Seeing in infrared

This exercise is a part of Educator Guide: Coating Provides Infrared Camouflage / View Guide

Purpose: Students will explore how infrared radiation is used across a range of fields of work. Skills include researching, evaluating, synthesizing and presenting information, as well as analyzing images.

Procedural overview: After analyzing infrared images and answering associated questions, student groups will research how infrared imaging is used in a field of their choice. They will then present their findings to the class.

Approximate class time: 1 class period to complete the discussion, research, presentations and debriefing as a class.

Supplies:

Poster boards (one for each student research group)

Various art supplies (markers, colored pencils, glue, scissors, etc.)

Computer access

A printer

Printer paper

A projector for introducing the activity (optional)

Seeing in infrared student activity guide

Directions for teachers:

Introduce students to the idea of infrared light by having them read “Coating provides infrared camouflage,” Readability: 12.7. The story mentions how infrared cameras can be used to search for medical conditions or detect sources of heat behind thin walls. But infrared imaging is used in many fields of work to study a variety of phenomena. In this activity, students will explore the various applications of infrared technology. (For a good introduction to infrared waves, check out this NASA site.)

Also, review basic information about the electromagnetic spectrum and about how light is absorbed, transmitted or reflected by objects. All objects also emit energy, in the form of electromagnetic radiation, based on their temperature. To ensure that students understand how to interpret an infrared image, look at the first and second series of images at “Transverse banding: a signature of potential turbulence.” These visuals were taken by a weather satellite. You can project the visuals or hand out color copies.

Explain that the images are from a weather satellite viewing Earth at infrared wavelengths. The images measure the emission at two wavelengths, 10.7 µm and 6.5 µm. Infrared light emitted at a wavelength of 10.7 µm is a measure of thermal heat. The infrared light at a wavelength of 6.5 µm can be used to estimate the amount of water vapor in the atmosphere. 

As a class, answer the following questions about the visuals.

1. What main weather event are the infrared images showing?

The progress of a collection of thunderstorms as they move eastward across Nebraska and Iowa on July 19, 2016.

2. Instead of true-color, these visuals are called false-color images. What do you think this phrase means?

The colors used represent emissions of a specific wavelength and are not what we would see with our eyes or capture with a photograph.

3. The first images measure emitted radiation at the 10.7 μm wavelength. Using the key, what do the colors in these images represent and how would you interpret them?

The colors represent different amounts of light being emitted from the clouds based on their different temperatures. From the key at top, I would think that the black and red areas are warmest and green and blue are cooler.

4. The second images measure emitted radiation for the 6.5 μm wavelength. Using the key, what do the colors in these images represent and how would you interpret them?

The colors represent different amounts of water vapor in the air, indicating the locations of clouds. From the key at top, I would think that the green areas have the most water vapor, white areas have the second most water vapor and the blue areas have less water vapor but still have some water vapor.

5. A set of numbers are shown in both series of images, in yellow text in the first series and in blue text in the second. What does this data indicate?

The numbers represent places where pilots experienced turbulence.

6. How might these images be used?

These images might be used to identify the location and path of a storm system, to warn people, including pilots, of nearby weather, and to better study the formation and movement of storms and the turbulence they create.

7. How do images of Earth taken with a regular camera look different from these infrared images?

Images taken by a regular camera would correspond to what we see with our eyes — green vegetation, blue water, white clouds and snow and tan deserts — according to the wavelengths of light that these surfaces reflect within the visible region of the electromagnetic spectrum. These images instead use visible color to represent reflected wavelengths that are outside of the visible portion of the spectrum.

Explain to your students that infrared technology has many applications in a variety of fields of work. Ask students to form pairs or small groups and choose a field to explore. The website Cool Cosmos can provide some ideas, or students can select one of the fields listed below:

Astronomy

Archeology

Art history

Firefighting

Geology

Law enforcement

Medicine

Meteorology

Military/tactical

Oceanography

Search and rescue

Veterinary medicine

Instruct each group to find an infrared image that represents one example of how the technology is used in the field selected. Be sure to instruct students to use reputable sources (textbooks, peer-reviewed journal articles, websites ending with “.edu,” “.gov” or “.org,” and so on) when searching for images. One good resource is www.sciencenews.org.

Students should select an image that has links to the source, so they can find out what technology was used to capture the image and how it works. The image should include text information about what is shown and, if possible, a scale or key. If the image does not include a key, students should explain how color is used in the image.

Groups should answer the student questions provided and use those answers to prepare a poster board about their image and how infrared technology has been applied. Students can set up their poster boards as “museum exhibits” in the library or your classroom. Have the groups prepare two-minute oral presentations describing the image they selected and the infrared technology application it represents. The rubric below (out of a total of 100 points) can help you evaluate each group’s poster and oral presentation.

Poster (60 points):

Is there at least one infrared image in color? (10 points)

Does the infrared image include a written or visual key or student note explaining the coloring of the image? (10 points)

Does the infrared image have an explanation of what it is, how it is created and what information is gained from it? (10 points)

Is there an explanation of why this image is representative of infrared images in the selected field? (10 points)

Is the importance of infrared imaging to the field expressed in words as well as images? (15 points)

Does the poster include reputable sources? (5 points)

Oral presentation (40 points):

Was the infrared image and what it shows clearly explained? (10 points)

Was the reason this image is representative of the field’s use of infrared imaging explained? (10 points)

Was the importance of infrared imaging to the field explained? (10 points)

Did each member of the team contribute to the presentation? (5 points)

Did the group complete its presentation in the time allotted? (5 points)

After students share their presentations, answer these final questions to debrief as a class.

1. Which of the fields of work presented by the class use infrared technology for similar reasons? Make sure to include evidence to support any claims that you make.

Shared goals may include learning about the past, providing medical assistance to living beings, learning about the universe and helping to protect people or protect the planet from natural disasters. In order to support their answers, students should include details from peers’ presentations.

2. Which of the fields selected by other groups is most complementary to yours? Why? Explain the similarities and differences between how infrared imaging is used in the two fields.

3. Identify a possible project that people in two complementary fields could collaborate on with the help of infrared technology. How would that collaboration benefit each field?

Directions for students:

People in many different areas of work use infrared technology to study a variety of phenomena. Infrared radiation is used to monitor volcanic eruptions and temperature trends across Earth. It can be used to detect the presence of drawings underneath paintings, to diagnose diseases and to locate people and animals trapped in fires.

In your small group, you will research how infrared technology is used in a field of your choice. Once you have completed your research by answering the questions that follow, you will create a poster board of your findings and present your research to the rest of the class. Your findings will explain how infrared technology is used in your selected field and why it is important.

Selecting a field that uses infrared images

There are many applications of infrared imaging. Follow your teacher’s instructions to identify and select a field of work that uses infrared technology and answer the questions below.

1. What is the field your team chose and why are you interested in this field?

2. Summarize how you think infrared imaging might be used in this field. 

3. Why might infrared in this field be an advantage over regular photography?

Selecting your infrared image

Using reputable sources (textbooks, peer-reviewed journal articles, websites ending with “.edu,” “.gov” or “.org,” and so on.), find an infrared image that shows an example of how infrared imaging is used in the field you selected. The Science News website, www.sciencenews.org, is a good source.

Be sure to select an image that has links to the source, so you can find out what technology was used to capture the image and how it works. The image should include text information about what is shown and, if possible, a scale or key. If the image does not include a key, you should understand how color is used in the image. You may want to select an image that is accompanied by a regular photograph of the same (or very similar) area or object to show how the two images differ.

After selecting and studying your image, answer the questions below.

4. What is the infrared image you have selected? Describe the image in a short paragraph.

5. How is this image representative of how infrared imaging is used in the field you selected?

6. Why did your team select this particular image?

7. What does the infrared image you selected show that a regular photograph of the same location or object would not show?

8. Why is this important?

9. What do the various colors in your image represent?

10. What can you find out about the technology used to capture the infrared radiation and how it works? What is the wavelength and/or frequency of the captured radiation?

Creating your poster board

Your poster board is a visual representation of how infrared imaging is used in the field you selected. Include the image you selected on your poster. Include a description of the image, explaining what it is and why it is important. Include how the image was created, how it should be interpreted and why an infrared image provides an advantage over a regular camera photograph of the same location or object. Include other infrared images and/or diagrams to illustrate the importance of infrared technology to your selected field.

Also, be sure to incorporate the answers to your research questions and cite the sources you used for data and images.

Preparing your presentation

Based on your research, prepare a two-minute presentation with your group about how infrared imaging is used in the field you selected. Be sure to incorporate the answers to your research questions.

Tips on creating your presentation:

Use descriptive language.

Keep track of the resources and references you are using so you can easily cite them at the end of your project.

Create a list of key speaking points, and divvy them up among your group members.

Practice your presentation as a group, making sure each group member has a defined and equal role in the presentation.

After the presentations, your teacher will provide instructions for debriefing as a class.