•  On Wednesday, June 7, from 6:00 a.m. to 1:00 p.m. (US Mountain Time), the following data collections may not be available due to 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.

SMAP L1A Radiometer Time-Ordered Parsed Telemetry, Version 2 (SPL1AP)
Data set:
This is the most recent version of these data.
Version Summary

Changes to this version include:

  • Transitioned to Validated-Stage 2

  • Calibration parameters were adjusted to reduce calibration jumps and drift previously present in the Beta-release; as a result, calibration now meets its less than 0.4 K/month stability back to 31 March 2015

  • Additional bit-error checking was performed on Level-0 instrument telemetry

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


Each Level-1A (L1A) granule incorporates all radiometer data downlinked from the Soil Moisture Active Passive (SMAP) spacecraft for one specific half orbit. The data are scaled instrument counts of the following:

  • The first four raw moments of the fullband channel for both vertical and horizontal polarizations
  • The complex cross-correlations of the fullband channel
  • The 16 subband channels for both vertical and horizontal polarizations
Data Format(s):
Temporal Coverage:
31 March 2015 to present
Temporal Resolution:
49 minute
Spatial Resolution:
40 km
40 km
Spatial Coverage:
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

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.
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

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.