SU1385113A1 - Device for recording seismic data in digital form in water areas - Google Patents

Abstract

The invention relates to geophysics, in particular, to technical means for conducting marine geophysical studies. The purpose of the invention is to improve performance due to diagnostic testing. From the digital test signal generator input to the on-board part, a different control mode is carried out through the bi-directional three-input switch in both the transported and towed spit positions. With the help of an electric exciter introduced into the hose section of each channel, with the help of additional units inserted into electronic modules, the identity of the spit channels is assessed and their amplitude-frequency characteristics are estimated. 4 il. (ABOUT

Description

The invention relates to technical physics, in particular, to technical means for conducting marine geophysical studies. The purpose of the invention is to increase the productivity of work through diagnostic testing.

Figure 1 shows the functional diagonal circuitry of a digital piezo-seismometric streamer; Fig. 2 illustrates an exemplary embodiment of a compaction and regeneration device; Fig. 3 shows an example of a decoding device; 4 shows time diagrams of the device operation.

The multichannel digital piezoelectric motric streamer (Fig. 1) contains a fluid dielectric in the caloded channel of the towed part. For example, the hose section 1 and the electronic module 2 connected with a sealed electrical connector 3 with salt oil are inside the cavity of the hose section 4 data transmission lines corresponding to its length, segments 5 synchronization lines, and segments 6 control lines. at least one serial connection of a piezoelectric hydrophone 7 with an active band-pass filter 8 and an electrical exciter 9 of low-frequency elastic waves, which can be made differently, for example, based on a magnetostrictor, an electrodynamic transducer, or a bimorph bending-oscillating piezo element. Coordination with the signal source depending on the type of electrical exciter is provided by matching device 10 (current or voltage amplifier).

Each electronic module 2 contains a unidirectional switch 1 1 with signal inputs 12 and 13, as well as control input 14, voltage amplifier 15, analog-to-digital converter (ADC) 16, compacting unit 17 and regeneration unit, recovery circuit 18 and regenerator type pulses, two-input disjunctor 19 trigger 20, discriminator 2 pulses by duration, a decoder device 22 of the type of a serial code converter into an electric voltage of direct current. In the typesetting part, the braid ends with a digital receiver 23,

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which has 4 data transmission lines, as well as a synchronizer 24 and a digital test signal generator 25, which are connected to the synchronization line 5 and 6 control line sections via a bi-directional three-position switch 26, which contains three-position keys (electronic or relay) 27-30, the outputs of which are connected to the circuits 31 and 32 of the signal combination.

The structural construction and electronic implementation of the compression and regeneration unit 17 are known and explained in FIG. 2, where a pair 33 and 34 are the input-output of the block 17 for connecting the segments 4 data transmission lines of the adjacent hose sections 1, the pair 35 and 36 the input-output of the block 17 to connect the lengths 5 of the synchronization line of adjacent hose sections. Input 37 serves to receive the result of coding a signal from the ADC 16 via the tracing pulses (T) at the interpreting output 38 of the block 17 or at the output of the discriminator 21. The input of these pulses to the clock input 39 (ADC) is performed through the disjunctor 19. The block 17 contains ( 2) a two-input collecting circuit — a regenerator 40, a signature separation circuit 41, a delay device 42, a negative pulse driver 43 from output 47, a signature combining circuit 44, a positive polarity pulse driver 45 STI output 48, a cyclic converter 46 of the parallel code of the A / D converter 16 into a serial code for multiplexing signals into a transmission line, outputs 47 and 48 of the signature separation circuit 41.

The decoding device 22 is made, for example, in the form (FIG. 3) of the circuit 49 of signature signal separation by negative polarity at output 47 and by positive polarity at output 48, shift register 50, DAC 51 and pulse polarity inverter 52. In this case, the schemes 41 and 49 of the signature separation of signals are of the same type, and the schemes 44, 31 and 32 of the signature combination of signals are also of the same type and are known for their circuit design.

Figure 4 shows the signals: 53 - at the output of the circuit 31 in the modes

and Control-, 54 - at the output of circuit 32 in the Control-1 mode at the output of the circuit 31 7 Control-2 mode, 55 - start pulse (3) at the output of the 31 circuit in Control mode 2 and 56 - sample code of the test signal with delayed for a time clock pulse in the Control-2 mode.

The digital test-signal generator can be made in various ways, for example, in the form of a serial connection of a sinusoidal signal generator, an analog-diffraction converter and a shift register for converting a parallel binary code to a serial one. Technical means are known to control the frequency and amplitude of the output sinusoidal signal of the corresponding generator (synchronization and power lines, which are not essential for explaining the principle of operation of the invention, are not shown).

The multichannel digital piezoelectric mometric spit (Fig. 1) operates in three main modes of Operation, Control-, Control-2. In the Operation mode, the switches 27-30 of the switch 26 are in the first (upper) position, in the Control-1 mode - in the second (middle) position, in the Control-2 mode - in the third (lower) position.

Signals on lines 4-6 are transmitted in three levels: in the form of positive pulses, in the form of a zero voltage level, and in the form of negative pulses. In this case, the key 27 is designed to pass a positive polarity clock (T) into the synchronization line (FIG. 4), a key 28 - negative start pulse (3), a key 29 - clock pulses (T) with a delay of t supplied to the input of the control line, the key 30 is a sequential sampling code of a sinusoidal signal from the output of the generator 25. Informational pulses at the output of the key 30 can have; i: Ba level (O and 1), between which follow negative synchronization pulses (C) whose number corresponds to the number of bits avaemogo code, and it corresponds to the time of re cottages D. Clock pulses have an increased duration relative to the other in a ratio of at least 2: 1. Mentioned

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the pulses are formed by the corresponding electronic formers in blocks 24 and 25. Combination schemes 3 and 32 reduce the signals of different polarity from the key pairs 27-28, and 29-30 and excite the corresponding lines in segments 5 and 6.

In the Work mode, at the output of cxeNW 3, a signal of the form 53 (figure 4) is generated, and at the output of the circuit 32 - a signal of zero level. Signal 53 enters block 17 and, by circuit 4, is divided by fields so that pulse T is present at its output 48; formed in block 45, enters output 38 and launches through disjunctor 19 at clock input 39 an analog-to-digital converter 6 for encoding a sample received at its input through amplifier 15 and a switch. Pulse T comes from output 38 to the first setup input of trigger 20, the output of which is connected to control input 4 by switch 1 to input of amplifier 15 and output signal from hydrophone 7 through active band-pass filter 8. Negatives 1st pulse (3) from output 47 of the circuit 41 arrives at the start of the cyclic converter 46, which converts the parallel code of the previous measurement into a serial code and output during compaction time i through circuit 40 into a data transmission line (segment 4). In addition, the pulse (3) is delayed and formed by a circuit 42-43 for a delayed start of the next spit channel. Thus, each electronic module 2 passes in line 4 a serial code from previous channels and adds its data to it in circuit 40.

In the Control-1 mode, the output of the block 31 also contains a pulse 53 (Fig. 4), and the output of the circuit 32 is a pulse of the form 54. The latter, after compensating for attenuation, enter the separation circuit 49 of the device 22, where informational positive pulses (0.1) are input into the shift register 50 under control of the pulses C after their potential inversion of the inverter 52. A digital-to-analog converter 51 equipped with a register register converts the pa513 formed in the shift register

Parallel sample code of the test signal to the DC voltage, which is not passed directly by switch 11 to the input of amplifier 15, because under the described control of pulse T. through trigger 20, switch 1 passes a signal from a hydrophone 7, a sequence of step signals from The output of the device 22 in the form of a quantized sinusoidal signal is fed through a matching device to an electrical exciter 9, which forms an elastic pressure wave in the liquid dielectric, which fills the cavity of section 1.

 The hydrophone 7 converts the pressure wave into an electrical signal, which is subjected to encoding and compaction by the electronic module 2 into a data line in sections 4.

In the Control-2 mode, at the output of the key 27, a clock pulse T does not occur and the circuit 31 outputs only a negative start pulse (3) to the synchronization line (signal-55, FIG. 4) At the output of circuit 32, a serial code is generated, a sinusoidal test signal of type-54, to which key 29 and a combination circuit 32 add a time delayed clock pulse T (signal 56, fig. 4). The signal. From the output of the circuit 32 after the attenuation compensation is fed to the input of the decoding device 22 and is transformed by it into a sampling voltage corresponding to this code. The impulse T is not introduced into the device 22, since it is not followed by a service impulse.

shift C. However, the impulse T is in the gap

discriminator 21 and plays the role of triggering through disjunctor 19 for converter 16. In addition, pulse T, selected by discriminator 21, sets trigger 20 to the state where switch 11 connects input of amplifier 15 to output of device 22. Thus, module 2 performs coding and the seal in the transmission line of the test signal from the output of the device 22.

In the Control-2 mode, the identity of the electronic transmission path of each module can be assessed, and their amplitude-frequency response can be removed by tuning the signal of generator 25 in amplitude and frequency. After that, the transition to the Control mode can be evaluated

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the identity of the streamer channels as a whole, including hydrophones, and their amplitude-frequency response. The phase identity is metrologically provided by the simultaneous launch of all ADCs by a pulse T, and the amplitude identity by the code form of the transmission of the test signal and by increasing the reliability of the transmission by compensating for pulse attenuation by circuits 18. At the same time, the Control-1 and Control-2 modes can be performed in a spit in the transported state before transfer to the towed position, and periodically in the latter, during the work. Thus, the repair loss of time during operation can be minimized, as well as the time for analyzing the nature of rie-goodness due to simultaneous sampling of a signal of the same amplitude at all frequencies in the passband of each spit channel. Transition .v operation mode coupled with the inclusion of a probing seismic source when the generator is turned off 25.

Claims (1)

Invention Formula A device for recording seismic information in digital form on water areas, including towed and on-board parts, and a control device containing a generator, each channel of the towed part consists of a hose section with two electrical connectors at the ends, filled with a liquid dielectric, within which there are lines data transmission, synchronization and control, as well as at least one piezoelectric hydrophone connected to the active band-pass filter, and from the attached to the section by means of Electronic module connector with two additional electrical connectors, which contains a serially connected unidirectional switch, amplifier and analog-digital converter, as well as a pulse recovery circuit, the input and output of which are connected to the control line, the compressor and regeneration device, the corresponding pairs of inputs and outputs of which connected to the transmission and synchronization lines, while the output of the analog-to-digital converter is connected to the signal 713 the input of the compaction and reclamation device, and the first signal inputs of the unidirectional switch are connected to the corresponding outputs of the active bandpass filter, adjacent channels are interconnected by data, synchronization and control lines through the second electrical connectors of the hose sections and electronic modules, and the electronic module the first channel is connected to the data lines of the synchronization and control data of the onboard part, which contains a receiving device, the input of which is connected to the output of the transmission line and data, the synchronizer, the output of which is connected to the second input of the receiving device, is due to the fact that, in order to increase the productivity of work due to diagnostic testing, electrical electrically elastic waves, and a digital generator of the test signal was used as a generator, while the electrical exciter of elastic waves was placed - inside the hose section of each channel, into the electronic modules of which a pulse duration discriminator, two-input disjunctor, trigger er, decoder and matching device, and in the side - digital eight a test-signal generator and a bidirectional three-position switch, the decoder outputs are connected to the second inputs of the unidirectional switch and, via a matching device, to the input of the electrical exciter, the clock input of the analog-digital converter is connected to the output of the disjunctor, the first input of which is connected to the trigger output of the sealing device and regeneration and the first installation input of the trigger, the second installation input of which is connected to the second input of the disjunctor and the output disk iminator, the output of the decoder is connected to the output of the pulse recovery circuit and the discriminator input, the control input of the unidirectional switch is connected to the trigger output, while the second, third, and fourth outputs of the synchronizer are connected to the first, second, and third inputs of the bi-directional switch, the first output of which is connected to the input of the synchronization line, and the second output to the control input, the input of the digital generator of the test signal is connected to the fifth output of the synchronizer, and the output - from The fourth input is a bi-directional switch. / П / Oul П1 О О / П / / 7 ПГП / О О Г} Г Editor N.Gorvat K Srag Compiled by D. Zargar N Tehred M. Khodanich Proofreader M. Maksimishinets