This data set is retired and no longer available for download. We recommend using MEaSUREs Calibrated Enhanced-Resolution Passive Microwave Daily EASE-Grid 2.0 Brightness Temperature ESDR data set as an alternative. This data set contains enhanced-resolution brightness temperatures produced using the Scatterometer Image Reconstruction (SIR) algorithm developed by the Microwave Earth Remote Sensing (MERS) group at Brigham Young University (BYU). Enhanced-resolution brightness temperature images for the Arctic and Antarctic were generated using antenna temperature data from the Special Sensor Microwave/Imager (SSM/I) and the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) instrument. SSM/I images are available for 1995 through 2008, and AMSR-E images are available for 2002 through 2010. All available measurements for a single day are averaged into twice-daily gridded files for three different equal-area spatial coverages: Northern Hemisphere, Southern Hemisphere, and full global. The spatial resolution is 12.5 km for SSM/I channels 19 and 22 GHz, 7.5 km for 37 GHz, and 2.5 km for the 85 GHz channel. For AMSR-E, the resolution is 12.5 km for the 6, 10, 18, and 23 GHz channels; 7.5 km for the 36 GHz channel; and 2.5 km for the 89 GHz channel. Software for reading the SIR-formatted SSM/I and AMSR-E data is also available. As scatterometer and radiometer data complement each other, these enhanced-resolution radiometer data, together with SIR format scatterometer data available from BYU, will facilitate polar research that combines information from both radiometers and scatterometers. Data are stored as scaled 2-byte integers in binary arrays with a 512-byte header and are available via FTP.