BackForwardInstrument:  SSM/T-2 

Instrument details
Acronym SSM/T-2
Full name Special Sensor Microwave - Humidity
Purpose Humidity sounding in nearly-all-weather conditions
Short description 5 channels MW radiometer covering the 183 GHz band [see detailed characteristics below]
Background New development
Scanning Technique Cross-track: 28 steps of 42 km ssp, swath 1500 km - Along-track: one 48-km line each 8 s
Resolution 48 km st s.s.p.
Coverage / Cycle Global coverage once/day
Mass 13.6 kg Power 26 W Data Rate 320 bps

 

Providing Agency DoD
Instrument Maturity Flown on operational programme
Utilization Period: 1992 to 2000-08-07
Last update: 2019-11-14
Detailed characteristics
No. Central frequency (GHz) Bandwidth (MHz) Polarisation NEΔT
4 91.655 ± 1.250 3000 H 0.6 K
5 150.0 ± 1.250 1500 H 0.6 K
3 183.31 ± 7.0 500 H 0.6 K
1 183.31 ± 3.0 1000 H 0.6 K
2 183.31 ± 1.0 1500 H 0.8 K
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 No WIGOS subcomponents have been defined.
Mission objectives
Primary mission objectives
  • Specific humidity
Secondary mission objectives
  • Cloud ice Total Column
  • Cloud liquid water (CLW) total column
  • Integrated Water Vapour (IWV)
  • Precipitation intensity at surface (liquid or solid)
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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
Cloud ice3 - highNo specific limitation.MW channels around 90 GHz, and in 183 GHz band
Cloud ice Total Column3 - highNo specific limitation.MW channels around 90 GHz, and in 183 GHz band
Cloud liquid water (CLW)3 - highNo specific limitation.MW channels around 90 GHz, and in 183 GHz band
Cloud liquid water (CLW) total column3 - highNo specific limitation.MW channels around 90 GHz, and in 183 GHz band
Downward long-wave irradiance at Earth surface5 - marginalHighly indirect.MW channels in 183 GHz band to account for downward cloud radiation
Precipitation intensity at surface (liquid or solid)5 - marginalNo specific limitation.MW channels in the 183 GHz band. Suitable for solid precipitation over sea and land, Insensitive to surface emissivity
Specific humidity3 - highCoarse vertical resolution.MW channels in the 183 GHz band
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 183 GHz band to infer the impact of clouds on the upward LW radiation
Cloud drop effective radius5 - marginalHighly indirect.MW channels around 90 GHz, and in 183 GHz band
Cloud ice effective radius3 - highNo specific limitation.MW channels around 90 GHz, and in 183 GHz band