Data Set Document

Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR) Antenna Temperatures


The Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR) Antenna Temperature (TA) data set consists of antenna temperatures from passive microwave radiometers. Each file in the data set consists of daily antenna temperature data in swath format, i.e. the portion of the Earth's surface viewed by the scanning radiometer.

Because of spacecraft power limitations, the scanner operated only on alternate days. There are typically 14 days of coverage per month. Antenna temperature data are available from NSIDC for October 1978 to August 1987. In 1982, August 4, 8, and 16 are missing for both polar regions; in 1984, August 13 through 23 are missing for both polar regions.

SMMR was a ten channel passive microwave instrument using six conventional Dicke-type radiometers. It delivered orthogonally polarized antenna temperature data at 6.6, 10.69, 18.0, 21.0 and 37.0 GHz. The two 37.0 GHz radiometers operated continuously for each polarization. The other radiometers alternated polarizations on alternate scans. The size of each daily file is 35 MBytes. The data are distributed on FTP.


Francis, E. A. 1987. Calibration of the Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR), 1979-1984. Oregon State University, M.S. thesis, 248p.

Gloersen, P., and F. T. Barath. 1977. A scanning multichannel microwave radiometer for Nimbus-G and Seasat-A. IEEE J. Oceanic Eng. OE-2:172-178.

Gloersen, P., and L. Hardis. 1978. Scanning Multichannel Microwave Radiometer (SMMR) Experiment. Nimbus-7 User's Guide. NASA/Goddard Space Flight Center, Greenbelt, MD.

Contacts (for Data Production Information)

To request a copy of the data, please contact NSIDC User Services.

Document Information

Revision Date: 1 March, 1997
Review Date: March, 1997
Document ID: nsidc-0037


As a condition of using these data, you must cite the use of this data set using the following citation. For more information, see our Use and Copyright Web page.

Gloersen, P. and E. A. Francis. 2003. Nimbus-7 SMMR Antenna Temperatures. [indicate subset used]. Boulder, Colorado USA: NASA DAAC at the National Snow and Ice Data Center.

Document Curators: NSIDC Writers
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