Sample

Exercise


This exercise is based around Chapter 6, which uses the Sentinel Application Platform (SNAP) to display Landsat Level 1 data as a colour composite. It’s a summary of what’s in the book, as the exercises in the book describe each step in greater detail.

We describe in detail how to find, select and download Landsat data from the United States Geological Survey (USGS) website http://landsat.usgs.gov/ using GloVis (http://glovis.usgs.gov/) in Chapter’s 4 and 6. For this exercise, you’ll need to download an image captured on the 27 October 1990 by Landsat 5, covering an area around Warsaw in Poland; the WRS-2 path and row is 188 024.

Download the GeoTIFF data, which will be a compressed tar.gz file. This file will need to be fully unzipped in order to complete this exercise; this process is described in detail in Chapter 6. Once you have unzipped the data:

Figure 6-1a: Landsat 5 TM scene over Europe (path 188 row 024) with as the pseudo-true color composite. Data courtesy of USGS/NASA.

Figure 6-1a: Landsat 5 TM scene over Europe (path 188 row 024) with as the pseudo-true color composite. Data courtesy of USGS/NASA.

  • To import all the spectral wavebands into SNAP at once, go to the menu item File > Import > Optics Sensors > Landsat > Landsat (GeoTIFF) select the MTL file, e.g. “LT51880241990300KIS00_MTL.txt”, and press Open.
  • Then, click on Bands in the Product Explorer window and go to the menu item Window > “Open RGB Image Window…,’ which opens a dialog box, and select “Landsat-TM 3,2,1” from the Profile drop-down menu at the top. This will populate the RGB wavebands for Landsat 5, and clicking on OK will cause the image to appear both in the main window and in the navigation panel in the bottom left corner; it should look like what’s shown to the right [equivalent to Figure 6.1a in the book].

 

Using Earth Observation to answer questions about our planet’s resources and behaviour