Abstract: The SSM/I is a passive microwave sensor that detects microwave radiation at four frequencies: 19.35 GHz, 22.235 GHz, 37.0 GHz, and 85.5 GHz. The 19, 37, and 85 GHz channels have dual-polarization (vertical and horizontal), while the 22 GHz channel has only vertical polarization. This yields a total of seven channels. The instrument is a conical scanning device sweeping out an approximately 1400 km ... wide swath as it looks forward (F8 looks backward) at an angle of about 45 degrees from vertical. The instrument scans through 102 degrees for each scanning revolution. The Global Hydrology Resource Center (GHRC) has been processing and archiving Special Sensor Microwave / Imager (SSM/I) data since 1990. Prior to May 1995, the SSM/I data source for the GHRC was the National Environmental Satellite Data and Information Service (NESDIS). Since May, 1995, the source has been the Fleet Numerical Meteorology and Oceanography Center (FNMOC). Data is obtained from FNMOC and processed at the GHRC within hours of its reception. Each day full resolution or -swath- brightness temperatures (Tb's) and reduced resolution -gridded- data sets are generated. Browse images of the gridded files are created in both HDF raster and GIF formats. HDF represents the Hierarchical Data Format, the data format standard for NASA's Earth Observing System Data and Information System.
[Summary provided by the University of Alabama, Huntsville.]