On Wednesday, September 22nd from 9:00 a.m. to 11:00 a.m. (USA Mountain Time), the following data collections may not be available due to planned system maintenance: AMSR-E, Aquarius, High Mountain Asia, IceBridge, ICESat/GLAS, ICESat-2, MEaSUREs, MODIS, NISE, SMAP, SnowEx, and VIIRS.

Mailing List

Print
SMAP Level 2 and Level 3 soil moisture products will version up in mid-October of 2021. At that time additional products may also be reprocessed. Should you have questions, please contact user services at nsidc@nsidc.org. Thank you for your patience while we update the data.
Data Set ID: 
SPL1AP

SMAP L1A Radiometer Time-Ordered Parsed Telemetry, Version 2

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

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/data_versions.

COMPREHENSIVE Level of Service

Data: Data integrity and usability verified; data customization services available for select data

Documentation: Key metadata and comprehensive user guide available

User Support: Assistance with data access and usage; guidance on use of data in tools and data customization services

See All Level of Service Details

Parameter(s):
  • MICROWAVE > SENSOR COUNTS
Data Format(s):
  • HDF5
Spatial Coverage:
N: 86.4, 
S: -86.4, 
E: 180, 
W: -180
Platform(s):SMAP
Spatial Resolution:
  • 40 km x 40 km
Sensor(s):SMAP L-BAND RADIOMETER
Temporal Coverage:
  • 31 March 2015
Version(s):V2
Temporal Resolution49 minuteMetadata XML:View Metadata Record
Data Contributor(s):Piepmeier, J. R., E. J. Kim, P. Mohammed, J. Peng, and C. Ruf.

Geographic Coverage
Other Access Options

Other Access Options

Close

Download Via HTTPS: An Earthdata Login account is required to access these data.

Once you have logged in, you will be able to click and download files via a Web browser. There are also options for downloading via a command line or client. For more detailed instructions, please see Options Available for Bulk Downloading Data from HTTPS with Earthdata Login.

Earthdata Search: This application allows you to search, visualize, and access data across thousands of Earth science data sets. Additional customization services are available for select data sets, including subsetting, reformatting, and reprojection.

Subscription Service: Subscribe to have new data automatically delivered to you as they become available at NSIDC. Subscriptions apply only to future data as they are delivered to NSIDC; they cannot be used to receive data already in NSIDC's archive.

As a condition of using these data, you must cite the use of this data set using the following citation. For more information, see our Use and Copyright Web page.

Piepmeier, J. R., E. J. Kim, P. Mohammed, J. Peng, and C. Ruf. 2015. SMAP L1A Radiometer Time-Ordered Parsed Telemetry, Version 2. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: https://doi.org/10.5067/JGV8EY3FGAH1. [Date Accessed].

It appears your Web browser is not configured to display PDF files. Download adobe Acrobat or click here to download the PDF file.

How To

Programmatic Data Access Guide
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 or through our Application Programming Interface (API). Our API offers you the ability to order data using specific temporal and spatial filters... read more
How to learn more about SMAP ancillary data
SMAP Ancillary data sets are used to produce SMAP Level-1, -2, -3, and -4 standard data products. Several of these ancillary data sets are produced by external organizations, such as NOAA, the NASA Global Modeling and Assimilation... read more
Filter and order from a data set web page
Many NSIDC data set web pages provide the ability to search and filter data with spatial and temporal contstraints using a map-based interface. This article outlines how to order NSIDC DAAC data using advanced searching and filtering.  Step 1: Go to a data set web page This article will use the... read more
How do I convert an HDF5/HDF-EOS5 file into binary format?
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. Full instructions for installing and using h5dump on Mac/Unix and... read more

FAQ

What are the latencies for SMAP radiometer data sets?
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. Short name Title Latency Required Actual (mean1) SPL1AP SMAP L1A... read more
Access complete Knowledge Base

Questions? Please contact:
NSIDC User Services
Phone: 1 303 492-6199
Email: nsidc@nsidc.org