• The SMAP data acquired after anomaly recovery have been determined to have high quality consistent with the data acquired prior to the anomaly. The radiometer calibration is stable within 0.1 K and the footprint uncertainty is within 3 km. L1 brightness temperature, L2-L3 radiometer soil moisture, and freeze/thaw products acquired since anomaly recovery will be available at NSIDC on October 7, 2022. The L4 Soil moisture/Carbon products will restart assimilation of SMAP TB observations beginning with data from October 3, 2022.

SMAP L1B Radiometer Half-Orbit Time-Ordered Brightness Temperatures, Version 5 (SPL1BTB)
Data set:
SPL1BTB
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This is the most recent version of these data.
Version Summary
Changes to this version include:
- An improved calibration methodology was applied to Level-1 brightness temperatures, which uses:
* the internal instrument reference load (instead of the global ocean as in V4)
* deep space measurements during monthly cold sky maneuvers and special cold sky maneuvers with stable open-ocean background to concurrently retrieve all calibration parameters
* a longer temporal baseline of cold sky records.

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

Overview

This Level-1B (L1B) product provides calibrated estimates of time-ordered geolocated brightness temperatures measured by the Soil Moisture Active Passive (SMAP) passive microwave radiometer. SMAP L-band brightness temperatures are referenced to the Earth's surface with undesired and erroneous radiometric sources removed.
Data Contributor(s):Piepmeier, J. R., P. Mohammed, J. Peng, E. J. Kim, G. De Amici, J. Chaubell, and C. Ruf.
Parameter(s):
ANTENNA TEMPERATURE 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
47 km
Spatial Coverage:
N:
86.4
S:
-86.4
E:
180
W:
-180

Data Access & Tools

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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. 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.
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 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. 

Getting started

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.