BackForwardInstrument:  ILAS-I 

Instrument details
Acronym ILAS-I
Full name Improved Limb Atmosperic Spectrometer - I
Purpose Atmospheric chemistry. Species: CH4, CFC11, H2O, HNO3, N2O, NO2, O3 and aerosol
Short description Two grating spectrometers: one in the IR range 6.21-11.77 µm (850-1610 cm-1) with spectral resolution 0.2 cm-1; the other one with 1024 NIR channels in the range 0.753-0.784 µm
Background New development
Scanning Technique Limb sounding by sun occultation. Simultaneous vertical scanning by linear array detectors. About 30 occultations/day
Resolution Vertical: 2 km in the volume 10-60 km; horizontal: 300 km along-view
Coverage / Cycle Latitudinal zones 56-70 ºN and 63-88 ºS, once each 3 days
Mass 130 kg Power 78 W Data Rate 517 kbps

 

Providing Agency JAXA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 1996 to 1997
Last update: 2017-03-29
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
  • UV/VIS/NIR/IR/MW limb sounders
  • UV/VIS/NIR/IR occultation limb sounder
Mission objectives
Primary mission objectives
  • C2H2
  • C2H6
  • CFC-11
  • CFC-12
  • CH4 mole fraction
  • CO2 mole fraction
  • COS
  • H2O
  • HNO3
  • N2O mole fraction
  • NO2
  • O3
  • PAN
  • SF6
  • SO2
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 temperature5 - marginalLimited to high atmosphere.. Limited to high latitudes.TIR limb sounding by solar occultation. Self-calibrating
C2H6*5 - marginalLimited to high atmosphere.. Limited to high latitudes.TIR spectrometry. C2H6 lines around 12 micrometers. Limb sounding by solar occultation. Self-calibrating
CH4 mole fraction*5 - marginalLimited to high atmosphere.. Limited to high latitudes.TIR spectrometry. CH4 lines around 7.7 micrometers. Limb sounding by solar occultation. Self-calibrating
COS*5 - marginalLimited to high atmosphere.. Limited to high latitudes.TIR spectrometry. COS lines around 11.6 micrometers. Limb sounding by solar occultation. Self-calibrating
N2O mole fraction*5 - marginalLimited to high atmosphere.. Limited to high latitudes.TIR spectrometry. N2O lines around 7.7 micrometers. Limb sounding by solar occultation. Self-calibrating
PAN*5 - marginalLimited to high atmosphere.. Limited to high latitudes.MWIR and TIR spectrometry. PAN lines around 5.7, 8.6 and 12.5 micrometers. Limb sounding by solar occultation. Self-calibrating
PSC occurrence5 - marginalLimited to high atmosphere.. Limited to high latitudes.TIR spectrometry. Limb sounding by solar occultation. Self-calibrating
Specific humidity5 - marginalLimited to high atmosphere.. Limited to high latitudes.TIR spectrometry in the water vapour band around 6.3 micrometers Limb sounding by solar occultation, Self-calibrating
CO2 mole fraction*5 - marginalLimited to high atmosphere.TIR spectrometry. CO2 lines around 15 micrometers. Limb sounding by solar occultation. Self-calibrating
C2H2*5 - marginalLimited to high atmosphere.TIR spectrometry. C2H2 lines around 7.5 and 13.7 micrometers. Limb sounding by solar occultation. Self-calibrating
CFC-11*5 - marginalLimited to high atmosphere.TIR spectrometry. CFC-11 lines around 9.2 and 11.7 micrometers Limb sounding by solar occultation. Self-calibrating
CFC-12*5 - marginalLimited to high atmosphere.TIR spectrometry. CFC-12 lines around 8.8 and 10.8 micrometers. Limb sounding by solar occultation. Self-calibrating
SF6*5 - marginalLimited to high atmosphere.TIR spectrometry. SF6 lines around 10.5 micrometers. Limb sounding by solar occultation. Self-calibrating
H2O*5 - marginalLimited to high atmosphere.MWIR/TIR spectrometry in a range centred on 6.3 micrometers. Limb sounding by solar occultation. Self-calibrating
O3*5 - marginalLimited to high atmosphere.TIR spectrometry. Ozone band around 9.7 micrometers. Limb sounding by solar occultation. Self-calibrating
SO2*5 - marginalLimited to high atmosphere.TIR spectrometry. SO2 lines around 7.3 and 8.6 micrometers. Limb sounding by solar occultation. Self-calibrating
HNO3*5 - marginalLimited to high atmosphere.MWIR and TIR spectrometry. HNO3 lines around 5.9, 7.6 and 11.3 micrometers. Limb sounding by solar occultation. Self-calibrating
N2O55 - marginalLimited to high atmosphere.MWIR and TIR spectrometry. N2O5 lines around 5.8 and 8 micrometers. Limb sounding by solar occultation. Self-calibrating
NO2*5 - marginalLimited to high atmosphere.TIR spectrometry. NO2 lines around 6.1 micrometers. Limb sounding by solar occultation. Self-calibrating