Buying Right: Satellite Navigation for Civilian Budgets


Outside magazine, April 1996

Buying Right: Satellite Navigation for Civilian Budgets
By Jerry Gibbs

Even when your hiking trips don’t call for serious orienteering, it can be comforting to have a guide with area-specific savvy. But then, a handheld global positioning system (GPS) device might be all the local wisdom you need. Conceived by the U.S. military, GPS is a
navigational system that uses 24 earth-orbiting satellites to determine the coordinates of your location. The system is capable of the missile-down-the-chimney precision we saw in Desert Storm, but military wisdom has seen fit to degrade the civilian world’s signals by introducing small errors. Still, we nonsoldiers get readings accurate to within 100 meters (328 feet).

The average GPS receiver’s learning curve is no steeper than that of a new laptop. Some are graphically oriented; others are heavy in numeric displays. All will save the data for any location (or “waypoint,” in GPS jargon) you choose. Some units use fewer, larger function keys to perform multiple duties, so you have to learn and remember what they do. The myriad smaller keys on
other models are more function-specific, though harder to work with gloved hands.

A more graphically oriented device, the Garmin GPS 40 ($350) has a great “moving map” feature, which allows you to view waypoints beyond the periphery of your current position–while an “active plot trail” continues to show your travel path. The
large cursor control and six function keys make one-hand operation easy. At nine ounces, it’s the lightest handheld GPS unit on the market.

The lowest-priced unit to date, the $200 Magellan GPS 2000 is easily learned. Particularly handy is a plotter screen that lets you create an instant “backtrack”–a mirror image of your recent travel–which can be a lifesaver if the route ahead
becomes unmanageable.

Sheer graphic power and a large display make the Eagle AccuNav Sport ($400) the IMAX of GPS. In a single screen you can watch your moving position and back trail, note a series of “event markers” and waypoints, and get distance and bearing information from your present position to any spot on the screen. Thirteen small keys sport computerlike
alphanumeric labels, making operation logical and easy. (And there’s even a help menu for each mode and screen.) This is the largest receiver of the bunch, but still no burden at eight by three and a half inches.

The Trimble ScoutMaster Topo ($849) will take you into the realm of orienteering, with a topographic database that offers easy, fast plotting on any USGS topo map. The unit tells you which map to use and, as a reference point, the specific quadrant within it. Then, using a ruler, you measure the distance from the reference point on your map (the unit
tells you how many inches), and that’s where you are. The sophisticated Trimble takes some study, but it works beautifully.

See also:
Where to Find It