N: 85.044 S: -85.044 E: 180 W: -180
TABLE OF CONTENTS
Description
This Level-3 (L3) soil moisture product provides a composite of daily estimates of global land surface conditions retrieved by the Soil Moisture Active Passive (SMAP) passive microwave radiometer. SMAP L-band soil moisture data are resampled to a global, cylindrical 36 km Equal-Area Scalable Earth Grid, Version 2.0 (EASE-Grid 2.0).
Version Description
Changes to this version include:
• An improved processing methodology was applied to the input Level-2 radiometer brightness temperatures.
• The data algorithms, structure, content, or processor code are otherwise unchanged from the previous version.
For the full major and minor version history, go to https://nsidc.org/data/smap/version-history
Product Summary
Platforms
Instruments
Spatial Extent
Spatial Resolution
36 Kilometers x 36 Kilometers
Spatial Reference System(s)
WGS 84 / NSIDC EASE-Grid 2.0 Global (EPSG:6933)
Location
GLOBAL LAND
Coordinate System
CARTESIAN
Granule Spatial Representation
CARTESIAN
Temporal Extent
2015-03-31 to Present
Temporal Resolution
1 Day
Concept ID
C2938664585-NSIDC_CPRD
Data State
ACTIVE
Number of Files/Granules
4101
Processing Level
3
Published
Science Keywords
Brightness Temperature
,
Surface Soil Moisture
Citation
Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.
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ONeill, P., Chan, S., Njoku, E., Jackson, T., Bindlish, R., & Chaubell, J. (2023). SMAP L3 Radiometer Global Daily 36 km EASE-Grid Soil Moisture, Version 9 [Dataset]. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/4XXOGX0OOW1S Date Accessed: 2026-09-16
@misc{oneill_chan_njoku_jackson_bindlish_chaubell_2023,
title={SMAP L3 Radiometer Global Daily 36 km EASE-Grid Soil Moisture, Version 9},
url={http://nsidc.org/data/SPL3SMP/versions/9},
DOI={10.5067/4XXOGX0OOW1S},
publisher={NASA National Snow and Ice Data Center Distributed Active Archive Center},
author={ONeill, Peggy and Chan, Steven and Njoku, Eni and Jackson, Thomas and Bindlish, Rajat and Chaubell, Julian},
year={2023},
}
ONeill, P., Chan, S., Njoku, E., Jackson, T., Bindlish, R., & Chaubell, J. (2023). SMAP L3 Radiometer Global Daily 36 km EASE-Grid Soil Moisture, Version 9 [Dataset]. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/4XXOGX0OOW1S Date Accessed: 2026-09-16
ONeill, Peggy, et al. “SMAP L3 Radiometer Global Daily 36 Km EASE-Grid Soil Moisture, Version 9.” NASA National Snow and Ice Data Center Distributed Active Archive Center, 2023, https://doi.org/10.5067/4XXOGX0OOW1S. Date Accessed: 2026-09-16
TABLE OF CONTENTS
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ALGORITHM THEORETICAL BASIS DOCUMENT (ATBD)
DATA PRODUCT SPECIFICATION
GENERAL DOCUMENTATION
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Publications Citing This Dataset
Filters
| Title | Year Sort ascending | Author | Topic |
|---|---|---|---|
| Improving Global Surface Soil Moisture Prediction Through PhysicsGuided Deep Learning and ClusterBased Regionalization | Xi, Xuan, Zhuang, Qianlai | Brightness Temperature, Surface Soil Moisture | |
| An operational global L-band soil moisture and vegetation optical depth dataset from optimized 40 SMOS brightness temperatures for 20102024 | Xing, Zanpin, Li, Xiaojun, Frappart, Frederic, De Lannoy, Gabrielle, Jagdhuber, Thomas, Peng, Jian, Fan, Lei, Ma, Hongliang, Karthikeyan, Lanka, Liu, Xiangzhuo, Wang, Mengjia, Zhao, Lin, Liu, Yongqin, Wigneron, Jean-Pierre | Land Use/Land Cover Classification, Vegetation Index, Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), Plant Phenology, Brightness Temperature, Surface Soil Moisture | |
| National Oceanic and Atmospheric Administration Soil Moisture Operational Product System: An overview and data assimilation applications | Yin, Jifu, Zhan, Xiwu, Liu, Jicheng, Kim, Jong, Jeon, ChanHoo, Petro, Gillian | Brightness Temperature, Surface Soil Moisture | |
| A Hybrid Physics-Guided Machine Learning for Soil Moisture Monitoring and Drought Assessment From CYGNSS in Complex Terrain | Rhadiouini, Charafa El, Jin, Shuanggen, Yeboah, Emmanuel, Sarfo, Isaac, Okrah, Abraham | Surface Pressure, Heat Flux, Longwave Radiation, Shortwave Radiation, Surface Temperature, Humidity, Evapotranspiration, Surface Winds, Rain, Precipitation Rate, Snow, Soil Moisture/Water Content, Soil Temperature, Land Surface Temperature, Snow Water Equivalent, Runoff, RADAR IMAGERY, Terrain Elevation, Topographical Relief Maps, Digital Elevation/Terrain Model (DEM), Vegetation Index, Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), Brightness Temperature, Surface Soil Moisture, Radar Cross-Section, Radar Reflectivity | |
| Assimilation of ASCAT Soil Moisture and SMAP Brightness Temperature Observations into the NASA GEOS Land Data Assimilation System | Fox, Andrew M., Reichle, Rolf H., Liu, Qing | Brightness Temperature, Surface Soil Moisture | |
| Benchmarking and evaluating the NASA Land Information System (version | He, Cenlin, Lin, Tzu-Shun, Mocko, David M., Abolafia-Rosenzweig, Ronnie, Wegiel, Jerry W., Kumar, Sujay V. | Albedo, Anisotropy, Brightness Temperature, Surface Soil Moisture, Albedo, Snow Cover | |
| Assessing the capability of Triton GNSS-Reflectometry for land surface hydrological monitoring | Setti, Paulo T., Tabibi, Sajad | Radar Cross-Section, Radar Reflectivity, SIGMA NAUGHT, Flight Data Logs, Total Surface Water, Brightness Temperature, Surface Soil Moisture | |
| Refined semi-empirical models for soil moisture retrieval in spaceborne | Dong, Zhounan, Yan, Qingyun, Jin, Shuanggen, Li, Li, Chen, Guodong | Land Use/Land Cover Classification, Brightness Temperature, Surface Soil Moisture | |
| Nonlinear Soil Moisture Loss Function Reveals Vegetation Responses to Water Availability | Araki, Ryoko, Morgan, Bryn E., McMillan, Hilary K., Caylor, Kelly K. | Digital Elevation/Terrain Model (DEM), Land Use/Land Cover Classification, Normalized Difference Vegetation Index (NDVI), Soil Classification, Soil Texture, Surface Roughness, Brightness Temperature, Surface Soil Moisture, Root Zone Soil Moisture | |
| Vegetation signal crosstalk present in official SMAP surface soil | Crow, Wade T., Feldman, Andrew F. | Land Use/Land Cover Classification, Vegetation Index, Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), Brightness Temperature, Surface Soil Moisture, Root Zone Soil Moisture | |
| Two-stage downscaling and correction cascade learning framework for | Li, Jie, Wei, Yingtao, Lin, Liupeng, Yuan, Qiangqiang, Shen, Huanfeng | Brightness Temperature, Surface Soil Moisture, Vegetation Index, Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), Land Surface Temperature, Emissivity, Precipitation, Precipitation Amount, Precipitation Rate, Snow, Rain, Albedo, Anisotropy | |
| Lightning density and its coupled covariates within the Continental United States | Eisenacher, Steffen, Fluhrer, Anke, Bliefernicht, Jan, Short Gianotti, Daniel J., Kunstmann, Harald, Jagdhuber, Thomas | Brightness Temperature, Surface Soil Moisture | |
| Value of microwave soil moisture and thermal-infrared evapotranspiration retrievals for the mapping of irrigation coverage | Crow, Wade T., Anderson, Martha C., Volk, John M., Colliander, Andreas | Brightness Temperature, Surface Soil Moisture | |
| Real-time estimation of SMAP soil moisture in mountainous areas and its impact on rainfall-runoff simulation | An, Huicong, Ouyang, Chaojun, Chen, Xiaoqing | Brightness Temperature, Surface Soil Moisture | |
| Reprocessed NOAA SMOPS Blended Soil Moisture Product as a Climate Data Record | Yin, Jifu, Zhan, Xiwu, Liu, Jicheng, Barlage, Michael, Meng, Huan, Kalluri, Satya, Yang, John Xun, Ogden, Fred L., Goldberg, Mitchell D., Zhao, Limin, Cosh, Michael, Ferraro, Ralph R. | Brightness Temperature, Surface Soil Moisture | |
| Analysis of hydrological time-lag effects using multiple GNSS techniques: GNSS-R-retrieved soil moisture, GNSS-derived coordinates, and GNSS-based water vapor ... | Yong, Weiao, Wang, Xiaolei, Tu, Jinsheng, Gao, Ying | Brightness Temperature, Surface Soil Moisture | |
| An Algorithm for Downscaling SMAP Soil Moisture to 3 km Using CYGNSS Observations | Zhu, Yifan, Guo, Fei, Yang, Wentao, Zhang, Zhiyu, Li, Zheng, Wu, Ziheng, Zhang, Xiaohong | Brightness Temperature, Surface Soil Moisture, Soil Moisture/Water Content | |
| A Hybrid Approach for Soil Moisture Upscaling Based on Dense Monitoring With Consideration of Heterogeneity | Guo, Shitong, Guo, Ge, He, Xiurong, Liu, Shaomin, Chai, Linna, Zhao, Tianjie, Zhu, Zhongli, Xu, Ziwei | Brightness Temperature, Surface Soil Moisture | |
| A parametric approach for global estimation of forest above-ground biomass with SMOS and SMAP L-band radiometer data | Cartus, Oliver, Santoro, Maurizio, Jimenez, Carlos, Prigent, Catherine, Schwank, Mike, Wegmuller, Urs | Brightness Temperature, Surface Soil Moisture | |
| Spatio-temporal dynamics of L-band zeroth-order vegetation scattering albedo from SMAP observations in tropical forests | Liu, Yuqing, Li, Xiaojun, Ciais, Philippe, Frappart, Frederic, Liu, Xiangzhuo, G. Cosio, Eric, Zheng, Yi, Xing, Zanpin, Wang, Huan, Fan, Lei, Chaubell, Mario Julian, Wigneron, Jean-Pierre | Brightness Temperature, Surface Soil Moisture | |
| Improved soil moisture estimation and detection of irrigation signal by incorporating SMAP soil moisture into the Indian Land Data Assimilation System (ILDAS) | Chakraborty, Arijit, Saharia, Manabendra, Chakma, Sumedha, Kumar Pandey, Dharmendra, Niranjan Kumar, Kondapalli, Thakur, Praveen K., Kumar, Sujay, Getirana, Augusto | Brightness Temperature, Surface Soil Moisture | |
| Comprehensive Analysis of CYGNSS GNSS-R data for Enhanced Soil Moisture Retrieval | Setti, Paulo, Tabibi, Sajad | Radar Cross-Section, Radar Reflectivity, Radar Cross-Section, Radar Reflectivity, Soil Temperature, Soil Moisture/Water Content, SIGMA NAUGHT, Flight Data Logs, Brightness Temperature, Surface Soil Moisture | |
| Estimating Backward Scattering using GNSS-Reflectometry Measurements for Soil Moisture Retrieval | Perez-Portero, Adrian, Rodriguez-Alvarez, Nereida, Francesc Munoz-Martin, Joan, Bosch-Lluis, Xavier, Oudrhiri, Kamal | Vegetation Index, Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), Brightness Temperature, SIGMA NAUGHT, Soil Moisture/Water Content, Surface Soil Moisture | |
| Influence of SMAP soil moisture retrieval assimilation on runoff estimation across South Asia | Ahmad, Jawairia A., Forman, Bart A., Getirana, Augusto, Kumar, Sujay V. | Surface Pressure, Heat Flux, Longwave Radiation, Shortwave Radiation, Surface Temperature, Humidity, Evapotranspiration, Surface Winds, Rain, Precipitation Rate, Snow, Soil Moisture/Water Content, Soil Temperature, Land Surface Temperature, Snow Water Equivalent, Runoff, Ground Water, Brightness Temperature, Surface Soil Moisture | |
| Optimal model-based temperature inputs for global soil moisture and vegetation optical depth retrievals from SMAP | Xiao, Yao, Li, Xiaojun, Fan, Lei, De Lannoy, Gabrielle, Peng, Jian, Frappart, Frederic, Ebtehaj, Ardeshir, de Rosnay, Patricia, Xing, Zanpin, Yu, Ling, Dong, Guanyu, Yueh, Simon H., Colliander, Andress, Wigneron, Jean-Pierre | Precipitation, Precipitation Amount, Precipitation Rate, Snow, Rain, Brightness Temperature, Surface Soil Moisture |