Activity 3: Processing Satellite Images

Materials:

Graph paper, lab hand-out, color magazine photograph, enlarged magazine article, color markers or crayons article, pencils

About this activity:

This activity involves a laboratory investigation and a teacher demonstration. The investigation shows how digital information is received and translated into an image.

Procedure:

  1. Explain that images are composed of pixels. Pixel:  a picture element that produces a single dot of color. The remote sensing sensor divides the earth into blocks or pixels. Each pixel is recorded as a brightness value from 0 - 255. These numbers are the data which are transferred with a computer.

  2. Show the students a color picture from a newspaper. Have them make observations. Then show the students the same article, but enlarged. The students should notice the dots of different colors. An image is made up in the same way.

  3. Divide students into pairs for this activity. Students will use a color scale to make an image from data. Pass out the lab hand-out.

  4. When the students finish, have them compare their pictures with their classmates. Discuss the results of the activity.

  5. Pass out graph paper. Using the same color scale, have students select numbers that would show an image or design. The image must have at least ten rows and ten columns.

  6. Have the students describe some of the difficulties in making an image.
Lab Handout: Processing Satellite Images
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[LMGFP home page] Contact Karen Krupinsky (kgurley@gsfc.nasa.gov) or
Tammy Seergae (tseergae@umd.edu) for further information.