Near-real-time images are derived from gridded brightness temperatures (TBs) from the Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave Imager/Sounder (SSMIS) passive microwave radiometer. The TBs are calculated for each 25 kilometer grid cell. An algorithm is applied to produce an estimate of melt or no melt present for each grid cell. The data, images, and graphs are produced daily.
Melt data are provided by Thomas Mote at University of Georgia. The data and documentation are accessible via NSIDC as the MEaSUREs Greenland Surface Melt Daily 25km EASE-Grid 2.0 data set. This data set is based on SSMIS passive microwave data obtained from NSIDC, the Near-Real-Time DMSP SSM/I-SSMIS Daily Polar Gridded Brightness Temperatures.
Isolated areas of missing data occasionally occur in near-real-time data. The daily melt map shows any areas of missing data as dark gray regions, speckles, or spider web patterns. However, in the time series chart we account for the missing data by averaging the extent for that region from the day before and the day after the gap, a mathematical technique called interpolation.