Once the standard of the “Where am I?” or “Where am I going?” question, the common hand held compass is quickly finding its way into obsolescence.  This is directly due to the advent of the modern day GPS (Global Positioning Satellite) system.  GPS technology has been around for quite awhile with its birthplace in the military applications arena. War planners needed a way to find their troops and their equipment quickly in order to assure their safety while directing them to enemy positions and equipment.  With the modern day technologies resulting from the space program, a person is now able to pinpoint their position anywhere on the planet as long as they have a clear view of the surrounding sky.
The clear view of the sky is necessary as there are approximately 24 satellites placed into orbit by the United States Department of Defense. These satellites are constantly circling the earth’s orbit twice a day at approximately 12,000 miles above us.  They are constantly broadcasting data on their relative positions and the actual time the data is sent.  The time is so precise as a result of the atomic clocks on each of the satellites. However, at any given time, only 4 satellites are necessary to determine relative location of a unit. These satellites are constantly broadcasting information which is in turn received by many types of technologies here on the earth – such as the different types of GPS units.
There are different types of GPS systems that are available in the marketplace today. GPS portable systems are available not only in automobiles for directions.  In addition, there are hand held units that a hiker might us in the forest to determine direction. Also, there are mapping GPS systems that allow one to enter their desired location into the unit and the GPS software will automatically find the quickest most efficient way to get there. Finally, there are technical grade GPS systems that are the most accurate but also the most expensive – remember in the GPS market place the more accurate a system, the higher price for the system.  Many of today’s modern surveying or mapping GPS systems can be accurate to tenths of an inch in either the horizontal or vertical direction. These levels of accuracy are necessary when plotting real estate, building structures or surveying vast expanses of space for sale.  With all this type of accuracy, one has to decide what type of system is really required.
Before purchasing a GPS system, a person should ask themselves what they are using the equipment for (i.e. mapping, finding directions somewhere or tracking people or goods and equipment). Then a person needs to decide if they prefer a hand held device (which is the most popular), or a fixed device which might be bolted or secured inside of a vehicle. The hand held devices are most popular as they can be moved from one vehicle to another.  Regardless of what type one might consider, you must do your homework to assure you get the type of unit that is right for you.