Summary

Description

The Nimbus-6 Scanning Microwave Spectrometer (SCAMS) Level 2 data product contains water vapor and temperature profiles. The 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, which block conventional satellite infrared sensors. 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 Scanning Microwave Spectrometer(SCAMS) experiment on Nimbus-6 is a follow on experiment to the successful Nimbus-5 NEMS experiment. The SCAMS continuously monitored emitted microwave radiation at frequencies of 22.235, 31.65, 52.85, 53.85 and 55.45 GHz. The three channels near the 5.0-mm oxygen absorption band were used primarily to deduce atmospheric temperature profiles. The two channels near 10 mm permitted water vapor and cloud water content over calm oceans to be estimated separately. The instrument, a Dicke-superheterodyne type, scanned plus or minus 45 deg normal to the orbital plane with a 10-deg field of view. The three oxygen channels shared common signal and reference antennas. Both water vapor channels had their own signals and reference antennas. The absolute rms accuracy of the oxygen channels was better than 2 deg K and that of the water vapor channels better than 1 deg K. The SCAMS Principal Investigator was Prof. David H. Staelin from MIT. The Nimbus-6 SCAMS data are available from June 15, 1975 (day of year 166) through May 31, 1976 (day of year 152). (These data were previously archived at NASA NSSDC under the entry ID ESAD-00093).