO) consistent with precipitation temporal variability
Specific humidity2 - very highCoarse vertical resolution.MW channels in the 183 GHz band, and 54 GHz for temperature and liquid water corrections. Frequent sampling (GEO) enables monitoring instability onset
Integrated Water Vapour (IWV)2 - very highNo specific limitation.MW channels in the water vapour band around 183 GHz
Upward long-wave irradiance at Earth surface5 - marginalHighly indirect.MW channels is the 54 and 183 GHz bands to infer the impact of clouds on the upward LW radiation