How to Use GPS


National Park Image Gallery A man and woman consult GPS to find their way through the forest. See more pictures of national parks.
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You could let your heart be your guide. But when you're hiking through unfamiliar wilderness, a GPS receiver is probably a better lead. This magical little device provides its user with four main things: location, distance and directional information, tracking and route creation. With this information, hikers and travelers learn where they are and, more importantly, how to reach where they want to go. The information provided by the GPS system is constantly updated, which helps you to stay on track.

Between 24 and 32 satellites orbit the Earth, and these satellites provide the answer to the GPS receiver's aching question, "Where am I?" The satellites calculate this through a process called trilateration. Receivers lock signals with several different satellites orbiting the Earth, and based on the time it took those signals to reach the different satellites, a calculation is made about the receiver's location on Earth. Long story short, you look down at your receiver and see exactly where you are on a digital map.

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It wasn't that long ago that GPS technology was used only by the military. But in recent years, that has changed dramatically. Receivers are now very affordable. For less than the cost of a quality tent and not much more than a pair of sturdy hiking books, outdoor enthusiasts can find a functional GPS that floats, is waterproof and is durable enough to withstand the rigors of a rough trail.

Although GPS receivers are affordable, many consumers still wonder if they have the skill to use one. When you consider that the GPS must send a signal to satellites orbiting the Earth, wait to receive a signal back, and then convert that signal to not only your location but the speed at which you're traveling and how long it will take you to reach a particular destination, the gadget can seem pretty fantastical and intimidating. But the truth is, the receiver does the bulk of the work itself. If you can navigate by map and compass, reading a GPS will be an easy skill for you to learn. Let's get started.

GPS Waypoint and Go-to

To accurately determine your location, a GPS receiver needs to lock onto four different satellites. The signal it receives from these satellites must be strong. If the signal is weak or the GPS receiver cannot lock onto four satellites, the information you receive may not be accurate.

To get a signal, turn the GPS receiver on and push the satellite button. It may take a few minutes, but you'll be able to see the number, location and strength of the satellites that the GPS receiver is locked onto. If the signal is weak, or there are less than four satellites on the screen, you should navigate using a map and compass.

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Sometimes the area where you're standing can have an effect on your signal strength. If the signal is spotty or weak, try moving to a location without any overhead obstructions. Both trees and canyon walls can interfere with the GPS's ability to communicate with satellites. Move into a meadow or a parking lot while the GPS system locks onto the satellites. Once it has locked on, the receiver usually can maintain a connection when you enter the woods.

Two important functions of a GPS receiver are the waypoint and the go-to functions. Waypoints are points that you can enter into the memory of your GPS for a particular journey. They may be the spot you plan to camp, where you parked your car or other interesting places along the trail. You can enter more than one waypoint for each trip. While you're hiking, you can see the waypoints and your relationship to them on the GPS screen.

The go-to function guides you exactly where you want to go. When you're ready to head to camp or home, simply press the go-to button, and a selection of waypoints will appear on your screen. Select the waypoint you want, and the GPS receiver will immediately let you know how far away it is and what direction you need to travel to get there. It will continually update as you hike, so you'll know if you're drifting off course and how much farther you need to travel.

GPS technology has greatly improved in the past several years, but receivers still get confused. While hiking, attach the GPS receiver to your shoulder or the top of your backpack. You need easy access to it, but carrying it in your hand or clipping it to your waistband can create problems. The motion of swinging your hand while hiking can be enough to confuse it and it may not hold a connection with the satellites.

Laying a Track with GPS

Two mountain bikers find their way with a GPS unit.
Two mountain bikers find their way with a GPS unit.
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Laying a track is another important GPS receiver skill. You can use your GPS to leave a virtual trail, which allows you to follow your trail out if you become lost. Your GPS will have a button that's responsible for dropping track points. You can drop the track points as close together or as far apart as you like. The closer together you place your track points, the more accurate this trail will be if you have to follow it out. When you use the tracking feature, you don't need to manually enter the track points, the GPS will automatically mark them for you at the distance you specify before your trip.

All of the features available on GPS receivers are nice to have, but these features come with a drawback. GPS receivers can be hard on batteries. Lithium batteries have the longest battery life, but may cause distracting lines across the GPS screen when they're new. To eliminate this problem, many people use lithium batteries in another piece of equipment for a few minutes before putting them in their receiver.

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You can prolong the life of your batteries, no matter what type they are, by turning off nonessential functions. Backlighting, compass mode and other auxiliary functions can be switched off. Also, if your GPS loses its satellite lock, turn it off to conserve battery power until you find an open area to lock in on the satellites again.

Loading Maps onto GPS

GPS receivers are only as good as the maps they're used with. If you're proficient with a map and compass, then you're probably familiar with the various types of topography maps. The U.S. Geological Survey is one source of high-quality maps for all areas in the United States. Regardless of where you plan to backpack, it's important you have accurate and easy-to-read maps.

Your receiver will come loaded with a variety of maps. If the maps you want aren't preloaded onto your GPS, you can probably purchase them in CD-ROM format and load them onto your receiver. Some companies also provide microSD memory cards that are preloaded with maps that can easily be added to your GPS. Finally, the Internet has a wealth of downloadable maps available for receivers.

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GPS receivers are bound to become a more intimate part of our lives as more people become comfortable with the technology. Some people first learn to use them through their jobs. More and more workplaces are using GPS to track company vehicles or employees who work outside the office.

Once you become proficient with a GPS receiver, you may find you're interested in adding one to your vehicle. Whether you're using a GPS receiver while hiking or driving, the drawback is the same. GPS receivers are not capable of recognizing obstacles in their paths, so both a road detour or a rushing river will require you to reconsider your route. For this reason, it's unlikely that maps will become obsolete any time soon.

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More Great Links

Sources:

  • Barlett, David. "The Future of GPS." (April 15, 2009) http://www.ingenia.org.uk/ingenia/articles.aspx?Index=473
  • Howe, Steve. "GPS Basics." Backpacker Magazine. April 2004. (April 12, 2009)http://www.backpacker.com/april_2004_gear_gps_basics/gear/10541?page=1.
  • Lanza, Mike. "How to Speak GPS." Backpacker.com. (April 12, 2009)
  • Milne, John. "Getting There with GoTo." GORP.com. (April 15, 2009)http://gorp.away.com/gorp/activity/hiking/skills/navigation/goto.htm.
  • Milne, John. "Getting the Track Back." GORP.com. (April 15, 2009)http://gorp.away.com/gorp/activity/hiking/skills/navigation/track.htm.
  • Milne, John. "Staying the Course." GORP.com. (April 15, 2009) http://gorp.away.com/gorp/activity/hiking/skills/navigation/route.htm.