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Today, the fourth generation HIRS (HIRS/4) is a 20-channel sounder that provides calibrated atmospheric profile data for assured global accuracy. The radiometric data is used to generate global temperature mapping at 40 different atmospheric profiles: temperature, ozone, cloud top height, water vapor, and sea and land surface temperature. The HIRS/4 is flying on National Oceanic and Atmospheric Administration's (NOAA) Polar-orbiting Environmental Satellite (POES), satellites NOAA-N and NOAA-N Prime, and the European Space Agency's MetOp-A and MetOp-B satellites.

HIRS was first carried on NIMBUS 6, which launched in 1975. Subsequent integrations include TIROS-N, launched October 1978; NOAA-7, launched June 1981; and NOAA-15, launched May 1998.