BackForwardInstrument:  ATSR 

Instrument details
Acronym ATSR
Full name Along-Track Scanning Radiometer
Purpose Multi-purpose imagery, with emphasis on very accurate sea surface temperature for climate
Short description 4-channel SWIR/TIR radiometer with dual view for accurate atmospheric corrections. Supported by an associated nadir-viewing Microwave Sounder with channels at 23.8 and 35.6 GHz for water vapour correction [see detailed characteristics below]
Background New development
Scanning Technique Conical oblique (cross-nadir and 47° fore); 2000 pixel of 1 km ssp; swath 500 km; scan rate 400 rpm
Resolution 1 km s.s.p. (supporting MW sounder: 20 km)
Coverage / Cycle Global coverage in 3 days (TIR) or 6 days (SWIR)
Mass Power Data Rate

 

Providing Agency UKSA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 1991 to 2000-03-10
Last update: 2012-09-05
Detailed characteristics
Central wavelength/frequency Bandwidth SNR or NEΔT @ specified input 
1.61 µm 1.46-1.76 µm 20 @ 0.5 % albedo
3.70 µm 3.55-3.85 µm 0.08 K @ 270 K
10.85 µm 10.35-11.35 µm 0.05 K @ 270 K
12.00 µm 11.50-12.50 µm 0.05 K @ 270 K
23.8 GHz 400 MHz 0.5 K
36.5 GHz 400 MHz  0.5 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 top height
  • Cloud top temperature
  • Sea surface temperature
Secondary mission objectives
  • 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 cover3 - highNo specific limitation.VIS, MWIR and TIR channels
Cloud drop effective radius4 - fairAt cloud top.. Daylight only.VIS and MWIR channels and different viewing angles (for differentiation).
Cloud ice effective radius4 - fairAt cloud top.. Daylight only.VIS and MWIR channels with different viewing angles (for differentiation).
Cloud optical depth5 - marginalLow-density cloud only.. Daylight only.VIS channel(s) with different viewing angles
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, MWIR and TIR channels with more viewing angles
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 temperature2 - very highCloud sensitive.MWIR and TIR window channels with different viewing angles for atmospheric correction
Sea surface temperature1 - primaryCloud sensitive.MWIR and TIR window channels around 3.7 and 11 micrometers with different viewing angles for atmospheric correction
Sea-ice cover4 - fairCloud sensitive.VIS, MWIR and TIR channels
Snow cover5 - marginalCloud sensitive.. Daylight only.VIS channel(s)
Soil moisture at surface5 - marginalCloud sensitive.. Index only.VIS and MWIR window channels. Soil moisture inferred from thermal inertia
Integrated Water Vapour (IWV)4 - fairCloud sensitive.. Low troposphere dominant.TIR channels in the 11 micrometers split window
Wind (horizontal)5 - marginalCloud or water vapour tracers needed.. Polar regions only.TIR channel(s) around 11 micrometers window