My friend bought a car to install satellite positioning system I am interested in my friend explained that I would like to ask who knows the professional interpretation (product principle) who knows who
1 floor network replication pullIn fact, GPS satellite positioning systemSatellite positioning as the name of the car transmitter to send a satellite to do the positioning of the transmitter receiver phone principleWith the image of the host GPS through the satellite positioning to find the location of the display
It can be seen that the role of the GPS navigation satellite system is to continuously transmit navigation messages. However, because the user receives the clock and satellite machine using a carrier clock may not always synchronized, so in addition to the 3D coordinates of X, y, Z users, but also the introduction of a t that is the time difference between the satellite and the receiver as unknown, and then use the 4 equation the 4 unknowns out. So if you want to know the location of the receiver, at least to receive the signal of 4 satellites.The GPS receiver may receive for accurate timing information to nanosecond time; for forecasting ephemeris in the next few months which the approximate location of the satellite; used to calculate the required positioning satellite coordinates of the broadcast ephemeris, the accuracy of several meters to tens of meters (each satellite is different at any time change) and GPS system information; such as satellite status.The GPS receiver can get the distance from the satellite to the receiver by the measurement of the code, because it contains the receiver satellite clock error and atmospheric propagation error, it is called the pseudo distance. The pseudo distance measured by the 0A code is called the pseudo distance of the UA code, the precision is about 20 meters, the pseudo distance measured by the P code is called the pseudo distance of the P code, and the precision is about 2 meters.
