| GPS works through triangulation, matching three separate signals from some of the 24 tracking satellites. It works in this way. The first signal tells us that our position is somewhere on a circular line that is a specific distance from the satellite. The second narrows that further and the third tells us where all three are likely to intersect. The GPS position is then displayed on the GPS unit: this unit could be in a car, truck, airplane or boat. The point is the user knows where they are, on or over the surface of the earth.
The time issue with the satellites vs. the GPS unit demand extremely accurate clocks to measure the time. The signal takes a certain amount of time to arrive at the GPS and return. By measuring this time accurately we can mathematically figure the distance from a satellite to the GPS unit. Doing this from three well-spaced satellites gives an accurate GPS position. This is the base for how GPS works.
Knowing where the satellites are in their orbit is crucial to GPS working. Because these satellites were put into orbit on very precise mathematical orbit plans, we know where they are at any given time from any place on earth. As an added case for even better accuracy we also monitor each satellites position with very precise radar. With this knowledge, we can accurately fix each satellite’s position. Since we know where they all are at any given point in time, we can use any selected three to tell our position.
Error correction is a real time problem with GPS/satellite timing. Modern GPS units are capable of making these corrections and therefore maintain terrific GPS accuracy.
Modern GPS units are quite small in size when compared to the units that were originally used. The new units are comprised of small computer boards that are able to analyze and then display accurately the result of the signals from the satellites. Their small size and low cost means GPS can be used in all types of moving vehicles. Due to their low cost and accuracy, they can even be used in farm equipment.
The minimization also means they can be hand carried and used by individuals and not just on vehicles. When you consider how well GPS works, you begin to see further possibilities for its use and convenience. The use of GPS can and does prevent friendly fire problems in military situations. It can be used to find down pilots or helicopters. If it is important to know the position of a person or vehicle, these devices can be used for that purpose also. GPS is the direct result of our ability to use satellites, small high tech computer boards and super computer driven mathematical answers.
GPS works because we have mastered another highly technical field and can use it to make our life simpler. |
GPS TRACKING INFORMATION
