GPS - Global Positioning System. Presented By Brindha Narayanan. What is GPS?. The Global Positioning System (GPS usually called GPS receiver) is a satellite-based navigation system made up of a network of 24 satellites placed into orbit. The GPS is made up of three parts :
If a person lost somewhere and he gets the information from somebody.
First person say that you are in 625 miles from Boise, Idaho
Second person says that you are in 690 miles from Minneapolis, Minnesota.
Third person says that you are in 615 miles from Tucson, Arizona.
So now you know that you are exactly in Denver, Colorado.
The same rule is applied in GPS satellites. The GPS receivers in the earth has to locate at least three satellites in the orbit and figure out the distance between each of those and calculates the location.
1. The basis of GPS is “trilateration" from satellites.
2. To "triangulate," a GPS receiver measures distance using the travel time of radio signals.
3. To measure travel time, GPS needs very accurate timing which it achieves with some tricks.
4. Along with distance, you need to know exactly where the satellites are in space. High orbits and careful monitoring are the secret.
5. Finally you must correct for any delays the signal experiences as it travels through the atmosphere.
Frequencies used by GPS include
2. http://en.wikipedia.org/wiki/Global_Positioning_System The basic webpage where you can get the basic information and up to date information in the site.