• On Wednesday, June 12 from 9:00 a.m. to 12:00 p.m. (US Mountain Time), the following data collections may not be available due to a planned system maintenance: ASO, AMSR Unified, AMSR-E, Aquarius, High Mountain Asia, IceBridge, ICESat/GLAS, ICESat-2, LVIS, MEaSUREs, MODIS, Nimbus, SMAP, SnowEx, SSM/I-SSMIS and VIIRS. Users of the SMAP near real-time products should use the NASA LANCE HTTPS File System for data access. 

  • A more recent version of these data is currently available from 04 Dec 2023 through the present. Data from 31 March 2015 through December 2023 will become available as part of this newer version as they are reprocessed. There may be gaps in the reprocessed time series that will be filled in as they are identified. Once this reprocessing is complete, this version will be retired.

SMAP L1C Radiometer Half-Orbit 36 km EASE-Grid Brightness Temperatures, Version 5
Data set id:
SPL1CTB
DOI: 10.5067/JJ5FL7FRLKJI
There is a more recent version of these data.
Version Summary
Changes to this version include:
- An improved calibration methodology was applied to the input Level-1B 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

Overview

This Level-1C (L1C) product contains calibrated and geolocated brightness temperatures acquired by the Soil Moisture Active Passive (SMAP) radiometer during 6:00 a.m. descending and 6:00 p.m. ascending half-orbit passes. This product is derived from SMAP L-band Level-1B time-ordered brightness temperatures resampled to an Earth-fixed, 36 km Equal-Area Scalable Earth Grid, Version 2.0 (EASE-Grid 2.0) in three projections: global cylindrical, Northern Hemisphere azimuthal, and Southern Hemisphere azimuthal. This L1C product is a gridded version of the SMAP time-ordered Level-1B radiometer brightness temperature product.
Parameter(s):
BRIGHTNESS TEMPERATURE
Platform(s):
SMAP
Sensor(s):
SMAP L-BAND RADIOMETER
Data Format(s):
HDF5
Temporal Coverage:
31 March 2015 to present
Temporal Resolution:
  • 49 minute
Spatial Resolution:
  • 36 km
  • 36 km
Spatial Reference System(s):
WGS 84 / NSIDC EASE-Grid 2.0 North
EPSG:6931

WGS 84 / NSIDC EASE-Grid 2.0 South
EPSG:6932

WGS 84 / NSIDC EASE-Grid 2.0 Global
EPSG:6933
Spatial Coverage:
N:
85.044
S:
-85.044
E:
180
W:
-180
Blue outlined yellow areas on the map below indicate the spatial coverage for this data set.

Data Access & Tools

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

Help Articles

General Questions & FAQs

SMAP Ancillary data sets are used to produce SMAP Level-1, -2, -3, and -4 standard data products.
The following table describes both the required and actual latencies for the different SMAP radiometer data sets. Latency is defined as the time (# days, hh:mm:ss) from data acquisition to product generation.
This short article describes the customization services available for SMAP data using Earthdata Search.

How to Articles

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.Users have the option to
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.
The following are instructions on how to import and geolocate SMAP Level-1C HDF5 data in ENVI. Testing notes Software: ENVI Software version: 5.3 and above. If using version 5.3, service pack 5.3.1 is needed.  Platform: Windows 7
Data subscriptions are available for select NSIDC DAAC data collections. Once signed up, the 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. 
NASA Earthdata Search is a map-based interface where a user can search for Earth science data, filter results based on spatial and temporal constraints, and order data with customizations including re-formatting, re-projecting, and spatial and parameter subsetting.
NASA Worldview is a map interface that allows users to interactively browse imagery, create visualizations, and download the underlying data.
NASA's Global Imagery Browse Services (GIBS) provides up to date, full resolution imagery for selected NSIDC DAAC data sets.