NSSDCA ID: 1978-098A-07
Mission Name: Nimbus 7The objective of the Nimbus 7 Earth Radiation Budget (ERB) experiment, a follow-on to the Nimbus 6 ERB, was to determine the earth radiation budget on both synoptic and planetary scales by simultaneous measurements of incoming solar radiation and outgoing earth-reflected (shortwave) and emitted (longwave) radiation. Both (1) fixed wide-angle sampling of terrestrial fluxes at the satellite altitude and (2) scanned narrow-angle sampling of the angular radiance components, were used to determine outgoing radiation (reflected and emitted). The ERB subsystem consisted of a 22-channel radiometer containing separate subassemblies to perform the required solar, earth-flux (wide angle), and scanned earth radiance (narrow angle) measurements. The systems used optical filters for spectral discriminations, and for uncooled thermal detectors, thermopile detectors in the solar and fixed-earth-flux channels, and pyroelectric detectors in the scanning channels. The 10 solar channels observed the sun in front of the observatory in the X-Y plane. The solar channels obtained usable solar data only during a period of about 3 min in each orbit when the spacecraft was over the Antarctic region. Their full response field of view (FOV) was 0.18 rad. The solar channel subassembly was pivoted plus or minus 0.35 rad in the X-Y plane to compensate for sun-angle deviation when required. The channel 10c solar channel was a model H-F self-calibrating cavity thermopile used for monitoring the total solar irradiance (0.2 to 50 micrometers). The four fixed earth-flux channels (numbered 11-14) were mounted so that they could continuously view the total earth disk, and record data at 0.25-s intervals. The eight narrow FOV scanning channels were mounted in the scanning head. The NFOV channels consisted of four shortwave (0.2 to 4.8 micrometers) and four longwave (4.5 to 50+ micrometers) channels. The scanning head was gimbal-mounted in the radiometer unit main frame. The FOVs of the telescopes were asymmetric (4.4 by 89.4 mrad) and those of the shortwave and longwave channels were coincident. The 89.4 mrad FOVs of the four pairs of channels were not contiguous, but covered only alternate 89.4 mrad angular intervals along the horizon. For a more detailed description, see Section 3 in "The Nimbus 7 Users' Guide" (TRF B30045), available from NSSDC, and "The earth radiation budget (ERB) experiment: an overview" by H. Jacobawitz, et al., J. Geophys. Res., v. 89, n. D4, pp. 5021-5038, 1984. The narrow-view scanner failed in June 1980.
Mass: 32.7 kg
Power (avg): 36.3 W
Bit rate (avg): 4.5 kbps
Questions and comments about this experiment can be directed to: Coordinated Request and User Support Office
Name | Role | Original Affiliation | |
---|---|---|---|
Dr. Herbert Lee Kyle | Team Leader | NASA Goddard Space Flight Center | lkyle@ame.gsfc.nasa.gov |
Dr. Herbert Jacobowitz | Team Leader | NOAA National Environmental Satellite, Data and Information Service | |
Dr. Larry L. Stowe | Team Member | NOAA National Environmental Satellite, Data and Information Service | l.l.stowe@noaa.gov |
Dr. Albert Arking | Team Member | NASA Goddard Space Flight Center | arking@aa.gsfc.nasa.gov |
Dr. John R. Hickey | Team Member | Eppley Laboratory, Incorporated | |
Dr. Thomas H. Vonder Haar | Team Member | Colorado State University | vonderhaar@cira.colostate.edu |
Dr. Frederick B. House | Team Member | Drexel University | fhouse@physics.drexel.edu |
Dr. Andrew P. Ingersoll | Team Member | California Institute of Technology | api@gps.caltech.edu |
Prof. K. L. Coulson | Team Member | University of California, Davis | |
Dr. G. Louis Smith | Team Member | NASA Langley Research Center | g.l.smith@larc.nasa.gov |
Dr. G. Garrett Campbell | Team Member | Colorado State University | |
Mr. R. Maschhoff | Team Member | Gulton Industries, Incorporated |