2026-04-18T22:27:43Zhttp://nsidc.org/api/dataset/metadata/oaioai:nsidc.org/SPL2SMAP.0032026-03-03T21:04:09Zcumulusnasa_nsidc_daac
SPL2SMAP.003SMAP L2 Radar/Radiometer Half-Orbit 9 km EASE-Grid Soil MoistureEntekhabi, D., Das, N., Njoku, E. G., Johnson, J. T. & Shi, J.SMAP L2 Radar/Radiometer Half-Orbit 9 km EASE-Grid Soil Moisture2016-04-29Boulder, Colorado USANASA NSIDC DAAC: NASA National Snow and Ice Data Center Distributed Active Archive Center3false10.5067/8YTYSV6JGBK2https://nsidc.org/sites/default/files/spl2smap-v003-userguide.pdfSPL2SMAPTechnical ContactNSIDCUser Servicesnsidc@nsidc.org1-303-492-61991-303-492-2468CIRES, 449 UCBUniversity of ColoradoBoulderCO80309-0449USAEARTH SCIENCESPECTRAL/ENGINEERINGMICROWAVEBRIGHTNESS TEMPERATURE EARTH SCIENCESPECTRAL/ENGINEERINGRADARSIGMA NAUGHT EARTH SCIENCELAND SURFACESOILSSOIL MOISTURE/WATER CONTENT Climatology/Meteorology/AtmosphereGeoscientific InformationEASE-Grid SM-projectL2RadarRADIOMETERSMAP-projectSMAP-project-L2Soil MoistureSoil Moisture Active PassiveSMAP L-BAND RADARSMAP L-Band RadarSMAP L-BAND RADIOMETERSMAP L-Band RadiometerSMAPSoil Moisture Active and Passive Observatory2015-04-132015-07-07complete-85.04485.044-180180GEOGRAPHIC REGIONGLOBAL LAND9 km9 km49 minuteSMAP products provide multiple means to assess quality. Each product contains bit flags, uncertainty measures, and file-level metadata that provide quality information. For information regarding the specific bit flags, uncertainty measures, and file-level metadata contained in this product, refer to the Data Fields and Metadata Fields documents.
Each 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 NSIDC. 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 each data file. QA files are ASCII text files that contain statistical information in order to help users better assess the quality of the associated data file.
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.These data are freely, openly, and fully accessible, provided that you are logged into your NASA Earthdata profile (https://urs.earthdata.nasa.gov/).These data are freely, openly, and fully available to use without restrictions, provided that you cite the data according to the recommended citation at https://nsidc.org/about/use_copyright.html. For more information on the NASA EOSDIS Data Use Policy, see https://earthdata.nasa.gov/earth-observation-data/data-use-policy.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 ColoradoBoulderCO80309-0449USAHTTPS500 MBHDF5Bolten, J., V. Lakshmi, and E. Njoku. 2003. Soil Moisture Retrieval Using the Passive/Active L- and S-band Radar/Radiometer. IEEE Trans. Geosci. Rem. Sens., 41:2792-2801.
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.
Brodzik, 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.
Das, N. N., D. Entekhabi, S. Dunbar, E. G. Njoku, and S. Yueh. 2015. Uncertainty Estimates in the SMAP Combined Active-Passive Downscaled Brightness Temperature. IEEE- TGARS. Accepted, in press.
Das, N. N., and R. S. Dunbar. 2015. SMAP Level 2 Active/Passive Soil Moisture (L2_SM_AP) Product Specification Document. SMAP Project, JPL D-72548, Jet Propulsion Laboratory, Pasadena, CA. (http://nsidc.org/data/docs/daac/smap/sp_l2_smap/pdfs/SMAP L2_SM_AP PSD_10312015.pdf, 3 MB)
Das, N. N., D. Entekhabi, E. G. Njoku, J. Johnston, J. C. Shi, and A. Colliander. 2014. Tests of the SMAP Combined Radar and Radiometer Brightness Temperature Disaggregation Algorithm Using Airborne Field Campaign Observations. IEEE-TGARS. 52:2018–2028.
Das, N. N., D. Entekhabi, and E. G. Njoku, 2011. An Algorithm for Merging SMAP Radiometer and Radar Data for High Resolution Soil Moisture Retrieval. IEEE-TGARS. 9: 1504-1512.
Das, N. N., et al. 2015. Soil Moisture Active Passive (SMAP) Project Calibration and Validation for the L2/3_SM_AP Beta-Release Data Products. SMAP Project, JPL D-93984. Jet Propulsion Laboratory, Pasadena, CA. (http://nsidc.org/data/docs/daac/smap/sp_l2_smap/pdfs/SMAP-AP_Assessment_Report_Final.pdf, 4 MB)
Entekhabi, D. et al. 2014. SMAP Handbook–Soil Moisture Active Passive: Mapping Soil Moisture and Freeze/Thaw from Space. Pasadena, CA USA: SMAP Project, JPL CL#14-2285, Jet Propulsion Laboratory.
Entekhabi, D., N. Das, E. Njoku, J. Johnson, and J. Shi. 2014.SMAP Algorithm Theoretical Basis Document: L2 & L3 Radar/Radiometer Soil Moisture (Active/Passive) Data Products. SMAP Project, JPL D-66481. Jet Propulsion Laboratory, Pasadena, CA. (http://nsidc.org/data/docs/daac/smap/sp_l2_smap/pdfs/277_L2_3_SM_AP_RevA_web.pdf, 16.6 MB)This Level-2 (L2) soil moisture product provides estimates of global land surface conditions retrieved by both the Soil Moisture Active Passive (SMAP) radar and radiometer during 6:00 a.m. descending half-orbit passes. SMAP L-band backscatter and brightness temperatures are used to derive soil moisture data, which are then resampled to an Earth-fixed, global, cylindrical 9 km Equal-Area Scalable Earth Grid, Version 2.0 (EASE-Grid 2.0).VIEW RELATED INFORMATIONhttps://nsidc.org/sites/default/files/spl2smap-v003-userguide.pdfSMAP L2 Radar/Radiometer Half-Orbit 9 km EASE-Grid Soil Moisture, Version 3 User GuideGET DATAhttps://search.earthdata.nasa.gov/search/granules?p=C2830464428-NSIDC_CPRDEarthdata SearchGET DATAhttps://cmr.earthdata.nasa.gov/virtual-directory/collections/C2830464428-NSIDC_CPRDHTTPSGET DATAhttps://nsidc.org/data/data-access-tool/SPL2SMAP/versions/3/Data Access ToolGET DATAhttps://earthaccess.readthedocs.io/en/stable/earthaccessCEOS IDN DIFVERSION 9.92016-04-292026-03-03NSIDCVersion SummaryChanges to this version include:
<ul><li>Transitioned to Validated-Stage 2</li>
<li>Uses SPL2SMA V3 Validated and SPL2SMP V3 Validated as input</li>
<li>Snapshot beta parameter estimation</li>
<li>Updated soil texture files (renormalized cases where sand+clay > 100%)</li>
<li>Updated default beta parameter</li>
</ul>
For the full major and minor version history, go to <a href="https://nsidc.org/data/smap/version-history">https://nsidc.org/data/smap/version-history</a>NSIDCMinor VersionR13080Changed with Version 3 update. 2015-04-132015-07-071NSIDCCurrent Version1NSIDCSpatial Reference SystemsEPSG:6933WGS 84 / NSIDC EASE-Grid 2.0 GlobalNSIDCLevel of ServiceComprehensiveNSIDCFull Dataset CitationEntekhabi, D., Das, N., Njoku, E. G., Johnson, J. T. & Shi, J. (2016). <i>SMAP L2 Radar/Radiometer Half-Orbit 9 km EASE-Grid Soil Moisture</i>. (SPL2SMAP, Version 3). [Data Set]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. <a href="https://doi.org/10.5067/8YTYSV6JGBK2">https://doi.org/10.5067/8YTYSV6JGBK2</a>. [<i><describe subset used if applicable></i>].NSIDCRetiredfalseNSIDCRelated Servicesapplication/vnd.nasa.cmr.umm+jsonfalsembeigmmt_service_55181S3213793274-NSIDC_CPRDNSIDC_CPRD8service2025-10-21T17:27:36.334Zhttps://harmony.earthdata.nasa.gov/NSIDC_CPRD_Harmony_Trajectory_SubsetterNOT PROVIDED1Harmony Transformation ServicesPrepare analysis ready data and reduce time-to-science. Achieve seamless access to data across different NASA data centers. Customization options, which vary by data set, can include spatial, temporal, and variable subsetting, as well as regridding and reformatting.https://harmony.earthdata.nasa.gov/docsVIEW RELATED INFORMATIONNASA Earthdata Harmony documentationPublicationURLhttps://nsidc.org/data/user-resources/help-center/search-order-and-customize-nsidc-daac-data-nasa-earthdata-searchVIEW RELATED INFORMATIONSearch, order and customize NSIDC DAAC data using NASA Earthdata SearchPublicationURLhttps://nasa-openscapes.github.io/earthdata-cloud-cookbook/tutorials/Harmony.htmlVIEW RELATED INFORMATIONSubsetting NASA Earthdata using Harmony (harmony-py)PublicationURLhttps://nsidc.org/data/user-resources/help-center/harmony-api-quickstart-guide-customizing-nasa-nsidc-daac-data-earthdata-cloudVIEW RELATED INFORMATIONHarmony API Quickstart Guide: Customizing NASA NSIDC DAAC data in Earthdata CloudPublicationURLUSER SERVICESNSIDC DAAC User ServicesEmailnsidc@nsidc.orgDATA CUSTOMIZATIONDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESDATA ACCESS/RETRIEVALDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESThis is the most current release of this service. Last updated date is unknown.DEVELOPERPUBLISHERSERVICE PROVIDERMaintenance 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://harmony.earthdata.nasa.gov/docsapplication/vnd.nasa.cmr.umm+jsonfalsebookerlmmt_service_52052S3107386427-NSIDC_CPRDNSIDC_CPRD3service2024-12-03T17:04:33.698Zhttps://cmr.earthdata.nasa.gov/virtual-directory/collections/NSIDC_CPRD_HTTPS_File_SystemNOT PROVIDED1HTTPS File SystemQuickly download a few files using a web browser, or access data through a command-line utility such as WGET.https://nsidc.org/data/user-resources/help-center/nasa-earthdata-cloud-data-access-guide#anchor-download-to-a-local-computer-from-earthdata-cloudVIEW RELATED INFORMATIONNASA Earthdata Cloud Data Access GuidePublicationURLUSER SERVICESNSIDC DAAC User ServicesEmailnsidc@nsidc.orgDATA ACCESS/RETRIEVALDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESSee https://github.com/nasa/Common-Metadata-Repository/releases for more information on the latest version.DEVELOPERMaintenance and Development, Earth Observing System Data and Information System, Earth Observing System,Goddard Space Flight Center, NASANASA/GSFC/EOS/EOSDIS/EMDORIGINATORPUBLISHERSERVICE PROVIDERNASA National Snow and Ice Data Center Distributed Active Archive CenterNASA NSIDC DAACNSIDC DAAC home pagehttps://nsidc.org/daacNASA Distributed Active Archive Center (DAAC) at NSIDC home page.https://cdn.earthdata.nasa.gov/umm/service/v1.4UMM-S1.4https://cmr.earthdata.nasa.gov/virtual-directory/collections/C2830464428-NSIDC_CPRDapplication/vnd.nasa.cmr.umm+jsonfalseamy.steikermmt_service_25004S2472217299-NSIDC_CPRDNSIDC_CPRD1service2022-09-20T22:05:06.185Zs3://nsidc-cumulus-prod-protected/NSIDC_CPRD_S3NOT PROVIDED1.0NASA Earthdata Cloud (AWS S3)Access data directly from the NASA Earthdata Cloud via Amazon Web Services Simple Storage Service (AWS S3). This access option is only available when working within the us-west-2 region and requires additional AWS S3 credentials.https://nsidc.org/data/user-resources/help-center/nasa-earthdata-cloud-data-access-guideVIEW RELATED INFORMATIONNASA Earthdata Cloud Data Access GuidePublicationURLhttps://data.nsidc.earthdatacloud.nasa.gov/s3credentialsVIEW RELATED INFORMATIONAWS S3 CredentialsPublicationURLUSER SERVICESNSIDC DAAC User ServicesEmailnsidc@nsidc.orgDATA ACCESS/RETRIEVALDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESThis is the most current release of this service. Last updated date is unknown.SERVICE PROVIDERNASA National Snow and Ice Data Center Distributed Active Archive CenterNASA NSIDC DAAChttps://cdn.earthdata.nasa.gov/umm/service/v1.4UMM-S1.4https://nsidc.org/data/user-resources/help-center/nasa-earthdata-cloud-data-access-guideNSIDCRelated Toolsapplication/vnd.nasa.cmr.umm+jsonfalsembeigmmt_tool_50907TL3010466318-NSIDC_CPRDNSIDC_CPRD4tool2024-05-28T17:29:12.271Zhttps://zenodo.org/badge/latestdoi/399867529DOWNLOAD SOFTWAREhttps://earthaccess.readthedocs.io/en/latest/DistributionURLNSIDC_CPRD_EARTHACCESSDownloadable Tool0.9.0earthaccessearthaccess is a python library to search and access NASA Earth science data with just a few lines of code.https://github.com/nsidc/earthaccessVIEW RELATED INFORMATIONGitHub RepositoryPublicationURLDATA ACCESS/RETRIEVALDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESDATA SEARCHDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESPUBLISHERNSIDC DAAC User ServicesEmailnsidc@nsidc.orgPUBLISHERNASA National Snow and Ice Data Center Distributed Active Archive Centerhttps://nsidc.org/daac/NASA NSIDC DAACPUBLISHERNational Snow and Ice Data Centerhttp://nsidc.orgNSIDCDEVELOPERAlaska Satellite Facilityhttps://www.asf.alaska.edu/ASFDEVELOPERInstitute for the Study of Earth, Oceans, and Space, University of New Hampshirehttp://www.eos.unh.edu/UNH/EOSDEVELOPERAtmospheric Science Data Center, Science Directorate, Langley Research Center, NASAhttps://asdc.larc.nasa.gov/NASA/LARC/SD/ASDCMIT License
Copyright (c) 2021 Luis Lopez
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.2024-02-29T00:00:00.000ZAs a condition of use, we request that you properly cite the earthaccess library to acknowledge the creators. Formal citations also make it easier for us to track the use and impact of our data and tools, and helps us report data distribution activity and tool usage metrics to funding agencies.
If you have used earthaccess in your research, please cite as:
Barrett, A., Battisto, C., Bourbeau, J., Fisher, M., Kaufman, D., Kennedy, J., Lopez, L., Lowndes, J., Scheick, J., & Steiker, A. (2024). earthaccess (Version 0.9.0) [Computer software]. https://doi.org/10.5281/zenodo.8365009
See https://github.com/nsidc/earthaccess/releases for more information on the latest version.https://cdn.earthdata.nasa.gov/umm/tool/v1.0UMM-T1.0Python3.8 or higherhttps://earthaccess.readthedocs.io/en/latest/application/vnd.nasa.cmr.umm+jsonfalsecrumlydmmt_tool_12314TL4019511337-NSIDC_CPRDNSIDC_CPRD1tool2026-02-11T17:42:34.275ZGOTO WEB TOOLhttps://nsidc.org/data/data-access-tool/DistributionURLNSIDC_CPRD_Data_Access_ToolWeb User Interface3.1.0Data Access ToolFilter files before downloading based on date, spatial area, or file name. Choose from various download options, such as Python script. Export bounding boxes as a GeoJSON.https://nsidc.org/support/how/search-filter-and-order-nsidc-dataVIEW RELATED INFORMATIONHow to filter and order from a data set web pagePublicationURLhttps://nsidc.org/data/user-resources/help-center/how-to-use-earthdata-downloadVIEW RELATED INFORMATIONHow to use Earthdata DownloadPublicationURLDATA SEARCHDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESDATA ACCESS/RETRIEVALDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESSERVICE PROVIDERNSIDC User ServicesEmailnsidc@nsidc.orgDEVELOPERPUBLISHERSERVICE PROVIDERNASA National Snow and Ice Data Center Distributed Active Archive Centerhttps://nsidc.org/daac/NASA NSIDC DAAC2025-04-16T00:00:00.000ZChromeFirefoxSafariSee https://github.com/nsidc/data-access-tool-ui/blob/main/CHANGELOG.md for more information on the latest version.https://cdn.earthdata.nasa.gov/umm/tool/v1.0UMM-T1.0https://nsidc.org/data/data-access-tool/SPL2SMAP/versions/3/application/vnd.nasa.cmr.umm+jsonfalsecrumlydmmt_tool_12821TL4019517520-NSIDC_CPRDNSIDC_CPRD1tool2026-02-11T17:45:02.724ZGOTO WEB TOOLhttps://search.earthdata.nasa.gov/searchDistributionURLNSIDC_CPRD_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/granules?p=C2830464428-NSIDC_CPRD