Moving Around the Earth


Google Earth gives you a wide variety of tools you can use to “move around” while you explore the satellite images. This section helps you become familiar with the way to use your mouse or keyboard to navigate around the satellite image.

Using the hand that Google gave you

The mouse cursor, when placed over the satellite image appears as a hand. This means you can “grab” the image and move it in any direction you like. When you click the left mouse button you will see the fingers grab the image. In the grab position, you can move your mouse and the image moves in the direction of your mouse. This is particularly useful for making fast moves in a particular direction.

You can also grab the image and “toss it” in a particular direction. Grab the image, move it in a direction, and let the mouse button up while the mouse is still moving. This causes the image to continue moving in the direction you toss it. To stop the image from moving, simply click once on the image. This is great for viewing large sections of a map without needing to use the navigational buttons or continually grabbing and pulling the image. Be careful. You can toss too hard and the image can start moving rather rapidly.

When the mouse cursor is over an informational icon, it changes to an arrow, meaning that you can click for more information. When you right-click, the hand changes to an up and down arrow cursor. While depressing the right mouse button you can easily zoom in and out by moving the mouse up and down.

Using the navigational controls

In the upper-right corner of the satellite image, you find a number of controls floating over the image (see Figure 13.3). Placing your cursor over the compass causes hidden controls to display that allow you to move the image in straight lines, rotate the image in a 360° circle, tilt the image, and zoom in.

image from book
Figure 13.3: Use the navigational controls to move, zoom, and tilt the image.

The up, down, left, and right arrows cause you to move in a direction that can best be described as parallel to the ground. By default, clicking the up arrow moves you in a northerly direction, the down arrow toward the south and so on. But, once you use the rotation ring, which rotates the image, the up arrow moves you in an up direction in the image, which is not necessarily associated with north. You can refer to the compass to determine which direction you are heading by using these navigational keys. To use the rotation ring, click anywhere on the compass circle and drag this ring in either direction to rotate the image. You can also use the small gear-like icon in the center of the ring to rotate the Earth in any direction by clicking on it with your mouse and pulling it in the direction you want to travel.

Tip 

The up-, down-, left-, and right-arrow keys on your keyboard provide the same function as the controls displayed in Google Earth.

The tilt slider (horizontal slider along the top) causes the satellite image to appear as though you are looking at the image from an angle. Because Satellite imagery is taken from directly above, it is not possible to view features such as mountains or buildings in 3-D. However, there are overlays that allow you to see representations of buildings and terrain in 3-D, making the tilt feature very useful. Tilt the image in either direction using the slider. In the default view of the image, you are looking straight down. The tilt-up direction of the slider does nothing until the image is tilted down using either the slider or the tilt-down button on the right side of the slider. You can reset the tilt to directly overhead by double-clicking the tilt-up button found to the left of the tilt slider.

Tip 

Control the tilt by pressing the Page Up (PgUP) and Page Down (PgDn) keys on your keyboard.

The vertical slider on the right side of the Navigation tools (see Figure 13.3) consists of the zoom buttons and zoom adjustment slider. Using these buttons, you can zoom in or out. For example, clicking the + button causes the image to zoom in; click the button to zoom out. This changes the appearance of altitude. As you zoom in, you appear to be viewing the scene from a lower altitude. You can view your apparent altitude in the status bar located along the bottom of the image.

The 411

Google Earth provides a status bar that is superimposed over the bottom of the satellite image. It contains three essential pieces of information, as shown in Figure 13.4. On the left side of the bar you can read the latitude and longitude of the location over which the mouse cursor is hovering. Move the mouse cursor and you see the latitude and longitude in the status bar change as well.

image from book
Figure 13.4: Information about the location you are viewing is located in the status bar at the bottom of the image.

The center of the bar displays the status of the image being streamed to your computer. This means that the images are sent to the Google Earth program running on your computer in stages. At first, before streaming has completed, you are able to view a lower-resolution image. As the data from the Google server streams to your computer, the image resolution slowly improves until it reaches 100 percent, meaning that the image you see is at its maximum resolution.

Note 

The streaming speed depends on the speed of your Internet connection. Upgrading to Google Plus also helps with streaming speed.

The Eye alt status on the right side of the status bar shows you the apparent elevation over the Earth depending on your level of zoom. Clicking the zoom buttons or moving the zoom slider causes this value to change. It’s not an exact measurement but a good approximation. The maximum distance you can zoom out is 39,353.69 miles from the Earth. The closest distance you can zoom in is around 28 feet, but the resolution of even the best image is relatively poor at that elevation. The measurement changes from miles to feet at an altitude of ten miles above the Earth.



Google Power Tools Bible
Google Power Tools Bible
ISBN: 0470097124
EAN: 2147483647
Year: 2004
Pages: 353

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