BackForwardInstrument:  MWI (WSF-M) 

Instrument details
Acronym MWI (WSF-M)
Full name MicroWave Imager on WSF-M
Purpose - A follow-on for the DoD Windsat radiometer - Primarily to measure ocean surface winds and tropical cyclones
Short description

A conical scanning microwave radiometer with a 1.8m antenna It measures at 6 different frequencies in the 10 to 89 GHz range (see below for details) 3 channels have full polarimetric capability (see below) resulting in 17 channels overall. The 3rd and 4th stokes vectors are obtained by digitally sampling and cross-correlating v-pol and h-pol amplitude signals. More information here
Background

This is a new development to support the U.S. Defence program.
Scanning Technique

Conically scanning
Resolution 38x23 km at 10 GHz 15x10 km at 89 GHz
Coverage / Cycle
Mass Power Data Rate

 

Providing Agency DoD
Instrument Maturity Flown on operational programme
Utilization Period: 2024 to 2035
Last update: 2024-04-12
Detailed characteristics
Channel

Centre frequency (GHz)

Bandwidth (MHz)

 Polarisations Beamwidth (deg) 3dB footprint(km) NEΔT

1

 10.85 500 V,H,3rd,4th 1.06 38x23
2 18.85 500 V,H,3rd,4th 0.66 23x15
3 23.8 370 V,H 0.58 21x13
4 36.75 500 V,H,3rd,4th 0.43 15x10
5 37.3 <2500 V,H 0.43 15x10
6 89 <6000 V,H 0.43 15x10
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
  • Conical scanning microwave radiometer
WIGOS Subcomponents
  • Subcomponent 1
  • MW imagery [in SSO]
  • MW imager [in SSO]
Mission objectives
Primary mission objectives
  • Precipitation intensity at surface (liquid or solid)
  • Wind speed (near surface)
  • Wind vector (near 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
Accumulated precipitation4 - fairPoor time sampling.. Time sampling to be interpolated by GEO.MW channels around 10, 19, 23, 37 and 90 GHz
Cloud liquid water (CLW)3 - highNo specific limitation.MW channels around 37 and 90 GHz
Cloud liquid water (CLW) total column3 - highNo specific limitation.MW channels around 37 and 90 GHz
Land surface temperature5 - marginalCoarse spatial resolution.MW channels around 10 GHz
Long-wave Earth surface emissivity4 - fairLong time series needed.MW channels around 10, 19, 37 and 90 GHz. Emissivity across this MW range inferred by statistical analysis
Precipitation intensity at surface (liquid or solid)*4 - fairNo specific limitation.MW channels around 10, 19, 23, 37 and 90 GHz, to cover sea and land, heavy and light precipitation
Sea surface temperature5 - marginalWarm temperature only.MW channels around 10 GHz
Sea-ice cover3 - highNo specific limitation.MW channels around 10, 19, 37 and 90 GHz
Sea-ice type4 - fairNo specific limitation.MW channels around 10, 19, 37 and 90 GHz. Type interpreted as age/roughness
Snow cover3 - highCoarse spatial resolution.MW channels around 19, 37 and 90 GHz. Higher frequencies less sensitive to emissivity from ground under snow
Snow status (wet/dry)2 - very highCoarse spatial resolution.MW channels around 19, 37 and 90 GHz. Higher frequencies less sensitive to emissivity from ground under snow
Snow water equivalent2 - very highCoarse spatial resolution.. Ground stations network needed.MW channels around 19, 37 and 90 GHz. Higher frequencies less sensitive to emissivity from ground under snow
Soil moisture at surface3 - highCoarse spatial resolution.. Strongly affected by vegetation.MW channels around 10 GHz
Integrated Water Vapour (IWV)3 - highOver sea only.MW channel(s) in the water vapour band around 23 GHz
Wind speed (near surface)*3 - highOver sea only.MW channels around 10, 19 and 37 GHz
Wind vector (near surface)*3 - highOver sea only.MW channels for 3 or 4 Stokes parameters at frequencies around 10, 19 and 37 GHz