Summary

Description

The Nimbus-6 High Resolution Infrared Radiometer (HIRS) Level 1 Calibrated Radiances for the Global Atmospheric Research Program (GARP) data product contains daily infrared radiances. The HIRS was designed to measure surface temperature and albedo, temperature and H2O profiles, cloud liquid water content, cloud amount and outgoing longwave fluxes in the infrared. The data, originally written on IBM 360 machines, were recovered from 9-track magnetic tapes. The data are archived in their original IBM 32-bit word binary record format, also referred to as a binary TAP file, and contain one orbit of measurements. The Nimbus-6 satellite was successfully launched on June 12, 1975. The High-Resolution Infrared Radiation Sounder (HIRS) experiment on Nimbus-6 is a follow on experiment to the successful Nimbus-5 ITPR experiment. HIRS scans The HIRS was a multi-channel filter radiometer with a Cassegrain telescope before the chopper assembly. The instrument scans in the cross track direction with 21 scans on each side of the subtrack point with about 30 km x 55 km resolution at nadir. HIRS measured radiances primarily in five spectral regions: (1) seven channels near the 15-micrometer CO2 absorption band, (2) two channels (11.1 and 3.7 micrometers) in the IR window, (3) two channels (8.2 and 6.7 micrometers) in the water vapor absorption band, (4) five channels in the 4.3-micrometer band, and (5) one channel in the visible 0.69-micrometer region. The HIRS Principal Investigator was Mr. W. L. Smith from the NOAA National Environmental Satellite Service. The Nimbus-6 HIRS data are available from August 17, 1975 (day of year 229) through March 4, 1976 (day of year 238). (These data were previously archived at NASA NSSDC under the entry ID ESAD-00017 together with the merged retrieval data set).