BackForwardInstrument:  MLS  

Instrument details
Acronym MLS
Full name Microwave Limb Sounder
Purpose Chemistry of the high atmosphere.  Tracked species: ClO, H2O, H2O2 and O3.
Short description 3 bands / 6 sub-bands: 63 GHz, 183 GHz (2 sub-band) and 205 GHz (3 sub-band).
Background New development
Scanning Technique Limb scanning
Resolution Vertical: 4 km, in the altitude range 5-85 km.  Horizontal effective resolution: ~ 300 km (limb geometry)
Coverage / Cycle Global coverage every 3 d for cells of 300 km side
Mass 280 kg Power 163 W Data Rate 1.25 kbps


Providing Agency NASA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 1991 to 2005
Last update: 2018-03-18
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
  • Limb sounders
  • Limb sounder
WIGOS Subcomponents
  • Subcomponent 2
  • Sub-mm imagery
  • Sub-mm imager
  • UV/VIS/NIR/IR/MW limb sounders
  • UV/VIS/NIR/IR/MW scanning limb sounder
Mission objectives
Primary mission objectives
  • ClO
  • H2O
  • HNO3
  • O3
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 temperature4 - fairLimited to high atmosphere.Mm-submm spectrometry in 60-250 GHz range
ClO*2 - very highLimited to high atmosphere.Mm-submm spectroscopy. ClO lines around 205 GHz.
Cloud ice1 - primaryLimited to high atmosphere.Mm-submm spectrometry in the 60-650 GHz range
Cloud liquid water (CLW)4 - fairLimited to high atmosphere.Mm-submm spectrometer in the 60-650 GHz range
H2O*4 - fairLimited to high atmosphere.Mm-submm spectrometry. H2O lines in 183 GHz band.
HNO3*3 - highLimited to high atmosphere.Mm-submm spectrometry. HNO3 lines in bands around 190 GHz.
O3*4 - fairLimited to high atmosphere.Mm-submm spectrometry. Ozone lines around 240 GHz.
Specific humidity4 - fairLimited to high atmosphere.Mm-submm spectrometry of water vapour bands at frequency up to 250 GHz (main: around 183 GHz)