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Description

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 and 6:00 p.m. ascending 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).

Version Description

Changes to this version include: (1) Added 6:00 p.m. ascending half orbits, which provide: more frequent regional/global coverage (critical in flood monitoring); soil moisture diurnal variability information (useful in data assimilation systems); and consistency with other similar satellite-based soil moisture products. (2) Derived frozen ground flag (bit 7 of surface_flag) autonomously using Normalized Polarization Ration (NPR)-based passive freeze-thaw retrieval; replaces former radar-based freeze/thaw flag.

Product Summary

Platforms
SMAP
Instruments
SMAP L-BAND RADAR
Spatial Extent

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

Spatial Resolution
36 Kilometers x 36 Kilometers
Location
GLOBAL LAND
Coordinate System
CARTESIAN
Granule Spatial Representation
GEODETIC
Temporal Extent
2015-03-31 to 2018-06-04
Temporal Resolution
49 Minute
Concept ID
C4100780315-NSIDC_CPRD
Data State
DEPRECATED
Number of Files/Granules
0
Processing Level
2
Published
Updated
Science Keywords
Brightness Temperature ,
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

ONeill, P., Chan, S., Njoku, E., Jackson, T., & Bindlish, R. (2016). SMAP L2 Radiometer Half-Orbit 36 km EASE-Grid Soil Moisture, Version 4 [Data set]. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/XPJTJT812XFY Date Accessed: 2026-05-27

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