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Description

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).

Version Description

Changes 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>

Product Summary

Platforms
SMAP
Instruments
SMAP L-BAND RADAR ,
SMAP L-BAND RADIOMETER
Spatial Extent

N: 85.044 S: -85.044 E: 180 W: -180

Spatial Resolution
9 Kilometers x 9 Kilometers
Geographic Region
GLOBAL LAND
Coordinate System
CARTESIAN
Granule Spatial Representation
GEODETIC
Temporal Extent
2015-04-13 to 2015-07-07
Concept ID
C2830464428-NSIDC_CPRD
Data State
COMPLETE
Number of Files/Granules
1170
Processing Level
2
Published
Science Keywords
Brightness Temperature ,
SIGMA NAUGHT ,
Soil Moisture/Water Content

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.

Copy Citation

Entekhabi, D., Das, N., Njoku, E., Johnson, J., & Shi, J. (2016). SMAP L2 Radar/Radiometer Half-Orbit 9 km EASE-Grid Soil Moisture, Version 3 [Data set]. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/8YTYSV6JGBK2 Date Accessed: 2025-12-28

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