GPS Systems: How Do They Guide Us?

Having some knowledge of how GPS systems work will make you more appreciative of their complexity and make you less likely to balk at the cost.  More and more often, GPS gadgets are being added as standard features in the latest cars and personal electronics such as PDAs and cellular phones.  This writer isn’t an engineer or scientist, so this article is a simplified explanation of how GPS systems function. If you need a more technical explanation, there are other articles on the web that cover that.

The ABCs of GPS

You may be astonished to learn that there are over 2500 satellites that are orbiting our planet at this very moment.  Rather a large percentage of them are GPS system satellites.  But only 36 of them are actually still in operation with many others having been retired.  These satellites transmit a consistent low-power signal which is picked up by GPS receivers such as the unit in your auto.  By precisely measuring the distance from three of these satellites, the global positioning system can calculate its exact position on earth.

When their solar power panels are completely unfolded, a GPS satellite can be about seventeen feet wide.  Yes, they run on solar power and also have backup batteries installed for use when solar isn't available.  They generally survive ten years or more if all goes well. There is a "senior" satellite that has been working since 1978.  His task is to tell the newer satellites how tough it was in his time and how much easier the new models have it. Yes, I'm joking!

But Seriously

So what is a GPS receiver?  Any electronic device that is able to receive signals transmitted by the GPS satellites is a GPS receiver.  One may be on a commercial cruise liner, another in a taxicab and yet another is that Navigon 7100 GPS in my neighbor's car.  Personal GPS systems currently average around $300 for a well-equipped model.  When you recognize that you didn't have to pay to design, build or launch a gps satellite into orbit, $300 doesn't appear excessive at all.

The US government is responsible for paying the costs required in fabricating and launching satellites into orbit.|Our government here in the US has decided to take on the costs needed in creating this network of GPS satellites. So you can sit back and relax in your car, knowing that this network of satellites will quickly and dependably direct you to your destination. So now you should have a reasonably good understanding of what goes on behind the scenes when you switch on your GPS system.