BackForwardInstrument:  HRIR 

Instrument details
Acronym HRIR
Full name High Resolution Infrared Radiometer
Purpose Cloud observation
Short description Single-channel IR radiometer, 3.4-4.2 ?m, temperature range 210-330 K, NE?T 1 K @ 260 K. In Nimbus-3 the band is dual, with a 0.7-1.3 ?m bandpass that dominated the signal during daylight
Background New development, prototype of operational IR imaging radiometers
Scanning Technique Cross-track, horizon-to-horizon by a 45° inclined mirror, 48 rounds/min, 7.8 km line-to-line for continuous coverage
Resolution 8.5 km at s.s.p.
Coverage / Cycle Global, twice/day
Mass 8 kg Power 8 W Data Rate Analogue: 0.4 kHz base band

 

Providing Agency NASA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 1964 to 1972-01-22
Last update: 2017-03-26
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
Mission objectives
Primary mission objectives
  • Cloud cover
  • Land surface temperature
  • Sea surface temperature
Secondary mission objectives
  • Fire fractional cover
Opportunity objectives
  • Fire radiative power
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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
Fire radiative power4 - fairCloud sensitive.. Coarse spatial resolution.MWIR channels
Fire temperature4 - fairCloud sensitive.. Coarse spatial resolution.MWIR channels
Sea surface temperature4 - fairCloud sensitive.. Affected by sunlight.MWIR window channel(s) around 3.7 micrometers (cloud impact reduction)
Cloud cover5 - marginalNo specific limitation.MWIR channel(s)
Land surface temperature4 - fairCloud sensitive.. Affected by sunlight.MWIR window channel(s) (high sensitivity to high temperature, cloud impact reduction)
Fire fractional cover5 - marginalCloud sensitive.. Coarse spatial resolution.MWIR channels