Eyes in the Sky II > GIT Web Course > Module 3 > Week 9 > Intro to Google Earth

Week 9: Googling Around

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Intro to Google Earth

If you have not installed Google Earth or updated your existing copy of the program to the current version (version 6), please refer to the installation instructions on the Module 2 Review & InstallInstalling Google Earth page before continuing.

What is Google Earth?

Google Earth has been described as "a map of the world on steroids." It's a free tool for exploring spatial data in an interactive 3D environment. As you use Google Earth, you'll come to realize that it's actually a special-purpose GIS tool, capable of displaying many types of data in 4 dimensions3 spatial dimensions plus (in some locations, anyway) a time dimension. In the past few years, with help from NASA researchers and data, Google Earth has been expanded to include maps of Earth's ocean floor, as well as the Moon, Mars, and the Sky, all using the same familiar 3D interface.

Like the other tools you've been playing wither, learning to usein Eyes in the Sky II, we'll only scratch the surface of what you can do with Google Earth and how you might use it in your classroom.

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The Google Earth Interface

Let's start our exploration by launching Google Earth and learning the parts of its interface.

ge_win_icon
  1. Launch Google Earth by double-clicking its icon on your computer's desktop or by clicking its icon in the Start menu or launch bar (Win) or the dock (Mac).

    google_earth_ui
  2. Locate the following elements of the Google Earth window:
    • 3D ViewerView the globe and map features in this window.
    • Search PanelFor finding, getting directions to, and flying to places in Google Earth's extensive database.
    • Places PanelFor saving, organizing, and returning to your favorite places. Clicking the Add Content button lets you import new content from Google Earth users and contributors.
    • Layers PanelFor displaying features of interest. (The Layers Panel is like the Table of Contents in AEJEE and ArcGIS.)
    • Toolbar ButtonsFor adding your own features to the map, measuring, and turning display options on and off.
    • Navigation Controls
      • Look JoystickRotates and tilts the view.
      • Move JoystickPans the map in any direction.
      • Zoom SliderZooms in and out on the map.
    • Status BarShows coordinates, elevation, imagery date, and the streaming status of the map.

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Google Earth Imagery

Google Earth was inspired by a flipbookCharles and Ray Eames' book, Powers of Ten. When designing the software, the Google Earth team decided they would start in outer space with a view of the entire globe, and then zoom in closer and closer.

To achieve full-globe coverage from such a wide range of vantage points, Google Earth pulls in imagery from many different data sources and dates, and patches them together into a mosaic. The images you see in Google Earth come from satellites, airplanes, hot air balloons, and even kites. You can find out where the imagery comes from by looking at the copyright information along the bottom of the Google Earth window. You must have a live Internet connection while using Google Earth. As you move around and zoom in and out, new images are streamed (downloaded to your computer on the fly) from Google's servers.

Because of the wide variety of data sources, Google Earth images come in a wide range of spatial resolutions. Most land areas are at shown at 15-meter resolution, but the most detailed Google Earth images have resolutions as fine as 15 centimeters (6 inches). You may be wondering why high-resolution images aren't available for all regions. High resolution satellites like GeoEye-1 only photograph about 1% of Earth's surface on each orbital pass. On top of that, these images are only suitable for Google Earth if the sun is at a high angle so there are fewer shadows, and when there is little or no cloud cover, haze, dust, or pollution.

The average Google Earth image is about three years old, although some are older and some are as recent as 3 hours old (Cloud layer). Google Earth 5 has a new historical imagery feature, which gives you the option of viewing different images for one location from different times. In some cases, the historical image archive includes images that are newer than the default imagery. Google Earth will typically default to older images with higher resolution or clarity rather than newer low-resolution images.


The first set of skills you need to learn involves navigating in Google Earth. Please be sure to try each technique before moving on to the next.

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Navigate by Zooming

Zoom In by Double-Clicking the Map

The simplest way to zoom in to an area on the map is to double-click directly on the location you want to zoom in to.


Zoom to a Feature Using the Search Panel

You can also zoom in to a specific place by entering a street address, latitude/longitude coordinates, or a name in the Search Panel.

  1. Enter a street address in the Fly to box. Be sure to include the city and state, as well as the zip code, if you know it.
  2. Click the Begin Search button.

  3. If only one feature matches your address, the map will automatically zoom to that location. If your search matches more than one location, you'll get a list of matching locations to choose from.

    To zoom to a feature using the Search Panel:

    1. In the Search Panel, enter the address in the Fly to box.

    2. ge_flyto_address
    3. The map will zoom to your address. ge_flyto_white_house

  4. Enter the location of your Eyes in the Sky II summer workshop (Johnson Space Center, Goddard Space Flight Center, or Jet Propulsion Laboratory) in the Fly to box and click the Begin Search button.
  5. Google Earth will return several possibilities for each of these places. Look over the list at the bottom of the Search Panel, choose the most likely suspect, and double-click its name to zoom to the NASA center you chose.
  6. You can also enter latitude/longitude coordinates in the Fly To box. Enter latitude/longitude coordinates using either N/S or +/- for latitude and E/W or +/- for longitude. (CAUTION: don't use both a compass direction and a sign or mix compass directions and signs when entering coordinates.) Enter the following coordinates to see where they take you:
    • 43.88,-103.46
    • 38.8814,-77.0366
    • 48.858N,2.2945E
    • 33.8567S,151.2151E
    • Mount Rushmore
    • The Jefferson Memorial
    • The Eiffel Tower
    • The Sydney Opera House

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Zoom In Using Placemarks

In Google Earth, a placemark is a symbol that marks a location. The default placemark symbol is a pushpin with a text label.

Zoom in on the Grand Canyon using an existing placemark:

  1. In the Places Panel, turn on and expand (by clicking the + (Win) or triangle (Mac) in front of) the Sightseeing folder.
  2. Double-click the Grand Canyon place entry. Google Earth will zoom to the Grand Canyon.

To zoom to a feature using placemarks:

  1. Turn on and expand the Sightseeing folder in the Places Panel.
    ge_places_sightseeing
  2. Scroll down and double-click the Grand Canyon placemark.
  3. The map will zoom to the Grand Canyon.
    ge_places_grand_canyon

NOTE: For maximum effect, turn on the Terrain layer at the bottom of the Layers Panel.


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Zoom Out and In Using the Mouse

Zoom out from the Grand Canyon with your mouse, using one of these methods:


Zoom in to the Grand Canyon with your mouse, using one of these methods:


Mouse-based navigation in Google Earth also includes a throw featureif you release a mouse button while the mouse is still moving, the map will keep zooming, rotating, or moving in that direction until you click. The faster your mouse is moving when you release the button, the faster the map will move. It takes some practice, but it's fungive it a try now! If you get lost and can't find the canyon again, double-click the Grand Canyon entry in the Places Panel.


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Zoom Out and In Using the Navigation Controls

ge_zoom_slider

The navigation controls are in the top right corner of the 3D Viewer window. They offer the same navigation actions as mouse navigation, plus some additional features. The navigation controls disappear when you aren't using them, but re-appear when you move your mouse over them.

  1. Click and hold the Zoom Out button (at the bottom of the Zoom Slider) to zoom out.
  2. Click and hold the Zoom In button (at the top of the Zoom Slider) to zoom in.
  3. Drag the Zoom Slider control up and down to zoom in and out. (As with the mouse zoom, if you zoom in far enough the view will tilt up until you are looking parallel to the ground.)


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Navigate by Tilting

Tilt Using Your Mouse

Tilting lets you change the downward angle of your view, from a nadir (straight down) view to a tangent or horizon (parallel to the ground) view. Of course, for the maximum effect, you must turn on the Terrain layer (in the Layers Panel).

  1. In the Layers Panel, be sure the Terrain box is checked.
  2. Zoom to the Grand Canyon using your mouse or the navigation controls.
    The Eye Alt value at the right end of the Status Bar represents the elevation of your viewpoint. Watching the Eye Alt value, zoom to a viewpoint of about 35,000 feet.)
  3. If your mouse has a scroll wheel or trackball, tilt the view by holding down the SHIFT key and scrolling DOWN to tilt the Earth toward nadir view, or scrolling UP to tilt the Earth toward horizon view.
  4. If your mouse doesn't have a scroll wheel, hold down the left mouse button while you move the mouse forward or backward to tilt the view.


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Tilt Using the Navigation Controls

ge_look_joystick

You can tilt simply by zooming in. Once you zoom in far enough, Google Earth tilts your view up toward the horizon.

To tilt the view using the navigation controls:

  1. Click and hold the up arrow on the Look Joystick to tilt up toward the horizon.
  2. Click and hold the down arrow on the Look Joystick to tilt down toward the nadir.


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Tilt Using the Keyboard

You can also tilt using the keyboard:

  1. Hold down the SHIFT key and press the up arrow key on your keyboard to tilt up toward the horizon.
  2. Hold down the SHIFT key and press the down arrow key to tilt down toward the nadir.


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Navigate by Looking and Moving Around

Look and Move Around

In Google Earth, you can look around and move around. These are different, and it's useful to know the difference. Think of looking around as turning your head around from one vantage point to another. Moving around involves walking from one place to another. Both actions change your perspective. ge_look_joystick

To look around:

  1. On the Look Joystick, click and hold the right arrow to rotate the view clockwise.
  2. Click and hold the left arrow on the Look Joystick to rotate the view counterclockwise.
  3. You can increase the speed of rotation by clicking and holding an arrow, then dragging away from the Look Joystick.
  4. To look around using the mouse, hold down the SHIFT key while moving the mouse from side to side. (Moving the mouse diagonally while holding the SHIFT key tilts the view as it rotatesbeware of motion sickness if you do this too much!)
  5. Click and drag the outer compass ring of the Look Joystick. To return to a "north up" view, click the N on the compass ring or press N on your keyboard.
  6. To look around using the keyboard, hold down the SHIFT key and press the right arrow key to rotate clockwise and the left arrow key to rotate counterclockwise.

To move around:

  1. To move around with the mouse, click and drag directly on the map in any direction. ge_move_joystick
  2. To move around using the navigation controls, click and drag around the outer edge of the Move Joystick. To speed up the movement, drag the mouse farther away from the Move Joystick.
  3. You can also move around using the arrow keys on your keyboardup (forward), down (backward), left, and right.

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Explore the World and Review Your Skills

Spend time exploring the world and practicing your Google Earth navigation skills using the:


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Resources

To learn more about using the features of the navigation controls, see:

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