BackForwardInstrument:  SSU 

Instrument details
Acronym SSU
Full name Stratospheric Sounding Unit
Purpose Stratospheric temperature sounding
Short description Pressure-modulated spectrometer, operating around the wavelengths 14.92, 14.93 and 14.94 µm
Background Follow-on of SCR flown on Nimbus-4/5 and PMR flown on Nimbus-6. Part of the TIROS Operational Vertical Sounder (TOVS) package
Scanning Technique Cross-track, swath 1470 km
Resolution 150 km at s.s.p.
Coverage / Cycle Global, each day
Mass Power Data Rate 480 bps


Providing Agency UKSA
Instrument Maturity Flown on operational programme
Utilization Period: 1979 to 2007
Last update: 2012-09-14
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
  • Cross-nadir infrared sounder, possibly including VIS channels
WIGOS Subcomponents No WIGOS subcomponents have been defined.
Mission objectives
Primary mission objectives
  • Atmospheric temperature
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
Atmospheric temperature*4 - fairCloud sensitive.. Very coarse vertical resolution.. Inaccurate in low troposphere.TIR in the CO2 15 micrometer band