How GPS Systems Work
Today, GPS navigation systems are everywhere; people use handheld units when they go hiking, or just walking through a city they are unfamiliar with, but by far the most popular use of the GPS device is in the automobile. When using a GPS navigation system in your car you can know exactly where you are at all time, as well as exactly how to get to your destination.
Though GPS systems are very popular, not everyone understands exactly how this technology works.
Basically a GPS unit is a receiver that receives precise microwave signals from the Global Positioning System, which is a Global Navigation Satellite System. The Global Positioning System uses a constellation of between 24 and 32 Medium Earth Orbit satellites to transmit these signals. When a GPS unit receives these signals it is able to determine its position, speed, direction, and time.
To calculate its position, a GPS receiver times the signals sent by the constellation of GPS satellites high above the Earth. At the speed of light, each satellite repeatedly transmits messages containing information, such as the time the message was sent, a precise orbit for the satellite, etc. The receiver then measures the distance to each satellite thus determining where the GPS receiver is on the surfaces of spheres at each satellite. In addition there is some estimation done by the GPS software to help to determine exact location, especially while traveling. The positioning information is then displayed on the unit in an understandable fashion, such as with a map.
The technology was first developed by the United States Department of Defense under the name NAVSTAR-GPS, and was originally created for defense purposes and military operations, and even today the Global Positioning System is managed by the United States Air Force 50th Space Wing. There are several different nations that now have their own version of this technology in development, including Russia, China, India, and Europe.
Although the Defense Department had access to this technology for many years, it was not until 1983 that the technology became available to the public, and today is used for many different things, including map-making, land surveying, commerce, scientific uses, and worldwide navigation.
Some additional uses of this technology include, such things as 911, where emergency personnel can pinpoint where an emergency call is coming from through GPS technologies. It is also used by wildlife management agencies in tracking devices, location based media, and asset tracking. Asset tracking with GPS has grown in popularity in recent years; today everything from tools to automobiles can be tracked through GPS technology.
Fortunately today’s drivers have use of this wonderful technology that is not only convenient, but can even keep you safe while you are on the road.
