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There's Nothing More Embarrassing Than Being Lost Modern technology now gives us something worse--being lost without the GPS manual. Not that a GPS is a bad thing, I have one and someday I'm determined to learn how it works from start to finish, but in spite of all the advantages over the usual system of map and compass it still has to have batteries, a clear view of the sky and hopefully the satellites in it, and somebody who remembers the instructions. The GPS I own is a few years old, and now a discontinued product, but so far as locating my position on the Earth, it's still up there with the big boys. It has twelve channels the same as the twelve in the cutting edge models, but the new versions still have many of the same old problems. They still can't see through thick forest canopy, even though they do have a better chance of it. The new ones win because they're a lot more than a GPS. |
What's That? Up in the Sky! |
GPS units work by triangulation--the important part for end users is that you need three satellites in view to calculate your position. Low end units might work with five at most; high end units can handle input from 12. Anything over three sats in sight is just gravy. You have to have three. As you can see in the graphic above, that usually isn't a problem. There are enough GPS |
Satellites up there that we usually half a dozen or more floating around in view. But they'll be in different places at different times of the day and night, so it's possible that right now you'd need a clear view of the southern sky to get a good fix, and six hours from now you'd be looking to the east and north for your info. The unit takes care of that for you, but it depends on line of sight radio that can get scattered by obstacles like trees, mountains, buildings, ravine walls, etc. Older units like mine have compass features that depend on the Sat system. If you don't have the satellites in view, you don't have a compass that works. The new models--if you have the cash to get one--are better. They use electronic compasses that work independently of the satellite system. Wherever you happen to find yourself, even if you lose the GPS feature you will still have the compass. That's a big improvement. Some units even know how to take care of themselves. Battery life, for continuous use, is generally about ten hours. Maybe you could stretch it to twelve, but don't count on that. If you intend to keep an electronic record of |
a weekend outing, you might need two sets of batteries. If you want to record a week of hiking, you might need six sets. That's a lot of AA's if you're a backpacker. They get heavy. The key here is "continuous use." The better units today will shut off |
unnecessary features like the electronic compass (which you only need if you're looking at it) and keep the critical circuits running. It might be nice to have an electronic record of every step you take, but in rough country you probably won't get that perfect record even with a top of the line GPS. There will be gaps, because you will walk through areas where the GPS can't triangulate. Cut back on battery usage, if you want, by shutting it down and taking "waypoint" readings when you stop for breaks. With the top end GPS units, you'll get much more than a tracking system and compass. SD memory expansions allow installation of detailed topographic maps. Built in cameras eliminate the need for an extra piece of photographic gear. Digital voice recorders let you keep a verbal record of adventures. Touch screen controls and push button keyboards make navigation of the nav system much more user friendly (although you should still make room for the manual). Some even incorporate LED flashlights. |
GPS systems a few years ago were new toys. Now they are more--reliable enough to depend upon as essential gear. But, there's a learning curve. You need to master their operation before you hit the trail. Take some practice hikes, go for walks in the neighborhood, and track your adventures close to home before you take your toy to the wildlands. Don't make the mistake of depending upon it totally. You might lose it, or drop it on a rock, or run out of batteries. Then you need the old reliable paper map and magnetic compass. They don't cost much, don't weigh much, and you can fit them in a pocket where you won't even notice them until the GPS display goes out. |
Photo by D. M. Turner |
Unobstructed Views are not Guaranteed |
Old Compass--New Compass |
Photo by P. Anderson |
Photo by unknown at MorgueFiles |
Trees and GPS Don't Mix |
Photo by Dani Simmons |
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