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TIROS Operational Vertical Sounder (TOVS)

NSSDCA ID: 1991-032A-02

Mission Name: NOAA 12
Principal Investigator:


The TIROS Operational Vertical Sounder (TOVS) on NOAA-12 consists of two instruments: the high-resolution infrared radiation sounder modification 2 (HIRS/2), and the microwave sounding unit (MSU). Both instruments are designed to determine radiances needed to calculate temperature and humidity profiles of the atmosphere from the surface to the stratosphere (approximately 1 mb). The HIRS/2 instrument has 20 channels in the following spectral intervals: channels 1 through 5, the 15-micrometer CO2 bands (15.0, 14.7, 14.5, 14.2, and 14.0 micrometers); channels 6 and 7, the 13.7 and 3.4-micrometer CO2/H2O bands; channel 8, the 11.1-micrometer window region; channel 9, the 9.7-micrometer ozone band; channels 10 through 12, the 6-micrometer water vapor bands (12.55, 7.3, and 6.7 micrometers); channels 13 and 14, the 4.57- and 4.52-micrometer N2O bands; channels 15 and 16, the 4.46- and 4.40-micrometer CO2/N2O bands; channels 17, 18 and 19, the 4.25-, 4.0- and 3.7-micrometer window bands; and channel 20, the 0.7-micrometer window band. Resolution for all channels is 17.4 km at nadir. The HIRS/2 instrument provides data for calculations of temperature profiles from the surface to 10 mb, water vapor content at three levels of the atmosphere. The second nstrument, the MSU, has four channels operating in the 50- to 60-GHz oxygen band (50.31, 53.73, 54.96 and 57.95 GHz) to obtain temperature profiles which are free of cloud interference. The same experiments are flown on other spacecraft in the TIROS-N/NOAA series. The NOAA-12 does not carry the SSU instrument as on the NOAA-9 and NOAA-11 TOVS.

Alternate Names

  • TOVS

Facts in Brief

Mass: 63.4 kg
Power (avg): 75 W

Funding Agency

  • NOAA National Environmental Satellite Service (United States)


  • Earth Science: Atmospheric Dynamics

Additional Information

Questions and comments about this experiment can be directed to: Coordinated Request and User Support Office



NameRoleOriginal AffiliationE-mail
Principal InvestigatorNOAA National Environmental Satellite, Data and Information Service
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