• Due to planned system maintenance taking place on Wednesday, October 5 from 10 - 11 a.m. (USA Mountain Time), data set landing pages and other related data pages may be temporarily unavailable or behave unexpectedly during that timeframe.

  • On Wednesday, October 5, from 9 a.m. to 12 p.m. (Mountain Time), the following data collections may not be available due to planned system maintenance: AMSR Unified, AMSR-E, Aquarius, High Mountain Asia, IceBridge, ICESat/GLAS, ICESat-2, LVIS, MEaSUREs, MODIS, SMAP, SnowEx, SSM/I-SSMIS and VIIRS.

SMAP L3 Radar Northern Hemisphere Daily 3 km EASE-Grid Freeze/Thaw State, Version 3 (SPL3FTA)
Data set:
SPL3FTA
Citation
Subscribe
Service
This is the most recent version of these data.
Version Summary
Changes to this version include:
  • Transitioned to Validated-Stage 2

  • Uses SPL1CS0 V3 Validated data as input

  • Using full swath except for nadir-anomaly flagged areas to provide better coverage

  • Resolved some flag and fillValue errors



For the full major and minor version history, go to https://nsidc.org/data/smap/version-history

Overview

This Level-3 (L3) product provides a daily composite of Northern Hemisphere landscape freeze/thaw conditions retrieved by the Soil Moisture Active Passive (SMAP) radar from 6:00 a.m. descending and 6:00 p.m. ascending half-orbit passes. SMAP L-band backscatter data are used to derive freeze/thaw data, which are then resampled to an Earth-fixed, Northern Hemisphere azimuthal 3 km Equal-Area Scalable Earth Grid, Version 2.0 (EASE-Grid 2.0).
Data Contributor(s):
Dunbar, R. S., X. Xu, A. Colliander, C. Derksen, K. C. McDonald, E. Podest, E. G. Njoku, J. S. Kimball, and Y. Kim.
Parameter(s):
FREEZE/THAW SIGMA NAUGHT TRANSITION DIRECTION
Platform(s):
SMAP
Sensor(s):
SMAP L-BAND RADAR
Data Format(s):
HDF5, HDF5
Temporal Coverage:
13 April 2015 to 7 July 2015
Temporal Resolution:
1 day
Spatial Resolution:
3 km
3 km
Spatial Coverage:
N:
85.044
S:
45
E:
180
W:
-180

Data Access & Tools

A free NASA Earthdata Login account is required to access these data. Learn More

Help Articles

How To

Many NSIDC DAAC data sets can be accessed using the NSIDC DAAC's Data Access Tool. This tool provides the ability to search and filter data with spatial and temporal constraints using a map-based interface.
To convert HDF5 files into binary format you will need to use the h5dump utility, which is part of the HDF5 distribution available from the HDF Group. How you install HDF5 depends on your operating system.
Data subscriptions are available for select NSIDC DAAC data collections (found below). Our subscription service automatically sends you new data as they are delivered from active NASA satellite missions.
All data from the NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC) can be accessed directly from our HTTPS file system, using wget or curl. Basic command line instructions are provided in the article below. 

Getting started

OPeNDAP, the Open-source Project for a Network Data Access Protocol, is a NASA community standard DAP that provides a simple way for researchers to access and work with data over the internet.
SMAP Ancillary data sets are used to produce SMAP Level-1, -2, -3, and -4 standard data products.
The following table describes the data subsetting, reformatting, and reprojection services that are currently available for SMAP data via the NASA Earthdata Search, a Data Subscription, and Programmatic Access.