Introduction of GPS
The Global Positioning System (GPS) is the most significant recent advance in navigation and positioning technology. In the past, the stars were used for navigation.
Today's world requires greater accuracy. The new constellation of artificial stars provided by the Global Positioning System serves this important need.
GPS is an aerospace technology that uses satellites and ground equipment to determine position anywhere on Earth. Anyone with a small receiver can use the system at no cost.GPS has drastically changed methods of navigation and is fast becoming important in everyday life.
The Global Positioning System (GPS) is the only fully functional Global Navigation Satellite System (GNSS). Utilizing a constellation of at least 24 Medium Earth Orbit satellites that transmit precise microwave signals, the system enables a GPS receiver to determine its location, speed, direction, and time.
Other similar systems are the Russian GLONASS (incomplete as of 2007), the upcoming European Galileo positioning system, the proposed COMPASS navigation system of China, and IRNSS of India.
Developed by the United States Department of Defense, GPS is officially named NAVSTARGPS (Contrary to popular belief, NAVSTAR is not an acronym, but simply a name given by Mr. John Walsh, a key decision maker when it came to the budget for the GPS program).
[1] The satellite constellation is managed by the United States Air Force 50th Space Wing. The cost of maintaining the system is approximately US$750 million per year,
[2] including the replacement of ageing satellites, and research and development.
Following the shootdown of Korean Air Lines Flight 007 in 1983, President Ronald Reagan issued a directive making the system available for free for civilian use as a common good.
[3] Since then, GPS has become a widely used aid to navigation worldwide, and a useful tool for map-making, land surveying, commerce, and scientific uses. GPS also provides a precise time reference used in many applications including scientific study of earthquakes, and synchronization of telecommunications networks.
Electronic Innovations
Electronic navigation introduced all-weather capability, ease of use, and eventually, increased accuracy. In the 1930's radio beacons were used to provide bearings from airfields.
In the 1960s the Omega system provided worldwide electronic navigation coverage for the first time. These land-based electronic navigation systems were accurate to within several miles, equivalent to celestial navigation.
During World War II radio navigation systems were developed, the best known being
LORAN, or Long Range Aid to Navigation. Positions were determined by the timing of signals received from different LORAN transmitter stations
In the mid-1960's the U.S. Navy's Navigation Satellite System (NAVSAT), also known as
TRANSIT, was developed to provide more accurate positions for ships and submarines.
GPS Revolution
Throughout the 1960's the U.S. Navy and Air Force worked on a number of systems that would provide navigation capability for a variety of applications. Many of these systems were incompatible with one another. In 1973 the Department of Defense directed the services to unify their systems.
The basis for the new system would be atomic clocks carried on satellites, a concept successfully tested in an earlier Navy program called TIMATION. The Air Force would operate the new system, which it called the NAVSTAR Global Positioning System. It has since come to be known simply as GPS.
The new system called for three components: ground stations that controlled the system, a "constellation" of satellites in Earth orbit, and receivers carried by users. The system was designed so that receivers did not require atomic clocks, and so could be made small and inexpensively.
The Soviet Union also developed a satellite-based navigation system, called GLONASS,which is in operation today....
Navigation through GPS
GPS is a powerful tool that can save a ship's navigator hours of celestial observation and calculation. GPS has improved efficient routing of vessels and enhanced safety at sea by making it possible to report a precise position to rescuers when disaster strikes.
GPS improves efficiency on land as well. Delivery trucks can receive GPS signals and instantly transmit their position to a central dispatcher. Police and fire departments can use GPS to dispatch their vehicles efficiently, reducing response time.
GPS helps motorists find their way by showing their position and intended route on dashboard displays. RailroXads are using GPS technology to replace older, maintenance-intensive mechanical signals...
Social Plugin