SSMI and SSMIS Monitoring and Documentation

Summary

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. By the year 2010 the military and civilian operational meteorological satellite systems will be merged into a single, national program. This program is known as the National Polar-orbiting Operational Environmental Satellite System (NPOESS), and is designed to employ three or more satellites to integrate remote sensing, surface data collection, and search and rescue payloads. This system will replace both the Polar-orbiting Operational Environmental Satellite (POES) and the DMSP series.

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) is undertaking the task of recovering SSMI data starting from the first successful launch of the F-8 platform in 1987.

The first Special Sensor Microwave Imager/Sounder (SSMIS) sensor is onboard the DMSP F-16 platform that 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.

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:

• SSMIS Calibration/Validation (Cal/Val) Final Report (Nov. 2005) (warning! 142 Mb PDF file)
• Algorithm and Data User Manual (ADUM) for the Special Sensor Microwave Imager/Sounder (SSMIS)
• SSMIS Upper Air Sounding Algorithm
• SSMIS Lower Air Temperature and Thickness Retrieval Algorithm
• SSMIS Lower Air Humidity Sounding Algorithm
• SSMIS Beam Location Algorithm
• Doppler Correction Algorithm in Brightness Temperature Computation

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

• SSMIS TDR Calibration/Validation Technical Report (March 2007)

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.

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

Contact

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
E-mail: ncdc.satorder@noaa.gov