Exercise 1: Inspecting the images
Highway BR 364
The imagery we will use in this exercise comes from the Landsat 5 TM sensor. Find out more about this sensor by going to 'Earth observaation satellites' in the 'Remote Sensing Principles' section of the Eduspace website.
A zipped file (Rondonia.zip) containing all the images can be downloaded from the right menu. The data that will be used in this exercise is the following:
- Landsat 5 TM of 17/07/1989: Rondonia_1989
- Landsat 5 TM of 29/07/1999: Rondonia_1999
- Landsat 5 TM of 09/07/2009: Rondonia_2009
The Landsat images have an enlarged pixel size of 150x150 metres. This enables us to inspect a wider area without increasing the file size.
Forest along small gravel road
The data we will need for this exercise is the following:
- Rondonia_1989_band1.tif, Rondonia_1989_band2.tif, Rondonia_1989_band3.tif, Rondonia_1989_band4.tif
- Rondonia_1999_band1.tif; Rondonia_1999_band2.tif; Rondonia_1999_band3.tif; Rondonia_1999_band4.tif
- Rondonia_2009_band1.tif; Rondonia_2009_band2.tif; Rondonia_2009_band3.tif; Rondonia_2009_band4.tif
Open the LEOWorks image processing software which can be downloaded from the right menu.
Open Rondonia_1989_band1.tif. This opens a greyscale image of the forest in Rondonia. One image gives us a certain amount of information, but much more information can be obtained through the analysis of multiple images, comprising other spectral bands of the Landsat scene.
Open band 2, band 3 and band 4 of the Rondonia file of 1989.
Some of these bands are rather dark. In order to improve their visibility, you must enhance the images by using Interactive Stretching.
Do this for the four bands you have opened.
1. Using the image information, calculate the height and width of the image in kilometers.