Adapted for the IDES workshop by permission from an introductory GIS and spatial reasoning exercise by Prof. Ming Tsou, San Diego State University.

1.0 Simple Navigation in Google Earth

1.1 Interface and Functions

As depicted in Figure 1 below, the interface of Google Earth includes three operational panels (1-3), navigation controls (4), and, of course, the terrific map view (5). The three panels are the Search Panel (1), the Places Panel (2), and the Layers Panel (Panel 3). For more detailed information, you can also go to earth.google.com/userguide/v5 (but not required for this exercise).


Figure 1: The Google Earth Interface
1: Search Panel; 2: Places Panel; 3: Layers Panel; 4: Navigation Controls; 5: Map View.




1.1.1 The Search Panel (Figure 2)


Figure 2: Fly to tab of the Search Panel.

Type the words Portland, OR in the Fly To tab and then press the Enter key. This will fly you to the center of the Rose City (Figure 3).


Figure 3: Flying to a city center.

You may have already done this in the past, but try entering your home address to take a look at where you live from a bird's eye view. Google regularly updates its imagery, so the view this time might be different.

You can also try to find a business. Enter Chipotle Mexican Grill and Corvallis, OR in the Find Businesses tab (Figure 4).


Figure 4: Find Businesses tab of the Search Panel.

Similarly, the Directions tab can provide driving directions if you give it both starting and ending addresses (Figure 5). Enter Portland, OR in the "From" field and San Diego in the "To" field (Figure 5).


Figure 5: Directions tab of the Search Panel.

If you click on the Printable view link, the directions (Figure 6) will be linked to directly to Google Maps for you (Figure 7). Give this a try and then return to Google Earth.


Figure 6: Directions, in this example, from New York to San Diego.


Figure 7: A printable Google Maps output with the directions included.

For more detailed information on directions, see earth.google.com/userguide/v5/ug_findplaces.html#directions (but not required for this exercise).


1.1.2 The Places Panel (Figure 8)


Figure 8: The Places panel.

In the Places Panel (Figure 8), Google Earth provides a virtual tour. Check the box next to Sightseeing if not already checked. Select and expand the item so that you can see the places in the list. Then click on the Play button to quickly tour the world's most famous places.

For future reference (not for this exercise), you can also create your own sightseeing tour by right-clicking on
My Places, then Add --> Placemark. You can add placemarks to your map view to make your own virtual tour (Figure 9).


Figure 9: Creating a new placemark.




1.1.3 The Layers Panel (Figure 10)

Map layers are lists of map features, data, or imagery that can be added, overlain, or stacked together, not unlike layers in a cake or toppings on a burger (yum!). You can manipulate the layers by turning them on/off or expanding them (Figure 10). For instance, turn on the Global Awareness layer and see how the map view display changes accordingly. Now turn off that layer. Next, turn on the 3D Buildings layer. Find and turn on a Roads layer if not already turned on.


Figure 10: The Layers panel from an earlier version of Google Earth.

Even though you have turned on some layers, their associated features may not be visible until you sufficiently zoom in or go to the geographic areas where they occur (Figure 11). This is called "scale-dependency." It would not make sense to show all buildings on the map when you are zoomed out all the way to the point where you can see the entire planet! In real life, you would not see all of these features from outer space. Google Earth and other "geobrowsers" make features such as roads, buildings, parks, etc. visible only when they would be visible in real life.


Figure 11: Map layers (left) and their scale-dependent features as shown in the map view (right).




1.1.4 Navigation Controls

Go to the View pull-down menu and toggle on the Overview Map by clicking on the option from the list. If it is already selected, leave it alone.

Below is a list of some of the basic controls, buttons and their functions. Take a few minutes to practice with them.

The "Look Joystick" control: Use the Look joystick to look around as if you were turning your head. Click an arrow to look in that direction or continue to press down on the mouse button to change your view. After clicking an arrow, move the mouse around on the joystick to change the direction of motion.

The "Move Joystick" control: Use the Move joystick to move your position from one place to another. Click an arrow to look in that direction or continue to press down on the mouse button to change your view. After clicking an arrow, move the mouse around on the joystick to change the direction of motion.

The "Zoom Slider": Use this to get closer to the ground to see more detail but in a smaller geographic area. Try clicking and dragging the slider toward the plus/minus signs or try double-clicking on any part of the image.

The "Hide/Show Sidebar" button: Use this to conceal or display the side bar (Search, Places and Layers panels).

The "Add Placemark" button: Use this to add a placemark for a location. For more detailed information, see earth.google.com/intl/en/userguide/v5/ug_placemarks.html (but not required for this exercise).

The "Measure" button: Use this to measure a distance or the size of an area.

The "Add Overlay" buttons: Use these to create and add your own overlay features in Google Earth. You can draw a polygon, a line, or add a graphic image to the map, which Google Earth will then then "drape" over the terrain.

The "Email" button: Use this to send the current view as either a KMZ or graphic image to someone else. On Windows machines you need to already have a Gmail account.

The "View in Google Maps" button: Use this to show the current view in Google Maps within your web browser.

The "Switch between Sky and Earth" button: Click this to view stars, constellations, galaxies, planets and the Earth's moon. For more detailed information, see earth.google.com/intl/en/userguide/v5/ug_sky.html (but not required for this exercise).




1.2 Navigation Exercise

Now let's go to the Grand Canyon in Arizona! Fly to it by entering Grand Canyon in the Fly To Search tab (Figure 12).

Click on the "Look Joystick" control until you see the terrain (Figure 12).

Explore the local area by moving around (panning) and zooming in and out.


Figure 12: Searching for the Grand Canyon in Arizona and exploring it in 3D.

Next, fly to any city of your choice by entering its name in the Fly To Search tab. Then use the navigation tools such as zoom in and out, tilt, pan, etc. to explore your city. This should be quite fun especially now that you have the 3D Buildings layer turned on (Figure 13).


Figure 13: Flying into a 3D city.




1.3 The Google 3D Warehouse

It's truly amazing that there are so many 3D buildings in Google Earth (including on the OSU campus!). Many of these buildings have been created by average people by way of computer-aided design (CAD), which is the use of computer technology to aid in the design of 3D models and/or 2D drawings of physical components. Google has developed its own CAD software, Google Sketchup. You can use it to create, modify and share 3D models. It's easier to learn than other 3D modeling programs, which is why so many people are already using it.

The Google 3D Warehouse is an online repository of 3D models. Anyone can search for and download models, but in order to publish your own, you'll need to sign in using your Google account. If you model 3D buildings and would like to share them with the world, you can also do so through the "Best of the 3D Warehouse" collection in Google Earth. Only the very best models are selected for inclusion here.

Using your web browser go sketchup.google.com/3dwarehouse (Figure 14).


Figure 14: Google's 3D Warehouse.

As a salute to the 2010 World Cup, look at Featured Collections and click on South Africa football stadiums.

Click on "View in Google Earth".

Choose a football stadium of interest to navigate to and explore (Figure 15). (Note that not all 3D models may be available yet for viewing in Google Earth.)


Figure 15: Viewing artificial 3D models from Google's 3D Warehouse.




2.0 Richer Content in Google Earth

As you have already seen with the 3D "Sketchup" models there is a treasure trove of rich content available in Google Earth from people all over the world who are creating and sharing that content. So it's not just the GIS analysts and computer scientists employed by Google who are doing this. Most of the rich, user-generated content in Google Earth is available in KML (applications written in the Keyhole Markup Language) or KMZ (zipped KML files). These applications give us additional content to view in the map view of Google Earth or connect us to services that bring in even more content, often in real-time.

We will now explore two examples of this rich content.

2.1 Flight Tracking Services

Go to the web site flightwise.com/flighttracking which provides flight tracking services that can be visualized in Google Earth. For example, one may look at inbound flight traffic for Los Angeles International Airport (LAX).



Figure 16: Viewing near-real-time inbound air traffic at LAX.

Let's try this for Seattle International Airport. On the web site look to the upper left of the page for 3D Flight Tracking. Click on the link for (SEA) Seattle/Tacoma airport. This should cause a .kml file to be downloaded to your computer (hopefully to the Desktop). Locate and double-click on this file and it should show you the current inbound airplane traffic for Seattle/Tacoma area.

Question: For the inbound traffic at the time you are viewing the map, how many planes are below the altitude of 2,000 feet? List their flight numbers and their altitudes (using the "Tilt" control may give you a better perspective).


2.2 Tracking Disease

Next, let's take a look at how infectious diseases may be tracked around the world using Google Earth. Bird flu is one such infectious disease that is still very dangerous. It is a contagious viral infection that can affect all species of birds. The contagious virus lives primarily in the respiratory systems of infected birds, but human infection may occur when people come into contact with infected birds or contaminated surfaces. There are thought to be millions of migratory ducks and other kinds of wildfowl which carrying the disease (and no this is NOT a swipe at the University of Oregon!). Worldwide, according to the World Health Organization, more than 135 human infections of the virus have been recorded.

Nature magazine Senior Reporter Declan Butler thoroughly researched the frightening avian flu outbreak of 2005 and published confirmed cases of the disease as a Google Earth KML. His avian outbreak map included human cases, as well as a time series of placemarks showing the progression of the flu over a period of 18 months. To see what he found for yourself, download his KML file from www.nature.com/nature/googleearth/avianflu1.kml. Double-click the KML file to launch his data in Google Earth (Figure 17).


Figure 17: Tracking bird flu in Google Earth.

Look in the Places Panel and select and expand Additional Datasets. This will allow you to view the poultry density for any continent you are interested in. You can focus on the human cases or bird breakouts by selecting the respective places. For example, you may notice that there were quite a few human cases in the first several months of 2006 in the Middle East (Figure 18).


Figure 18: Bird flu cases in the Middle East, circa 2006.

Go to the Middle East and spend some clicking on the symbols there so that you can learn the details of the outbreaks throughout that region. Note how the density of poultry is spatially related to the number of human cases and bird outbreaks. Go to Asia to see what happened there.




3.0 Keyhole Markup Language (KML) and Google Earth Customization

As you have now seen in the previous examples KML (Keyhole Markup Language) is a very powerful way to encode and display geographic information in Google Earth. KML is an XML-based document with tags describing names and attributes of locations, symbolization styles, and image overlaying. It is easy to work with because it can be created and/or edited with a simple text editor or a word processor.

Anyone can create a KML file to display geographic features within Google Earth. However, KML is best shared as an HTML link so that others can easily download that file to their desktop and edit to suit their needs.

Let's try creating our own KML file. This is best done by editing an existing one to make it our own. Using your web browser, download the KML tutorial sample at services.google.com/earth/kmz/google_earth_tutorial_files.kml. Double-click this kml file so that you can view it in Google Earth. Look for Google Earth Examples in the Places panel, and make sure to turn on and expand this item (Figure 19).


Figure 19: Google Earth KML examples to practice with as part of its simple KML tutorial.

Right-click on the yellow pushpin "Simple placmark" and choose "Save Place As" to save it as a .kml file to your desktop (do NOT save it as a .kmz file!). Rename the file to "MyPlacemark.kml". Open MS-Word and bring in your "MyPlacemark.kml" file. Notice the structure of the file which is similar to HTML (Figure 20). The black text in Figure 20 shows you the kinds of information that you can edit.


Figure 20: Contents of a Google Earth KML document with the tag types shown in green.

Of course this is only the tip of the iceberg in terms of what you can do with KML, but should get you started and give you some ideas. For a much more detailed introduction, see earth.google.com/kml/whatiskml.html and for the full tutorial, see earth.google.com/kml/kml_tut.html (but not required for this exercise).

For future reference, there is a broader Google Earth Community web site where you can post questions and discuss all things Google Earth (Figure 21).


Figure 21: The Google Earth online community.

And finally, there are many Google Earth Blogs and "tricks and tips" web sites available, including:

The End!

Last update: July 22, 2011
http://dusk.geo.orst.edu/GE
OSU Web Disclaimer | Send a question or comment