Lost About GPS? Heres Some Direction!

by : Keith Thompson

If you've been confounded by all the technical jargon and hype surrounding GPS, confusing what's turning out to be a very useful tool, allow me to shed a little light on your roadmap to deciding whether or not this technology is for you! Originally designed with military applications in mind, the technology was made available to mere mortals in hte 1980's for the many and varied uses we've found so far for these special tools. Not only handy for auto navigation, GPS units have made their way into maritime navigation, backcountry uses, and much, much more!

How does GPS work? GPS (which stands for Global Positioning System) allows you to pinpoint your position anywhere on the planet to within an average of 15 meters, with some units doing much better than that. Twenty-four GPS satellites, paid for and placed in orbit by the Dept. of Defense courtesy of your tax dollars, send signals back to terra firma 24/7. These signals are retrieved by your handy dandy GPS receiver which uses three sources (satellites) to triangulate this information and compute your actual position. If there are four data sources, even altitude can be determined. Since there are normally eight satellites in line of sight from anywhere on earth, the opportunity for accurate positioning exists. Other things that can be determined besides latitude, longitude, and altitude would include things like speed, sunrises and sunsets, bearing, distance and more. While they will work in any weather, some hindrances would be electronic interference, buildings, and certain terrain. A good rule of thumb is that the units will generally not perform underwater, indoors, or underground. There are currently two Global Navigation Satellite Systems in use. Besides GPS, there is the Russian Global Navigation Satellite System (GLONASS) Protocols are constantly being refined to enhance the abilities of these systems. A bright light on the horizon is Galileo, scheduled to go online in 2008, which promises even greater accuracy and functionality.

So how do I know which GPS unit is for me? Quite a few choices now exist for consumers in the GPS marketplace. Whether you need a handheld unit for backpacking or boating, or one for your automobile (they are becoming an attractive option!) or for one of a myriad of uses, there are several reputable manufacturers of quality GPS units out there to help you find your way through the maze of choices. Names like Magellan, Garmin, Rino, Etrex and Meridian lead the market, and are readily available. Take your time, check out the various features each has to offer, and get yourself outfitted with one of the more useful and efficient navigational tools out there today!