On Wednesday, June 27 from 8:30 a.m. to 5:00 p.m. (USA Mountain Time), the following data collections will not be available due to planned system maintenance: AMSR-E, Aquarius, ASO, High Mountain Asia, IceBridge, ICESat/GLAS, MEaSUREs, MODIS, NISE, SMAP, SnowEx, and VIIRS. 
Data Set ID: 
SPL2SMP

SMAP L2 Radiometer Half-Orbit 36 km EASE-Grid Soil Moisture, Version 1

This Level-2 (L2) soil moisture product provides gridded estimates of global land surface conditions retrieved by the Soil Moisture Active Passive (SMAP) passive microwave radiometer during 6:00 a.m. descending and 6:00 p.m. ascending half-orbit passes. Input SMAP L-band brightness temperature data used to derive soil moisture are resampled to an Earth-fixed, global, cylindrical 36 km Equal-Area Scalable Earth Grid, Version 2.0 (EASE-Grid 2.0). A variety of ancillary data are also used as input, such as soil texture and vegetation opacity.

Note: These data are Beta-release quality, meaning that they have not undergone full validation and may still contain significant errors. Currently, in this Beta release, 6:00 p.m. ascending half-orbit granules are not considered by the SPL2SMP processing software; however, that inclusion is expected after further analysis. In addition, the data fields that indicate retrieval quality, called retrieval qual flag and retrieval qual flag option[1-5], were found to contain incorrect information. Users are advised to ignore these data fields in Version 1 of this product.

Version Summary: 

First public data release

Geographic Coverage

Parameter(s):
  • Snow/Ice > Albedo
  • Microwave > Brightness Temperature
  • Soils > Soil Moisture/Water Content
  • Topography > Surface Roughness
  • Vegetation > Plant Characteristics > Vegetation Water Content
Spatial Coverage:
  • N: 85.044, S: -85.044, E: 180, W: -180

Spatial Resolution:
  • 36 km x 36 km
Temporal Coverage:
  • 9 September 2015 to 25 October 2015
Temporal Resolution: 00:49:00
Data Format(s):
  • HDF5
Platform(s) SMAP Observatory
Sensor(s): SMAP L-BAND RADIOMETER
Version: V1
Data Contributor(s): O'Neill, P. E., S. Chan, E. G. Njoku, T. Jackson, and R. Bindlish.

Data Citation

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.

O'Neill, P. E., S. Chan, E. G. Njoku, T. Jackson, and R. Bindlish. 2015. SMAP L2 Radiometer Half-Orbit 36 km EASE-Grid Soil Moisture, Version 1. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: https://doi.org/10.5067/HF1KOE0Q85V7. [Date Accessed].
A user guide is not available for this data set.

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
What data subsetting, reformatting, and reprojection services are available for SMAP data?
The following table describes the data subsetting, reformatting, and reprojection services that are currently available for SMAP data via the NASA Earthdata Search tool. Short name Title Subsetting... read more

How To

How do I programmatically request data services such as subsetting, reformatting, and reprojection using an API?
The subsetting, reformatting, and reprojection services provided by NSIDC through NASA Earthdata Search can also be accessed programmatically as a synchronous REST interface. This programmatic access is provided via an HTTPS URL containing a series of... read more
How to import and geolocate SMAP Level-1C and Level-2 data in ENVI
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 Data set: SMAP L1C... read more
How do I visualize SMAP data in Worldview?
This video tutorial provides step-by-step instructions on how to visualize SMAP data in Worldview (http://worldview.earthdata.nasa.gov/). NASA Worldview is a map-based application... read more
How do I search, order, and customize SMAP data using Earthdata Search?
This video tutorial and attached PDF document provide step-by-step instructions on how to search, order, and customize SMAP data using Earthdata Search (https://search.earthdata.nasa.... read more
How do I interpret the surface and quality flag information in the Level-2 and -3 passive soil moisture products?
SMAP data files contain rich quality information that can be useful for many data users. The retrieval quality flag and surface flag bit values and interpretations are documented in the respective product Data Fields pages: Level-2 soil moisture product (SPL2SMP)... read more