SMEX03 Soil Climate Analysis Network (SCAN): Georgia

Summary

This data set contains measurements taken during the Soil Moisture Experiment 2003 (SMEX03) from 1 June 2003 to 31 July 2003 from sensors at the Soil Climate Analysis Network (SCAN) station located in Little River, GA, USA. Parameters measured include precipitation, air temperature, solar radiation, wind speed, wind direction, relative humidity, soil moisture, soil temperature, and soil salinity. Data are provided as tab-delimited ASCII text and are available via FTP.

These data were collected as part of a validation study for the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E). AMSR-E is a mission instrument launched aboard NASA's Aqua Satellite on 04 May 2002. AMSR-E validation studies linked to SMEX are designed to evaluate the accuracy of AMSR-E soil moisture data. Specific validation objectives include assessing and refining soil moisture algorithm performance; verifying soil moisture estimation accuracy; investigating the effects of vegetation, surface temperature, topography, and soil texture on soil moisture accuracy; and determining the regions that are useful for AMSR-E soil moisture measurements.

Citing These Data

We kindly request that you cite the use of this data set in a publication using the following citation example. For more information, see our Use and Copyright Web page.

Bosch, D. and G. Schaefer. 2006. SMEX03 Soil Climate Analysis Network (SCAN): Georgia. [indicate subset used]. Boulder, Colorado USA: NASA DAAC at the National Snow and Ice Data Center.

Overview Table

Category Description
Data format Tab-delimited ASCII text.
Spatial coverage and resolution

Southernmost Latitude: 31.51º N
Northernmost Latitude: 31.51º N
Westernmost Longitude: 83.56º W
Easternmost Longitude: 83.56º W

Temporal coverage and resolution Data were collected hourly from 1 June 2003 through 31 July 2003. In addition, a daily file is available.
Tools for accessing data View data using a browser or text editor.
File naming convention Scan2027_Hourly.txt
Scan2027_Daily.txt
File sizes File sizes are 2.7 KB and 265 KB.
Parameters Precipitation, air temperature, solar radiation, wind speed, wind direction, relative humidity, soil moisture, soil temperature, and soil salinity.
Procedures for obtaining data Data are available via FTP.

Table of Contents

1. Contacts and Acknowledgments
2. Detailed Data Description
3. Data Access and Tools
4. Data Acquisition and Processing
5. References and Related Publications
6. Document Information

1. Contacts and Acknowledgments

Investigators

David D. Bosch
USDA Agricultural Research Service (ARS) Southeast Watershed Research Laboratory
Tifton, Georgia
USA

Garry Schaefer
USDA Natural Resources Conservation Service (NRCS)
Portland, Oregon
USA

Technical Contact

NSIDC User Services
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
Boulder, CO 80309-0449  USA
phone: +1 303.492.6199
fax: +1 303.492.2468
form: Contact NSIDC User Services
e-mail: nsidc@nsidc.org

Acknowledgements

We would like to acknowledge the USDA Natural Resources Conservation Service (NRCS) http://www.nrcs.usda.gov/.

2. Detailed Data Description

Format

Data are provided as tab-delimited ASCII. Two types of files are available: hourly and daily. Table 1 displays the station identification number, the station name, and the station location of the SCAN station included in this data set. Please visit http://www.wcc.nrcs.usda.gov/scan for more information on SCAN stations.

Table 1: SMEX03 Georgia SCAN Station Specifications
SCAN Station No. Station Name Location Coordinates (Latitude and Longitude)
2027 Little River Tift County, GA 31.51º N, 83.56º W

Table 2 lists the column headings and definitions in the hourly file, and Table 3 lists the column headings and definitions in the daily file. Please visit http://www.wcc.nrcs.usda.gov/scan/sensors.html for more information on these parameters.

Note: In both files, missing data values are denoted by either -99.9 or -99.99.

Table 2: Column Headings and Definitions for the Hourly File
Column
Description Units
ATHA6
Average air temperature degrees Celsius
ATHC6
Current air temperature degrees Celsius
ATHN6
Minimum air temperature degrees Celsius
ATHX6
Maximum air temperature degrees Celsius
c1rdc
Current soil dielectric constant an two inch depth no units
c1sal
Current soil salinity at two inch depth grams per liter
c1smv
Current soil moisture at two inch depth percent water by volume
c1tmp
Current soil temperature at two inch depth degrees Celsius
c2rdc
Current soil real dielectric constant at four inch depth no units
c2sal
Current soil salinity at four inch depth grams per liter
c2smv
Current soil moisture at four inch depth percent water by volume
c2tmp
Current soil temperature at four inch depth degrees Celsius
c3rdc
Current soil real dielectric constant at eight inch depth no units
c3sal
Current soil salinity at eight inch depth grams per liter
c3smv
Current soil moisture at eight inch depth percent water by volume
c3tmp
Current soil temperature at eight inch depth degrees Celsius
c4rdc
Current real dielectric constant at 20 inch depth no units
c4sal
Current soil salinity at 20 inch depth grams per liter
c4smv
Current soil moisture at 20 inch depth percent water by volume
c4tmp
Current soil temperature at 20 inch depth degrees Celsius
c5rdc
Current soil real dielectric constant at 40 inch depth no units
c5sal
Current soil salinity at 40 inch depth grams per liter
c5smv
Current soil moisture at 40 inch depth percent water by volume
c5tmp
Current soil temperature at 40 inch depth degrees Celsius
Day
Day of measurement  
Hour
Hour of measurement Eastern Standard Time (EST)
Month
Month of measurement  
PCPIN
Cumulative total precipitation inches
RH1C1
Current relative humidity percent
RH1N1
Minimum relative humidity percent
RH1X1
Maximum relative humidity percent
SRHA
Average solar radiation watts per square meter
WDHA
Average wind direction degrees from true north
WSPHA
Average wind speed meters per hour
WSPHX
Maximum wind speed meters per hour
Year
Year of measurement  

Table 3: Column Headings and Definitions for the Daily File
Column
Description Units
ATA6
Average air temperature degrees Celsius
ATN6
Minimum air temperature degrees Celsius
ATX6
Maximum air temperature degrees Celsius
Date
Date of measurement  
ENHUM
Average relative humidity in enclosure percent
Month
Month of measurement  
WDDA
Average wind direction degrees from true north
WSPDA
Average wind speed meters per hour
Year
Year of measurement  

File and Directory Structure

Table 4 lists the files contained in this data set.

Table 4: Files Contained In This Data Set
File Name Description File Size
Scan2027_Hourly.txt This is a tab-delimited ASCII text file of the data in hourly measurements.
265 KB
Scan2027_Daily.txt This is a tab-delimited ASCII text file of the data in daily averages.
2.7 KB

Spatial Coverage

Southernmost Latitude: 31.51º N
Northernmost Latitude: 31.51º N
Westernmost Longitude: 83.56º W
Easternmost Longitude: 83.56º W

Temporal Coverage

Data were collected between 1 June 2003 and 31 July 2003.

Temporal Resolution

Hourly measurements are averages computed as the sum of all measurements taken during an hour divided by the number of measurements taken during that hour. Daily values are averages computed as the sum of all hourly measurements taken during a day divided by the number of hourly measurements taken during that day.

Parameters

Parameter Descriptions

Table 5 describes the parameters in the hourly file.

Table 5: Parameters in Hourly File
Parameter Description
Precipitation Current value
Air temperature Maximum, minimum, average, and current values
Relative humidity Maximum, minimum, average, and current values
Wind speed Maximum and average values
Wind direction Averages
Solar radiation Averages
Soil salinity Current values at 2, 4, 8, 20, and 40 inch ground depths
Soil temperature Current values at 2, 4, 8, 20, and 40 inch ground depths
Soil moisture as percent water by volume Current values at 2, 4, 8, 20, and 40 inch ground depths
Soil r eal dielectric constant Current values at 2, 4, 8, 20, and 40 inch ground depths

Table 6 describes the parameters in the daily file.

Table 6: Parameters in Daily File
Parameter Description
Temperature Daily maximum, minimum, and average values
Wind speed Daily average
Wind direction Daily average
Enclosure relative humidity Current value

Sample Data Records

The following sample shows the first four records from the hourly file Scan2027_Hourly.txt. The first six and last six columns are displayed.

Year
Month
Day
Hour
PCPIN
ATHC6
...
c4sal
c4rdc
c5smv
c5tmp
c5sal
c5rdc
2003
6
1
0
33.29
25.81
...
0.1
7.1
26.6
23.92
0.13
14.81
2003
6
1
1
33.29
25.62
...
0.1
7.1
26.36
23.92
0.14
14.66
2003
6
1
2
33.29
25.15
...
0.09
7.24
26.36
23.92
0.14
14.66
2003
6
1
3
33.29
24.22
...
0.1
7.15
26.6
23.92
0.13
14.81

The following sample shows the first four records from the daily file Scan2027_Daily.txt. All nine columns are displayed.

Year
Month
Date
ATX6
ATN6
ATA6
WSPDA
WDDA
ENHUM
2003
6
1
33.14
18.44
26.67
5.1
233.85
59.37
2003
6
2
30.6
17.97
25.37
4.98
326.59
62.1
2003
6
3
32.19
15.73
24.86
2.64
101.36
61
2003
6
4
26.08
20.76
23.54
4.72
180.04
65.4

3. Data Access and Tools

Data Access

Data are available via FTP.

Volume

The total data set volume is 268 KB.

Software and Tools

Data files are viewable with a browser or text editor.

Related Data Collections

Please visit the SMEX03 Web site for other data sets that are related to the SMEX03 experiment.

4. Data Acquisition and Processing

Sensor or Instrument Description

Each SCAN station houses multiple sensors that automatically record data. These data are uploaded at regular intervals to the NRCS Data Processing Center, Portland, Oregon, USA. Table 7 describes the sensors housed in the SCAN station and the parameters they measure.

Table 7: SCAN Station Sensors and Measured Parameters
Sensor Name Parameters Measured Method of Measurement
Tipping bucket rain gauge
Precipitation
Cumulative inches of precipitation are recorded.
Shielded thermistor
Air temperature
The instrument is raised six feet from the surface. Current temperature and the previous hour's maximum, minimum, and average temperatures are recorded.
Soil sensors
Soil moisture, soil temperature, soil salinity
Sensors are located at depths of 2, 4, 8, 20, and 40 inches below the surface. Current soil moisture, temperature, and salinity are recorded.
Thin film
capacitance-type sensor
Relative humidity
The sensor is raised six feet from the surface. Current relative humidity and the previous hour's maximum and minimum relative humidities are recorded.
Anemometer
Wind speed, wind direction
The instrument is raised 10 feet from the surface. Hourly averages are computed from continuous measurements.
Pyranometer
Solar radiation
The sensor is raised 10 feet from the surface. Hourly average readings of total incoming solar energy are computed.

5. References and Related Publications

Please visit the SMEX03 Web site for more information, and see the NSIDC SMEX Web site to access data.

6. Document Information

Acronyms and Abbreviations

The following acronyms and abbreviations are used in this document.

AMSR-E Advanced Microwave Scanning Radiometer - Earth Observing System
ASCII American Standard Code for Information Interchange
FTP File Transfer Protocol
NASA National Aeronautics and Space Administration
NSIDC National Snow and Ice Data Center
NRCS Natural Resources Conservation Service
SCAN Soil Climate Analysis Network
SMEX03 Soil Moisture Experiment 2003
URL Uniform Resource Locator
USDA United States Department of Agriculture

Document Creation Date

June 2006

Document URL

http://nsidc.org/data/docs/daac/nsidc0294_smex03_scan_ga.gd.html