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[CDT-L] GPS vs. weight question
- To: CDT-L <firstname.lastname@example.org>
- Subject: [CDT-L] GPS vs. weight question
- Sent: Sunday, February 20, 2000 12:31 AM
> i was always curious about GPS systems aren't they heavy. i mean if you
> still need to carry around a backup (incase they break or the batteries go
> south) is not that a huge amount of extra weight you need to carry
They are getting lighter all the time. My Garmin GPS 12 weighs only 6 oz. w/
batteries but, I would not take it on a week long backpacking trip. The
backup is the compass (including the map) which is required to navigate
*even* with a GPS at speeds under ~3 mph. The map is always needed.
> i am not a very experienced hiker but i am building towards becoming one
> i always saw these GPS units as somehtign else heavy to carry in your pack
> something you could go with out making it a "fluff" item. after all you
> always should know how to use a map and compass and even other more basic
> methods older than the map and compas incase something really stupid
> happens.. right?
"Fluff?" Yes and no. For the average hiker (even the bushwhacker) a GPS is
not usually a requirement and is, as you put it, "fluff." However, in
situations where travel in low visibility is necessary, the GPS can be a
valuable asset. I use one as an aid to updating topo quads as a volunteer
for the USGS -- Saves a lot of time. Traveling near the magnetic poles
compass needles tend to spin around and not point toward any specific
direction. Also, traveling over featureless land can be extremely difficult
without the aid of a GPS. The GPS is also an excellent educational tool.
The science and innovation behind it is amazing.
Look at it this way. If you are very good with a map & compass and you have
enough experience to estimate distances traveled & elevation change and can
identify stubtle features on a topo map, it would be difficult to become
truly lost. Add an altimeter to the kit and you have some additional
flexibility to do limited navigation in the mountains with poor visibility.
Add a GPS and you have a navigational tool kit that will get you just about
anywhere with or without visibility. You are correct though, the basics are
just that -- Basics, and they must be learned first.
> what are your opinions i would be interesed to change my opinion based on
> good reasoning?
Determining location is not always an absolute, but is based on factors that
given values that when viewed together give the experienced navigator a
confidence level of his location and that he is on course. Those factors
1. Direction - The compass is pointing the right way and you have
correctly adjusted for declination
2. Terrain - The terrain you are walking on matches the map based on your
3. Obvious Landmarks - If there are two or more, triangulation can be used
to determine location
as good, or better, than a GPS. If only one landmark is visible, you
can use your line of travel as a second point to determine location
4. Distance Traveled - Mental estimate based on time and terrain
Hint: Only in ideal circumstances will *all* these factors be known. Often
you have only #1 & #4 to rely own. If visibility is good and the map is
1:24000 or better, #2 is often a good indicator, but not always.
A good navigator will always know his position with 1/2 mile and usually
within 1/4 mile. Several times during the day they will know exactly where
they are. GPS removes the confidence factor and replaces it with an
accurate position (with a few caveats).
> how many of you people out there that go off trail and bushwack a lot
> know how to use a map and compass and more importantly something semi
> reliable that does not require a compass or anything but your head and
> surroundings even if to just figure out how to follow a general north,
> north-east track.
Analog watch and sun (or a shadow from the sun). A straight course can be
steered using an analog watch and any planet or star. The sun alone can be
used, but reduces accuracy even further.
> i have my first few no trail "bushwacking" day trips planned for after
> winter. i have a compass and a map(i am to poor to buy a GPS those thing
> are expensive and i want to learn map and compass better) and have known
> to use them since my father taught me as a little boy many many years ago
> when i was out with my sister and him on a girl scout thing (i must have
> been only 5-6) and again by my father and others during my short stint in
> the boyscouts(12-14 yuear sold i guess). never got real good at it but
> need to practice to get better than i am now... i just make sure i pick an
> area where if i get lost and end up on some nameless peak far from where i
> intended. i can hike due east(or close to it) and hit a big N-S road or
> soemthing of that sort. and try again some better day.
Have fun. Your method for not getting lost is called a "baseline." It can
be a river, mountain range, road or anything that would be very difficult to
miss. There are other techniques you may want to read up on.
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