SU991343A1 - Multi-channel digital seismic registering system - Google Patents

Description

The invention relates to seismic techniques for seismic surveys, intended for the study of subterranean formations covered by a layer of water, in particular, to multichannel digital seismic recording systems, and can be used in marine geophysical work on the shelf and in the ocean. Known multichannel qi | A seismic recording system containing a towed digital receiver, an on-board digital receiver and a recorder made on the basis of a digital tape recorder with mobile recording heads 1. The disadvantage of such systems is low bandwidth of low-frequency magnetic drives with fixed recording heads, which limits the bandwidth the system as a whole, high consumption of magnetic carrier, due to the fact that in the known register device; Qi information is produced either continuously or on fixed OTv time slices, while not taking into account the temporal attenuation of the seismic signal, so the information flow is recorded to the magnetic drive, some of which does not carry useful information. To match the received digital information stream with the stream recorded on the magnetic storage device, an intermediate high-frequency recorder based on a video recorder with rotating recording heads can be used, which allows several times to increase the capacity of digital seismic systems for implementing super-multi-channel seismic for high-frequency seismic. The closest technical solution to the present invention is a multichannel digital seismic

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recording system comprising sequentially; connected towed digital receiving device, on-board digital receiver, digital filter, interface device, video recorder, error corrector, and also the Drive control device, the output of which is connected to the input of the magnetic storage device (FZ) bandwidth also has a high consumption of magnetic media.

The purpose of the invention is to reduce the volume recorded on the drive C (-).

The goal is achieved by the fact that a multichannel digital seismic recording system containing a serially connected towed digital receiver, an onboard digital receiver, a digital filter, a coupler, a video recorder and an error corrector, as well as a drive control device whose output is connected to the input of a magnetic storage device, input control cell, code delay device and channel clock pulse selector, with this signal and synchronization control cell inputs connected to the output of the error corrector and the output of the channel clock pulse selector, respectively, the first output of the control cell is connected to the control input of the delay device, the signal input of which is connected to the output of the error corrector, the second output of the control cell is connected to the control input of the control device whose input is connected to the output of the delay device codes, and the control input of the error corrector is connected to the output of the channel pulse selector, the input of which is connected to the output of the video nitofon.

The control cell contains a scaling circuit that accumulates the adder, a code delay element, a subtractive device and a comparison circuit, and the output of the scaling circuit whose input is connected to the output of the channel clock selector selector is connected to the input of the zero accumulator accumulator and the control inputs of the code delay element detractors and comparison circuits, with the output of the accumulating adder, whose input is under 4

It is connected to the output of the error corrector, connected to the input of the code delay device and the first input of the detractor device, the second input of which is connected to the output of the code delay device, and the output is connected to the first input of the comparison circuit, the second input of which is connected to the threshold level source.

The math fi (, 1 is a block diagram of the multichannel digital seismic recording system in FIG. 2, signal plots at various points of the system, explaining the principle of operation

control cells and the system as a whole. The multichannel seismic monitoring system contains a series-connected towed digital receiving device 1, an on-board digital receiver 2, a digital filter 3, an interface k, a video recorder 5 and an error corrector 6, as well as a storage control device 7, the output of which is connected

to the input of the magnetic storage unit 8, the control cell 9, the device 10 of the code delay and the selector of the clock pulses of the channel 11 with the signal and clock inputs of the cell

9 controls connected to the output

the error corrector 6 and the output of the clock pulse selector 11, respectively, the first output of the control cell 9 is connected to the control input of the device 10 code delays, the signal input of which is connected to the output of the error corrector 6, the second output of the control cell 9 is connected to the control input of the device 7 drive control, the input of which is connected to the output of the device 10 delay codes, and the control input of the error corrector 6 is connected to the output of the channel pulse selector 11, input

which is connected to the output of a VCR 5 "

The control cell 9 contains a scaling circuit 12, a code 1 delay accumulator 13, a deduction device 15 and a comparison circuit 16, and the output of the scaling circuit 12, whose input is connected to the output of the channel pulse selector 11, is connected to the set input zero accumulating adder 13 and control inputs. device delay codes, subtractor device 15 and comparison circuit 1b, the output of accumulating adder 13, whose input is connected to the output of the error corrector 6, is connected to the input of devices And the delay codes and the first input of the subtractor 15, the second input to torogo connected to the output of delay device codes, and an output coupled to the first input of the comparing circuit 16, the second input of which is connected to a threshold level source. , FIG. 2 shows the output signal 17 of the clock pulse selection of channel 11, the signal 18 at the output of peresmetnaya circuit 12, the output code 19 of accumulating adder 13, the output signal 20 at the output of subtractive circuit 15, the output signal 21 of control cell 9 at the output of circuit 16 nothing A multichannel digital seismic recording system operates as follows. I -. Reflected seismic signal of the form M S (n UJo (t) t, where ji is the attenuation coefficient) is perceived by the towed digital receiver 1 and is transmitted in serial binary form to the input of the onboard digital receiver 2, which determines the polling order of receivers of the towed part the system and the order of issuing digital information to the input of a digital tunable band-pass filter 3, from the output of which information is fed through the device i interface to the input of the video recorder 5, when recording seismic information on the video signal The interphone increases the probability of its distortion, and, in addition, the recording and reading of information is performed in a sequential form, therefore the Binary Code from the VCR 5 to the magnetic storage device 8 reads the information to the error corrector 6, where it is monitored, corrected and is converted into a digital computer format, at the same time the output signal of the VCR 5 is fed to the input of the clock pulse selector channel 11 whose output signal 17 is supplied to the synchronization input of the control cell 9, to the signal input For which, from the output of corrector 6 errors, a parallel code of one of the channels of the towed receiving device 1 of the form: NiM & i) AeP ihuuc (Hiit) i: M / iA3, where At is the period of the following clock pulses of channel 17, and n is a natural number. Since the temporal attenuation of the seismic signal on all channels of the device 1 is almost the same, then whose control 9 performs the analysis of the level of the seismic signal for only one channel. The control cell 9 under the effect of the output signal 17 of the pulse selector channel 11 generates a pulse signal 18, which from the first output of the control cell 9 is fed to the control input of the device 10 of the code delay with a delay time of the output signal of the correction signal 6 errors equal to the same time 9, the control compares the difference between the signals accumulated at the elementary accumulation sites Sc - and THz with the threshold level NffopH produces at the second output a potential signal 21 arriving at the control input storage control devices 7. Depending on the output signal 21 of control cells 9, corresponding to the level of the seismic signal, storage control device 7 fbiroviruet START or STOP signals that determine the discrete mode of operation of the storage device 8, and this is the goal of reducing the consumption of a magnetic storage device. Cell 9 control works as follows. The accumulating adder 13 integrates the absolute values of the parallel binary code of one of the channels of the towed part of the system, coming from the output of the offset 6 error box. The elementary integration interval Tc is determined by a recalculated circuit 12, the input of which receives clock pulses of the 17 signal. From the output of accumulating adder 13, the result 19 accumulated at the next accumulation interval T n- goes to the device Vk of the code delay with a delay time n and reading device 15, the second input of which receives the result.

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Accumulated At the previous -elementar, as well as a device for managing the Yite {5 V9l4 accumulation .. by the driver and the drive, which is inputCommunication | subtractive device is connected to the output of the device yhvom 15, the difference between the signals accumulated

on elementary plots of accumulation — so that in order to reduce consumption

Neither TC. and enters the first magnetic carrier by reducing the input of the circuit 20 | Comparison, the second volume input recorded on the accumulator which is connected to the source of the cellular signal, it contains the cell of the N value. Fahn circuit 16, comparing the difference of the signal 20 with the threshold level NpQp, generates a potential signal 2J arriving at the control input of the accumulator control device 7 . If the level of the useful reflected seismic signal, which is a harmonic signal attenuated by the expxent, exceeds the noise level, tr in this case, the accumulation in the elementary accumulation interval -Cu, significantly exceeds the result accumulated in the elementary accumulation interval t ,, and, accordingly, the difference of these results will exceed the threshold sign, which indicates the need to register information on the storage device 8. Over time, the level.

(ioro the reflected signal attenuates, the accumulation results in the Stsd and T elementary areas are approximately equal and determine only the noise level and, accordingly, the difference between the accumulation results will be less than the threshold level N then, which is an indicator of the magnetic storage disconnection 8

Thus, the structural design of the proposed system due to the introduction of a control cell, a code delay device, a clock selector of the source channel of the threshold level N ..: - provides a discrete (start-stop) operation of the magnetic storage device, thereby achieving the goal of skill | 1% of magnetic storage device storage by 20-50%; claims 1. A multichannel digital seismic recording system comprising a towed digital receiving device connected in series, board a new digital receiver, a cue filter, an interface device, a video recorder and a fault corrector,

It contains a scaling circuit that accumulates the adder, a code delay element, a subtractor, and a comparison circuit. The output of the scaling circuit, whose input is connected to the output of the channel clock selector, is connected to the input of the accumulator zero accumulator and the code delay device inputs. detractors and comparison circuits, the output of the accumulating adder, whose input is connected to the output of the error corrector, is connected to the control input, the delay device codes and the village the channel clock pulse, wherein the signal and clock inputs of the control cell are connected to the output of the error corrector and the output of the channel clock pulse selector, respectively, the first output of the control cell is connected to the control input of the code delay device, the signal input of which is connected to the output of the error corrector, the second output the control cells are connected to the control input of the control device, the input of which is connected to the output of the delayed code device, and the control input of the error corrector with one with the selector clock channel output pulses, whose input is connected to the output of the VCR. 2, The system of claim 1, wherein the control delay code and the first input of the subtractor IF device, the second input of which is connected to the output of the code delay device, and the output connected to the first input of the comparison circuit, the second input which is connected to the source of the threshold level. Sources of information accepted during the examination 1. USSR author's certificate No. 558236, cl. G 01 V 1/2, 1977. 2. Savit C, N., Siems L.E., A-500. Channe streamer System. , Progress 9 AnnaQff shore Techno togy. 1977, V, 2, p.201-208 (npotoTHn) l

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Claims (2)

1. A multi-channel digital seismic acquisition system containing a towed digital receiver in series, ⁵⁵ on-board digital receiver / digital filter, a pairing device, a VCR and an error corrector, as well as a drive control device and a drive, the input of which is connected to the output of the control device, characterized in chtf in order to reduce the consumption of magnetic medium by reducing the volume of signals recorded on the drive, it contains a control cell, a delay device ki codes and a channel clock selector, while the signal and clock inputs of the control cell are connected to the output of the error corrector and the output of the channel clock selector, respectively, the first output of the control cell is connected to the control input of the code delay device, the signal input of which is connected to the output of the error corrector, the second output of the control cell is connected to the control input of the control device, the input of which is connected to the output of the code delay device, and the control input is correct A set of errors is connected to the output of the clock selector of the channel whose input is connected to the output of the VCR. 2, The system according to claim 1, characterized in that the control cell contains a conversion circuit accumulating an adder, a code delay element, a subtracting device, and a comparison circuit, while the output of the conversion circuit whose input is connected to the output of the channel clock selector is connected to the zero accumulation adder and the control inputs of the code delay device, the subtracting device and the comparison circuit, the output of the accumulating adder, the input of which is connected to the output of the error corrector, is connected to the input code delay device and the first input of the subtractor, the second input of which is connected to the output of the code delay device, and the output is connected to the first input of the comparison circuit, the second input of which is connected to the threshold level source. Sources of information taken into account during the examination