about GPS question of excursion, first of all from the principle of GPS positioning Jiangqi, from the mathematical point of view, is the space of three known locations, and you go to these three points of the relative distance, and your location, which is three-dimensional geometry In a very simple question, is the mathematical principles of GPS.

 Corresponds to the actual application, the location of three known, is not responsible for the three satellites, because the satellite is in accordance with the “ephemeris” precision operation, so it at a certain time we can know the location, which meet the mathematical principle , The first problem solving; second condition is that you need to know that the relative distance from three satellites, satellite launch a specific radio signal, the GPS receiver you receive this signal is later than the time difference, because the radio Transmission speed is known, through this time difference is you can calculate the distance between the satellites. Two conditions are met, you will come out of position.

These are only the GPS principle of a simple description, but also practical applications much more complex, in fact reached 3 D positioning, at least four satellites, to more than one is used to award the.  Interested friends can access the relevant information to satisfy your curiosity.

 Understand the principles of GPS positioning, we will find out that, although the mathematical principle is very simple, but through physical means to achieve the two known conditions, is a very complicated matter.

First, the satellite in the sky to fly, who can not guarantee that it can not slightest difference in their tracks, there are always more or less the deviation.  Second, the GPS receiver, you can not on a cesium atomic clock, the transmission speed of radio waves per second is about 300,000 km, a simple calculation you can see, if the error 0.00001 second time, the number of poor distance?  Even if you do not have the time error, the radio waves will spread in the air by many factors, such as weather. The impact of the above is not the most important, more important reason is that the impact of how much you can receive satellite signals.  GPS signals are very weak, then receiver on a small ceramic antenna, you can also count on what is good effect?  So basically what they are irresistible, you will not received signals, even if you have received a 10 eight strong satellite signal, we will certainly be very accurate? No. If you just catch up with this Zhacheng 10 satellites are a bunch of meetings, or a neat line of home school team, then you will have some trouble