SU1462230A1 - Method of comparing scales of remote time keepers - Google Patents

Abstract

The invention can be used in devices for reproducing and comparing time scales and allows improving the comparison accuracy. The master standard 2 times generates a sequence of time signal pulses with a repetition period equal to the interval between the centers of adjacent channels in a long-distance communication system with frequency division channels. The oscillation frequency of the carrier frequency generator 1 corresponds to the middle of the linear frequency spectrum occupied by the system, and is located in one of its interchannel gaps. The sequence of radio pulses received from the imaging unit 3 triggers the modulator 4, which generates radio signals for link 5. The demodulator 6 selects the radio pulses of the received time signal, and the selector 7 performs their detection using the generator 8 of the reference frequency. P1 pulses coming from a matching standard time 11 are delayed by a controllable delay element 9 and shifted in time until they coincide with the received time signal pulses. The moment of coincidence is recorded with the help of the integrator 10, and the discrepancy of the time scales is recorded in the meter 12 time intervals. 4 il. i W c to tsd od

Description

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The invention relates to measuring technique and can be used in devices for reproducing and comparing scales: time.

The aim of the invention is to improve the comparison accuracy.

It shows a functional device that implements the linear spectrum of Mbi information transfer systems in Fig. 2; FIGS. 3 - 1 show the structure of the frequency division of the linear spectrum into channels; in Fig. A - the spectrum of a pulse train of a time signal,

; The method consists in forming time signals in the form of a sequence of radio pulses, transmitting them to the communication link of a rao-channel system with a frequency section of j-THei i channels with a repetition period inversely proportional to the frequency interval between the center of the w channels, and JC, the carrier frequency selected in magnitude from the interchannel frequency gap of the used linear frequency spectrum, radio pulses are extracted at the receiving end of the communication line, the relative temporal position of the received time signal pulses is measured relation to the pulses of the local time scale and exclude the time delay of the time signal during transmission.

A device5 that implements the method contains a carrier frequency generator 1, setting a standard 2 times ;, a driver. 3 ,, modulator 4j line 5, connection demodulator b, selector 7, reference frequency generator 8, element 9 controlled by the ZadlerId integrator lOj, time standard to be compared 11 and: measured 12 time intervals. The method is carried out as follows.

The D / 1I transmission of the time signal uses, for example, a multi-channel distance system, such as Kt1920. Its linear spectrum is shown in FIG. 2; The total width of the spectrum of the system is about 8 MHz, which makes it possible to transmit a pulse with a duration of 0.25 of the ISS, without distortion.

The signal-time form in the form of a sequence of radio pulses, with a carrier frequency equal to 4671.55 kHz. This frequency is obtained from the carrier frequency generator t. The repetition rate is set to 4 kHz, which is

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corresponds to a repetition period of 0.25 ms - step frequency division channels in the system. The duration of the pulses can be arbitrarily selected. However, to study the need for high precision comparisons, the minimum duration is set to Oe25 ms. . Radioglpulses form in the imaging unit 3, where the time signal from the setting standard 2 arrives. The moment of the code.pulses corresponds to the mark of the reference time. The received radio signal is input in ka, - 5 forebuilding equipment - modulator 4 of the last stage of the transform - tel. Frequency. . . .

At the receiving end of line 5, after demodulation using a frequency detector or heterodyning in demodulator 6, a time signal present in the linear spectrum is fed to selector 7. Selection is carried out by the synchronous detection method. A reference signal in the form of pulses with a repetition rate of 4671.5 kHz is obtained from generator 8 for performing detection. By means of element 9, the control delays shift the reference pulses in time until the output voltage of the integrator 10 is maximum. Having achieved such a state, the time position of the reference pulse, corresponding to the moment of arrival of the time pulse, and the pulse from the reference standard 11 are measured. The time interval is measured using a 12-time meter. The discrepancy between the time scales of the reference standard and the time storage bin is determined by excluding the propagation delay from the readings of meter 12. This operation can be performed either after receiving the readings by the operator or computer, or by introducing a preset of the control delay element 9.

To implement the method, the carrier frequency of the radio pulses must be set with an error of no more than i.0.4 kHz, and the repetition frequency with an error of no more than +0.2 Hz.

The lower sideband of the linear spectrum of the K-1920 system ranges from 804 to 4634 kHz. If the carrier frequency of the radio pulses is chosen to be 4670.5 kHz and the repetition frequency is 4 kHz, then the spectral composition is

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0

five

0

five

Near the upper boundary of the considered sideband, the frequencies observed are: 4,626.5 kHz; 4,630.6 kHz; 4,634.5 kHz, etc.

The boundaries of interchannel gaps in this region are: (4,626.0 - 4,626.9) kHz; (4630.0-4630.9) kHz, etc.

From a comparison of the values of the boundaries of the gaps and frequencies of the spectral components, it can be seen that these components do not fall into the working channels and do not interfere with the normal functioning of the system in the I multi-channel communication.

When implementing the method, the normal operation of the system control devices is not disturbed. These devices operate using service signals (control frequencies). The service signals are transmitted in the inter-channel gaps (three to four), are harmonic oscillations and

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Fishing at the receiving end is performed using narrow-band filters (ten hertz), so the control devices do not feel present in the time signal line.

Claims (1)

Invention Formula The method of comparison of the scales of the remote time keepers, which consists in forming a time signal as a sequence of radio pulses, entering it into the communication link 15 of a multichannel frequency division multiplex system, separating the sequence of radio pulses at the receiving end of the communication link, measuring the time position the pulses of the received time signal in relation to the pulses of the local time scale and exclude the time delay of the time signal during transmission, characterized in that, in order to increase the have a spectrum in the form of a single spectra 25 of the accuracy of the comparison, the introduction of a radio component. If the pulses are shifted to the communication line, the carrier frequency of the radio pulses is performed by transmitting them with a repetition period relative to the reference frequency of the system, which is inversely proportional to readings at (200-300) Hz, then the corresponding spectral components will be rebuilt from the service signals by the same amount. Mutual overlap and the influence of signals on each other will not. The allocation of service signature interval between the centers of 30 adjacent channels, and with the carrier frequency selected in magnitude from the inter-channel frequency gap of the used linear frequency spectrum. 0 Fishing at the receiving end is performed using narrow-band filters (ten hertz), so the control devices do not feel present in the time signal line. Invention Formula The method of comparison of the scales of remote time keepers, which consists in forming a time signal as a sequence of radio pulses, entering it into the communication line 5 of a multichannel system with frequency division channels, isolating a sequence of radio pulses at the receiving end of the communication line, measuring the time position the pulses of the received time signal in relation to the pulses of the local time scale and exclude the time delay of the time signal during transmission, characterized in that, in order to increase Neither is the comparison accuracy, the introduction of radio pulses into the communication line is carried out by transmitting them with a repetition period inversely proportional to the single interval between the centers of adjacent channels, and with the carrier frequency selected from the inter-channel frequency gap of the used linear frequency spectrum. W m 6N ШВ 4700 FIG. 2 ddg d54 LLLALDDDDDD-4 FIG. FIG. with