BackForwardInstrument:  SMMR 

Instrument details
Acronym SMMR
Full name Scanning Multichannel Microwave Radiometer)
Purpose Multi-purpose MW imagery
Short description 5-frequency / 10-channel MW radiometer operating in the range 6.6-37 GHz [see detailed characteristics below]
Background Prototype of multi-channel conical scanning MW imagers
Scanning Technique Conical scanning, 15 rpm (26 km/line), 50.2° incidence angle, swath 780 km
Resolution Changing with frequency, ranging from 22 km at 37 GHz to 120 km at 6.6 GHz, consistent with a 80-cm antenna diameter
Coverage / Cycle Global in 2 days
Mass 52.3 kg Power 60 W Data Rate 2 kbps

 

Providing Agency NASA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 1978 to 1994-08-01
Last update: 2012-11-29
Detailed characteristics

Central frequency (GHz)

Bandwidth (MHz)

Polarisations

NEΔT

IFOV

Pixel

6.6

250

V, H

0.9 K

95x160 km

40x26 km

10.7

250

V, H

0.9 K

60x100 km

20x26 km

18.0

250

V, H

1.2 K

35x60 km

20x26 km

21.0

250

V, H

1.5 K

30x50 km

20x26 km

37.0

250

V, H

1.5 K

17x29 km

10x26 km

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
Mission objectives
Primary mission objectives
  • Sea surface temperature
  • Sea-ice cover
  • Wind speed over the surface (horizontal)
Secondary mission objectives
  • Biomass
  • Integrated Water Vapour (IWV)
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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)5 - marginalPoor time sampling.. Time sampling to be interpolated by GEO.MW channels around 10, 19, 23 and 37 GHz
Biomass4 - fairIndex only.. Coarse spatial resolution.Derived from differential effect of vegetation across MW frequencies around 7, 10 and 19 GHz
Cloud liquid water (CLW)5 - marginalNo specific limitation.MW channels around 37 GHz
Cloud liquid water (CLW) total column4 - fairNo specific limitation.MW channels around 37 GHz
Land surface temperature4 - fairCoarse spatial resolution.MW channels around 7 and 10 GHz
Long-wave Earth surface emissivity4 - fairLong time series needed.MW channels around 7, 10, 19 and 37 GHz. Emissivity across this MW range inferred by statistical analysis
Precipitation intensity at surface (liquid or solid)4 - fairInaccurate over land.MW channels around 10, 19, 23, and 37 GHz; 10 GHz very important for heavy precipitation over the sea
Sea surface temperature3 - highNo specific limitation.MW channels around 7 and 10 GHz
Sea-ice cover4 - fairNo specific limitation.MW channels around 7, 10, 19 and 37 GHz
Sea-ice type5 - marginalNo specific limitation.MW channels around 7, 10, 19 and 37 GHz. Type interpreted as age/roughness
Snow cover4 - fairCoarse spatial resolution.MW channels around 19 and 37 GHz
Snow status (wet/dry)4 - fairCoarse spatial resolution.MW channels around 19 and 37 GHz
Snow water equivalent5 - marginalCoarse spatial resolution.. Ground stations network needed.MW channels around 19 and 37 GHz
Soil moisture (in the roots region)4 - fairCoarse spatial resolution.. Affected by vegetation.MW channels around 7 GHz. Assimilation process required
Soil moisture at surface3 - highCoarse spatial resolution.. Affected by vegetation.MW channels around 7 and 10 GHz
Integrated Water Vapour (IWV)2 - very highOver sea only.MW channel(s) in the water vapour band around 23 GHz
Wind speed over the surface (horizontal)2 - very highOver sea only.MW channels around 7, 10, 19 and 37 GHz