by Marty Demarest
It's good to know that wherever you go, there you are. But what's even better is to know where that is. Whether you're camping, hiking, canoeing or simply out strolling, knowing your precise point of location on the planet has gotten a lot easier thanks to GPS, or Global Positioning Systems. The GPS is a $12 billion project by the U.S. Department of Defense that has resulted in two dozen satellites orbiting the earth, enabling some devices to determine their location on the planet's surface within several inches. And rather than keep the technology for themselves, the DOD has allowed GPS receivers to be integrated into devices small enough to carry in your pocket.
The use for such technology seems obvious: rather than rely on direction headings and distance measurement to navigate, users simply head for unchanging coordinates. Add the fact that many GPS receivers also allow users to set a number of "waypoints" -- fixed markers that the machine remembers -- and good old-fashioned compasses seem almost obsolete.
For most of us -- just folks trying not to get lost -- Garmin's eTrex line of GPS receivers is a good place to start. Not only does the basic unit try to keep track of as many as 12 satellites -- you only need contact with one -- but it also calculates the speed you've been traveling and stores as many as 500 waypoints. This makes it possible to establish a course and retrace it later, or return for that perfect Christmas tree you found while walking during the summer. And while it costs barely $100, it devours batteries.
A more elaborate device is the Magellan Meridian Platinum (about $300), which does everything that the eTrex does but also includes a database of major cities and roads, has more memory and features an antenna so that satellite connection can be made even in heavy tree cover. That way, if you still manage to get lost, you'll have something spectacular to blame.