Now we will load our first actual LandSat images. The file format we will work with is an "imagine image" file, which is a file format that allows more than three layers to be stored at a time. Each image file will have all seven LandSat bands.

Step 1. Loading a LandSat image.

1. Click on the "Add Data" tool, and just like the animation to the right, you need to:

  • Move up one level (the up arrow)
  • Double-click on "Activity2"
  • Select by clicking once (do not double-click) on the file "composite_november_2011.img"
  • Click "Add" to add it to your map.

Once the image loads you'll see a much blockier version of our neighborhood - each of those 30m x 30m pixels is clearly visible, but it's no longer possible to see fine details on the ground.

If you do accidentally double-click the image, just click on the up arrow to get back to the Activity2 folder, and try again - a single click with the left mouse button is what you want.

2. Zoom to the LandSat image's extent - right-click on the "composite_november_2011.img" file, and select "Zoom to layer".

You'll see that now you have a broader view of the area, and it's possible to see where the developed areas are for San Marcos, Vista, Escondido, Oceanside, and Carlsbad. You will also see the high-resolution image is peeking out around the sides of the LandSat data, so the LandSat data is covering it up. If you click on the black check mark next to the composite_november_2011.img layer it is turned off, and you can see the high resolution image again. Obviously, the 30 m x 30 m pixel size in the LandSat images is way to coarse to see detailed features on the ground, but when you zoom out to the full image extent you can make out what's in the image just fine.

If you turned the LandSat image off, turn it back on, and then proceed to Step 2 to learn how to assign layers to channels.