The Basics Of How A GPS Receiver Works
http://www.netarticles.com/The-Basics-Of-How-A-GPS-Receiver-Works/a2017_1
Roselyn G Gayatin
By Roselyn G Gayatin
Published on 02/14/2008
The GPS is a widely used navigation aid today, from land surveying to map-making, commerce, and even for scientific uses. Know how it really works.
The GPS is a widely used navigation aid today, from land surveying to map-making, commerce, and even for scientific uses. Know how it really works.The Basics Of How A GPS Receiver Works
There was once a time when ancient people had to do rather “extreme measures” to avoid getting lost. They had to erect monumental landmarks, create meticulously detailed sketched maps, and had to learn to read the “stars”. Today however, it’s much easier. For less than a hundred dollars, one can have pocket-sized gadgets that tell them exactly where they are on earth, and at any time. With a GPS receiver and a clear sky, a person will never get lost again.
What exactly is a GPS?
When people say “GPS”, this generally means a “GPS receiver”. GPS or Global Positioning System is basically a constellation of twenty-seven “earth-orbiting” satellites. Twenty-four of these satellites are operating and the other three are reserved in case a satellite fails.
The United States military built and employed the use of this satellite network as a navigation system for the military. After 1983’s Korean Air Lines shootdown, former President Ronald Reagan ordered a directive to make the system available to the public for free as a “common good”.
Soon enough, it was opened for everybody else. GPS has turned into an extensively used system for aiding navigation globally. Also, it has since been a very useful tool for land surveying, map-making, scientific uses, and commerce. GPS has also provided precise “time reference” utilized in various applications, including the scientific study of earthquakes, as well as the synchronization of the telecommunications networks.
Every single one of these “solar-powered” satellites is 3,000 to 4,000 pounds, and goes around the globe at approximately twelve thousand miles. This makes two complete earth rotations daily.
The satellites’ orbits have been arranged in such a way that at whatever time, as well as anyplace on earth, will have at least four “visible” satellites in the sky. The job of the GPS receiver is to trace four or more satellites, determine each satellites distance from one another, and utilize the information to construe its own location.
The GPS operation is based on a straightforward mathematical principle known as “trilateration”.
How does trilateration work for GPS?
Trilateration is the underlying mathematical principle behind GPS function. Basically, trilateration is the technique of determining relative positions of certain objects with the use of the “geometry of triangles”. Trilateration uses known positions of two or more points of reference, and the known distance between these two points and the subject.
In order to create this simple “calculation”, the GPS receiver must know two facts: the position of at least three satellites, and the distance between the subject and every one of those satellites. The GPS will figure out these things through analyzing “high-frequency, low-power” radio signals coming from the GPS satellites. Some GPS receivers are better, as they have multiple receivers that pick up signals from more than a few satellites simultaneously.
Since radio waves are “electro magnetic energy”, they travel at the speed of light. The GPS then figures out the amount of distance the signal has traveled through timing how long it took for the signal to be received.
GPS and Telecommunications
The cost for adding “telecommunications equipment” into a GPS system will considerably have an impact on the marginal benefit attained through the implementation of a “vehicle tracking system”. The latest systems have integrated GPS with the telecommunications hardware in one package. A communication system that has been integrated with GPS will include MAP27, Cellular Messenger, and GSM using Short Message Service or SMS.
GPS Modernization
The new demands for the system has led to modernized GPS system that aims to improve accuracy and availability for every user. It involves new satellites, new ground stations, and four added navigation signals.
With GPS, the ability to find out a receiver’s exact location becomes an excellent tool for navigation, as well as has enabled revolutionized ways for other significant uses.
What exactly is a GPS?
When people say “GPS”, this generally means a “GPS receiver”. GPS or Global Positioning System is basically a constellation of twenty-seven “earth-orbiting” satellites. Twenty-four of these satellites are operating and the other three are reserved in case a satellite fails.
The United States military built and employed the use of this satellite network as a navigation system for the military. After 1983’s Korean Air Lines shootdown, former President Ronald Reagan ordered a directive to make the system available to the public for free as a “common good”.
Soon enough, it was opened for everybody else. GPS has turned into an extensively used system for aiding navigation globally. Also, it has since been a very useful tool for land surveying, map-making, scientific uses, and commerce. GPS has also provided precise “time reference” utilized in various applications, including the scientific study of earthquakes, as well as the synchronization of the telecommunications networks.
Every single one of these “solar-powered” satellites is 3,000 to 4,000 pounds, and goes around the globe at approximately twelve thousand miles. This makes two complete earth rotations daily.
The satellites’ orbits have been arranged in such a way that at whatever time, as well as anyplace on earth, will have at least four “visible” satellites in the sky. The job of the GPS receiver is to trace four or more satellites, determine each satellites distance from one another, and utilize the information to construe its own location.
The GPS operation is based on a straightforward mathematical principle known as “trilateration”.
How does trilateration work for GPS?
Trilateration is the underlying mathematical principle behind GPS function. Basically, trilateration is the technique of determining relative positions of certain objects with the use of the “geometry of triangles”. Trilateration uses known positions of two or more points of reference, and the known distance between these two points and the subject.
In order to create this simple “calculation”, the GPS receiver must know two facts: the position of at least three satellites, and the distance between the subject and every one of those satellites. The GPS will figure out these things through analyzing “high-frequency, low-power” radio signals coming from the GPS satellites. Some GPS receivers are better, as they have multiple receivers that pick up signals from more than a few satellites simultaneously.
Since radio waves are “electro magnetic energy”, they travel at the speed of light. The GPS then figures out the amount of distance the signal has traveled through timing how long it took for the signal to be received.
GPS and Telecommunications
The cost for adding “telecommunications equipment” into a GPS system will considerably have an impact on the marginal benefit attained through the implementation of a “vehicle tracking system”. The latest systems have integrated GPS with the telecommunications hardware in one package. A communication system that has been integrated with GPS will include MAP27, Cellular Messenger, and GSM using Short Message Service or SMS.
GPS Modernization
The new demands for the system has led to modernized GPS system that aims to improve accuracy and availability for every user. It involves new satellites, new ground stations, and four added navigation signals.
With GPS, the ability to find out a receiver’s exact location becomes an excellent tool for navigation, as well as has enabled revolutionized ways for other significant uses.