A.P. Romanov, A.M. Aleshechkin

Given article examines the methods of increasing the metrological characteristics the ground-based radio-navigation systems, the intended for determining the coordinates sea above-water objects. Solution of the problem presented is achieved due to the use of the developed method of the synchronization of the reference stations, located on the coast also of the forming network strong points of ground-based radio-navigation system. Are examined the existing methods of the task of the united time scale of reference navigation points, used in the satellite and ground-based radio-navigation systems. The proposed method of the synchronization of ground reference stations lies in the fact that at each supporting station besides the transmitter of wide-band navigation signal is established the receiver. The given receivers ensure the reception of the signals of those radiated by both their station and by other reference stations, located on the known distance from their reference station. Since the distance between the stations is known, it is possible to determine the disagreement of the time scales other reference stations relative to the time scale of its reference station. Those obtained as a result of the measurements of correction to the time scales of strange stations are emitted in the form navigation message to each of the reference stations in the composition of its navigation ranging codes. The onboard station of ground-based radio-navigation system, located on the sea object receives the signals of coast reference stations and extracts of them information about the corrections, by using which it is possible to reduce the time scales of all stations to united time scale, which will ensure an increase in the accuracy of navigation task solution. In this case onboard station can achieve the navigation solution in the time scale of any of supporting stations of them, for example the station, for which is observed the greatest signal-to-noise ratio. During the signals code division the reception of the remote signals against the background of the powerful radiated signal of its reference station is hindered, since the ratio of the powerful interfering signal to the useful received signal of its supporting station proves to be too great. For the solution of the problem of the suppression of the powerful interfering signal of its supporting station is proposed the schematic of the automatic equalizer, which consists of the band-pass filter, the block of restoring the form of powerful signal, line of delay, schematic of control of correlation feedback, adder and unit of measuring the time scale errors. Thus, the proposed in this article method of the synchronization of radio-navigation system reference stations makes it possible to exclude the temporary disagreement of the time scales of ground reference stations on board the user via the reception of digital information from each reference station, which carries together with the ranging information, information about the time scale corrections. The presence of the automatic equalizer of its own powerful radiated signal makes it possible to continuously receive signals from other reference station, which makes it possible to solve the problem of determining the corrections to their time scales in the real time without disruption of radio-navigation system function.