Lost About GPS? Here's Some Direction! by Keith Thompson

If you've been confounded by all the technicallike speed, sunrises and sunsets, bearing, distance
jargon and hype surrounding GPS, confusingand more. While they will work in any weather,
what's turning out to be a very useful tool, allowsome hindrances would be electronic
me to shed a little light on your roadmap tointerference,buildings, and certain terrain. A good
deciding whether or not this technology is for you!rule of thumb is that the units will generally not
Originally designed with military applications in mind,perform underwater, indoors, or underground.
the technology was made available to mereThere are currently two Global Navigation Satellite
mortals in hte 1980's for the many and variedSystems in use. Besides GPS, there is the Russian
uses we've found so far for these special tools.Global Navigation Satellite System (GLONASS)
Not only handy for auto navigation, GPSunits haveProtocols are constantly beingrefined to enhance
made their way into maritimethe abilities of these systems. A bright light on the
navigation,backcountry uses, and much, muchhorizon is Galileo, scheduled to go online in 2008,
more!which promises even greater accuracy and
How does GPS work? GPS (which stands forfunctionality.
Global Positioning System) allows you to pinpointSo how do I know which GPS unit is for me?
your position anywhere on the planet to within anQuite a fewchoices now exist for consumers in
average of 15 meters, with some units doingthe GPS marketplace.
much better than that. Twenty-four GPSWhether you need a handheld unit for
satellites, paid for and placed in orbit by the Dept.backpacking or boating, or one for your
of Defense courtesy of your tax dollars, sendautomobile (they are becoming an attractive
signals back to terra firma 24/7. These signals areoption!) or for one of a myriad of uses, there are
retrieved by your handy dandy GPS receiverseveral reputable manufacturers of quality GPS
which uses three sources (satellites) to triangulateunits out there to help you find your way through
this information and compute your actual position.the maze of choices. Names like Magellan, Garmin,
If there are four data sources, even altitude canRino, Etrex and Meridian lead the market, and are
be determined. Since there are normally eightreadily available. Take your time, check out the
satellites in line of sight from anywhere on earth,various features each has to offer, and get
the opportunity for accurate positioning exists.yourselfoutfitted with one of the more useful and
Other things that can be determined besidesefficientnavigational tools out there today!
latitude, longitude, and altitude would include things