Getting to Know Google Earth

By David A. Crowder from Google Earth For Dummies

Google Earth is not just another map program or some kind of digitized globe inside your computer, but rather, a social phenomenon. Although it can stand on its own with other Geographic Information System (GIS) software, its focus is on giving the public a unique experience.

With everything from National Geographic articles to live Webcams to local commentaries built into it, the program doesn't just display maps and photos but launches the era of satellite tourism. Calling it a 3-D interface to the planet, the folks at Google are backing it to the hilt with both their incredible wealth and their enviable marketing savvy, and it seems destined to grow into one of the largest of all the online communities.

With Google Earth, you have wings. You can fly high above the planet or zoom right down to the ground. In seconds, you can zip from the deserts of the American West to the tropic isle Tahiti. No tickets to buy, no bags to pack, no long lines or customs or anything else. Just go!

Because Google relies upon many outside providers for its satellite and aerial imagery, the quality of images in different locations varies somewhat. Detail in major metropolitan areas is generally better than images of rural areas, which have not been as extensively photographed from space. This is not a limitation of Google Earth but rather of the current state of available data, and this constraint applies to all GIS programs. The simple rule is that the more expensive the real estate, the more likely it is to have been the subject of detailed — and costly — satellite analysis.

Although it relies upon imagery from satellite photos taken anytime in the past three years, Google Earth isn't merely a static collection of warmed-over satellite images from dusty sources. Rather, it's continuously kept current through a vigorous program of updates. Such attention to detail and timeliness is one of the reasons why people ranging from casual users to real estate professionals have come to rely upon the Google Earth service.

Google Earth also makes it a point to respond quickly to breaking news. As an example, when a deadly earthquake struck Pakistan, Google Earth had updated, higher-quality satellite imagery of the quake area available online in less than a week, freely available to everybody from news junkies to international rescue workers. The first time such on-the-fly updating was used was during the Hurricane Katrina response. Google Earth, working with the National Oceanographic and Atmospheric Administration (NOAA), had very detailed imagery of the entire affected region online within five days after the event.