Data Set ID: 

SMAPVEX12 Core-Based In Situ Soil Moisture Data for Agricultural Area, Version 1

This data set contains in situ soil moisture data collected with coring devices at several agricultural sites as part of the Soil Moisture Active Passive Validation Experiment 2012 (SMAPVEX12).

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Geographic Coverage

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Data: Data integrity and usability verified

Documentation: Key metadata and user guide available

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  • Soils > Soil Moisture/Water Content > Gravimetric Soil Moisture
  • Soils > Soil Moisture/Water Content > Volumetric Soil Moisture (Fraction)
Spatial Coverage:
N: 49.96, 
S: 49.44, 
E: -97.85, 
W: -98.51
Spatial Resolution:
  • 3.2 km x 3.2 km
Temporal Coverage:
  • 7 June 2012 to 19 July 2012
Temporal Resolution: 1 day to 5 days
Data Format(s):
  • ASCII Text
Version: V1
Data Contributor(s): Paul Bullock, Aaron Berg

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.

Wiseman, G., A. Berg, and P. Bullock. 2014. SMAPVEX12 Core-Based In Situ Soil Moisture Data for Agricultural Area, Version 1. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: [Date Accessed].

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The documentation for this data set was provided solely by the Principal Investigator(s), and was not further developed, thoroughly reviewed, or edited by NSIDC. Thus, support for this data set may be limited.

Detailed Data Description

This data set contains in situ soil moisture data collected with coring devices at several agricultural sites as part of the Soil Moisture Active Passive Validation Experiment 2012 (SMAPVEX12).


Data are provided in ASCII text files. Table 1 describes the soil sampling data columns of the data file, SV12CSMA_Soil_Vol_Moisture_ver4.txt.

Table 1. Data Fields and Descriptions
Column Heading Description
OBJECT_ID ID of the sample
Sample_Date 4-digit year/2-digit month/2-digit day
Site_ID ID of the field and the sample point within the field
Vol_Moist_m3 Volumetric soil moisture content (m3 water/m3 oven-dry soil) calculated from the mass of water in each soil core (converted to volume) divided by the volume of the individual core.
Vol_Moist_2 Volumetric soil moisture content (m3 water/m3 oven-dry soil) derived from the gravimetric soil moisture content multiplied by the field average bulk density of the soil.
Gravimet_soil_moist_g_g Gravimetric soil moisture content (g water/g oven-dry soil) calculated by subtracting the oven-dry soil mass from the moist soil mass, then dividing the derived soil moisture mass by the oven-dry soil mass.

Table 2 describes the columns of the data file, Field_Sites_ver4_coords.txt.

Table 2. Data Fields and Descriptions
Column Heading Description
OBJECTID ID of the data record
Site_ID ID of the field and the sample point within the field
X UTM X coordinate
Y UTM Y coordinate
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File and Directory Structure

Data files are available on the HTTPS site in the directory. Associated Extensible Markup Language (XML) metadata files are also provided for each data file and are identified with the .MET.xml extension.

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File Naming Convention

SV12CSMA_Soil_Vol_Moisture_ver4.txt contains the soil moisture data from ground sampling. 

Field_Sites_ver4_coords.txt contains the UTM coordinates for the sampling points.

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File Size

The data files range from approximately 29-30 KB.

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Spatial Coverage

Southernmost Latitude: 49.44°N
Northernmost Latitude: 49.96°N
Westernmost Longitude: 98.51°W
Easternmost Longitude: 97.85°W

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Spatial Resolution

The spatial resolution was approximately 3.2 km. Sampling was performed on sites approximately one quarter section (0.8 km by 0.8 km) in size.

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Universal Transverse Mercator (UTM) 14 N, World Geodetic System 1984 (WGS84)

Grid Description

No grid.

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Temporal Coverage and Resolution

Measurements were taken every one to five days from 07 June 2012 through 19 July 2012.

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Parameter or Variable

Parameters in this data set include volumetric soil moisture and gravimetric soil moisture. The following table describes the units of measurement and sources of each parameter.

Table 3. Parameter Units and Sensors
Parameter Unit of Measurement Sensor
Volumetric soil moisture Water Fraction Volume (m3/m3) Coring device
Gravimetric soil moisture g/g Coring device

Parameter Range

Valid parameter values are as follows: 
Volumetric soil moisture: 0 - 0.6 
Gravimetric soil moisture: 0 - 0.6

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Software and Tools

No special tools are required to view these data. Any word-processing program or Web browser will also display the data.

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Data Acquisition and Processing

Theory of Measurements

Determination of the water content in the collected core samples was based on weighing the original sample, drying it, and weighing it again. The difference in the weight corresponds to the water content in the original sample.

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Processing Steps

During flight days, crews were instructed to collect one bulk density core per field (the primary reason for this was the calibration of the handheld sensors). The location of the one bulk density site was moved each flight day such that by the end of the campaign, one sample had been collected at each sampling location within each field. This strategy yielded more than 850 cores during the course of SMAPVEX12. The dimensions of the soil core were approximately 4.6 cm in height and 4.7 cm in diameter with a core volume of 80 cm3. When the crew arrived at the designated bulk density site for that particular sampling day, they took their three standard probe readings. As well, the crew collected a soil core and three additional probe readings. These three additional readings were located in close proximity to the location of the soil core extraction, and were recorded separately on the field sheets. Crews were careful to collect an undisturbed soil sample. These samples (soil and core) were placed in a soil tin with a lid, with the tin then being placed in a re-sealable plastic bag to minimize moisture loss. Soil cores were transported back to Winnipeg for weighing and drying. The entire sample (soil, core, tin and bag) was weighed. The tin was then removed from the plastic bag and placed in a soil drying oven. The samples were oven dried for 24 hours at 105°C. Following drying, the entire sample (soil, core, tin) was then re-weighed.

See more details in Section 2.1.1 of the SMAPVEX12 Database Report, released 18 December 2012.

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Error Sources

No unusual error sources were introduced to the measurement procedure during the campaign.

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Quality Assessment

The quality of the data corresponds to the quality of the soil moisture measurements carried out in similar soil moisture field experiments.

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References and Related Publications

Contacts and Acknowledgments

Grant Wiseman
Science and Technology Branch
Agriculture and Agri-Food Canada
200-303 Main Street
Winnipeg, Manitoba, R3C 3G7, Canada
phone: +1 204.259.4006

Paul Bullock
Department of Soil Science
University of Manitoba
13 Freedman Crescent
Winnipeg, Manitoba, R3T 2N2, Canada
phone: +1 204.474.8666

Aaron Berg
Department of Geography
University of Guelph
Guelph, Ontario, N1G 2W1, Canada
phone: +1 519.824.4120


Agriculture and Agri-Food Canada, National Aeronautics and Space Administration, U.S. Department of Agriculture, Environment Canada, U. Manitoba, U. Guelph, Massachusetts Institute of Technology, U. South Carolina, U. Colorado, U. Sherbrooke, Ohio State, U. Montana, Florida International U., U. Southern California, Texas A&M, Georgia Institute of Technology, U. Washington are acknowledged for their support for the campaign.

Field Sampling Team

Aaron Berg, University of Guelph
Alan Rich, University of Manitoba
Alicia Joseph, NASA GSFC
Alexandra Konings, MIT
Amine Merzouki, Agriculture and Agri-Food Canada
Bin Fang, U.S. Carolina
Brandon Wyryha, Agriculture and Agri-Food Canada
Brian Miller, University of Manitoba
Catherine Champagne, Agriculture and Agri-Food Canada
Craig Smith, Environment Canada
Christina Neva Rivera, Agriculture and Agri-Food Canada
Dominik Schneider, University of Colorado
Erika Podest, JPL
Erle Einarsson, Agriculture and Agri-Food Canada
Evan Rodgers, Agriculture and Agri-Food Canada
Grant Wiseman, Agriculture and Agri-Food Canada
Greg Gibbons, Agriculture and Agri-Food Canada
Heather McNairn, Agriculture and Agri-Food Canada
Hida Manns, University of Guelph
Hoda Jafarian, University of Sherbrooke
Jacqueline Freeman, Agriculture and Agri-Food Canada
Jeff Ouellette, Ohio State
Jennifer Watts, University of Montana
Jiali Shang, Agriculture and Agri-Food Canada
John Fitzmaurice, Agriculture and Agri-Food Canada
Jon Belanger, University of Guelph
Justin Adams, University of Guelph
Kalifa Goïta, University of Sherbrooke
Karel Janik, University of Sherbrooke
Kaighin McColl, MIT
Kurt Gottfried, Agriculture and Agri-Food Canada
Luis Perez, FIU – Florida International University
Marco Carrera, Environment Canada, Meteorological Research Division
Maria Abrahamowicz, Environment Canada
Mariko Burgin, University of Southern California
Maheshwari Neelman, Texas A&M
Matt Jones, University of Montana
Mehdi Hosseini, University of Sherbrooke
Mike Cosh, USDA, ARS Hydrology and Remote Sensing Laboratory
Mustafa Aksoy, Ohio State
Najib Djamai, University of Sherbrooke
Nandita Gaur, Texas A&M
Narendra Das, JPL
Parag Narvekar, MIT
Parinaz Rahimzadeh, University of Guelph
Patrick Rollin, Agriculture and Agri-Food Canada
Paul Bullock, University of Manitoba
Peggy O'Neill, NASA GSFC
Rachel Molloy, Agriculture and Agri-Food Canada
Rebecca Warren, University of Guelph
Rebecca Scriver, University of Guelph
Ramata Magagi, University of Sherbrooke
Robert Terwilleger, University of Florida
Rotimi Ojo, University of Manitoba
Ruzbeh Akbar, University of Southern California
Sab Kim, JPL
Sarah Banks, Agriculture and Agri-Food Canada
Sarah Dyck, Environment Canada
Saeid Homayouni, Agriculture and Agri-Food Canada
Shawna McKnight, Georgia Institute of Technology
Sonia Becenko, Agriculture and Agri-Food Canada
Stacie Westervelt, University of Manitoba
Steven Chan, JPL
Syed Anwar, Agriculture and Agri-Food Canada
Tien-Hoa Liao, University of Washington
Tracy Rowlandson, University of Guelph
Vanessa Escobar, NASA GSFC

Document Information


July 2014



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