Due to a problem involving the atmospheric correction algorithm used to process SMAP Level-1B (L1B) brightness temperatures, select half-orbit data files contain invalid brightness temperature values. The errors occur infrequently, about one half orbit per month, and affected files have been removed from the following data sets:
SMAP L1B Radiometer Half-Orbit Time-Ordered Brightness Temperatures (SPL1BTB), Version 3
Data Set DOI: http://dx.doi.org/10.5067/YV5VOWY5V446
SMAP L1C Radiometer Half-Orbit 36 km EASE-Grid Brightness Temperatures (SPL1CTB), Version 3
Data Set DOI: http://dx.doi.org/10.5067/E51BSP6V3KP7
SMAP L2 Radiometer Half-Orbit 36 km EASE-Grid Soil Moisture (SPL2SMP), Version 4
Data Set DOI: http://dx.doi.org/10.5067/XPJTJT812XFY
The SMAP Science Data System (SDS) team is working to correct the issue in forward processing. Until that time, files will continue to be affected with a frequency of approximately one half orbit per month. NSIDC DAAC will continue to identify and remove all affected files. Files currently affected are documented in a missing files spreadsheet, which will be updated and posted to the following How To article approximately once per month.
Users of L1B brightness temperature data will be able to identify affected files by looking at the first element in tb_lat, tb_lon, or ta_filtered_3. If the element contains the fill value -9999.00, the brightness temperatures stored in tb_v and tb_h will be invalid.
Users of L1C brightness temperature and L2 soil moisture data will need to identify the affected files based on the filenames or orbit numbers documented in the missing files spreadsheet (see the corresponding How To article).
All deleted files will be replaced during the next reprocessing from the beginning of the SMAP mission. Registered users will be notified when reprocessing occurs.