The NASA GES DISC has recovered and made public two data products from the Nimbus-6 mission (launched June 12, 1975): (1) Nimbus-6 High Resolution Infrared Radiation Sounder (HIRS) Level 1 Calibrated Radiances and (2) Nimbus-6 Scanning Microwave Spectrometer (SCAMS) Level 2 Water Vapor and Temperature. These data were originally archived on 9-track magnetic tapes stored at the Washington National Records Center. These data were then transferred to magnetic hard disks, from which the original data files were extracted for the current data product release. Nimbus-6 HIRS data were part of the Global Atmospheric Research Program (GARP).
HIRS provided global vertical temperature profiles up to 40 km and water vapor distribution in the troposphere. The instrument measured radiances in five spectral regions: (1) Seven channels near the 15-μm CO2 absorption band, (2) two channels at 11.1 and 3.7 μm in the IR window, (3) two channels at 8.2 and 6.7 μm in the water vapor absorption band, (4) five channels in the 4.3-μm band, and (5) one channel in the visible 0.69 μm region. Spatial resolution of the instrument is 25 km at nadir. HIRS was operational until May 27, 1976, when the filter chopper motor failed. The HIRS Level 1 calibrated radiance data are available for the time period August 17, 1975 to March 4, 1976. Each file contains about one orbit of data.
SCAMS was designed to map tropospheric temperature profiles, water vapor abundance, and cloud water content, to be used for weather prediction even in the presence of clouds. The instrument continuously monitored emitted microwave radiation at 22.235, 31.65, and 52.85 GHz (O2 absorption band), and 53.85 and 55.45 GHz (H2O band). Its ground resolution is approximately 145 km near nadir and 330 km at the scan edge. SCAMS ceased functioning on May 31, 1976, due to jamming of the scan mechanism. The SCAMS Level 2 temperature and H2O data are available for the time period June 15, 1975 to May 29, 1976. Typically, a file contains one orbit of data.
Nimbus heritage data set access and documentation can be found at: