Global Positioning Systems (GPS) are used by millions to help them navigate anywhere on the earth. This is a system that is comprised of 24 satellites that have been placed into orbit around the earth by the Department of Defense. It was originally designed and intended to be used by the U.S. military, but it was made available for civilians in the 1980’s. Users are able to access the satellites 24 hours a day in any type of weather.
The satellites that are used in the system rotate about the globe twice during a 24 hour period. They receive and transmit the GPS signals that are used to determine the precise location of a user. Received signals are compared to the time difference between when they were sent. This provides an idea of the distance between the sender and the satellite. When this information is compiled with the assistance of a few more satellites, it can give precise locations that may be either 3D or 2D.
A receiver must be passing signals to at least three satellites for the machine to give an accurate reading of a user’s location. These use the method of triangulation to ascertain the exact location. Four satellites can also be used to provide the latitude, longitude and the altitude of any receiver. Once the basics have been determined, the satellites and receivers are able to supply all types of information that is related to the trip distance, bearing, speed, tracking and destination times.
The satellites orbit the earth approximately 12,000 miles above our heads. They are constantly on the move and are powered by solar batteries. There are also back up batteries that are designed to function in the event of an eclipse. These satellites rely on low power radio signals to transmit information between themselves and receivers. They are built to last for 10 years before they need to be replaced by a newer model.
GPS is used by millions of people to help them navigate around the city or rural areas. The receivers are able to communicate with the 24 satellites that are orbiting around the earth, and this is how they provide a person’s location. Three satellites can triangulate the information that is relayed from a receiver, and this can provide the latitude and longitude of any particular machine. This can then be used in a host of equations to determine other aspects of travel.