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SSMI and SSMIS Monitoring and Documentation

SummaryDetails and DocumentsContact
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Data from the Special Sensor Microwave Imager (SSMI) instrument is collected under the Defense Meteorological Satellite Program (DMSP), which is a Department of Defense (DoD) program responsible for designing, building, launching, and operating polar-orbiting environmental satellites. In its 50 year history, 41 DMSP satellites have been successfully launched. Two satellites remain to be launched, as needed, and are maintained at the Lockheed Martin Space Systems facility in Sunnyvale, California.

The Special Sensor Microwave Imager (SSMI) is a seven channel, four frequency, linearly-polarized, passive microwave radiometric system which measures atmospheric, ocean, and terrain microwave brightness temperatures at 19.35, 22.24, 37.00, and 85.80. NOAA's National Climatic Data Center (NCDC) has undertaken the task of recovering SSMI data starting from the first successful launch of the F-8 platform in 1987.

The Special Sensor Microwave Imager/Sounder (SSMIS) sensor replaced the SSMI starting with DMSP F-16 platform which was launched on 18 October 2003 and became operational in November 2005. The SSMIS sensor is a passive conically scanning microwave radiometer that combines and extends the current imaging and sounding capabilities of three previously separate DMSP microwave sensors: the SSM/T-1 temperature sounder, the SSMI/T- 2 moisture sounder, and the SSMI. The SSMIS instrument measures microwave energy at 24 discrete frequencies from 19 to 183 GHz with a swath width of 1700 km.

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Details and Documents

Original Navy-NESDIS SSMI Data Information

  • Imagery SSMI Imagery are available for viewing from the three latest SSMI platforms (F-13, F-14, F-15). To view SSMI imagery for the last two days, check out the interactive SSMI Imagery website.

  • Statistics
    SSMI statistics were calculated on an orbit-to-orbit level. Statistical analysis includes mean, standard deviation, skewness, kurtosis and percentiles of all antenna and brightness temperatures from the three latest SSMI platforms (F-13, F-14, F-15). To view these statistics, check out the SSMI Statistics website.

  • Spatial and Spectral Coverage
    The spatial and spectral coverage of the SSMI data set are best summarized by this figure.

  • Temporal Coverage
    DMSP SSMI data began in 1987 and continues to the present time. Orbits are available thirteen to fifteen times per day with an orbital period of 101 minutes.

  • Data Record Format Descriptions
    The SSMI product format descriptions are contained in three separate documents: Antenna temperatures, known as Temperature Data Records (TDR), brightness temperatures, known as Sensor Data Records (SDR), and geophysical parameters, known as Environmental Data Records (EDR).

  • User Manual
    A comprehensive guide to the DMSP SSMI data is contained in the SSMI User's Interpretation Guide, (5.0 Mb) published by Raytheon Systems Company, 2000.

Original Navy-NESDIS SSMIS Data Information

Detailed spectral or channel information can be found in this table and this table. The SSMIS Temperature Data Record (TDR) document describes antenna temperature data. The Sensor Data Record (SDR) document describes brightness temperature data. Other relevant documents for the SSMIS instrument are:

NOAA Center for Satellite Applications and Research (STAR) Recalibrated SSMIS TDR Data (HDF-EOS format)

Other possible changes in data formats are currently being investigated. In the near future, SSMI and SSMIS TDR/SDR data will be provided in a netCDF format.

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Data Access
To obtain DMSP SSMI/SSMIS TDR, SDR, and EDR data, go to NOAA's Comprehensive Large Array-data Stewardship System (CLASS) website.

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Satellite Services Group
National Climatic Data Center
Room 120
151 Patton Avenue
Asheville, North Carolina 28801-5001
Telephone: 828-271-4850
Facsimile: 828-271-4876