The SMAP Project performs annual reprocessing of all its science data products based on improvements in the algorithms and supporting information. As part of this routine reprocessing, the SMAP Science Data System (SDS) has now released new versions of the following four Level-2 and -3 data products, accessible through the NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC):
SMAP L2 Radiometer Half-Orbit 36km EASE-Grid Soil Moisture, Version 8
SMAP Enhanced L2 Radiometer Half-Orbit 9 km EASE-Grid Soil Moisture, Version 5
SMAP L3 Radiometer Global Daily 36 km EASE-Grid Soil Moisture, Version 8
SMAP Enhanced L3 Radiometer Global and Polar Grid Daily 9 km EASE-Grid Soil Moisture, Version 5
The main change in these versions is that the baseline algorithm is now the Dual Channel Algorithm (DCA) as it has been shown to perform slightly better than the Single Channel Algorithm - Vertical Polarization (SCA-V), especially over agricultural croplands.
For the Level-2 and -3 enhanced products, the data are now also available in a 9 km EASE-Grid north polar projection, which is intended to mitigate the distortion of global-grid cells at high northern latitudes (> 50N). And for both L2 Soil Moisture products, two soil texture variables have been added: organic_content and sand_fraction.
Visit the NSIDC DAAC SMAP Data Collection for access to these data sets and documentation.