The issues causing Antenna Scan Angle (ASA) errors in the most recent re-processed SMAP data sets, accessible through the NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC), have been resolved and the bad files have been replaced. The ASA errors occurred in selected Level-1 half-orbits and propagated into the associated Level-2, -3, and -4 products. ASA errors affected data files between 05 October 2019 and 23 November 2019, as well as selected dates in 2020, specifically 04-05 February, 09 April, 30 May, and 18 June. The ASA errors resulted in a geolocation offset of up to 99 km in the along scan direction. Replacement files are now available at the NSIDC DAAC. Users can identify the replacement files in one of two ways:
- The product counter at the end of the file ID is greater than 001 (e.g. SMAP_L1B_TB_25702_D_20191123T232457_R17000_002.h5) or
- Files before 29 April 2021 that have a Composite Record Identification (CRID) number of R17030 (e.g. SMAP_L1B_TB_33446_D_20210506T113030_R17030_001.h5)
Access to the data and documentation is provided on the data set web page at the NSIDC DAAC: https://nsidc.org/data/smap