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Global Positioning
Systems FAQ's
Some common concerns
See Navigation
Glossary for explanation of terms
How do they work?
These devices receive a signal from multiple satellites and using triangulation
or even quadangulation are able to determine your location. Using waypoints (coordinates
(Longitude and Latitude - minutes and seconds) that are entered
manually or saved when previously at a desired location) they
can point the direction you need to travel in order to arrive at the
next waypoint.
Are GPS units worth buying?
This would depend on how much you value your life or saved time. With a
functioning GPS and an accurate waypoint you are never lost (Lost is defined as
not knowing how to get to a particular place and not the occurrence of not
knowing where you are), the path is always shown. This means you will not waste
precious resources wandering around hoping to stumble onto a familiar landmark.
Do I still need a compass and map.
Not all GPS units function as a compass. They need a
waypoint - see how do they work
- to be beneficial. If you have a map and can establish the coordinates
(Latitude / Longitude) and enter them. However you are going to have to
calculate the minutes and seconds if not you will only be
somewhere with in a 60 mile square (depending on your proximity to the
equator- Latitudes are always 60 miles apart but Longitudes narrow as
they near the poles). You narrow this by dividing the distance between
your Longitude and your Latitudes into 60 equal sections (minutes)
then the minutes that include your destination by 60 (seconds). Enter
these coordinates in your GPS and you should be with in visible
distance of your targeted location.
Having a map can also be reassuring in that you can translate the
present location coordinates from your GPS into a position on a map to
show your progress. Also a map (topo)will show you the terrain ahead
and allow you to plan for any upcoming difficulties such as water,
swamps, canyons etc.
A compass ins still nice to have to verify that you entered the
correct coordinates and are heading the right directions.
Can a GPS warn of deviations in the designated path?
Yes most can but that would mean that you would have to keep it
turned on all the time.
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.
Is there anything I need to do to get an accurate reading on my GPS?
Yes you need a clear view of the sky. This means that you need to hold it out
and up, tilted so you can still see it, if you don't your body will shield it
from a satellite signal that you need.
Are they waterproof?
Some are, some will even float.
Do they work in caves?
NO
If I turn it off to save the batteries will I lose the setting?
As far as we know all BPS unit will return to the last saved setting when
powered on and reflect your position in relation to the previously set path.
Do they work on rechargeable batteries?
This is something that will have to verified model by model. Some come with
chargers which expand the possibility of using solar and a inverter/converter.
Most have a jack and an adapter for connecting to a 12v system. Caution: Not all
GPSs can use 12 volts directly but need a transformer/adapter. While on the
other hand some are st up for working with 24 volt systems such as in some
aircraft and boats.
What do they cost?
This varies from about $169.00 to several thousands. You may find some
either new or used on the web for less money than at a sporting goods or boating
stores. However check out all the features and make sure they have a return
policy and good reputation.
What feature do I need? That depends on how you plan to use it.
Some things that all should include is:
A 12 channel System
Sunlight readable screen
Backlighting for night navigation
Battery saving and low consumption feature.
Lanyard ring or a case with a lanyard for loss protection.
Weight
Reputation
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