2024-03-19T11:13:25Zhttp://nsidc.org/api/dataset/metadata/oaioai:nsidc.org/SPL2SMP_E.0022024-01-25T13:16:54Zecsretirednasa_nsidc_daac
SPL2SMP_E.002SMAP Enhanced L2 Radiometer Half-Orbit 9 km EASE-Grid Soil MoistureO'Neill, P. E., S. Chan, E. G. Njoku, T. Jackson, and R. Bindlish.SMAP Enhanced L2 Radiometer Half-Orbit 9 km EASE-Grid Soil Moisture2018-06-06Boulder, Colorado USANASA NSIDC DAAC: NASA National Snow and Ice Data Center Distributed Active Archive Center2false10.5067/K4A1SNL5DLONhttps://doi.org/10.5067/K4A1SNL5DLONSPL2SMP_ETechnical ContactNSIDCUser Servicesnsidc@nsidc.org1-303-492-61991-303-492-2468CIRES, 449 UCBUniversity of ColoradoBoulderCO80309-0449USAEARTH SCIENCESpectral/EngineeringMicrowaveBrightness Temperature BRIGHTNESS TEMPERATUREEARTH SCIENCELand SurfaceSoilsSoil Moisture/Water Content SOIL MOISTUREGeoscientific InformationClimatology/Meteorology/AtmosphereEASE-Grid SM-projectSMAP-projectSMAP-project-L2SMAP L-BAND RADIOMETERSMAP L-BAND RADIOMETERSMAP ObservatorySoil Moisture Active and Passive Observatory2015-03-312019-08-13complete-85.04485.044-180180Geographic RegionGlobal Land9 km9 km49 minuteSMAPSoil Moisture Active PassiveEach 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).As a condition of using these data, you must cite the use of this data set using the recommended citation. For more information, see our Use and Copyright web page at https://nsidc.org/about/use_copyright.html.These data are offered free of charge. You may use these data freely, provided that you cite NSIDC DAAC as the source, and provide an acknowledgment in any published papers.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 ColoradoBoulderCO80309-0449USAHTTPS300 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. https://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. https://dx.doi.org/10.3390/ijgi1010032.
Chan, S., R. Bindlish, P. O'Neill, E. Njoku, T. Jackson, A. Colliander, F. Chen, M. Mariko, S. Dunbar, 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-Fernandez, A. Gonzalez-Zamora, M. Seyfried, D. Bosch, P. Starks, D. Goodrich, J. Prueger, M. Palecki, E. Small, M. Zreda, J. Calvet, W. Crow, and Y. Kerr. 2016. Assessment of the SMAP Passive Soil Moisture Product. IEEE Trans. Geosci. Remote Sens. 54(8):4994-5007. https://dx.doi.org/10.1109/TGRS.2016.2561938.
Chan, S. K., R. Bindlish, P. O'Neill, T. Jackson, E. Njoku, S. Dunbar, J. Chaubell, J. Piepmeier, S. Yueh, D. Entekhabi, A. Colliander, F. Chen, M. H. Cosh, T. Caldwell, J. Walker, A. Berg, H. McNairn, M. Thibeault, J. Martiinez-Fernandez, F. Uldall, M. Seyfried, D. Bosch, P. Starks, C. Holifield Collins, J. Prueger, R. van der Velde, J. Asanuma, M. Palecki, E. E. Small, M. Zreda, J. Calvet, W. T. Crow, Y. Kerr, 2018. Development and assessment of the SMAP enhanced passive soil moisture product, Remote Sensing of Environment, 204: 931-941. https://doi.org/10.1016/j.rse.2017.08.025.
Jet Propulsion Laboratory (JPL). "SMAP Instrument." JPL SMAP Soil Moisture Active Passive. https://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. 2016. SMAP Algorithm Theoretical Basis Document: Level 2 & 3 Soil Moisture (Passive) Data Products, Revision C. SMAP Project, JPL D-66480, Jet Propulsion Laboratory, Pasadena, CA. (PDF, 4.9 MB; see Technical References)
Owe, M., De Jeu, R. A. M., and Walker, J. P. 2015. 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.
Poe, G. A. 1990. Optimum Interpolation of Imaging Microwave Radiometer Data. IEEE Transactions on Geoscience and Remote Sensing 28(5):800-810.
This enhanced Level-2 (L2) product contains calibrated, geolocated, brightness temperatures acquired by the Soil Moisture Active Passive (SMAP) radiometer during 6:00 a.m. descending and 6:00 p.m. ascending half-orbit passes. This product is derived from SMAP Level-1B (L1B) interpolated antenna temperatures. Backus-Gilbert optimal interpolation techniques are used to extract maximum information from SMAP antenna temperatures and convert them to brightness temperatures, which are posted to the 9 km Equal-Area Scalable Earth Grid, Version 2.0 (EASE-Grid 2.0) in a global cylindrical projection.VIEW RELATED INFORMATIONhttps://doi.org/10.5067/K4A1SNL5DLONDocumentationGET DATAhttps://nsidc.org/data/data-access-tool/SPL2SMP_E/versions/2/Data Access ToolCEOS IDN DIFVERSION 9.92018-06-062024-01-25NSIDCVersion Summary<p>Changes to this version include:</p>
<ul>
<li>Level-1B water-corrected brightness temperatures are used in passive soil moisture retrieval. This procedure corrects for anomalous soil moisture values seen near coastlines in the previous version and should result in less rejected data due to waterbody contamination. Five new data fields accommodate this correction: grid_surface_status, surface_water_fraction_mb_h, surface_water_fraction_mb_v, tb_h_uncorrected, and tb_v_uncorrected.</li>
<li>Improved depth correction for effective soil temperature used in passive soil moisture retrieval; new results are captured in the surface_temperature data field. This correction reduces the dry bias seen when comparing SMAP data to in situ data from the core validation sites.</li>
<li>Frozen ground flag updated to reflect improved freeze/thaw detection algorithm, providing better accuracy; new results are captured in bit 7 of surface_flag.
</li>
</ul>NSIDCMinor VersionR16000<ul>Changed with Version 2 update. Changes include:
<li>Level-1B water-corrected brightness temperatures are used in passive soil moisture retrieval. This procedure corrects for anomalous soil moisture values seen near coastlines in the previous version and should result in less rejected data due to waterbody contamination. Five new data fields accommodate this correction: grid_surface_status, surface_water_fraction_mb_h, surface_water_fraction_mb_v, tb_h_uncorrected, and tb_v_uncorrected.</li>
<li>Improved depth correction for effective soil temperature used in passive soil moisture retrieval; new results are captured in the surface_temperature data field. This correction reduces the dry bias seen when comparing SMAP data to in situ data from the core validation sites.</li>
<li>Frozen ground flag updated to reflect improved freeze/thaw detection algorithm, providing better accuracy; new results are captured in bit 7 of the surface_flag.</li></ul>2015-03-312018-06-141R16010No science change. CRID incremented to coincide with updates to L1-L3 radiometer products.2015-03-312018-11-072R16020Corrects an issue that occurred during cold-sky maneuvers, when the spacecraft nadir angle changed beyond normal ranges, causing data processing to fail for approximately 30 half-orbits. Half-orbits were reprocessed using the Earth incidence angles of the footprints and by setting a threshold beyond which data are ignored.2015-03-312018-12-313R16022No science change. CRID incremented to coincide with an update to the radiometer reflector ancillary file for January through December 2019.2018-12-312019-08-134NSIDCSpatial Reference SystemsEPSG:6933WGS 84 / NSIDC EASE-Grid 2.0 GlobalNSIDCLevel of ServiceNo Data AccessNSIDCFull Dataset CitationO'Neill, P. E., S. Chan, E. G. Njoku, T. Jackson, and R. Bindlish. 2018. <i>SMAP Enhanced L2 Radiometer Half-Orbit 9 km EASE-Grid Soil Moisture.</i> Version 2. [indicate subset used]. Boulder, Colorado USA: NASA National Snow and Ice Data Center Distributed Active Archive Center. <a href="https://doi.org/10.5067/K4A1SNL5DLON">https://doi.org/10.5067/K4A1SNL5DLON</a>. [Date Accessed].NSIDCRetiredtrueNSIDCRelated Servicesapplication/vnd.nasa.cmr.umm+jsonfalsejroebuckmmt_service_14315S2011082551-NSIDC_ECSNSIDC_ECS8service2023-05-11T22:54:38.255Zhttps://n5eil02u.ecs.nsidc.org/egi/requestNSIDC_ECS_EGI_API_SMAP_L1L2_PSESI23.1Customized Programmatic Data Access ServiceProgrammatically request selected data products through our API. This tool is valuable for selecting just the parameters you need from big data sets. Apply spatial and temporal filters, subsetting, reformatting, and reprojection.https://nsidc.org/support/how/how-do-i-programmatically-request-data-servicesVIEW RELATED INFORMATIONProgrammatic Data Access GuidePublicationURLUSER SERVICESNSIDC DAAC User ServicesEmailnsidc@nsidc.orgESRIGeoJSONKMLfalsetrueHDF5ASCIIGEOTIFFHDF-EOS5HDF5KMLNETCDF-3NETCDF-4WGS 84 / NSIDC EASE-Grid NorthEPSG:6931WGS 84 / NSIDC EASE-Grid GlobalEPSG:6933WGS 84 / NSIDC EASE-Grid SouthEPSG:6932GeographicEPSG:4326Polar StereographicUTM Northern HemisphereUTM Southern Hemisphere2023-04-19T00:00:00.000ZDATA INTEROPERABILITYDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESDATA REFORMATTINGDATA ACCESS/RETRIEVALDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESDATA CUSTOMIZATIONDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESREPROJECTIONSUBSETTING/SUPERSETTINGDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESSPATIAL SUBSETTINGSUBSETTING/SUPERSETTINGDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESVARIABLE SUBSETTINGThis is the most current release of this service.SERVICE PROVIDERNASA National Snow and Ice Data Center Distributed Active Archive CenterNASA NSIDC DAACNASA Distributed Active Archive Center (DAAC) at NSIDChttps://nsidc.org/daacNSIDC DAAC home page.DEVELOPERORIGINATORPUBLISHERMaintenance and Development, Earth Observing System Data and Information System, Earth Observing System,Goddard Space Flight Center, NASANASA/GSFC/EOS/EOSDIS/EMDEOSDIS Core System Maintenance and Developmenthttps://earthdata.nasa.gov/eosdisEOSDIS home page.https://cdn.earthdata.nasa.gov/umm/service/v1.4UMM-S1.4https://nsidc.org/support/how/how-do-i-programmatically-request-data-servicesapplication/vnd.nasa.cmr.umm+jsonfalsetdwilliaNSIDC_ECS_PROD_ECHO_ORDERS_serviceS1568899363-NSIDC_ECSNSIDC_ECS8service2023-05-31T15:37:55.746Zhttps://n5eil02u.ecs.nsidc.org/ops/cobi/ECHO ORDERS Service for NSIDC_ECS EOSDIS Service ImplementationNSIDC_ECS_ECHO_ORDERSECHO ORDERS1NSIDC_ECS EOSDIS ECHO ORDERS Service ImplementationNSIDC_ECS EOSDIS ECHO ORDERS Service ImplementationAvailableNONEDATA ACCESS/RETRIEVALDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESDATA DELIVERYDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESNONEPUBLISHERNASA National Snow and Ice Data Center Distributed Active Archive CenterNASA/NSIDChttps://cdn.earthdata.nasa.gov/umm/service/v1.4UMM-S1.4https://n5eil02u.ecs.nsidc.org/ops/cobi/application/vnd.nasa.cmr.umm+jsonfalseamy.steikermmt_service_12641S1977894169-NSIDC_ECSNSIDC_ECS9service2022-07-01T18:43:22.565Zhttps://n5eil01u.ecs.nsidc.org/NSIDC_ECS_DAAC_HTTPS_File_SystemNOT PROVIDED20.2HTTPS File SystemQuickly download a few files using a web browser, or access data through a command-line utility such as WGET.https://nsidc.org/support/how/how-do-i-programmatically-request-data-servicesVIEW RELATED INFORMATIONProgrammatic Data Access GuidePublicationURLUSER SERVICESNSIDC DAAC User ServicesEmailnsidc@nsidc.org2020-10-21T00:00:00.000ZDATA ACCESS/RETRIEVALDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESThis is the most current release of this service.ORIGINATORPUBLISHERSERVICE PROVIDERNASA National Snow and Ice Data Center Distributed Active Archive CenterNASA NSIDC DAACNASA Distributed Active Archive Center (DAAC) at NSIDChttps://nsidc.org/daacNSIDC DAAC home pageDEVELOPERMaintenance and Development, Earth Observing System Data and Information System, Earth Observing System,Goddard Space Flight Center, NASANASA/GSFC/EOS/EOSDIS/EMDhttps://cdn.earthdata.nasa.gov/umm/service/v1.4UMM-S1.4https://nsidc.org/support/how/how-do-i-programmatically-request-data-servicesNSIDCRelated Toolsapplication/vnd.nasa.cmr.umm+jsonfalseamy.steikermmt_tool_12821TL1977971361-NSIDC_ECSNSIDC_ECS6tool2022-07-01T18:41:00.427ZGOTO WEB TOOLhttps://search.earthdata.nasa.gov/searchDistributionURLNSIDC_ECS_NASA_Earthdata_SearchWeb User Interface1NASA Earthdata SearchSearch and order data from all NASA DAACs using spatial and temporal filters in a map interface. Reformatting, reprojecting, and subsetting options are available for some data sets.https://nsidc.org/support/how/search-order-and-customize-nsidc-daac-data-nasa-earthdata-searchVIEW RELATED INFORMATIONHow to search, order, and customize data with NASA Earthdata SearchPublicationURLDATA VISUALIZATIONDATA ANALYSIS AND VISUALIZATIONEARTH SCIENCE SERVICESDATA SEARCHDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESDATA ACCESS/RETRIEVALDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESSERVICE PROVIDERNSIDC DAAC User ServicesEmailnsidc@nsidc.orgSERVICE PROVIDEREarthdata Service DeskEmailsupport@earthdata.nasa.govAUTHORDEVELOPERORIGINATORPUBLISHERMaintenance and Development, Earth Observing System Data and Information System, Earth Observing System,Goddard Space Flight Center, NASAhttp://newsroom.gsfc.nasa.gov/NASA/GSFC/EOS/EOSDIS/EMDChromeFirefoxSafariThis is the most current release of this tool.https://cdn.earthdata.nasa.gov/umm/tool/v1.0UMM-T1.0https://search.earthdata.nasa.gov/search