Global Positioning Systems FAQ's Everything you want to know and more!A "Salvation For Lost Souls,"
proclaims one GPS (Global Positioning System) company ad in a June 1996 Outside
magazine. "Works in dense forests, deep canyons and river gorges," claims
another in a Backpacker magazine ad. "...Makes navigating easy for any
adventurer... A little encouragement to push it to the max, knowing it'll always
get you back," boasts yet one more ad in a recent Backpacker . In the summer of
1998, this writer received an e-mail from an Adventure Network visitor asking
if I would recommend a GPS unit since he was tired of getting lost and figured
a GPS would be the answer to his route-finding challenges. The way he saw it,
with a GPS and all that he heard they could do, he'd never be lost
again.
Are GPS units the
navigational messiah some imply they are, or is the GPS still just an elaborate
toy best suited for technophiles?
Enter the 12-channel or parallel
channel receiver, now offered by Lowrance, Garmin and, most recently, Magellan.
Still priced at $250 or under, these receivers use each channel to individually
lock onto and hold a satellite and the best four signals get used to provide
accurate, reliable and as close to instantaneous information as possible. As
for the older versions utilizing multiplexing receivers, I wouldn't give 'em
the time of day and have to wonder why the manufacturers still offer them.
12-channel or bust is my motto and recommendation to you.
You mean I can't toss my
compass or map even though I own a GPS?
Even with a GPS, you don't want
to toss your map or compass any time soon. In fact, one company, Lowrance and
Eagle uses its opening screens, whenever you switch on one of their GPS units,
to state in black and white not to use the GPS as a primary source of
navigation.
Why?
Because a GPS is not a compass
and does not know which way north is. When you turn it on, the only way a GPS
can guide you to a destination is if you have been there before and have the
coordinates entered (in which case you still need a compass to follow the
indicated bearing) or if you have a map and can establish the coordinates
(Latitude / Longitude or UTM) and enter them so the GPS can again show the
bearing needed to get there (which once again requires a compass).
Why would I want a GPS if I
still need a map and compass? Isn't it just one more thing to carry?
Well, yes, but don't overlook
the value of a GPS either. It is an ideal navigational tool when landmarks and
significant features are difficult to read (in a forest), are nonexistent (a
featureless plain or desert) or obscured completely--such as in a fog, whiteout
or at night. Can't find where you are? Turn on the GPS and, unless you're in a
deep canyon or thick forest, the GPS will establish a position fix allowing you
to use the Latitude / Longitude indications to find your exact position on the
map. Enter the coordinates of the destination desired, and the GPS will then
calculate the compass bearing needed to get there, on a straight line of
course.
Again, this is where the compass
and map become essential, and why a GPS can become dangerous in the hands of an
inexperienced navigator. (Note to the reader mentioned in the first paragraph:
sounds like you need to brush up on your navigational skills before you
purchase that GPS. Perhaps taking a map and compass course would be in
order?... you can begin by reading and using my book, Compass & Map
Navigator, co-published by ICS Books and Brunton.)
From Point A to Point B, a
straight line bearing indicated by the GPS might take you across a swamp or a
canyon or through a man-made hazard. Without a map, you wouldn't know and could
get yourself into deep, deep trouble. Consumers must realize that without
effective map and compass skills, a GPS cannot be used safely or properly.
What about a GPS's electronic
features designed to keep you on course? How useful are they?
A GPS's ability to estimate
travel speed, sound alarms when you are off course, and predict how long it
will take you to arrive at your destination are certainly valuable features, as
long as you're willing to burn battery power and keep the GPS out, on, and with
a clear view of the sky above--which means holding the unit at arm's length if
you are intending on hiking. Not exactly a practical use.
While it's true that an
increasing number of mountain bikers enjoy real time navigation capability,
which is why Garmin and Lowrance offer bike mounts for their units, real time
is not practical most of the time. Real time navigation is pretty neat, but
unless you are flying, driving or boating, it isn't critical
information.
For backcountry on foot, the
best use of a GPS is turning it on and off intermittently to establish position
fixes and obtain your next bearing. And this is why the new 12 channel
receivers are so valuable, because from the time you turn them on to the time
they establish a new fix takes mere seconds. Contributed By: Michael Hodgson
Michael Hodgson is a an award-winning journalist and author of numerous books including Camping for Dummies, Compass and Map Navigator, and Facing the Extreme. He is a volunteer instructor for the American Red Cross, Nevada County Sheriff's Search & Rescue team and was a former mountain guide. Michael is well-known for his sense of humor and eagerness to try anything once in the pursuit of a really good story. His friends remain amazed that he can still walk. He has partnered with his journalist-wife, Therese Iknoian, on four web sites: his own www.AdventureNetwork.com, plus www.GearTrends.com, www.TotalFitnessNetwork.com, and www.SNEWSnet.com |