• New versions of SMAP Level-1, Level-2, and Level-3 data sets are now available from 2015 to the present. This version will be retired on 16 December 2024. After that date, data access will only be available for the newest version.

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
The NASA Earthdata Cloud is the NASA cloud-based archive of Earth observations. It is hosted by Amazon Web Services (AWS). Learn how to find and access NSIDC DAAC data directly in the cloud.
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) is directly accessible through our HTTPS file system using Wget or curl. This article provides basic command line instructions for accessing data using this method.
This article highlights the NSIDC DAAC data sets available with customization options and outlines a workflow for searching, ordering, and customizing data in NASA Earthdata Search. This approach is ideal for users who want to download data to their local machine.
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.