For the lost, the wanderers; for those looking for their place in the world, now there is GPS. What once was spoken only by the most avid Bass fishermen, is now rapidly becoming a household acronym. For those who don’t already know, GPS stands for Global Positioning System. It locates the bearer of the device relative to latitude, longitude, or, now, with more elaborate systems, an electronic map.
Why are we telling you all this? We want you to be in the know, up to date, and current on the latest gizmos. And this is one of the latest. It will be one of those things that, after we’ve had it for a while, we’ll look at ourselves in the mirror one morning and wonder out loud: “How did we ever get along without this before?”
First, a little history. The Department of Defense created the first system that was to become the GPS we have now. This was way back in 1978. It was, of course, limited to military use. In 1983, after the crash of the Korean Airlines flight 007, then President Reagan allowed the use of the system for airplanes. Then, in 1995, the US Department of Defense and the US Department of Transportation signed an agreement for wide area broadcasts. This was closely followed by the Federal Aviation Agency (FAA) forming an agreement with a private company to develop systems for FAA applications.
In a nutshell, how it works is that there is a constellation of 24 satellites (21 active and 3 spares) in an orbit 10,900 nautical miles above the earth. They are positioned so that at least four satellites will be available from any point on the earth at any time. These satellites can determine time, velocity, and location. The time part is easy because each satellite has an atomic clock on board. Precise timing is necessary to perform the other two functions.
Calculating velocity is something we should all remember from high school: Distance per unit of time and we look at our speedometers every day, which talk to us in miles per hour. Velocity is just the distance the object moves in a specified unit of time.
Now, the location calculation function is a little more difficult because all the data collected must be compared with a map of some sort. So the information from the GPS device is received from earth by the satellite and the satellite beams signals down to earth. During this process, the satellite must continually update a referential map in order to maintain location of the moving object.
Some of the uses are obvious. Like, if you’re an air traffic controller, knowing exactly where your planes are, or if you’re in international shipping line, knowing exactly where all your shipments are on the ocean. What if you’re out hunting in the wilderness and get lost or you’re fishing and your boat has merrily floated downstream? What if your car has been stolen? In all of these situations, a GPS device could be of immediate assistance.
Many of the GPS devices on the market are designed for cars. As a matter of fact, many auto manufacturers are including a GPS as standard equipment in their new cars. Until recently, it’s been only the luxury cars that had GPS systems in them. But now, many manufacturers include them as optional equipment on less high-priced models.
How the GPS system works in a car is quite nifty. There’s a screen, much like a computer screen, which locates you as a dot moving through electronic streets. So, not only can you see right where you are, but you can choose alternate routes if necessary. Most of the devices also allow you to program them for a “best route.” And you can reprogram them for an alternate route if you run into a traffic jam or construction is blocking your path.
If you want a GPS for your car but don’t what to go out and buy a new car to get one, devices are available that plug into your cigarette lighter socket and have all the bells and whistles.
New applications are being written as you read this article, most notably for wireless devices such as cell phones and PDAs. So, with your trusty cell phone or cell phone/PDA in hand (wireless enabled) you can pinpoint your location at any time.
Now, the next generation of devices are a little way out. How about GPS chips that can be embedded under the skin so a person (like a prisoner) can be monitored? Devices like this are now being manufactured that are about the size of a grain of rice and can be implanted without leaving a mark. The initiative for this application of GPS devices is for keeping track of people who are likely kidnapping targets, particularly in South America. But it is also aimed at keeping track of parolees. Similar devices have been in use for several years for locating pets.
GPS technology has become popular to the degree that all you have to do is go to your favorite search engine and type in “GPS” and you will get somewhere in the neighborhood of 3.6 million hits; plenty of information.
In closing, we thought we’d provide you with a bird’s eye view, or should we say a satellite’s eye view, of our little planet to help put everything into perspective. This will work best if you have a high-speed connection, but if you don’t, be patient, it will work just as well, but will take a little longer to come up on the computer.
Click for a view of the earth from a satellite in Earth’s orbit, or for a view of the Earth from the Sun
or the Moon
. One of my favorites is looking at the night side
of the Earth. All of these marvelous images are provided courtesy of the Fourmi Lab in Switzerland. To find the above images and many more, you can go to their web site at http://www.fourmilab.ch
. There you can see just where in the world we all are. It’s a beautiful planet. Enjoy.