SMEX03 Land Use Classification Data: Georgia

Summary

This data set is a subset of data acquired from the United States Geological Survey's (USGS) National Land Cover Dataset (NLCD). The NLCD is comprised of Landsat data collected during 2001 that are representative of the land cover conditions present in the Georgia, USA regional study area during the Soil Moisture Experiment of 2003 (SMEX03). The data were exported from NLCD 2001 with Environmental Research Systems Institute (ESRI) ArcMap software and are provided in one ASCII text file. The volume of the data file is approximately 19 megabytes, and the file is 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

The following example shows how to cite the use of this data set in a publication. For more information, see our Use and Copyright Web page.

Cosh, Michael H. and Joanna Birch. 2008. SMEX03 Land Use Classification Data: Georgia. Boulder, Colorado USA: National Snow and Ice Data Center. Digital media.

Overview Table

Category	Description
Data format	ASCII text
Spatial coverage and resolution	Southernmost Latitude: 30.96° N Northernmost Latitude: 31.90° N Westernmost Longitude: 83.97° W Easternmost Longitude: 83.36° W 30 m
Temporal coverage and resolution	June - July 2003
Tools for accessing data	Any text editor or Web browser
File naming convention	ga_landcover.txt
File size	~19 MB
Parameter(s)	Land Use Classification
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

Investigator(s)

Michael H. Cosh
Hydrology/Remote Sensing Laboratory
US Department of Agriculture (USDA) - Agricultural Research Service (ARS)
Bldg. 007, Rm. 104, BARC-West
Beltsville, MD 20705 USA

Joanna Birch
Hydrology/Remote Sensing Laboratory
US Department of Agriculture (USDA) - Agricultural Research Service (ARS)
Bldg. 007, Rm. 104, BARC-West
Beltsville, MD 20705 USA

 

Technical Contact

2. Detailed Data Description

Format

Data are provided in one ArcInfo ASCII Grid data file named ga_land_cover.txt. The first six rows of the file contain header information, while the remaining rows contain the actual grid data. Refer to Table 1 for clarification of ASCII Grid header variables, or to the Sample Record section of this document to view the sample data record. Missing data are represented by -9999. The Georgia study area image dimensions are 3440 rows by 1840 columns.

 

Table 1. ArcInfo ASCII Grid Header Values

Variable	Description
ncols	Number of columns in the grid
nrows	Number of rows in the grid
xllcorner	Western edge of the grid
yllcorner	Southern edge of the grid
cellsize	Spatial resolution of the grid
NODATA_value	Refers to value representing missing data, such as -9999

 

File and Directory Structure

Both the ga_land_cover.txt data file and readme.txt file are available on the FTP site in the following directory:

/soil_moisture/SMEX03/Georgia/ancillary_data/landuse_classification/

File Naming Convention

The abbreviation ga in the ASCII file name ga_land_cover.txt indicates Georgia as the regional study area.

File Size

The data file is approximately 19 MB.

Spatial Coverage

Southernmost Latitude: 30.96106485° N
Northernmost Latitude: 31.90325745° N
Westernmost Longitude: 83.97084687° W
Easternmost Longitude: 83.36425277° W

Spatial Resolution

The pixel size is 30 m by 30 m.

Projection

Universal Transverse Mercator (UTM), Zone 17, North American Datum 1983 (NAD 83)

Temporal Coverage

The NLCD 2001 land use classification data are representative of typical conditions in Georgia during the approximate timeline of the SMEX03 campaign, conducted between June and July 2003.

Parameter or Variable

The measured parameter for this data set is land use classification.

Parameter Range

The parameter range for Georgia land cover types is described in Table 2. Valid values range from 1 to 99, with not all values present in the Georgia study area. For more complete descriptions of land cover types, and for more information on land cover types not present in the Georgia study area, please refer to the USGS National Map Seamless Server Web site.

Table 2. Land Cover Parameter Range and Description

Parameter Values	Description
11	Open Water
21	Developed, Open Space
22	Developed, Low Intensity
23	Developed, Medium Intensity
24	Developed, High Intensity
31	Barren Land (Rock/Sand/Clay)
41	Deciduous Forest
42	Evergreen Forest
43	Mixed Forest
52	Shrub/Scrub
71	Grassland/Herbaceous
81	Pasture/Hay
82	Cultivated Crops
90	Woody Wetlands
95	Emergent Herbaceous Wetlands

 

Sample of Data Record

Figure 1 displays a sample of the data file ga_land_cover.txt containing Georgia land use classification data. The first six rows display ArcInfo ASCII Grid header information, while the last six rows of this partial data record contain land use classification measurements. Only the first thirteen columns and first twelve rows of the data record are shown in this sample. For clarification of ASCII Grid header variables, refer to Table 1 in the Format section.

Figure 1. Sample Data Record

ncols			1840
nrows			3440
xllcorner			219000
yllcorner			3429000
cellsize			30
NODATA_value			-9999
42	42	42	41	41	41	90	42	42	42	42	42	90	...
43	42	42	41	90	41	90	42	42	42	42	42	82	...
41	43	43	90	90	90	90	42	42	42	41	42	42	...
41	43	90	90	90	41	41	42	42	41	41	42	82	...
43	90	90	90	90	41	42	42	43	41	41	42	42	...
41	43	41	41	90	41	43	41	41	41	43	43	43	...
...	...	...	...	...	...	...	...	...	...	...	...	...	...

 

3. Data Access and Tools

Data Access

Data are available via FTP.

Volume

Total volume is approximately 19 MB.

Software and Tools

Any text editor or Web browser is recommended to view these data.

Related Data Collections

• AMSR-E Validation Data: Soil Moisture Data Web site: Data sets from SMEX campaigns available at NSIDC.
• AMSR-E/Aqua Data at NSIDC Web site: AMSR-E standard products available at NSIDC.

4. Data Acquisition and Processing

Data Acquisition Methods

The Georgia land use classification data were retrieved from an online USGS database called The National Map Seamless Server, a Landsat-based land cover database with several independent data layers. From this database, the National Land Cover Dataset (NLCD) for 2001 was selected. The NLCD 2001 data were then exported with ArcMap as ArcInfo ASCII Grid data files. No extensive ground-based land cover retrieval was conducted as part of SMEX03. Instead, the NLCD 2001 is considered the base land cover map since land cover over the SMEX03 study regions is minimally dynamic.

5. References and Related Publications

Homer, C., C. Huang, L. Yang, B. Wylie, and M. Coan. 2004. Development of a 2001 National Land-Cover Database for the United States. Photogrammetric Engineering and Remote Sensing 70:829-840.

Please visit the USDA SMEX03 Web site for in-depth information on the science mission and goal of the SMEX project.

6. Document Information

Acronyms and Abbreviations

Table 3 lists the acronyms and abbreviations used in this document.

Table 3. Acronyms and Abbreviations

AMSR-E	Advanced Microwave Scanning Radiometer - Earth Observing System
ARS	Agricultural Research Service
ASCII	American Standard Code for Information Interchange
DAAC	Distributed Active Archive Center
ESRI	Environmental Systems Research Institute
FTP	File Transfer Protocol
GA	Georgia
N/A	Not Applicable
NAD 83	North American Datum 1983
NASA	National Aeronautics and Space Administration
NLCD	National Land Cover Dataset
NSIDC	National Snow and Ice Data Center
SCAN	Soil Climate Analysis Network
SMEX03	Soil Moisture Experiment 2003
USGS	United States Geological Survey
UTM	Universal Transverse Mercator
URL	Uniform Resource Locator

Document Creation Date

January 2009

Document URL

http://nsidc.org/data/docs/daac/nsidc0364_smex03_landcover_ga/index.html