Landsat MSS and TM Imagery

FLINT HILLS, CENTRAL KANSAS

Introduction

This exercise is based on Landsat MSS and TM imagery for part of the Flint Hills upland southwest of Emporia. The scenes include parts of southern Chase, northern Butler, and northwestern Greenwood counties. Landsat MSS scenes were acquired on March 19, 1988 and October 13, 1988, a drought year. The TM data come from July 14, 1984, a near-normal year. Set up a "main working folder" for this exercise on your computer. Copy all "FX" files (via FTP) into your main working folder, where you will conduct the exercise.

The BNSF Railroad and Kansas Turnpike (I-35), including Matfield Green service area, cross the area. The region is predominantly grassland with limited cropland. Rivers of four drainage basins have their headwaters in the area: South Fork Cottonwood, Verdigris, Walnut, and Fall. Fox Lake is an artificial reservoir, dammed on the Walnut River in the southwest corner of the scene. Smaller ranch ponds are found throughout the region.

Kite aerial photograph overlooking Flint Hills landscape in central Chase County. Note the mix of prairie grassland and wooded stream courses. This locality is included in the Landsat MSS scene and was taken in October, same time of year as the FX2 dataset. Photo date 2001, © S.W. & J.S. Aber.

Go to Flint Hills physiographic region.

Exercise

Begin by working with the Landsat MSS scenes (FX1 and FX2); make two standard false-color composites (bands 1, 2, 4; linear with saturation, 1%). Note: you can display multiple images at the same time--move one image to the side. Use "end" and "home" keys to maximize and minimize displays for viewing purposes.

1. What ground cover features dominate the March scene?

2. What ground cover features dominate the October scene?

3. Both of these scenes display drainage patterns very clearly. Describe the factors that emphasize the drainage features in each scene.

Stream erosion is gradually dissecting the Flint Hills upland. The geomorphology of divide regions can be quite dynamic, as streams erode headward from different directions at different rates. Notice some unusual features displayed by stream patterns in these two scenes. These anomalies may be related to variations in bedrock, such as folds, faults and fractures, or to former stream captures, in which headwaters of one stream were diverted into another drainage basin.

4. Describe some anomalous drainage features visible in these two scenes.

Now turn your attention to the Landsat TM scene (FX3), which covers a small portion of the MSS images. Refer to lecture notes for information about TM technical characteristics. Check "Metadata" information, and display the images (no legend, grey palette) to begin analyzing the individual bands of TM data.

5. How many rows and columns of pixels are included in this subscene; what ground area (km²) does the subscene represent?

6. Explain why the red-light band is generally darker than the other visible bands.

7. Of the short- and mid-IR bands, which shows the clearest (most naturalistic) variations in land cover? Explain why.

8. Prepare a linear stretch image with saturation points (5%) for band 6. Explain the fundamental differences in spectral and spatial factors for this band compared to other TM bands. What does this band show about the landscape.

You are now ready to carry out more elaborate manipulation of the Landsat TM data set, in order to further enhance the visual display of scene features. Make color composites using "linear with saturation points" (1%), and provide appropriate titles as indicated in the table.

Composite Type Bands File Name
Natural-color 1, 2, 3 FX3-123
Standard false-color 2, 3, 4 FX3-234
Infrared false-color 5, 4, 7 FX3-547

9. Examine the composite images you have made and describe the general appearence of each. Pay particular attention to colors, shapes, and patterns of features. What features are prominent in each; which features are poorly depicted?

Now experiment with making several of your own composite images using various Landsat TM bands (1-7) and different color assignments. In the author's experience, the most interesting and useful TM composites are those that depict a visible band (1-3) in blue, band 4 in green, and bands 5 or 7 in red. In this way, three major portions of the spectrum (visible, near-infrared, and mid-infrared) are included in the composite. Assigning band 4 to green gives active vegetation a natural appearance.

Choose the one you like best, and name it FX3-BEST. Use this image as the basis for a composition with the following features.

To create the text, use the editor (6th icon from right). Name the file BEST.TXT and write a short paragraph. Place the text, scale bar, and north arrow to right of the image on the composition. Save your composition as FX-BEST, and make a digital image file (jpg) to turn in.

10. What declination value did you use for the north arrow?

Turn in

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© Notice: ES 771 is presented for the use and benefit of students enrolled at Emporia State University. Any other use of text, imagery or curriculum materials is prohibited without permission of the instructor, J.S. Aber.