BackForwardInstrument:  AVHRR/2 

Instrument details
Acronym AVHRR/2
Full name Advanced Very High Resolution Radiometer / 2
Purpose Multi-purpose imagery
Short description 5-channel radiometer covering VIS, NIR, MWIR and TIR [see detailed characteristics below]
Background Follow-on of the AVHRR flown on TIROS-N and NOAA 6/8/10. TIR channel now split
Scanning Technique Cross-track: 2048 pixel of 800 m s.s.p., swath 2900 km - Along-track: six 1.1-km lines/s
Resolution 1.1 km s.s.p. IFOV
Coverage / Cycle Global coverage twice/day (IR) or once/day (VIS)
Mass 33 kg Power 27 W Data Rate 621.3 kbps

 

Providing Agency NOAA
Instrument Maturity Flown on operational programme
Utilization Period: 1981 to 2007-08-10
Last update: 2017-03-26
Detailed characteristics
Central wavelength Spectral interval SNR or NEΔT @ specified input
0.615 µm 0.55 - 0.68 µm 9 @ 0.5 % albedo
0.912 µm 0.725 - 1.10 µm 9 @ 0.5 % albedo
3.74 µm 3.55 - 3.93 µm 0.12 K @ 300 K
10.80 µm 10.3 - 11.3 µm 0.12 K @ 300 K
12.00 µm 11.5 - 12.5 µm 0.12 K @ 300 K
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
Biomass5 - marginalCloud sensitive.. Index only.. Daylight only.VIS and NIR channels. Biomass inferred from NDVI
Cloud cover2 - very highNo specific limitation.VIS, NIR, MWIR and TIR channels
Cloud drop effective radius5 - marginalAt cloud top.. Daylight only.VIS, NIR and MWIR channels (for differentiation)
Cloud ice effective radius5 - marginalAt cloud top.. Daylight only.VIS, NIR and MWIR channels (for differentiation)
Cloud optical depth5 - marginalLow-density cloud only.. Daylight only.VIS and NIR channels
Cloud top height3 - highNo specific limitation.TIR window channels to estimate cloud top height from its temperature
Cloud top temperature3 - highNo specific limitation.TIR window channels
Cloud type2 - very highNo specific limitation.VIS, NIR, MWIR and TIR channels
Downward short-wave irradiance at Earth surface5 - marginalCloud sensitive.. Highly indirect.VIS and NIR channels
Fire fractional cover3 - highCloud sensitive.. Coarse spatial resolution.VIS, MWIR and TIR channels
Fire radiative power3 - highCloud sensitive.. Coarse spatial resolution.MWIR and TIR channels
Fire temperature3 - highCloud sensitive.. Coarse spatial resolution.MWIR and TIR channels
Land surface temperature4 - fairCloud sensitive.MWIR and TIR window channels (high sensitivity to high temperature, cloud impact reduction, water vapour correction)
Leaf Area Index (LAI)5 - marginalCloud sensitive.. Daylight only.VIS and NIR channels. LAI inferred from NDVI
Normalised Difference Vegetation Index (NDVI)2 - very highCloud sensitive.VIS and NIR channels
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 cover3 - highCloud sensitive.VIS, NIR (for contour enhancement), MWIR and TIR channels
Short-wave cloud reflectance4 - fairNo specific limitation.VIS and NIR channels
Snow cover5 - marginalCloud sensitive.. Daylight only.VIS and NIR channels
Soil moisture at surface4 - fairCloud sensitive.. Index only.VIS, NIR, MWIR and TIR channels. Soil moisture inferred from differential brightness and thermal inertia
Integrated Water Vapour (IWV)4 - fairCloud sensitive.. Low troposphere dominant.TIR channels in the 11 micrometers split window
Upward short-wave irradiance at TOA5 - marginalSpectral interpolation needed.. Information on BRDF needed.VIS and NIR channels
Aerosol volcanic ash5 - marginalCloud sensitive.. Daylight only.VIS and NIR channels
Aerosol volcanic ash (Total column)5 - marginalCloud sensitive.. Daylight only.VIS and NIR channels
Wind (horizontal)5 - marginalCloud or water vapour tracers needed.. Polar regions only.TIR channel(s) around 11 micrometers window