Assessment of version 4 of the SMAP passive soil moisture standard product

P. O'Neill, S. Chan, R. Bindlish, T. Jackson, A. Colliander, S. Dunbar, F. Chen, J. Piepmeier, S. Yueh, D. Entekhabi, M. Cosh, T. Caldwell, J. Walker, X. Wu, A. Berg, T. Rowlandson, A. Pacheco, H. McNairn, M. Thibeault, J. Martinez-FernandezA. Gonzalez-Zamora, E. Lopez-Baeza, F. Udall, M. Seyfried, D. Bosch, P. Starks, C. Holifield, J. Prueger, Z. Su, R. Van Der Velde, J. Asanuma, M. Palecki, E. Small, M. Zreda, J. C. Calvet, W. Crow, Y. Kerr

Research output: Chapter in Book/Report/Conference proceedingConference PaperOther

7 Citations (Scopus)


NASA's Soil Moisture Active Passive (SMAP) mission launched on January 31, 2015 into a sun-synchronous 6 am/6 pm orbit with an objective to produce global mapping of high-resolution soil moisture and freeze-thaw state every 2-3 days. The SMAP radiometer began acquiring routine science data on March 31, 2015 and continues to operate nominally. SMAP's radiometer-derived standard soil moisture product (L2SMP) provides soil moisture estimates posted on a 36-km fixed Earth grid using brightness temperature observations and ancillary data. A beta quality version of L2SMP was released to the public in October, 2015, Version 3 validated L2SMP soil moisture data were released in May, 2016, and Version 4 L2SMP data were released in December, 2016. Version 4 data are processed using the same soil moisture retrieval algorithms as previous versions, but now include retrieved soil moisture from both the 6 am descending orbits and the 6 pm ascending orbits. Validation of 19 months of the standard L2SMP product was done for both AM and PM retrievals using in situ measurements from global core cal/val sites. Accuracy of the soil moisture retrievals averaged over the core sites showed that SMAP accuracy requirements are being met.

Original languageEnglish
Title of host publication2017 IEEE International Geoscience and Remote Sensing Symposium
Subtitle of host publicationInternational Cooperation for Global Awareness, IGARSS 2017 - Proceedings
PublisherIEEE, Institute of Electrical and Electronics Engineers
Number of pages4
ISBN (Electronic)9781509049516
Publication statusPublished - 1 Dec 2017
EventIEEE International Geoscience and Remote Sensing Symposium 2017 - Fort Worth, United States of America
Duration: 23 Jul 201728 Jul 2017
Conference number: 37th (Proceedings)


ConferenceIEEE International Geoscience and Remote Sensing Symposium 2017
Abbreviated titleIGARSS 2017
Country/TerritoryUnited States of America
CityFort Worth
Internet address


  • Accuracy assessment
  • Cal/val
  • Passive microwave
  • SMAP
  • Soil moisture

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