BackForwardInstrument:  VHRR (ATS) 

Instrument details
Acronym VHRR (ATS)
Full name Very High Resolution Radiometer
Purpose Multi-purpose imagery and wind derivation by cloud tracking
Short description 2-channel VIS/IR radiometer, 0.55-0.75 and 10.5-12.5 µm
Background New development
Scanning Technique Mechanical, 3-axis stabilised satellite, E-W continuous, S-N stepping
Resolution 5.5 km (VIS) and 11 km (IR)
Coverage / Cycle Full disk in 25 min
Mass Power Data Rate

 

Providing Agency NASA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 1974 to 1979
Last update: 2017-03-27
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
  • Passive optical radiometer or spectrometer
  • Moderate resolution optical imager
WIGOS Subcomponents
  • Subcomponent 1
  • Multi-spectral VIS/IR imagery With rapid repeat cycles [in GEO]
  • Multi-spectral VIS/IR imager with rapid repeat cycles [in GEO]
Mission objectives
Primary mission objectives
  • Cloud cover
  • Cloud top temperature
  • Cloud type
  • Wind (horizontal)
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
Cloud cover*4 - fairNo specific limitation.VIS and TIR channels
Cloud top temperature*5 - marginalNo specific limitation.TIR window channel(s)
Cloud type*4 - fairDaylight only.VIS and TIR channels
Fire fractional cover4 - fairCloud sensitive.. Coarse spatial resolution.VIS and TIR channels
Fire radiative power5 - marginalCloud sensitive.. Coarse spatial resolution.TIR channels. Frequent sampling (GEO) enables early detection
Fire temperature5 - marginalCloud sensitive.. Coarse spatial resolution.TIR channels. Frequent sampling (GEO) enables early detection
Precipitation intensity at surface (liquid or solid)3 - highConvective precipitation dominant.. Calibration by MW needed.TIR channel(s) in the 11 micrometers window. Frequent sampling (GEO) consistent with precipitation temporal variability
Sea surface temperature5 - marginalCloud sensitive.TIR window channel(s) around 11 micrometers .
Snow cover5 - marginalCloud sensitive.. Daylight only.VIS channel(s). Frequent sampling (GEO) improves probability of cloud-free views
Soil moisture at surface4 - fairCloud sensitive.. Index only.VIS and TIR window channels. Soil moisture inferred from thermal inertia, that is accurately measured by frequent sampling (GEO)
Aerosol volcanic ash Total Column1 - primaryCloud sensitive.TIR channel(s). Frequent sampling (GEO) enables early detection of ash plumes
Wind (horizontal)*4 - fairCloud or water vapour tracers needed.VIS channel(s) and TIR channel(s) around 11 micrometers window. Frequent sampling (GEO) enables inference from cloud motion
Accumulated precipitation4 - fairConvective precipitation dominant.. Calibration by MW needed.TIR channel(s) in the 10-13 micrometers range. Frequent sampling (GEO) is essential for accumulated precipitation.