The Global Positioning System (GPS) was created by the US Department of Defense to answer the second most important question an army has: “Where are we?” (The most important question being: “Where’s the chow line?”)
Today, GPS satellites constantly send signals ground-ward; these signals are picked up by GPS receivers, which calculate position. It didn’t take long for police and fire departments, construction crews and other civilian operations to see the value of GPS.
For consumers, the industry needed to refine GPS tracking system into user-friendly, consumer electronics. For example, it does little good to know you’re at 40 degrees 33 minutes 24 seconds north 118 degrees 48 minutes 36 seconds west, unless you already know that’s where is located and you’re trying to parachute onto the office roof. So, manufacturers added street by street visual directions.
The Global Position System has three sectors:
Twenty-four active plus five standby satellites orbit the Earth twice each day. At least four should be ‘visible’ to the ground at all times, allowing GPS tracking system users to precisely determine latitude, longitude and altitude.
Command and control system
Currently under the direction of the Air Force Space Command, certain areas are managed by other agencies, such as the Coast Guard Navigation Center (for maritime issues).
GPS units are receive-only electronics; they do not transmit data or interact with other sectors of the system. This allows an unlimited number of simultaneous users. In other words, this may be the only operation of the US government that is available 24/7 and will never put you on hold!
Consider its use before buying a GPS unit:
Probably the most popular application, all car GPS units include street maps; high-end models offer turn-by-turn voice instructions. Frills include touch screen operation, cell phone connectivity, video games, radio, CD or DVD players and computer links to receive software updates. Read more »