Exercise 1: Inspecting the images (cont'd)
Small houses near BR 364 inhabited by relocated Indians
True colour image
Using LEOWorks, you can combine these bands into an RGB colour composite image that will tell us more about the state of the forest in Rondonia. To construct a true colour image, select band3 for the red channel, band2 for the green channel, and band1 for the blue channel.
The combination of these wavelengths creates an image that is close to the colours we expect to see, which is why it is called a ‘true colour image’.
Save this colour composite as Rondonia_1989_321 on a folder on your computer.
2. Based on this true colour image, try to distinguish the following land cover classes:
Agricultural fields
Rainforest
Roads
River
3. Describe the extent of the agricultural area and the area still covered by rainforest.
4. Describe the road pattern.
False colour image
Besides the three channels we used to create a true colour composite, a Landsat image contains four more bands. With different band combinations, other features in the image are highlighted. We will compare the true colour composite with a false colour composite.
To construct a false colour image, select band4 for the red channel, band3 for the green channel, and band2 for the blue channel.
Save this colour composite as Rondonia_1989_432 on your computer.
5. Can you see some features more clearly now?
6. Focus on the differences between forest vegetation and agricultural vegetation.
7. Explain, with the aid of the information on the Eduspace website (Remote sensing in depth), how the differences in vegetation become clear in such a false colour image.
Zoom in to find and describe the agricultural areas. (Hint: There are two different types.)
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