The NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) has recovered and made public the Nimbus 7 Temperature-Humidity Infrared Radiometer (THIR) Level 1 Calibrated Located Radiance Data at 6.7 and 11.5 microns (μm). Nimbus 7, launched on October 28, 1978, was the final satellite of NASA’s Nimbus program. The THIR data were originally recorded on 9-track magnetic tapes and stored at the Washington National Records Center. The data, in its original format, has been transferred to magnetic hard disks, from which individual files representing data from each orbit, along with the accompanying metadata, are then extracted and archived at the GES DISC. The resulting files contain THIR calibrated radiances and geolocation, time, and other instrument housekeeping information.
The THIR flown on Nimbus 7 was nearly identical to those flown previously on Nimbus 4 through 6, except that the data were digitized on board the Nimbus 7 satellite. The THIR instrument was a two-channel, high resolution, scanning radiometer designed to perform two major functions:
1. The 6.7 μm channel gave information on the moisture content of the upper troposphere and stratosphere and the location of jet streams and frontal systems. The water vapor channel had a nadir resolution of 20 km and operated mostly at night.
2. The 11.5 µm channel provided both day and night cloud top or surface temperatures. The nadir resolution was 6.7 km, and the channel operated day and night.
The THIR Level 1 data are available from October 30, 1978 through May 13, 1985. A data file typically contains one orbit’s acquisition of data.
Nimbus heritage data set access and documentation can be found at:
Reference for image:
L. L. Stowe, C. G. Wellemeyer, H. Y. M. Yeh, T. F. Eck, and The Nimbus-7 CLOUD DATA PROCESSING TEAM, 1988: Nimbus-7 Global Cloud Climatology, part I: Algorithms and Validation, J. Climate, 1, 445–470. (Note: H. Lee Kyle, cited in the text of this paper as the head of the Cloud Data Processing Team at the time of publication, subsequently became a GES DISC staff member for several years.)