2026-07-23T12:09:02Zhttp://nsidc.org/api/dataset/metadata/oaioai:nsidc.org/SPL2SMP.0032026-03-23T21:16:40Zcumulusretirednasa_nsidc_daac
SPL2SMP.003SMAP L2 Radiometer Half-Orbit 36 km EASE-Grid Soil MoistureO'Neill, P. E., Chan, S., Njoku, E. G., Jackson, T. & Bindlish, R.SMAP L2 Radiometer Half-Orbit 36 km EASE-Grid Soil Moisture2016-04-29Boulder, Colorado USANASA NSIDC DAAC: NASA National Snow and Ice Data Center Distributed Active Archive Center3false10.5067/PLRS64IU03IThttps://nsidc.org/sites/default/files/documents/user-guide/spl2smp-v003-userguide.pdfSPL2SMPTechnical ContactNSIDCUser Servicesnsidc@nsidc.org1-303-492-61991-303-492-2468CIRES, 449 UCBUniversity of ColoradoBoulderCO80309-0449USAEARTH SCIENCESPECTRAL/ENGINEERINGMICROWAVEBRIGHTNESS TEMPERATURE EARTH SCIENCELAND SURFACESOILSSOIL MOISTURE/WATER CONTENT Climatology/Meteorology/AtmosphereGeoscientific InformationSMAP-projectSoil MoistureSoil Moisture Active PassiveSMAP L-BAND RADARSMAP L-Band RadarSMAPSoil Moisture Active and Passive Observatory2015-03-312016-12-07deprecated-85.04485.044-180180GEOGRAPHIC REGIONGLOBAL LAND36 km36 km49 minuteEach HDF5 file contains metadata with Quality Assessment (QA) metadata flags that are set by the Science Data Processing System (SDS) at the JPL prior to delivery to the National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC). A separate metadata file with an .xml file extension is also delivered to NSIDC with the HDF5 file; it contains the same information as the HDF5 file-level metadata.
A separate QA file with a .qa file extension is also associated with the HDF5 file; it contains useful statistics such as the percentage of elements having various quality conditions. If a product does not fail QA, it is ready to be used for higher-level processing, browse generation, active science QA, archive, and distribution. If a product fails QA, it is never delivered to NSIDC DAAC.
The information in the following sections has been adapted from O'Neill et al. (2015).These data have been retired and are no longer accessible, though a more recent version of these data may be available.These data have been retired and are no longer available for use, though a more recent version of these data may be available. Cite any prior or planned use of these data according to the recommended citation at https://nsidc.org/about/data-use-and-copyright. For more information on the NASA ESDIS Data Use Guidance, see https://www.earthdata.nasa.gov/engage/open-data-services-software-policies/data-use-guidance.EnglishNASA/JPL/SMAPNASA NSIDC DAACNASA National Snow and Ice Data Center Distributed Active Archive Centerhttps://nsidc.org/daacData Center ContactNSIDCUser Servicesnsidc@nsidc.org1-303-492-6199National Snow and Ice Data CenterCIRES, 449 UCBUniversity of ColoradoBoulderCO80309-0449USAHTTPS21 MBHDF5FTP21 MBHDF5Brodzik, M. J., B. Billingsley, T. Haran, B. Raup, and M. H. Savoie. 2014. Correction: Brodzik, M. J. et al. EASE-Grid 2.0: Incremental but Significant Improvements for Earth-Gridded Data Sets. ISPRS Int. J. Geo-Inf 2012. 1(1):32-45 ISPRS Int. J. Geo-Inf. 3(3):1154-1156. http://dx.doi.org/10.3390/ijgi3031154.
Brodzik, M. J., B. Billingsley, T. Haran, B. Raup, and M. H. Savoie. 2012. EASE-Grid 2.0: Incremental but Significant Improvements for Earth-Gridded Data Sets. ISPRS Int. J. Geo-Inf. 1(1):32-45. http://dx.doi.org/10.3390/ijgi1010032.
Chan, Steven, and R. Scott Dunbar. 2015. Soil Moisture Active Passive (SMAP) Level 2 Passive Soil Moisture Product Specification Document, Beta Release. Pasadena, CA USA: SMAP Project, JPL D-72547, Jet Propulsion Laboratory. (http://nsidc.org/data/docs/daac/smap/sp_l2_smp/pdfs/SMAP L2_SM_P Beta-Level PSD (PRIMARY).pdf, 421 KB)
Entekhabi, Dara et al. 2014. SMAP Handbook–Soil Moisture Active Passive: Mapping Soil Moisture and Freeze/Thaw from Space. SMAP Project, JPL CL#14-2285, Jet Propulsion Laboratory, Pasadena, CA.(https://smap.jpl.nasa.gov/files/smap2/SMAP_Handbook_FINAL_1_JULY_2014_Web.pdf, 4.1 MB)
Jackson, T., P. O'Neill, E. Njoku, S., Chan, R. Bindlish, A. Colliander, F. Chen, M. Burgin, S. Dunbar, J. Piepmeier, M. Cosh, T. Caldwell, J. Walker, X. Wu, A. Berg, T. Rowlandson, A. Pacheco, H. McNairn, M. Thibeault, J. Martínez-Fernández, Á. González-Zamora, M. Seyfried, D. Bosch, P. Starks, D. Goodrich, J. Prueger, M. Palecki, E. Small, M. Zreda, J. Calvet, W. Crow, Y. Kerr, S. Yueh, and D. Entekhabi. 2015. Calibration and Validation for the L2/3_SM_P Beta-Release Data Products, Version 2. SMAP Project, JPL D - 93981. Jet Propulsion Laboratory, Pasadena, CA. (http://nsidc.org/data/docs/daac/smap/sp_l2_smp/pdfs/SMAP L2_SM_P Beta-Level Assessment Report FINAL.pdf, 3 MB)
Jackson, T., P. O'Neill, E. Njoku, S., Chan, R. Bindlish, A. Colliander, F. Chen, M. Burgin, S. Dunbar, J. Piepmeier, M. Cosh, T. Caldwell, J. Walker, X. Wu, A. Berg, T. Rowlandson, A. Pacheco, H. McNairn, M. Thibeault, J. Martínez-Fernández, Á. González-Zamora, M. Seyfried, D. Bosch, P. Starks, D. Goodrich, J. Prueger, M. Palecki, E. Small, M. Zreda, J. Calvet, W. Crow, Y. Kerr, S. Yueh, and D. Entekhabi. 2016. Calibration and Validation for the L2/3_SM_P Version 3 Data Products. SMAP Project, JPL D - 93720. Jet Propulsion Laboratory, Pasadena, CA. (http://nsidc.org/data/docs/daac/smap/sp_l2_smp/pdfs/L2SMP_validated_assess_rpt_rel2_v10a_final.pdf, 4.11 MB)
Jet Propulsion Laboratory (JPL). "SMAP Instrument." JPL SMAP Soil Moisture Active Passive. http://smap.jpl.nasa.gov/observatory/instrument/ [20 August 2015].
NASA EOSDIS Land Processes DAAC. 2015. Land Water Mask Derived from MODIS and SRTM L3 Global 250m SIN Grid. Version 005. NASA EOSDIS Land Processes DAAC, USGS Earth Resources Observation and Science (EROS) Center, Sioux Falls, SD. (https://lpdaac.usgs.gov/dataset_discovery/modis/modis_products_table/mod44w), [20 August 2015].
O'Neill, P. E., E. G. Njoku, T. J. Jackson, S. Chan, and R. Bindlish. 2015. SMAP Algorithm Theoretical Basis Document: Level 2 & 3 Soil Moisture (Passive) Data Products. SMAP Project, JPL D-66480, Jet Propulsion Laboratory, Pasadena, CA. (https://nsidc.org/data/docs/daac/smap/sp_l2_smp/pdfs/L2_SM_P_ATBD_v7_Sep2015-po-en.pdf. 3.3 MB)
Owe, M., De Jeu, R. A. M., and Walker, J. P. A Methodology for Surface Soil Moisture and Vegetation Optical Depth Retrieval Using the Microwave Polarization Difference Index. IEEE Transactions on Geoscience and Remote Sensing, 39(8): 1643–1654, 2001.
Piepmeier, J.R., D.G. Long, and E.G. Njoku. 2008. Stokes Antenna Temperatures. IEEE Trans. Geosci. Remote Sens. 46(2):516-527.This Level-2 (L2) soil moisture product provides estimates of global land surface conditions retrieved by the Soil Moisture Active Passive (SMAP) passive microwave radiometer during 6:00 a.m. descending half-orbit passes. SMAP L-band brightness temperatures are used to derive soil moisture data, which are then resampled to an Earth-fixed, global, cylindrical 36 km Equal-Area Scalable Earth Grid, Version 2.0 (EASE-Grid 2.0).VIEW RELATED INFORMATIONhttps://nsidc.org/sites/default/files/documents/user-guide/spl2smp-v003-userguide.pdfSMAP L2 Radiometer Half-Orbit 36 km EASE-Grid Soil Moisture, Version 3 User GuideVIEW RELATED INFORMATIONhttp://nsidc.org/data/smap/index.htmlSMAP Data at NASA NSIDC DAACVIEW RELATED INFORMATIONhttp://nsidc.org/data/smap/validation/val-data.htmlSMAP Validation Data at NASA NSIDC DAACPROJECT HOME PAGEhttp://smap.jpl.nasa.gov/SMAP Web Site at the Jet Propulsion LaboratoryVIEW RELATED INFORMATIONhttps://www.asf.alaska.edu/smap/SMAP Data at NASA ASF DAACVIEW RELATED INFORMATIONhttps://nsidc.org/data/docs/daac/smap/sp_l2_smp/pdfs/L2_SM_P_ATBD_v7_Sep2015-po-en.pdfAlgorithm Theoretical Basis Document (ATBD)CEOS IDN DIFVERSION 9.92016-04-292026-03-23NSIDCVersion SummaryChanges to this version include: (1) Transitioned to Validated-Stage 2. (2) Uses updated SPL1CTB V3 Validated data as input.NSIDCMinor VersionR13080Changed with Version 3 update. 2015-03-312016-12-071NSIDCLevel of ServiceNo Data AccessNSIDCFull Dataset CitationO'Neill, P. E., Chan, S., Njoku, E. G., Jackson, T. & Bindlish, R. (2016). <i>SMAP L2 Radiometer Half-Orbit 36 km EASE-Grid Soil Moisture</i>. (SPL2SMP, Version 3). [Data Set]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. <a href="https://doi.org/10.5067/PLRS64IU03IT">https://doi.org/10.5067/PLRS64IU03IT</a>. [<i><describe subset used if applicable></i>].NSIDCRetiredtrue