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Description

This enhanced Level-3 (L3) product provides a daily composite of global and Northern Hemisphere landscape freeze/thaw conditions retrieved by the Soil Moisture Active Passive (SMAP) radiometer from 6:00 a.m. descending and 6:00 p.m. ascending half-orbit passes. This product is derived from SMAP enhanced Level-1C brightness temperatures (SPL1CTB_E). Backus-Gilbert optimal interpolation techniques are used to extract maximum information from SMAP antenna temperatures and convert them to brightness temperatures. The data are then posted to two 9 km Earth-fixed, Equal-Area Scalable Earth Grids, Version 2.0 (EASE-Grid 2.0): a global cylindrical and a Northern Hemisphere azimuthal.

Product Summary

Platforms
SMAP
Instruments
SMAP L-BAND RADIOMETER
Spatial Extent

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

,

N: 85.044 S: 45 E: 180 W: -180

Spatial Resolution
9 Kilometers x 9 Kilometers
Geographic Region
GLOBAL ,
NORTHERN HEMISPHERE
Coordinate System
CARTESIAN
Granule Spatial Representation
CARTESIAN
Temporal Extent
2015-03-31 to Present
Concept ID
C2938664439-NSIDC_CPRD
Data State
ACTIVE
Number of Files/Granules
3838
Processing Level
3
Published
Science Keywords
Transition Direction

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

Xu, X., Dunbar, R., Derksen, C., Colliander, A., Kim, Y., & Kimball, J. (2023). SMAP Enhanced L3 Radiometer Global and Northern Hemisphere Daily 9 km EASE-Grid Freeze/Thaw State, Version 4 [Data set]. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/NQLCDOZJYAKX Date Accessed: 2025-12-14

Documents

USER'S GUIDE

GENERAL DOCUMENTATION