SMAP/Sentinel-1 L2 Radiometer/Radar 30-Second Scene 3 km EASE-Grid Soil Moisture, Version 2

Data set id:

SPL2SMAP_S

DOI: 10.5067/KE1CSVXMI95Y

Data Citation and Acknowledgment
As a condition of using these data, you must cite the use of this data set. Such a practice gives credit to data set producers and advances principles of transparency and reproducibility.

10.5067/KE1CSVXMI95Y

Das, N., Entekhabi, D., Dunbar, R. S., Kim, S., Yueh, S., Colliander, A., O'Neill, P. E., Jackson, T., Jagdhuber, T., Chen, F., Crow, W. T., Walker, J., Berg, A., Bosch, D., Caldwell, T. & Cosh, M. (2018). SMAP/Sentinel-1 L2 Radiometer/Radar 30-Second Scene 3 km EASE-Grid Soil Moisture. (SPL2SMAP_S, Version 2). [Data Set]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/KE1CSVXMI95Y. [describe subset used if applicable]. Date Accessed 11-19-2024.

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When using this data product in a publication, please include the following citations in addition to the data product citation provided above:

Das, N., Entekhabi, D., Dunbar, S., Chaubell, J., Colliander, A., Yueh, S., Jagdhuber, T., Chen, F., Crow, W. T., O'Neill, P. E., Walker, J., Berg, A., Bosch, D., Caldwell, T., Cosh, M., Holifield -Collins, C., Lopez-Baeza, E. & Thibeault, M.. 2019. The SMAP and Copernicus Sentinel 1A/B microwave active-passive high resolution surface soil moisture product. Remote Sensing of Environment. 233. DOI: 10.1016/j.rse.2019.111380.

There is a more recent version of these data.
Version Summary

Changes to this version include:

Implemented a new method of identifying and eliminating spurious sigma0 values in Sentinel-1A/B Level-1 sigma0 data using a hybrid approach that combines a median filter with thresholding. As a result, fewer spurious sigma0 values (mainly due to small man-made structures) bias the aggregated 1 km data.

Replaced the previous 3 km resolution urban fraction map with a new 1 km map.

Adjusted the thresholds used with the new 1 km urban fraction map to: 0.25 (no flag), 0.25 – 0.5 (flagged, retrieval performed), and 0.5 (masked, no retrieval). These are provided in bit 3 of the surface_flag data field.

Adjusted the tau-omega parameters to be consistent with the values used in SPL2SMP/SPL2SMP_E algorithm.

Implemented minor bug fix to the SMAP and Sentinel-1 overlap computation code.

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

Overview

This Level-2 (L2) soil moisture product provides estimates of land surface conditions retrieved by both the Soil Moisture Active Passive (SMAP) radiometer during 6:00 a.m. descending and 6:00 p.m. ascending half-orbit passes and the Sentinel-1A and -1B radar. SMAP L-band brightness temperatures and Copernicus Sentinel-1 C-band backscatter coefficients are used to derive soil moisture data, which are then resampled to an Earth-fixed, cylindrical 3 km Equal-Area Scalable Earth Grid, Version 2.0 (EASE-Grid 2.0).Note: These data are Beta-release quality, meaning that they have not undergone full validation and may still contain significant errors.

Parameter(s):

BRIGHTNESS TEMPERATURESIGMA NAUGHTSOIL MOISTURE

Platform(s):

SENTINEL-1A, SENTINEL-1B, SMAP

Sensor(s):

C-SAR, SMAP L-BAND RADIOMETER

Data Format(s):

HDF5

Temporal Coverage:

31 March 2015 to 26 August 2020

Temporal Resolution:

30 second

Spatial Resolution:

3 km

3 km

Spatial Reference System(s):

WGS 84 / NSIDC EASE-Grid 2.0 Global

EPSG:6933

Spatial Coverage:

N:

60

S:

-60

E:

180

W:

-180

Blue outlined yellow areas on the map below indicate the spatial coverage for this data set.

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Data Access & Tools

This data set has been retired. There is a more recent version of these data.

Documentation

Help Articles

General Questions & FAQs

What data subsetting, reformatting, and reprojection services are available for SMAP data?

This short article describes the customization services available for SMAP data using Earthdata Search.

How to Articles

Filter and order from a data set web page using the Data Access Tool

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

Harmony API Quickstart Guide: Customizing NASA NSIDC DAAC data in Earthdata Cloud

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.

NSIDC DAAC Data Subscription Requests

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.

This articles provides an example MATLAB snippet to read and plot SMAP/Sentinel-1 L2 Radiometer/Radar 30-Second Scene 3 km EASE-Grid Soil Moisture HDF5 soil moisture and brightness temperature data, as well as the related surface and quality flags.

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.

Overview

Data Access & Tools

Documentation

User Guide

ATBDs

General Resources

Quality Assessment Reports

Product Specification Documents

Help Articles

General Questions & FAQs

How to Articles