What is GPS?

By Jason Gluckman

Global Positioning Systems or GPS are satellite navigational systems made-up of 24 satellites revolving round the earth. Each satellite has a corresponding receiver on the earth. The satellites orbit the earth at a height of about 12,000 miles. It makes two complete orbits everyday. The GPS satellites continuously transmit digital radio signals that contain data on the location of the satellites and the time taken for signal transmission.

GPS tracking is the term given to the process of being able to locate the exact location of a receiver on earth. Now that the production cost of GPS technology is significantly lower than when it first came into existence, many companies have found new ways to make use of this technology. In GPS tracking, the user is able to keep a track of where they have been using a portable GPS device. GPS tracking can be used in a better way when it is combined with other broadcast technologies, such as a wristwatch or radio. GPS watches, for example, can be fitted with a GPS receiver, which relays a signal to a central command center equipped with GPS software systems. The central command center can track the position of the watch and transmit that information to a third party. That third party may be anyone who needs the position of the wearer urgently. In fact, a variety of such GPS phones and wristbands are sold in the market today. This serves two purposes. Firstly, it provides the driver with an integrated GPS system, without the necessity to purchase a car navigation system, or a PDA-based GPS system. It also offers the possibility to relay that information via a radio or cell phone transmitter.

GPS systems have been used primarily as vehicle locators, especially in cases when a vehicle attached with such a system is stolen. The police, once informed, can find out from the control center where the vehicle is, and proceed to track it down. Tracking is also being used in other fields such as pet tracking, coordinated tracking and consumer tracking.

GPS provides detailed information on GPS, GPS Tracking, Handheld GPS, GPS Systems and more. GPS is affiliated with Free Cell Phone Number Search.

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What is GPS?
By Wikipedia
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.

Developed by the United States Department of Defense, it is officially named NAVSTAR GPS (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 aging satellites, and research and development. Despite these costs, GPS is free for civilian use as a public good.

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

Timeline
* In 1972, the US Air Force Central Inertial Guidance Test Facility (Holloman AFB) conducted developmental fight tests of two prototype GPS receivers over White Sands Missile Range, using ground-based pseudo-satellites.
* In 1978 the first experimental Block-I GPS satellite was launched.
* In 1983, after Soviet interceptor aircraft shot down the civilian airliner KAL 007 in restricted Soviet airspace, killing all 269 people on board, U.S. President Ronald Reagan announced that the GPS system would be made available for civilian uses once it was completed.
* By 1985, ten more experimental Block-I satellites had been launched to validate the concept.
* On February 14, 1989, the first modern Block-II satellite was launched.
* In 1992, the 2nd Space Wing, which originally managed the system, was de-activated and replaced by the 50th Space Wing.
* By December 1993 the GPS system achieved initial operational capability[32]
* By January 17, 1994 a complete constellation of 24 satellites was in orbit.
* Full Operational Capability was declared by NAVSTAR in April 1995.
* In 1996, recognizing the importance of GPS to civilian users as well as military users, U.S. President Bill Clinton issued a policy directive[33] declaring GPS to be a dual-use system and establishing an Interagency GPS Executive Board to manage it as a national asset.
* In 1998, U.S. Vice President Al Gore announced plans to upgrade GPS with two new civilian signals for enhanced user accuracy and reliability, particularly with respect to aviation safety.
* On May 2, 2000 "Selective Availability" was discontinued as a result of the 1996 executive order, allowing users to receive a non-degraded signal globally.
* In 2004, the United States Government signed a historic agreement with the European Community establishing cooperation related to GPS and Europe's planned Galileo system.
* In 2004, U.S. President George W. Bush updated the national policy, replacing the executive board with the National Space-Based Positioning, Navigation, and Timing Executive Committee.
* November 2004, QUALCOMM announced successful tests of Assisted-GPS system for mobile phones.[3]
* In 2005, the first modernized GPS satellite was launched and began transmitting a second civilian signal (L2C) for enhanced user performance.
* The most recent launch was on 17 November 2006. The oldest GPS satellite still in operation was launched in August 1991.
* On September 14, 2007, the aging mainframe-based Ground Segment Control System was transitioned to the new Architecture Evolution Plan.