BackForwardInstrument:  ACS-limb 

Instrument details
Acronym ACS-limb
Full name Atmospheric Composition Spectrometer (limb-scanning component)
Purpose Atmospheric chemistry. Tracked species: BrO, CH4, ClO, CO, CO2, H2O, HCHO, N2O, NO, NO2, NO3, O2, O3, O4, OClO, SO2 and aerosol.
Short description UV/VIS/NIR/SWIR grating spectrometer, eight bands, 2048 channels [see detailed characteristics below].
Background New development.
Scanning Technique Limb scanning of 100 km horizontal sector is provided. Also solar occultation: in this mode the instrument is self-calibrating (DOAS principle). The limb mode, the solar occultation mode and the cross-nadir mode are alternative to each other.
Resolution 300 km (horizontal), 3 km (vertical)
Coverage / Cycle If used full time, the limb mode would provide global coverage every 5 days (in daylight). Solar occultation: N/A
Mass Power Data Rate

 

Providing Agency Roscosmos
Instrument Maturity Flown on an R&D satellite
Utilization Period: TBD
Last update: 2021-11-27
Detailed characteristics

Spectral range

No. of channels

Spectral resolution

SNR @ specified input spectral radiance

214-334 nm

256

0.5 nm

..... @ ...... W m-2 sr-1 μm-1

320-452 nm

256

0.5 nm

..... @ ...... W m-2 sr-1 μm-1

430-800 nm

256

1.5 nm

..... @ ...... W m-2 sr-1 μm-1

755-910 nm

256

0.9 nm

..... @ ...... W m-2 sr-1 μm-1

900-1210 nm

256

0.9 nm

..... @ ...... W m-2 sr-1 μm-1

1200-1770 nm

256

2.0 nm

..... @ ...... W m-2 sr-1 μm-1

1934-2044 nm

256

0.5 nm

..... @ ...... W m-2 sr-1 μm-1

2259-2386 nm

256

0.5 nm

..... @ ...... W m-2 sr-1 μm-1
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 1
  • UV/VIS/NIR sounders, nadir and limb
  • UV/VIS/NIR scanning limb sounder
  • Subcomponent 2
  • UV/VIS/NIR/IR/MW limb sounders
  • UV/VIS/NIR/IR/MW scanning limb sounder
  • UV/VIS/NIR/IR occultation limb sounder
Mission objectives
Primary mission objectives
  • BrO
  • CH4 mole fraction
  • CO
  • CO2 mole fraction
  • ClO
  • H2O
  • HCHO
  • N2O mole fraction
  • NO
  • NO2
  • O3
  • 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
Aerosol mass mixing ratio5 - marginalLimited to high atmosphere.. Daylight only.UV, VIS, NIR and SWIR spectrometry.
Atmospheric temperature4 - fairLimited to high atmosphere.. Daylight only.UV, VIS, NIR and SWIR spectrometry.
BrO*3 - highLimited to high atmosphere.. Daylight only.UV spectrometry. BrO lines around 300 nm. Limb sounding mechanically or electronically
HCHO*3 - highLimited to high atmosphere.. Daylight only.UV spectrometry. HCHO lines around 350 nm.
CH4 mole fraction*4 - fairLimited to high atmosphere.. Daylight only.SWIR spectrometry. CH4 lines around 2.3 micrometers.
ClO*3 - highLimited to high atmosphere.. Daylight only.UV Spectrometry. ClO lines around 300 nm.
CO*4 - fairLimited to high atmosphere.. Daylight only.SWIR spectrometry. CO lines around 2.3 micrometers.
CO2 mole fraction*4 - fairLimited to high atmosphere.. Daylight only.SWIR spectrometry. CO2 lines around 1.6 and 2.1 micrometers.
H2O*4 - fairLimited to high atmosphere.. Daylight only.Spectrometry in UV and VIS (several weak bands), and NIR and SWIR (strong bands around 940 and 1380 nm).
N2O mole fraction*4 - fairLimited to high atmosphere.. Daylight only.SWIR spectrometry. N2O lines around 2.3 micrometers.
NO*4 - fairLimited to high atmosphere.. Daylight only.UV spectrometry. NO lines around 250 nm.
NO2*4 - fairLimited to high atmosphere.. Daylight only.UV and VIS spectrometry. Several lines in the ranges around 220 nm and 400 nm.
O3*4 - fairLimited to high atmosphere.. Daylight only.UV and VIS spectrometry. Ozone lines in the bands around 260 nm (Hartley) and/or 340 nm (Huggins) and 600 nm (Chappuis).
PSC occurrence4 - fairLimited to high atmosphere.. Daylight only.UV and VIS spectrometry.
SO2*4 - fairLimited to high atmosphere.. Daylight only.UV spectrometry. SO2 lines around 350 nm.
Specific humidity4 - fairLimited to high atmosphere.. Daylight only.UV, VIS, NIR and SWIR spectrometry with several water vapour bands (main: around 940 and 1380 nm nm).
Aerosol volcanic ash5 - marginalLimited to high atmosphere.. Daylight only.UV, VIS, NIR and SWIR spectrometry;