In the days of the spanish empire it could take months or even years to get a shipment from one place in the world to another -- if it got there at all. This was the age of the great explorers and cartographers, but for them much of the map was still Terra Incognita. They fiddled with sextants, stared at stars, tried futilely to determine their longitude at sea. If you told them that in the future you could determine their precise location to within a few feet, they probably would have turned you over to the Inquisition as a sorcerer. In many ways, the Global Positioning System still seems like a mysterious and futuristic technology, but it is already very real and affects the lives of millions of people -- whether or not they realize it.
Many people may know of GPS only through its recreational uses. Sailors and hikers are well acquainted, but others, hearing the term from tent-toting, granola-crunching friends, may assume GPS is some sort of health drink or nutritional supplement. But it's getting more difficult to avoid, even for those who consider the walk through the company parking lot a trek worthy of the Iditarod.
Like so many other technologies now being used and enjoyed by millions of private citizens, the system was originally devised and implemented by the U.S. military. It kicked into full operation in July of 1995. The benefits of such information in battle are obvious, and so the U.S. began launching a system of 24 satellites to help its soldiers. Each satellite sends out information about where it is located at a given moment, and once a receiver has the coordinates of four satellites, it can calculate its position.
But citizens, too, can use a GPS receiver to tap into this system of satellites. Until earlier this year, the system introduced deliberate errors into all non-military GPS data, but this May President Clinton removed "Selective Availability," making readings much more precise. Previously, the nearest approximation most receivers could get was within 100 meters of the actual location; it is now closer to 10. Some devices that use a slightly fancier calculation can tell within a meter -- less than the average person's armspan.
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For some industries, knowing exactly where you (or your merchandise) are at a given time is absolutely essential for doing business. The countless gold-laden galleons that sunk, just now being exhumed, are barnacle-encrusted evidence of the inefficiencies in the sixteenth-century supply chain. Now supply chains are more responsive and efficient than ever before, and the reliable delivery of goods and products is an important part of that. (Then again, some shipping companies find drawbacks to being so precise: Trucking companies that experiment with using GPS sometimes abandon it when the data shows that their drivers are travelling farther than is safe in a given amount of time.)
But knowing where you are can also be useful for individuals -- especially those that are on the move. GPS receivers could soon be finding their way into all sorts of mobile devices, including your cell phone, PDA, and the onboard computers of the company car. These would help with traditional location-based services -- telling a tow-truck where your tire blew out, for instance. This also could permit a whole new breed of Internet-enabled ones, as well.
Some services already anticipate delivering location specific information (where's a shoe store in this neighborhood?) and it comes as no surprise that some companies are already planning to push location-based advertising to users of mobile Internet devices. One wonders what punishment the conquistadors could devise for them.