GPS Technology Outdoor Lifestyles Page 1

		*Global Positioning System Units* (GPS)

	Just what is a GPS unit? How can it help me as an outdoor adventurer?

In the past, out-backers relied primarily on maps and compasses to help guide them on their adventures. Today, GPS technology takes many kinds of outdoor navigation to a whole new level.

The United States built a network of 24 orbiting satellites, these make two complete orbits around the earth every 24 hours. The satellites then transmit radio signals back to earth where the GPS picks up the signals and calculates its distance from a satellite by measuring the travel time of the satellites radio signal. By using the distance from at least 3 satellites, the GPS can triangulate your exact position on earth to within 100 feet. GPS technology works 24 hours a day in all kinds of weather conditions. For many years this technology was used solely by the military, today many manufacturers offer the GPS technology to to adventurers nationwide.

A GPS unit can determine your current location, as well as plot a route for you to get there. Search and rescue teams use the GPS to help locate lost or stranded out-backers that have encountered bad weather conditions or have been injured. Because the GPS uses actual latitude and longitude to report positions, when used with a topographical map a persons exact location can be determined. Keep in mind that is important to understand basic map and compass navigational skills before attempting to use a GPS. A compass reads direction; a GPS receiver reads position. The best topographical maps to use with the GPS are standard USGS format.

What are the differences in GPS units?
GPS units run anywhere from $150.00 to $250.00(USA). The number of channels, programmable routes, and battery life are a few differences among units that affect price. It is best to pick one that you feel comfortable with. Some GPS units have different screen viewing features and perks, but your basic GPS unit is more than adequate for your average outback hikers. ---Information from REI's GPS Product Information Guide.