GLONASS system structure and principle

3, the user segment. GLONASS GLONASS users to receive satellite signal receiver, and measure the pseudorange or carrier phase, combined with the satellite ephemeris for the necessary processing, the user can get the 3-dimensional coordinates, velocity and time.

GLONASS positioning principle is Intersection. GLONASS satellite position at any one time can be calculated by the satellite ephemeris, in theory, as long as users know the distance to three satellites, can calculate the user's location, but it requires a satellite and the user and the precision of time synchronization between the satellite and high, is still not fully satisfied, but to introduce a time parameter. As much an unknown quantity, so the actual positioning receiver to at least four satellite signals. GLONASS satellites simultaneously launch coarse code (C / A code) and precision code (P code), C / A codes are used to provide to the civil standard positioning, while the P code for the Russian military precision positioning or scientific research.

GLONASS and GPS in addition to using different systems and coordinate system of time outside the biggest difference between the two is: all GPS satellite signal transmission frequency is the same, and different GPS satellite launch code pseudo-random noise (PRN) is different , the user in order to distinguish the satellite, known as Code Division Multiple Access (CDMA); and all GLONASS satellites pseudo-random noise code is the same, different satellites transmitting frequency is different, to distinguish the different satellite, called for the frequency division multiple access (FDMA). In addition, with the different GPS, GLONASS does not reduce the accuracy of any artificial measures.