SU1218485A1 - Device for synchronizing seismic signal sources - Google Patents

Abstract

The invention relates to geo-g physical engineering and m. used to synchronize seismic sources. The purpose of the invention is to increase the synchronization accuracy while reducing the duration of the synchronization signal. The device contains a storage unit (BZ) 1, amplifier limiter 2, e-FINISHING OR. 3, noise-like signal generator 4, threshold unit 5, clock frequency generator 6, frequency divider 7, key 8, clock end selector 9, time selector (BC) 10, additional frequency divider Hi driver of write pulses 12, address counter 13. For the recording of each symbol of the M-sequence of the input clock signal in N cells of ZB1 and the decision of the VS 10 to correctly receive the input clock signal from two correctly received M-sequences is achieved compared to the prototype of a higher QB 8 times the syn synchronization while reducing the duration of the synchronization signal.5 Il. (L s (X 00 sd

Description

one

The invention relates to geophysical engineering and can be used to synchronize sources of seismic signals.

The aim of the invention is to improve the synchronization accuracy while reducing the duration of the sync signal.

Figure 1 shows a structural electrical circuit of a device for synchronizing sources of seismic signals; Fig 2 is the same as a noise-like signal generator; n FIG. 3 - the same threshold block; figure 4 is the same, the selector end of the hrosignal; Fig. 5 shows time diagrams of signals that explain the operation of a device for synchronizing sources of seismic signals.

The device for synchronizing sources of seismic signals contains memorization unit 1, amplifier-limiter 2, element EXCLUSIVE OR 3, generator 4 of noise-like noise, threshold unit 5, generator 6 of clock frequency, frequency divider 7, key 8, selector 9 of the sync signal end, time selector 10 , additional frequency divider, frequency driver 12 write pulses, address counter 13.

The noise-like signal generator 4 contains D-flip-flops 14-19, modulo two adders 20-23, resistor 24 and capacitance 25.

The threshold unit 5 contains counters 26, 27 pulses, elements AND NOT 28-33.

The selector 9 of the end of the sync signal contains the element AND-NOT 34, the element NO 35, D-flip-flop 36, the element NO 37, the capacitance 38, the resistor 39.

The device synchronization sources of seismic signals works as follows.

The input clock signal with a frequency of G, representing two M-sequences, one after the other, comes (from the telephone output of the radio station) to the input of the amplifier-limiter 2 (figure 1). A limiting amplifier 2 converts the input clock signal to a discrete form (sequence levels of logical zeros and ones). The signal from the output of the amplifier-limiter 2 is fed to the information input of the storage unit 1.

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The control of the work rekomom of the storage unit 1 is carried out by pulsed signals (FIG. 5, a) produced by the driver 12,

5 to the input of which a periodic sequence of pulses arrives at a frequency.

Upon receipt from the output of the imager 2 pulse signal with

0 by the zero level (write pulse) the storage unit 1 goes into the information recording mode. In the case that a pulse signal with a unit level arrives from the output of the shaper 12, the storage unit 1 goes into the information reading mode.

After turning on the power supply, the counter 13 of the address is set to an arbitrary state.

0 When the first and subsequent write pulses arrive at the control input of the storage unit 1, the last bit of the sync signal from the output of the limiting amplifier 2 is written in the last one in accordance with the address generated by the adres counter 13.

The recording pulse frequency is. In this case, one character of the M-sequence is recorded in the N cells of the storage unit 1, and the entire M-sequence, the number of characters equal to P, is recorded in NP .-. the cells

At the end of the write pulse, the storage unit 1 goes into the information reading mode (which lasts until the next write pulse appears). In this case, with the falling edge of the recording pulse, the additional divider ill of the frequency, the threshold unit 5, the selector 9 of the clock signal is set to the initial state (zeroing). When installing the selector 9 of the sync signal end (Fig. 4), an input with a zero level (Fig. 5, b) appears at the output of the O installation. It arrives at the control input of the key 8 and closes it. As a result, a sequence of clock pulses from the generator 6 enters the clock inputs of the address counter 13, an additional frequency generator 11 and the threshold block 5 (FIG. 5, c). With the frequency of following pulses, the address is increased at the outputs of the count 0

five

0

five

0

Chika 13 addresses. With the same frequency, the output of the storage unit 1 is read information.

The input of the noise-like signal generator 4 receives a sequence of clock pulses divided by N with an additional frequency divider 11. A noise-like signal generator 4, which is a six-bit shift register consisting of D-flip-flops 14-19, in which the output signals of the first, second, and fifth bits through modulators two 20 and 21 enter the modulator adder two 22, to another input of which a signal from the output of the sixth bit of the shift register is produced, generates a time-compressed copy of the M-sequence of the input clock signal. Since each character of the M-sequence contains N bits of information carried in memory block 1,

then changing the address to address, input

storage unit 1 occurs with

100 N times as large as the frequency of the sequence of clock pulses arriving at the clock input of the generator 4 of a noise-like signal.

In the case when the noise-like signal generator 4 fully generates a copy of the sync signal M-sequence (p symbols), unit level signals appear at the information inputs of the sync signal end selector 9. In this case, at the output of the selector 9 of the sync signal end (Fig. 4), a signal with a zero level appears, which is fed to the control input of the key 8. The key 8 opens. Further, the operation of devices for synchronizing sources of seismic signals is repeated when the next recording pulse arrives.

Consider the process of recording and reading information from the storage unit 1.

Key 8 is closed for the time forma- tion1 by generator 4 of the noise-like signal of the M-sequence. During this time interval, P clock pulses arrive at the clock input of the generator 4 of a noise-like signal, and PN clock pulses arrive at the input of the address counter 13. The conversion factor of the counter 13 address composition PN -1

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At the same time, the address counter 13 generates addresses for PN-1 cells of the storage unit 1.

Assume that during the action

5 of the first write pulse; the address counter 13 has generated address 1. Until the next write pulse, its clock input will receive PN clock pulses. Since the conversion factor of the address counter is PN-1-, then by the time the next write pulse arrives, the address 2 will be generated on the outputs of the address counter 13. And so on

15 from cycle to cycle, the address will be incremented by one. The recording of information will be made in the cells of the storage unit 1 with an incremental address. The readout of the n20 formation from the storage unit 1 will be performed sequentially, with the first reading of the information from the cell into which the latter was written (more than 5

0

The signals from the memory 1 and the output of the M-sequence of the generator 4 of the noise-like signal go to the first and second inputs of the EXCLUSIVE OR 3 element, the output of which is a single level signal when these signals do not match and the zero signal coincides with these signals .

Upon receipt from the output of the EXCLUSIVE OR element 3 signals with a zero level in the threshold block 5 (Fig. 3), the counters 26 and 27 count the number of clock pulses coinciding in time with these signals. When the number of clock pulses reaches a predetermined threshold, which corresponds to the correct reception of the first part of the input clock signal, a positive polarity pulse arrives at the output of the threshold unit 5 and is fed to the input of the time selector 10. When the second part of the input clock signal is correctly received at the output of the threshold unit 5 a second pulse of positive polarity appears, which is also fed to the input of the time selector 10. Time interval

5 between the first and second pulses of positive polarity, when receiving the expected input clock signal, coaxes P. When two

five

0

pulses of positive polarity, separated by time 1 / F P, at the output of the time selector 10, a signal is generated indicating that the input clock signal a is received in general. ,

Thus, in the proposed device for synchronizing the sources of seismic signals by recording each symbol of the M-sequence of the input clock signal in N dicks of the storage unit 1 and made by the temporary selector 10 about the correct reception of the input clock signal by two correctly received M-sequences is achieved in comparison with the known device is higher. (§ N 1 time) synchronization accuracy with a one-time reduction in the duration of the clock signal. .

Claims (1)

Invention Formula A device for synchronizing seismic sources containing a series-connected amplifier-limiter, a storage unit, an EXCLUSIVE OR element, and a prrog unit, a series-connected clock generator and a frequency divider, a series-connected noise-signal generator, and a key selector information To emvnaru nvniya eitrosilmaaa 3 BUT. The input of which is connected to the output of the clock generator, and the input of the amplifier-limiter is the input of the device, about the fact that, in order to increase the synchronization accuracy while reducing the duration of the synchronization signal, an additional divider is introduced into it the record, the address counter and the time selector, while the output of the frequency divider is connected to the control input of the memory unit and the inputs of the setting O of the additional d The frequency selector, the threshold unit and the sync signal end selector, the output of which is connected to the control input of the switch, the output of the frequency sensor is connected to the clock inputs of the additional frequency divider, the threshold unit and the address counter of the address whose outputs are connected to the corresponding address inputs of the storage unit, the output of the additional frequency divider is connected to the clock input of the noise-like signal generator, the bsod of the M-sequence of which is connected. to the second input of the EXCLUSIVE OR element, and the output of the threshold unit is connected to the input of the time selector, the output of the time selector being the output of the device. G Fig Editor N.Shvydka phage.5 Compiled by V. Orlov Tehred T.Tulik Proofreader A.Zimokosov 1139/61 Circulation 624 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Branch ShSh Patent, Uzhgorod, st. Project, 4