Google Earth (GE) is a spatial dataset interface available through the Internet search engine Google that can be downloaded free. This interface uses aerial and satellite photographs at a variety of spatial resolutions overlaid on digital elevation model datasets to give the images a three-dimensional quality. Since the data are geo-referenced in all three dimensions, they can be used to make measurements of distance with GE’s “path” and “line” measurement tools. Elevation, latitude, and longitude are continuously tracked for any specific location of the cursor and are displayed at the bottom of the screen. GE also offers navigation tools in the upper right corner of the screen that allow you to zoom in and out as well as to alter the azimuth and aspect of your view.
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One of the newest functions of GE is the ability to move backward in time at some locations by accessing archived spatial datasets. In the spirit of all Internet search engines, Google also provides a “Fly to” search window you can use to transport yourself to specific virtual locations. You can bookmark favorite locations as well as link locations to geo-referenced digital images taken at the same locations. Please make use of some or all of these tools while familiarizing yourself with the interface, and have fun doing it! For specific instruction on using Google Earth, go to Google Earth Tutorial at www.whfreeman.com/understandingearth7e.