BackForwardInstrument:  TMS 

Instrument details
Acronym TMS
Full name TROPICS Millimeter-wave Sounder
Purpose To provide frequent all-weather temperature and humidity profiles
Short description 12 MW channels total split into 1) 7 channels in the O2 118 GHz band, 2) 3 channels in the H2O 183 GHz band, 3) 2 window channel at 90 and 205 GHz respectively [see details below]
Background New development
Scanning Technique Cross-track, swath about 2200 km
Resolution Depending on frequency (see table)
Coverage / Cycle Limited by the satellite low inclination (30°). Average cycle by 7 satellites in 3 orbital planes: 45 min
Mass Power Data Rate

 

Providing Agency NASA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 2021 to 2032
Last update: 2023-05-15
Detailed characteristics

No.

Central frequency

Bandwidth

Effective resolution across scan

NE∆T

1

91.655 ± 1.4 GHz

1000 MHz

50.7 km

0.95 K

2

114.50 GHz

1000 MHz

41.2 km

0.55 K

3

115.95 GHz

800 MHz

41.2 km

0.60 K

4

116.65 GHz

600 MHz

41.2 km

0.70 K

5

117.25 GHz

600 MHz

41.2 km

0.70 K

6

117.80 GHz

500 MHz

41.2 km

0.75 K

7

118.24 GHz

380 MHz

41.2 km

0.85 K

8

118.58 GHz

300 MHz

41.2 km

1.00 K

9

184.41 GHz

2000 MHz

27.5 km

0.60 K

10

186.51 GHz

2000 MHz

27.5 km

0.60 K

11

190.31 GHz

2000 MHz

27.5 km

0.60 K

12

204.8 GHz

2000 MHz

26.0 km

0.60 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
  • Subcomponent 2
  • Constellation of high-temporal frequency MW sounding
  • Constellation of high-temporal frequency MW sounders
Mission objectives
Primary mission objectives
  • Atmospheric temperature
  • Cloud ice
  • Integrated Water Vapour (IWV)
  • Precipitation intensity at surface (liquid or solid)
  • Specific humidity
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
Atmospheric temperature*2 - very highCoarse vertical resolution.. Inaccurate in low troposphere.Many MW channels in the 118 GHz band. Nearly all-weather sounding
Cloud drop effective radius5 - marginalHighly indirect.MW channels around 90 GHz, and in 183 GHz band
Cloud ice*1 - primaryNo specific limitation.Channels above 200 GHz have more sensitivity to ice cloud
Cloud ice Total Column1 - primaryNo specific limitation.Channels above 200 GHz have more sensitivity to ice cloud
Cloud ice effective radius3 - 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 118 and 183 GHz bands to account for downward cloud radiation
Precipitation intensity at surface (liquid or solid)*4 - fairNo specific limitation.MW channels in the 118 and 183 GHz bands. Suitable for solid and, to a less extent, liquid precipitation over sea and land, Insensitive to surface emissivity
Specific humidity*2 - very highCoarse vertical resolution.MW channels in the 183 GHz band, and 118 GHz for temperature and ice water corrections
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 118 and 183 GHz bands to infer the impact of clouds on the upward LW radiation