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SMEX02 Land Surface Information: Land Use Classification

Summary

This data set consists of land use classification data collected for the Iowa Soil Moisture Experiment 2002 (SMEX02) study region. The land use classification image provides information about vegetation present in the study area. The classification is derived from Landsat Thematic Mapper (TM) imagery and has a resolution of 30 meters. Data were collected on 14 May 2002, 1 July 2002, and 17 July 2002.

Data are provided in a flat binary file, 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.

Doraiswamy, P. C. and A. J. Stern. 2004. SMEX02 Land Surface Information: Land Use Classification. [indicate subset used]. Boulder, Colorado USA: NASA DAAC at the National Snow and Ice Data Center.

Overview Table

Category Description
Data format Binary file, 3831 rows by 1851 columns with no header.
Spatial coverage and resolution Southernmost Latitude: 41.7° N
Northernmost Latitude: 42.04° N
Westernmost Longitude: 93.8° W
Easternmost Longitude: 93.2° W

Spatial resolution: 30 m
Temporal coverage and resolution Data were collected on 14 May 2002, 1 July 2002, and 17 July 2002.
Tools for accessing data Open the binary file in an appropriate image processing or image viewing application.
File naming convention Data are in a single file named "classification.bil".
File size 6.925 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) Name and Title

Paul C. Doraiswamy
US Department of Agriculture (USDA) Hydrology and Remote Sensing Lab
Beltsville, MD
USA

Alan J. Stern
US Department of Agriculture (USDA) Hydrology and Remote Sensing Lab
Beltsville, MD
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

The investigators thank the Soil Moisture Experiment 2002 Science Team, the National Soil Tilth Laboratory, the National Aeronautics and Space Administration (NASA), NASA Aqua AMSR Terrestrial Hydrology and Global Water Cycle Programs, and all those who collected and analyzed the data, including: Rogier Van der Velde, Ann Hsu, and Laura Kimes. They also want to thank the many graduate students and volunteers who collected field photographs.

2. Detailed Data Description

Format

Data are provided as one flat binary file, 3831 rows by 1851 columns with no header.

File and Directory Structure

Land use classification data are located under the SMEX02 ancillary data directory on the FTP site, as shown in this image:

File Naming Convention

Data are in a single file named "classification.bil."

File Size

6.925 MB

Spatial Coverage

Southernmost Latitude: 41.7° N
Northernmost Latitude: 42.04° N
Westernmost Longitude: 93.8° W
Easternmost Longitude: 93.2° W

Projection

Universal Transverse Mercator (UTM), Zone 15, Spheroid WGS84, Datum WGS84

Temporal Coverage

Data were collected for three dates: 14 May, 1 July, and 17 July 2002.

Parameter or Variable

Parameter Description

The parameters in this study are land use (vegetation) classifications. Land use classification distinguishes between crop types, water, roads, and urban areas. Pixels have a resolution of 30 m. The following table describes the values assigned to the vegetation and other elements in the land use classification file:

Value Class
0 Unclassified
1 Alfalfa
2 Corn
3 Grass
4 Soybean
5 Trees
6 Urban
7 Water
10 Overlaid roads

Sample Image

A sample image from the data is shown below:

Sample of land use classification image

Quality Assessment

Corn and soybean accuracies are good, but due to the large sample size of the corn and soybeans, accuracies in other land features are not as good. Small misclassifications in the soybean or corn areas can create larger inaccuracies in other classes. The following table shows the image readings and ground truth readings, and the accuracies calculated.

Image Alfalfa Corn Grass Soybean Trees Urban Water Total Accuracy
Alfalfa 66 - 3 20 1 - - 90 73.33333333
Corn 12 19291 209 379 17 - 10 19918 96.85209358
Grass 50 97 472 93 104 4 46 866 54.5034642
Soybean 136 66 63 14429 14 14 1 14723 98.00312436
Trees 18 100 45 72 77 - 63 375 20.53333333
Urban 3 2 7 20 1 2 0 35 5.714285714
Water - 7 5 1 6 - 56 75 74.66666667
Total 285 19563 804 15014 220 20 176
Accuracy 23.15789474 98.6096202 58.70646766 96.10364 35 10 31.81818 36082 95.319

Accuracies on the right in the chart are based on the image being the correct class for the ground truth. For example, of 90 classified alfalfa pixels, 66 of them are in the ground truth data for alfalfa, for 73 percent accuracy. The accuracy at the bottom of the chart is the ground truth compared to the image. For example, of the 285 pixels that were deemed to be alfalfa on the ground, only 66 of them were classified by Landsat Thematic Mapper (TM) to be alfalfa, while 136 of them were classified as soybean.

3. Data Access and Tools

Data Access

Data are available via FTP.

Volume

The file size is 6.925 MB.

Related Data Collections

4. Data Acquisition and Processing

Data Acquisition Methods

The land use classification data were derived from Landsat TM imagery and ground truth data. Landsat TM data were collected for three dates: 14 May, 1 July, and 17 July 2002. Data were used from Path 26, Row 30 and the southern portion of Path 26, Row 31, to cover the SMEX02 area. Ground truth data was collected on two separate trips in June and July 2002.

Processing Steps

The Landsat TM data was imported into ERDAS software for processing and classification. The land use classification image was registered to the road network provided by the Iowa Department of Transportation. The road network was converted into an image that showed each road as 60 meters wide. This image was embedded onto the classified image to remove the speckle along the roadways and to improve the image quality.

5. References and Related Publications

Please see the SMEX02 Web site for more information.

Dobson, M. C. and Ulaby, F. T. 1998. Mapping soil moisture distribution with imaging radar. In Principles & application of imaging radar, Henderson, F. M. and Lewis, A. J., 407- 430, New York: John Wiley & Sons.

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
FTP File Transfer Protocol
NASA National Aeronautics and Space Administration
NSIDC National Snow and Ice Data Center
SMEX Soil Moisture Experiment
SMEX02 Soil Moisture Experiment 2002
TM Thematic Mapper
URL Uniform Resource Locator
UTM Universal Transverse Mercator

Document Creation Date

November 2005

Document URL

http://nsidc.org/data/docs/daac/nsidc0276_smex02_landclass.gd.html