Part 1—Download Software and Data
Step 1 – Download and Install ImageJ Software
ImageJ is in the public domain. It can be freely downloaded and installed on any computer including those at schools, homes, and businesses.- Go to the ImageJ Download page and open it in a new window.
- Click the link that appears directly below the name of your computer's operating system (e.g., Mac, Linux, Windows). This action will transfer a compressed file of the software to your computer. Your browser should automatically expand the file, creating an ImageJ folder on your computer's hard drive. For more detailed instructions from the ImageJ website, click Installation Instructions ( This site may be offline. ) , then select your operating system.
Note to Windows Users: It is recommended that you install ImageJ in the Documents directory, rather than in the Program Files directory. For security reasons, Windows 7 and Windows Vista do not allow programs to alter themselves by writing files to the Program Files directory. If ImageJ is installed in the Program Files directory, then the update function in Step 2 below will not work properly. In addition, if you are a Windows Vista user, be sure to choose the correct version of ImageJ (either 32-bit or 64-bit) for your computer.
Step 2 – Update or Downgrade ImageJ
ImageJ update dialog box. Double-click the ImageJ icon 
to launch the application and choose Help > Update > ImageJ.... A window will appear, telling you the version you are currently running and a list of upgrade versions. Choose the version you want to upgrade to (usually the most recent, or default version) and click OK. After the update downloads, you will need to re-launch ImageJ to run the new version.
ImageJ update dialog box showing upgrade and downgrade options. ImageJ is a professional research and analysis tool, and is under constant development. If the latest update of the application introduces new bugs or errors, or has an unfamiliar interface that does not match written instructions, you can downgrade your copy of ImageJ to an older, more stable or familiar version.
Step 3 – Download Three Synthetic Aperture Radar (SAR) Images
Synthetic Aperture Radar (SAR) is a type of radar imagery produced with a microwave instrument. The microwave radiation penetrates clouds and haze, so that high-resolution imagery can be generated without interference from weather. SAR imagergy is able to detect small changes over time and is useful for vegetation studies.
- Before you begin, create a Forests folder to hold the three images you will download.
- These three SAR images were taken over the Amazon rainforest of northwest Brazil during the summer of 1994, 1995 and 1996. Right-click or control-click each link below to choose file Save Image As... Do not rename the files. Keep them as image_1994.tif, image_1995.tif, and image_1996.tif.
Image of 1994 (TIFF 15.9MB Dec25 09)
Image of 1995 (TIFF 15.9MB Dec25 09)
Image of 1996 (TIFF 15.9MB Dec25 09)
