Polar Pathfinder Sampler (PPSM): SMMR and SSM/I Pathfinder brightness temperature data (1978-1987)

The SMMR and SSM/I Pathfinder brightness temperatures provide scientists with more than 20 years of consistently processed, passive microwave data for use in climatological and earth science research. Each file represents gridded data for a single sensor channel and polarization, derived from either ascending or descending orbits for one day, thereby allowing discrimination of diurnal changes in earth surface processes. Each data sets consists of three series: the Northern and Southern Hemispheres and a global projection. Grids represent spatially interpolated data. The interpolation techniques maximize the radiometric integrity of original brightness temperature values, maintain high spatial and temporal precision, and involve no averaging of original swath data. SMMR coverage began October 1978 and continued through July 1987. Grid resolution is 25 km for all channels. SSM/I coverage began August 1987 and continues through the present. Processing is ongoing with current data available within three to six months of sensor data acquisition. Resolution is 25 km for all channels and 12.5 km for the 85 GHz channels. A sample data set comprising selected SSM/I EASE-Grid brightness temperature data and time files for all three projections from September 8 (day 251), 1997 is included on this CD-ROM.