GPS for Dummies.pdf - Engineering Surveyor

Chapter 20: Overhead Image Web Sites325 County: Enter a county in the United States (and optionally, its state). Animage with the center of the county will be displayed. Address: Enter a street address (United States) and the city and state(or ZIP code).After you enter your search criteria and click Search, TerraServer.comqueries its database for matches. The three possible search outcomes are Bupkis: No images in the TerraServer.com database meet your criteria.Check your spelling or change your search criteria before you give up. Multiple matches: A appears with the matching images; you select theone you want. For example, if you search for a city named Bend butdon’t specify the state, you get a list of cities in Oregon, Montana,California, Texas, and other states. Perfect match: TerraServer.com found a single match in its database.Pay dirt! From the list of available image types (with the supplier, date,and resolution), click the image you’d like to view.TerraServer.com has many international images, but don’t expect photos ofevery place on Earth. The international images are mostly large urban areasand aren’t available for all metropolitan areas outside the United States.Moving in a TerraServer.com imageAfter you display an image, you can change the image’s location by panningand its resolution by zooming in and out. Panning: Panning simply means moving the image to view an unseenarea. It’s like scrolling without the scroll bars. To pan the image1. Make sure that the Pan radio button to the left of the image isselected.2. Hold down the left mouse button on the image and drag thedirection you want to move the image.For example, to see more area to the north of the image, drag downtoward the bottom of the screen.3. Release the mouse button.After a moment, the new image is displayed. Zooming: TerraServer.com has a plus and minus button to the left of theimage (refer to Figure 20-5) to control zooming in and out. (There’s alsoa Zoom In by Click radio button that you can select so that when youclick the image, you automatically zoom in.)