Wednesday, March 3, 2010

Global Positioning Satellites

GPS systems are marvelous inventions. Friends of mine in a tandem sea kayak navigated the rocky coast of Maine using a GPS. For almost the entire trip, visibility was near zero due to heavy sea fog. My job was to pick them up at a certain dock miles up the road. They were there at the appointed time. It would have been nearly impossible to do that trip without a GPS system.

Now every other car has a Tom Tom or other GPS unit. Cars come with them already installed. Many cell phones come with a GPS feature.

As they become ubiquitous, certain problems have arisen. People are losing the ability to navigate. They plug in the address and follow the instructions. They don't know if they are going North, South, East or West. All they know is that they are going to take the next right in 500 feet. They don't actually know where they are.

If you use a map to find your way, you know something about where you are going. Even a road map will show woods, cities, rivers, and many other features you'll see along the way. A topological map will show things like elevation -how steep or flat the way will be. Maps are full of useful information. You have some idea what the terrain is like. Maps can give a person a feel for the area.

Just looking at a map may give a person different ideas about what route to take. Perhaps the shortest way is over the mountain, but if the weather is bad, avoiding the mountain route may be a good idea. Perhaps a trip on a pleasant two land road might suggest itself instead of fast highway travel. Interesting detours to see the sights may come to mind. If for some reason the chosen route is blocked, alternative routes can be found. A good map may reveal options that a GPS won't give you.

A compass provides very basic information -the direction to magnetic North. From your compass you can pick a general route. Just being able to head in a straight line is darn useful. In most places in the world, if you travel in a straight line far enough, you'll hit civilization. Traveling in circles can go on forever.

A good map and a good compass work well together. It's worth learning how to use them. I've hiked into some interesting trackless country using a map and compass. The map is a good tool to show what land features to expect: hills, streams, swamps, lakes, or what have you. The compass is darn useful for traveling though dense forests or swamps - or heavy sea fog for that matter. People traveling through country without obvious landmarks eventually walk in circles.

Even the sun or stars can aid in navigation. All these traditional methods work best when plenty of information is available. A traveler builds a map in his head. He looks for the real world to match up. For example, he may know that heading west he should cross two streams then climb a hill where he can see the way to the next town. From the hill he takes a compass bearing directly to the town. It's all basic map and compass navigation.

Enter the GPS. There is no longer a need, nor is it easy to build a mental map. This hit home a few years ago when I asked a relative how to get to a certain place. He didn't know what to tell me. He'd been there a hundred times, but always followed the GPS instructions. He had no idea how to get there any other way. He'd never even paid enough attention to the real world to memorize the way.

There's some real problems with being so reliant on one piece of technology. The GPS could malfunction. You may never even know -until you drive off a cliff. Sometimes the map the GPS uses is out and out wrong. My GPS unit thinks my house address is about a mile away from where it actually is. It will also try and send me across a bridge that's been restricted to pedestrians for the last 20 years. To be fair, most of the time a GPS unit will get you there. It might not be the best route. There's one route it tries to send me on that saves about 5 minutes. That's 5 minutes of savings only if there is no snow on the road. It's a steep and winding road for a few miles. In the winter, it also gets badly broken up with frost heaves, slowing travel. Knowing local conditions is important.

Here's one thing I discovered. An I-phone GPS relies on cell phone data to draw a map. No cell phone signal, no map. Discovered that one while snowshoeing in the woods across the street. My buddy's phone received the GPS signal fine, then displayed a dot in the middle of a blank screen. It was good for a laugh. Good thing we knew roughly where we were. Didn't need exact directions to get home.

I use a GPS, but also keep my other navigational skills sharp. Lets face it, I'm not very good at just following instructions. That friendly electronic voice doesn't have my complete trust. Should you be trusting it?


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