This is a technology that has filtered down from government to public use for the purpose of providing ones location anywhere, anytime, and with pinpoint accuracy in most cases.
Just like radio or television signals that are broadcast and we receive them via of a receiver such as a TV or an AM/FM radio, these signals from a Global Positioning System that are transmitted from orbiting satellites reach our portable GPS receivers providing us with information detailing our location.

These signals contain time codes that GPS receivers use to determine the length of time for the signal needed to reach the receiver, which is done by a microprocessor in the receiver that utilizes the delays in time as well as the satellites position for calculating the distance to the satellites, which in turn uses the information to provide the location.

This is called "triangulation" which is nothing more than a mathematical formula for pinpointing those points in 3D. The distance to each of the satellites as well as you're location are calculated thus providing you with what you need to know in order to reach you're destination.

Usually you're receiver will get the signals from one satellite at a time and depending on how good you're particular receiver is, will give you the best accuracy for you're location.

There is a term that is used called "reacquisition time, and this is nothing more than the time it will take to get an accurate fix of a satellites signals, and will vary according to where you are that may inhibit the ability for getting a fix in a set time as a result of being in an area with buildings, trees or other reasons that may cause you to lose a direct line of site to the satellites.

As technology gets better, the times will be shorter to get an accurate fix, and the more sophisticated receivers will be able to track up to a dozen satellites which will cut down on you're acquisition loss.

Since these satellites are over 12,000 miles up in space, any small error can greatly increase an error in you're position, which is why it is important that your receiver can track several widely dispersed satellites, as the combination of these signals from the different satellites is calculated to provide you with the most accuracy.

Learn more about this author, Richard Serra.
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