What is GPS?
The Global Positioning System (GPS) is the most accurate radio-navigation network in the world. Funded and controlled by the U.S Department of Defense, GPS employs a constellation of satellites placed in orbit by the United States. The satellites emit specially coded signals that can be processed by a GPS receiver, enabling it to compute position, velocity, and time. GPS works in any weather conditions, anywhere in the world, 24 hours a day.
The Department of Defense built GPS at a cost of about $12 billion. The system provides the U.S. military with a highly precise form of measuring position worldwide. The first satellite was launched in 1978, and a full constellation of 24 satellites was achieved in1994. The DoD made the technology available to civilians in the ‘80s. Growing in use, GPS is now employed by thousands of civilians worldwide.
Many critical activities depend on navigation and positioning. Yet the process has always been cumbersome. The global positioning system simplifies the process. GPS operates in five logical steps:
The basis of GPS is “triangulation” from satellites.
* To “triangulate” a GPS receiver measures distance using the travel time of radio signals.
* To measure travel time, GPS needs very accurate timing, which it achieves with the help of some tricks.
* In addition to distance, the exact position of the satellites must be known.
* High orbits and careful monitoring are the secret.
* Also necessary correction for any delays the signal experiences as it travels through the atmosphere is needed.
GPS technology is finding its way into a wide variety of applications. It’s used in cars, boats, planes, construction equipment, farm machinery, computer networks, television stations, and buses. GPS technology also has helped fire fighters fight blazes in Modesto, California. And recently the city of Chicago developed a tracking system to monitor emergency vehicles through its streets, saving precious time responding to 911 calls.
While GPS is also used to disseminate precise time, time intervals, and frequency. Time is a powerful commodity and exact time is more powerful still. One investment banking firm uses GPS to guarantee that its transactions are recorded simultaneously at its offices worldwide, And a Major Pacific Northwest utility company makes sure its power is distributed at just the right time along its 14,797 miles of transmission lines using this global positioning system. Soon, GPS will be as basic as the telephone.