GPS Units make sure you know where you are going no matter where you are. Gone are the days of getting lost easily. A GPS system can cost under $100 for a less-than-fancy model. However, what your GPS Unit looks like is not as important as what it actually does.
The GPS receiver is a handheld, sometimes portable device that works with the Global Positioning System (GPS) network. The GPS network is comprised of 27 satellites that constantly orbit the earth. As the earth rotates, so do the satellites. Of these 27, 24 of the satellites actually work, while three are used as backups. As you can imagine, running the GPS is quite costly.
The GPS network was originally developed by the United States military. The military used it to increase navigational accuracy. However, it was not long before the GPS network was open for use by anyone.
How it works is simple. First, the satellites have multiple orbit routes around the earth. At any one moment in the day, at least four of the satellites are able to transmit information from the satellites to GPS receivers. Of course, it is imperative that the view between the satellite and the GPS unit is unobstructed. That is...