Earth Analysis Techniques > Eyes on Satellite Data > Course Materials > Week 2

Week 2: Analyzing Change Over Time

ImageJ Change

You may have heard the phrase "The only constant is change." Well, this is certainly true of Earth. An eyes-in-the-sky perspective helps us better perceive, quantify, and interpret these changes. In Week 1, you were introduced to the idea of remote sensing, and the wealth of information it gives us about our home planet. You learned about programs designed to store, document, and distribute remote sensing data. These are incredible resources for learning about the world around us as well as worlds within and beyond us.

Remote sensing images fascinate us with their beauty and unique perspective, as well as the stories they tell. However, without tools designed to measure and analyze these images, they are often just pretty pictures. We may get a qualitative sense of what's going on, but science requires a quantitative analysis as well.

In Week 2, you will install and begin using ImageJ - a public domain image processing program - to unlock the secrets of digital images. ImageJ is a professional tool - developed, used, and supported by a rich community of scientists around the world, yet surprisingly accessible to student scientists. Best of all, it's free!


Weekly Goals

  • Develop a good working definition of a digital image.
  • Quantify observations of digital images by making distance and area measurements.
  • Understand how digital images can be used to analyze change over time and monitor environmental issues such as drought.
  • Share your ideas on using digital images and measurement in your classroom.
  • Provide feedback on what you are learning and the process of learning it.

This Week's Tasks

  • Download, install, and update ImageJ on your computer.
  • Use the basic functions of ImageJ to learn what digital images are and how to manipulate them.
  • Read background information about the effects of prolonged drought on Lake Mead, Nevada.
  • Spatially calibrate digital images.
  • Locate and download a remote-sensed image, spatially calibrate it in ImageJ, add a scale bar if necessary, and post it to your online discussion group.
  • Contribute to an online discussion about how you could integrate image calibration and measurement in your curriculum.
  • Answer the Week 2 Feedback questions.

A Look at the Week Page by Page

Intro to Image J

This page introduces you to the concept of a digital image. Zoom in and out, scroll around, investigate the numbers behind the image, and make your own false color image.

If you are pressed for time, just download and install ImageJ plus download the two images of Lake Mead. Then watch all the movies.

Eyes on Drought

This page provides background information about the effects of prolonged drought on Lake Mead, Nevada.

If you are pressed for time, read the background information and save the exploration of the resources for later.

Getting to Know Measuring in ImageJ

On this page, you are shown three ways to set a scale in ImageJ. Then you find an image, set a scale for it, and make some measurements. This is the image that you'll post to your discussion section.

This weekly activity is required and is due on Thursday, May 10, 2012.

Using ImageJ: Part 1
Using ImageJ: Part 2

These two pages provide an investigation that uses ImageJ to measure how Lake Mead has changed over time.

If you are pressed for time, at least complete Part 1 where you visually inspect, stack, and set a scale on the Lake Mead images.

Share and Discuss Assignment

Create a new discussion thread. Post an image that you downloaded, spatially calibrated, and added a scale bar to, along with a brief description of it. Then share one or more ideas about how you might use image measurement to teach change-related concepts or other processes to your students. Use the reply function to "talk" to others in your section about their ideas.

This weekly activity is required and occurs from Thursday, May 10, through Sunday, May 13, 2012.

Week 2 Feedback

This page gives you the opportunity to provide us feedback about the week's activities.

Feedback is optional and anonymous. However, if you have time to provide feedback, you can help us better meet your needs.


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