METHOD OF SYNCHRONISING ONBOARD TIME SCALE Russian patent published in 2010 - IPC G04G7/02 

FIELD: physics.

SUBSTANCE: synchronisation of onboard time scale involves setting digitisation code in accordance with the digitisation code of the ground time scale and time alignment of seconds signals of the onboard time scale with seconds marks of the ground time scale. According to the invention, a code package is sent aboard from a ground-based command-measurement system, with advance on the signal propagation time and taking into account delays in the onboard and ground-based equipment, as well as the difference in binding the phase of the pseudorandom signal during generation and processing, where the said package consists of quasi-optimum code (31*15) with binding of the end of the last symbol to the exact seconds mark of the onboard time scale and binding the end of each symbol to the i-th phase of the pseudorandom signal, and a shortened cyclic code M(59, 32), in the whose information part of which the digitisation code of the ground time scale is placed with a cock cycle which is synchronously formed with the i-th phase of the pseudorandom signal. Onboard, signals are successively picked up in the linear part of the receiver and then, using a two-section discrete matched filter (31*15) and using the (i-1) phase of the pseudorandom sequence of the reference signal as synchronising clock signals of the discrete matched filter, the resultant signal is picked up, through which the onboard time scale is phased, and the correctly decoded shortened cyclic code (59, 32) is used the digitisation code of the onboard time scale. Decoding results are transmitted to the earth in form of corresponding receipts.

EFFECT: high accuracy of synchronising onboard time scale and cutting on time for carrying out synchronisation.

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