Objective:Learn to identify features on several Landsat images.
Materials:
Set of 10 mystery pictures. The images are provided in either of two formats: a natural-color composite (TM bands 3, 2 and 1) and a false-color composite (TM bands 4, 3 and 2). Several of these images were obtained from a web site maintained by Ray Sterner (Johns Hopkins University). Remember that these images are from older Landsat satellites - check back here after launch for newer Landsat-7 images.
TM image 1 (agricultural site): natural-color composite, false-color composite
TM image 2 (beach): natural-color composite, false-color composite
TM image 3 (forest): natural-color composite, false-color composite
TM image 4 (golf course): natural-color composite, false-color composite
TM image 5 (residential area): natural-color composite, false-color composite
The following Landsat-4 images (false-color composite form) are available in .gif format from the web site http://fermi.jhuapl.edu/s1r/landsat/landsat.html
TM image 6 (airport): image is called a_dulles.gif
TM image 7 (bridge): bay_bridge.gif
TM image 8 (reservoir): r_prettyboy.gif
TM image 9 (Washington, DC): dc_1.gif
TM image 10 (Chesapeake Bay): overview.gif
Worksheet 1 (per student)
Engagement
Ask the students "What would roads, houses, water, and trees look like if they were take from an airplane?" "What kinds of information can these pictures provide?" Record their responses on the board. Tell them that they will be exploring a unique way of picture-taking because these pictures are taken from a satellite called Landsat-7.
Exploration
Lay each mystery picture around the classroom to create 10 stations. Give each student Worksheet 1 and divide them into 10 groups. Have each group go to each station and look at the images very carefully. Have the students predict what the pictures represent and have them record their predictions on Worksheet 1. After they have visited each station, go over each prediction with them by showing each of the pictures again and point out the distinctive features. For example, point out runways in an airport, roads in a city, and rectangular patterns in an agricultural field.
Explanation
Ask them what was different about the pictures than what they are normally used to seeing. Explain to them that these pictures are very unique because they were taken from space. Tell them that the instrument used to take these pictures (images) is called the Enhanced Thematic Mapper (ETM+). Formally introduce Landsat-7, its history, and its purposes by showing them a poster of Landsat-7 (see "Background of Landsat"). Explain how the new satellite will benefit us because the satellite will provide global coverage of the entire Earth. The larger Landsat images allow them to see the whole area (115 miles, the distance from Washington, D.C. to Ocean City, MD...about three hours in the car!) Also, Landsat-7 will become more affordable to the public, as each image will be less than $500.Lead the class into a discussion on how Landsat images can provide different and/or similar kinds of information. For example, a farmer may use these images to monitor the health of his crops without going out to the field; a geologist may use Landsat-7 images to study the types of minerals or rock structure found in a certain area; and a biologist may want to study the variety of plants in a certain location. Go back to the list of student responses on the board and ask them if they can add more responses to the list.
Extension
Have students define what Landsat images can do by going back to the responses on the board and ask them "Why do we need Landsat-7 to take pictures?" and "What kinds of information can Landsat-7 images provide?" Have them remove responses that do not describe information that can be obtained from Landsat-7 or its images. Have students complete Worksheet 2 - Questions #1, #2.Optional: Use the internet to learn more about Landsat-7, remote sensing, and its history. See the internet sites below.
Evaluation
Have the students answer the questions in Worksheet 2.
Tips for Teachers
It would be helpful to do Remote Sensing Lesson 2: Illustrating height perspective, available from the IMAGERS web site, before attempting this exercise.See additional information about Landsat-7 in the Background section.
The educational standards met in this lesson can be found in the Standards section.
Pertinent Internet Sites:
This site provides teachers and students with a variety of information on remote sensing. Topics include "Eyes in the Sky," "Learning without Touching," Remote Sensing in History," "Remote Sensing Resources," and "Remote Sensing Tools and Data."
Third from the Sun - Introduction:
Have students explore Third from the Sun. This is a web page designed for students in upper elementary school level. The web page has an "Introduction" page, a "Landsat Info" page, and a "Geographical Features" page where students can guess about features contained on Landsat images.
Detailed information about the Landsat Thematic Mapper sensor can be found at:
http://edcwww.cr.usgs.gov/glis/hyper/guide/landsat_tm
Information on understanding false-color composites can be found at:
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