Part 1—Download Software and Data
Step 1 Download Google Earth
- Access the Google Earth download page to download and install the free version of Google Earth for your operating system.
- Click on the http://www.google.com/earth/index.html to access the Google Earth Site. You will see the window shown below. On this page, click the Download Google Earth 6 button.
- A Downloads page will open. On this page click the Agree and Download button. Note: you may want to uncheck the "Include Google Chrome" check box.
- The download will begin. While the download is taking place, a Thank You page will display.
- The program installer will download to your Downloads folder. The Downloads window will show the progress of your download.
- Depending on your browser settings, the installer may start automatically; if not, follow the instructions in Step 2.
- At the end of the download, an alert box will tell you that the .dmg (Mac) or .exe (PC) file contains an application. Click the Continue (Mac) or Save (PC) button to finish the download.
Step 2 Install Google Earth
- When the download is complete, locate the downloaded (.dmg or .exe) file in your Downloads folder and double-click it to initiate the installation. In some systems the installer will start automatically.
- Follow the onscreen instructions to complete the installation. Typically, Google Earth is installed in the Applications (Mac) or Programs (PC) folder.
- On a Windows OS, open the GoogleEarthSetup.exe file and click Run. When installed, Google Earth launches automatically.
- Create a shortcut or alias to the program for easy access.
Step 3 Launch Google Earth and Explore the Program
Note: You must have a live Internet connection while using Google Earth. As you move around and zoom in and out, new images are downloaded to your computer on the fly from Google's servers. This step confirms that you have properly installed Google Earth.
- Launch Google Earth by double-clicking its icon in the Dock (Mac) or choosing it from the Programs list under the Start menu (PC). You will be asked if you want to open the program, Click OK.
- Because Google Earth is streaming images and data from the Internet, it takes a moment to launch. When it is running, you will see the main Google Earth window.
- If this is your first time using Google Earth, allow time to explore the features of the program. Practice turning layers on and off, zooming in and out, tilting and panning.
- Additional Google Earth instructions are available on the Internet in the Google Earth Online Tutorials . For the purposes of this chapter, you just need to focus on the navigation tools.
Alternatively, this Google Earth Online Student Users Guide is a very complete and helpful tutorial.
Step 4 Download the Population Density Data File
The Gridded Population of the World (GPW) dataset uses colors to show the distribution of human population across the globe: the darker the location, the higher the population density. White areas have fewer than one person per square kilometer and dark brown areas have more than 1000 persons per square kilometer. More about GPW...
- Access the World Population Density from the NASA NEO collection. Once on the NASA NEO page, choose the "Life" tab, scroll down the list and choose Population. A new map image of world population will display. From the Search Results below the map, choose "Open in Google Earth."
- Click the link to download the file "Population Density.kmz." Depending on preferences set on your computer, this action may automatically download the file and open it in Google Earth, or give you the opportunity to save the file. Choose to open the file if that is an option. If you need to save it instead, instructions in Part 2 will show you how to open it later.
Step 5 Access and Download Nitrogen Dioxide Concentration Files
NO2 concentrations are expressed in terms of vertical column densities. The color at each location indicates the amount of NO2 in a tall thin column of air. The columns measure 1 cm on each side and from the ground to the top of the troposphere in height. Measurements range from 0 to 10 quadrillion (1015) molecules of NO2 in each column.
- Access the NASA Aura NO2 Monthly Averages page.
- Scroll down through the images for 2010 and select the image for January 2010. Click the Google Earth icon below it. This will download the KML (Google Earth format) file to your computer.
- Right-click (PC) or control-click (Mac) the "NASA Aura NO2 Monthly Averages" link above and open the page in a new window.
- Scroll down to the file for January 2010.
- Under the thumbnail, click the Google Earth icon . The file may open directly into Google Earth, or give you the opportunity to save the file (in your Downloads folder, or the Desktop, for instance). The file's name is: EOS-Aura-OMI-L3-2010_01_NO2TropCS30.kml
- Locate the May 2010 image and click the Google Earth icon to open it as well.