BackForwardInstrument:  GLI 

Instrument details
Acronym GLI
Full name Global Imager
Purpose Multipurpose VIS/IR imagery
Short description 36-channel spectroradiometer covering the range 0.38-12.0 ?m (29 channels in UV/VIS/NIR, 7 in MWIR/TIR). 18 channels have 10 nm bandwidth, for ocean colour [see detailed characteristics below]
Background Evolution of OCTS flown on ADEOS
Scanning Technique Wiskbroom, 1600 km swath, capability of ± 20° off-pointing along track to avoid sunglint
Resolution 250 m s.s.p. for 6 VNIR channels, 1 km s.s.p. for the other 30 channels
Coverage / Cycle Global each day for LW channels, each two days for SW channels
Mass 450 kg Power 400 W Data Rate 4.1 Mbps

 

Providing Agency JAXA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 2003 to 2003-10-25
Last update: 2013-12-04
Detailed characteristics
Central wavelength Bandwidth SNR or NEΔT at specified input IFOV at s.s.p.
380 nm 10 nm .... @ .... W m-2 sr-1 μm-1 1000 m
400 nm 10 nm .... @ .... W m-2 sr-1 μm-1 1000 m
412 nm 10 nm .... @ .... W m-2 sr-1 μm-1 1000 m
443 nm 10 nm .... @ .... W m-2 sr-1 μm-1 1000 m
460 nm 10 nm .... @ .... W m-2 sr-1 μm-1 1000 m
460 nm 70 nm .... @ .... W m-2 sr-1 μm-1 250 m
490 nm 10 nm .... @ .... W m-2 sr-1 μm-1 1000 m
520 nm 10 nm .... @ .... W m-2 sr-1 μm-1 1000 m
545 nm 10 nm .... @ .... W m-2 sr-1 μm-1 1000 m
545 nm 50 nm .... @ .... W m-2 sr-1 μm-1 250 m
565 nm 10 nm .... @ .... W m-2 sr-1 μm-1 1000 m
625 nm 10 nm .... @ .... W m-2 sr-1 μm-1 1000 m
660 nm 10 nm .... @ .... W m-2 sr-1 μm-1 1000 m
660 nm 60 nm .... @ .... W m-2 sr-1 μm-1 250 m
678 nm 10 nm .... @ .... W m-2 sr-1 μm-1 1000 m
680 nm 10 nm .... @ .... W m-2 sr-1 μm-1 1000 m
710 nm 10 nm .... @ .... W m-2 sr-1 μm-1 1000 m
710 nm 10 nm .... @ .... W m-2 sr-1 μm-1 1000 m
749 nm 10 nm .... @ .... W m-2 sr-1 μm-1 1000 m
763 nm 8 nm .... @ .... W m-2 sr-1 μm-1 1000 m
825 nm 110 nm .... @ .... W m-2 sr-1 μm-1 250 m
865 nm 10 nm .... @ .... W m-2 sr-1 μm-1 1000 m
865 nm 20 nm .... @ .... W m-2 sr-1 μm-1 1000 m
1050 nm 20 nm .... @ .... W m-2 sr-1 μm-1 1000 m
1135 nm 70 nm .... @ .... W m-2 sr-1 μm-1 1000 m
1240 nm 20 nm .... @ .... W m-2 sr-1 μm-1 1000 m
1380 nm 40 nm .... @ .... W m-2 sr-1 μm-1 1000 m
1640 nm 200 nm .... @ .... W m-2 sr-1 μm-1 250 m
2210 nm 220 nm .... @ .... W m-2 sr-1 μm-1 250 m
3.715 μm 0.33 μm .... K @ 300 K 1000 m
6.7 μm 0.50 μm .... K @ 250 K 1000 m
7.3 μm 0.50 μm .... K @ 250 K 1000 m
7.5 μm 0.50 μm .... K @ 250 K 1000 m
8.6 μm 0.50 μm .... K @ 300 K 1000 m
10.8 μm 1.00 μm .... K @ 300 K 1000 m
12.0 μm 1.00 μm .... K @ 300 K 1000 m
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 optical radiometer or spectrometer
  • Moderate resolution optical imager
Mission objectives
Primary mission objectives
  • Cloud cover
  • Cloud optical depth
  • Cloud top height
  • Cloud top temperature
  • Cloud type
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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
Cloud cover1 - primaryNo specific limitation.VIS, NIR, SWIR, MWIR and TIR channels
Colour Dissolved Organic Matter (CDOM)1 - primaryCloud sensitive.. Daylight only.Many narrow-bandwidth VIS channels, suitable for more water types, in open ocean and coastal zone
Ocean chlorophyll concentration 1 - primaryCloud sensitive.. Daylight only.Many narrow-bandwidth VIS channels, suitable for more water types, in open ocean and coastal zone
Ocean Diffuse Attenuation Coefficient (DAC)1 - primaryCloud sensitive.. Daylight only.Many narrow-bandwidth VIS channels, suitable for more water types, in open ocean and coastal zone
Ocean suspended sediments concentration1 - primaryCloud sensitive.. Daylight only.Many narrow-bandwidth VIS channels, suitable for more water types, in open ocean and coastal zone
Upward long-wave irradiance at TOA5 - marginalSpectral interpolation needed.MWIR and TIR channels in windows around 3.7 and 11 micrometers, and in the water vapour band around 6.3 micrometers
Wind (horizontal)4 - fairLimited to high latitudes.. Cloud or water vapour tracers needed.TIR channels in the 11 micrometers window and the 6.3 micrometers water vapour band
Aerosol column burden3 - highCloud sensitive.. Daylight only.UV (for absorbing aerosol), VIS (with narrow bandwidth), NIR and SWIR channels including 760 nm for high-level aerosol
Aerosol Optical Depth3 - highCloud sensitive.. Daylight only.UV (for absorbing aerosol),VIS (with narrow bandwidth), NIR and SWIR channels including 760 nm for high-level aerosol
Aerosol effective radius3 - highCloud sensitive.. Daylight only.UV (for absorbing aerosol), VIS (with narrow bandwidth), NIR and SWIR channels including 760 nm for high-level aerosol
Aerosol mass mixing ratio3 - highCloud sensitive.. Daylight only.UV (for absorbing aerosol), VIS (with narrow bandwidth), NIR (including 760 nm for high-level aerosol) and SWIR channels
Aerosol type3 - highCloud sensitive.. Daylight only.UV (for absorbing aerosol), VIS (with narrow bandwidth), NIR and SWIR channels including 760 nm for high-level aerosol
Aerosol volcanic ash3 - highCloud sensitive.. Daylight only.UV, VIS, NIR and SWIR channels, including 760 nm for high-level ashes
Aerosol volcanic ash Total Column3 - highCloud sensitive.. Daylight only.UV (specifically sensitive to ash), VIS, NIR and SWIR channels, including 760 nm for high-level ashes
Integrated Water Vapour (IWV)2 - very highCloud sensitive.TIR channels around 6.3 micrometers and in the 11 micrometers split window
Specific humidity3 - highCloud sensitive.. Coarse vertical resolution.. Middle troposphere only.TIR channels in the water vapour band around 6.3 micrometers
Sea surface temperature2 - very highCloud sensitive.MWIR and TIR window channels around 3.7 and 11 micrometers (cloud impact reduction, water vapour correction)
Sea-ice cover1 - primaryCloud sensitive.VIS, NIR (for contour enhancement), SWIR (for discrimination from clouds), MWIR and TIR channels
Leaf Area Index (LAI)2 - very highCloud sensitive.. Daylight only.VIS, NIR and SWIR channels
Cloud top temperature2 - very highNo specific limitation.TIR channels in window and water vapour band (for emissivity)
Cloud top height3 - highNo specific limitation.TIR channels in window and water vapour band (for emissivity) to estimate cloud top height from its temperature
Cloud type1 - primaryNo specific limitation.VIS, NIR, SWIR, MWIR and TIR channels
Cloud optical depth3 - highLow-density cloud only.. Daylight only.VIS, NIR and SWIR channels
Cloud drop effective radius3 - highAt cloud top.. Daylight only.VIS, NIR, SWIR and MWIR channels (for differentiation)
Cloud ice effective radius3 - highAt cloud top.. Daylight only.VIS, NIR, SWIR and MWIR channels (for differentiation)
Upward short-wave irradiance at TOA4 - fairSpectral interpolation needed.. Information on BRDF needed.UV, VIS, NIR and SWIR channels
Short-wave cloud reflectance4 - fairNo specific limitation.VIS, NIR and SWIR channels
Downward long-wave irradiance at Earth surface4 - fairCloud sensitive.. Highly indirect.MWIR and TIR channels including the water vapour band
Downward short-wave irradiance at Earth surface3 - highCloud sensitive.. Highly indirect.VIS, NIR and SWIR channels
Earth surface albedo5 - marginalCloud sensitive.VIS channels
Upward long-wave irradiance at Earth surface4 - fairCloud sensitive.. Highly indirect.MWIR and TIR channels in windows around 3.7 and 11 micrometers, and in the water vapour band around 6.3 micrometers
Photosynthetically Active Radiation (PAR)3 - highCloud sensitive.VIS channels, range accurately sampled
Fraction of Absorbed PAR (FAPAR)3 - highCloud sensitive.VIS channels including Red at 700 nm
Oil spill cover5 - marginalCloud sensitive.. Daylight only.VIS channels with narrow bandwidth
Normalised Difference Vegetation Index (NDVI)3 - highCloud sensitive.VIS and NIR channels
Biomass4 - fairCloud sensitive.. Index only.. Daylight only.VIS, NIR and SWIR channels. Biomass inferred from NDVI and LAI
Soil moisture at surface4 - fairCloud sensitive.. Index only.VIS, SWIR, MWIR and TIR channels. Soil moisture inferred from differential brightness and thermal inertia
Land surface temperature3 - highCloud sensitive.MWIR and TIR window channels (high sensitivity to high temperature, cloud impact reduction, water vapour correction)
Fire fractional cover4 - fairCloud sensitive.. Coarse spatial resolution.VIS, MWIR and TIR channels
Fire temperature2 - very highCloud sensitive.. Coarse spatial resolution.MWIR and TIR channels
Fire radiative power2 - very highCloud sensitive.. Coarse spatial resolution.MWIR and TIR channels
Snow cover2 - very highCloud sensitive.. Daylight only.VIS, NIR and SWIR channels, enabling screening snow from clouds