SU557337A1 - Seismic data acquisition system - Google Patents

Description

Each line connects to each link through the isolating devices, each link is connected via the same isolating devices and phase demodulators to the recorder inputs. Observation points contain at least two seismic receivers or a group of seismic receivers, two two-wire communication lines, a channel switch and a multiple (for example, three-fold) phase difference manipulator with a single carrier frequency. The output of the seismic receiver through two-wire communication lines and the channel switch are connected to the input of the analog-code converter, the output of which is connected to the input of the key circuit through the multiple phase-difference manipulator.

1Na flg. 1 shows a general scheme of the proposed seismic data acquisition system; in fig. 2 is a block diagram of the information collection path; in fig. 3 shows a block diagram of the observation point and its inclusion through a connecting device in the communication; in fig. 4 is a diagram of synchronization of the operation of observation points over a common link; Fig. 5 is a diagram of the formation of the gang signal in the watch point.

The data acquisition system contains a single-time Meini 1 transmitter with communication channel 2, a collection point in |} of the terminal 3, a communication line 4 with connecting devices 5, observation points 6. An equipment combined with one collection point in the United States 3 forms subsystem 7 (in the drawing four subsystems are included in the seismic data acquisition system). Information collection points contain decoupling devices 8 phase demodulators 9, recorder 10, generator 11 with an external synchronization device, and a receiver of signals of a single time 12 with communication channel 2. Observation points 6 include control device 13, key circuit 14, multiple phase difference manipulator 15 converter analog-code 16, switch of channels 17 and seismic receivers or groups of seismic receivers 18.

The seismic data acquisition system starts work on a pulse 19 emitted by the transmitter of signals of a single time 1 through communication channel 2 and the receiver of signals of a single time 12 to an external synchronization device of the generator 11 In addition to the start pulse 19, the transmitter of signals of a single time 1 generates frames e 2 O and clock pulses 21 according to the number of observation points 6 operating on each communication line 4. In accordance with the number of the clock pulse 21, one of the observation points b is connected to each communication line 4 through key circuit 14 and the mouth A control device 13 reacting to one of the clock pulses 21 located between the frame pulses 20.

Thus, for the polling interval, determined by the frequency of personnel pulses JQ 20, data collection point 3 receives data (pulses) 22 sequentially from each observation point 6 via a separate communication line 4 and in parallel along several communication lines. Within each frame, determined by pulses 2O and equal to the interval of sampling of seismic signals, by a system of a single time, including blocks 1, 2, 11, 12, 20 clocks 21 are also sent to each link, with equal intervals. The control devices 13 of observation points 6 are reset to the initial state by personnel pulses 20 or by a start pulse 19. 5. The clock pulses 21 through the control device 13 by counting and decoding them control key circuit 14, providing alternate connection of observation points 6 to the common line zi 4,

0 Signals from the seismic receivers 18 are polled sequentially by the switch of channels 17 and converted to digital values by a common analog-code converter 16, from the output to

5, the digital value of each sample is fed to a multiple phase difference manipulator 15, where the serial code is re-formed into a parallel-serial one. Combination at the same time

0 incoming information symbols determines the phase change of the next carrier frequency relative to the previous one. In this case, the period of modulation frequency change, which determines the frequency band of communication line 4, for a three-fold phase difference manipulator 15 will be the same as that of the prototype, the observation point of which contains only one seismic receiver.

Thus, the number of seismic receivers in the proposed device, served by one communication link with the same parameters, is tripled.

Combining generator 11 with paragraph

gathering information 3 and switching on converters 8 provides an increase in the number of channels by connecting additional communication lines 4.

Claims (2)

The receiving-transmitting device (blocks 1, 12), communication channel 2 and the external synchronization device of the generator 11 both prevent an increase in the number of channels up to 100 or more by connecting additional systems 7. The data block formed at each observation point has the peculiarity that the first burst 23 is filled with oscillation from a certain phase in the multiple phase difference manipulator, therefore the data block (see pulses 22) will contain - K bursts, where mn is the size of the signal sampling code, T | - the multiplicity of the phase difference manipulator. For a triple manipulator, K t i-1- Other subsystems 7 work similarly. The proposed seismic data acquisition system provides a high degree of node unification due to the fact that observation points operate with time compression and high utilization of the communication link band due to preliminary phase compaction at the observation point. The general system of synchronization of the subsystems makes it possible to select the desired number of channels without restriction. Seismic data system allows to reduce the costs of the work associated with observations on the areas. Invention Seismic data acquisition system, comprising a generator, an instrument collection station with a recording device, a communication line in the form of a two-wire or coaxial cable, connecting devices located near observation points, which contain a seismic receiver or a group of seismic receivers that form one channel, a converter: analog-code, control device, and a key circuit that distinguishes so that, in order to increase the efficiency of signal multiplexing in the communication channel, it includes a single time signal transmitter, a single time signal communication channel, additional information collection points containing a single time signal receiver, phase demodulators, converters and additional communication lines, and the output of a single-time signal transmitter is connected via a communication channel of a single time signal, for example, via a radio channel through a single-time signal receiver to an input of an external device synchronization of the generator located at the central registration point, and the generator output is connected in parallel to each communication line through an isolating device, each communication line is connected through the same isolating devices and phase demodulators to the inputs of the recording device, the observation points contain at least two additional seismic receivers, two two-conductor communication lines, a channel switch and a multiple phase-difference mapper, and the outputs of the seismic receivers through two-conductor The communication and the channel switch are connected 1 to the analog-code converter input, the output of which is connected to the key circuit input via a multiple phase difference manipulator. Sources of information taken into account in the examination, 1. Pageng US No. 3652979, cl. 340-15.5, 1973. 2. The patent of France K 2O36151, cl. G 01 V 1/00, 1973 and in addition to it the patent of France No. 2185149, cl. G O1 d 5/00 / G 01 V 1 / 00,1974 UipOTO type). (rig. 1 FIG. 2 Fig.Z