SMEX03 Landsat Thematic Mapper Imagery: Georgia

Summary

This data set provides imagery developed from Landsat 5 Thematic Mapper (TM) data for use in studying land cover features during the Soil Moisture Experiment 2003 (SMEX03). One false color image is provided for the regional study areas northwest of Tifton, Georgia, USA for 20 July 2003. The image is the result of combining bands 2, 3, and 4 as blue, green, and red to generate false color composites. Data are provided in GeoTIFF formatted files 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

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. 2007. SMEX03 Landsat Thematic Mapper Imagery: Georgia. Boulder, Colorado USA: National Snow and Ice Data Center. Digital media.

Overview Table

Category	Description
Data format	GeoTIFF imagery (.tif) and TIFF world file (.tfw)
Spatial coverage and resolution	Southernmost Latitude: 30.90° N Northernmost Latitude: 31.96° N Westernmost Longitude: 83.97° W Easternmost Longitude: 83.36° W
Temporal coverage and resolution	20 July 2003
Tools for accessing data	A program which recognizes the GeoTIFF file format is recommended for these images.
File naming convention	TM5_GA_MMDDYY.tif and TM5_GA_MMDDYY.tfw
File size	1 KB to 18.1 MB
Parameter(s)	Infrared Imagery Visible Imagery
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
USDA ARS Hydrology and Remote Sensing Lab
Beltsville, MD 20705
USA

Technical Contact

Acknowledgements

The investigators would like to acknowledge the following people: The many graduate students and volunteers who worked to collect the field data. The Soil Moisture Experiment 2003 Science Team and the Southeast Watershed Research Laboratory (USDA-ARS) for their assistance. The National Aeronautics and Space Administration for their generous contributions to the study. This work was supported by the NASA Aqua AMSR, Terrestrial Hydrology and Global Water Cycle Programs.

2. Detailed Data Description

For this study, TM bands 2, 3, and 4 were combined to make false color composites.

• Vegetation appear as shades of red. Brighter reds indicate thicker vegetation.
• Soils with little or no vegetation appear as shades from white (sands) to green or brown, depending on moisture and vegetation content.
• Water appears blue.
• Urban areas appear as blue-gray.
• Clouds and snow appear bright white.

Format

Data are provided as a GeoTIFF image file with associated TIFF world file (TFW) containing georeferencing information. GeoTIFF defines a set of publicly available TIFF tags that describe cartographic and geodetic information associated with TIFF images. GeoTIFF enables referencing a raster image to a known geodetic model or map projection. The initial tags are followed by image data, that in turn may be interrupted by more descriptive tags. By using the GeoTIFF format, both metadata and image data can be encoded into the same file.

The TFW file provides georeference information for the image with the same file name and is a text file with six numbers. Refer to Table 1 for a description of the TFW file contents.

Table 1: TFW File Rows

Row	Description
1	the dimension of a pixel in map units in the x direction
2	rotation term for row
3	rotation term for column
4	the dimension of a pixel in map units in the y direction
5	x coordinate for upper left corner
6	y coordinate for upper left corner

File Naming Convention

Files are named according to the following convention:

Example File Names: TM5_GA_072003.tif and TM5_GA_072003.tfw

TM5_GA_MMDDYY.tif and TM5_GA_MMDDYY.tfw

Where

MM = month
DD = day
YY = year

File Size

File sizes are approximately 18.1 MB for the .tif file and 1 KB for the .tfw file.

Spatial Coverage

Southernmost Latitude: 30.90° N
Northernmost Latitude: 31.96° N
Westernmost Longitude: 83.97° W
Easternmost Longitude: 83.36° W

Spatial Resolution

The Landsat TM data are high-resolution 30 m data.

Projection

Universal Transverse Mercator (UTM) Zone 15.

Temporal Coverage

20 July 2003

Parameter or Variable

Infrared Imagery (Band 4)
Visible Imagery (Bands 2 and 3)

Parameter Description

Bands 2, 3, and 4 as blue, green, and red are used to generate a false color image that can be used to identify land cover and vegetation.

Parameter Source

TM scenes from Landsat 5 were acquired during the study period. The following table details the Landsat coverage for the dates of the study.

Table 2: Landsat Coverage Details

Date	Landsat Number	Path / Row
July 20	5	18 / 36

Sample Data Record

Figure 1: False Color Image of the Tifton Area, Sample from Image File TM5_GA_072003.tif.

3. Data Access and Tools

Data Access

Images are available via FTP.

Volume

Total volume is approximately 18.2 MB.

Software and Tools

A program which recognizes the GeoTIFF file format is recommended for this image.

Related Data Collections

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

4. Data Acquisition and Processing

Sensor or Instrument Description

TM is a multispectral scanning radiometer carried on Landsats 4 and 5. The TM has seven spectral bands, with a spatial resolution of 30 m for most bands.

5. References and Related Publications

U.S. Geological Survey (USGS). Landsat Missions. 1 May 2008. http://landsat.usgs.gov/ 1 May 2008.

Sheffner, Ed. Landsat Program. 5 October 1991. http://geo.arc.nasa.gov/sge/landsat/landsat.html 31 October 2007.

Please see 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

The following acronyms and abbreviations are used in this document.

Table 3: Acronyms and Abbreviations

AMSR-E	Advanced Microwave Scanning Radiometer - Earth Observing System
ARS	Agricultural Research Service
FTP	File Transfer Protocol
GeoTIFF	Georeferenced Tag(ged) Image File Format
NASA	National Aeronautics and Space Administration
NSIDC	National Snow and Ice Data Center
SMEX	Soil Moisture Experiment
TFW	TIFF World File
TIFF	Tag(ged) Image File Format
TM	Thematic Mapper
URL	Uniform Resource Locator
USDA	United States Department of Agriculture
UTM	Universal Transverse Mercator

Document Creation Date

15 November 2007

Document Revision Date

1 May 2008 - Updated new USGS Landsat web page.

Document URL

http://nsidc.org/data/docs/daac/nsidc0327_smex03_tm_geotiff_ga.gd.html