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How Does the GPS Satellite System Work?
The entire GPS satellite system is actually not that complex. The GPS satellite system is a satellite-based navigational system which is made up of a network of 24 satellites that have been placed into orbit by the U.S. Department of Defense. The original plan and purpose was for U.S. military reasons only, but it was later decided that the GPS satellite system would be opened up to the public.
How it basically works is that these GPS satellites circle the earth twice a day, transmitting signal information to earth. It is the GPS receivers that then take this information and use the matter of triangulation to then calculate a user’s exact location.
It should be known that a GPS receiver must be locked on to the signal of at least three satellites in order to be able to calculate a 2-dimensional position, and with four or more satellites in view, it can determine the user’s 3-dimensional position. Once a user’s position has been determined, the GPS satellite can then determine other information, such as speed, bearing, track, trip distance, distance to destination, sunrise and sunset time, and more.
The 24 satellites that make up the GPS satellite system are actually orbiting the Earth at about 12,000 miles above us. Each GPS satellite is constantly moving, making two complete orbits in less than a day’s span. Each GPS satellite is powered by solar energy, and they even have backup batteries onboard which will keep them running in the event of a solar eclipse.
There are also small rocket boosters on each GPS satellite which are there to keep them flying in the correct path. The signals that work in this system are important and basically essential to understand. What happens is that the GPS satellite s transmit two low power radio signals, and these signals travel by line of sight, which means that they will pass through clouds, glass and plastic, but they will not go through most solid objects such as buildings and mountains.
Regardless of all the positive benefits, there are however, as with basically everything else, inaccuracies that can occur. This can be due to any or more than one of the following: ionosphere and troposphere delays, signal multipath, receiver clock errors, orbital errors, number of satellites visible, satellite geometry and shading, intentional degradation of the satellite signal, and more.
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