DE2451238A1 - PROCEDURE AND ARRANGEMENT FOR SEISMIC EXPLORATION - Google Patents

Description

Our reference: T 1672

Procedure and arrangement for seismic exploration

The invention relates to seismic exploration and, more particularly, to real-time acquisition of raw seismic data at a main station through a point transmission spread spectrum from several data acquisition units (hereinafter referred to as DAU), which are at a distance from each other at unknown locations in an exclusion area are appropriate. Real-time seismic data is collected from each data acquisition unit DAU in response to an interrogation code group transferred to the main station. Distance data for each data acquisition unit DAU with respect to the main station and for a slave station are also recorded. In seismic exploration, the location of the shooting points, where the seismic energy is generated and the location of the seismic detector stations where the seismic energy is determined to be known precisely. So far it was with the shot points and with the detector locations a "recording station connected by cable. To determine its location in terms of azimuth angle and of the elevation angle, all stations were carefully measured. In the conventional pail seismic data

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transmitted via cable to a recording station, where the earth movement corresponding to the various seismic detectors analog data is converted into data in digital form. Digital samples of each of the seismic signals are obtained at 0.002 or 0.004 second intervals. Such digital representations are usually multiplexed and used for further purposes. Processing recorded on magnetic tapes using techniques available and known in the art. Representative processes are performed using systems manufactured, sold, leased and used by Texas Instruments Incorporated, Dallas, Texas, and known as Di ¹ S I-DFS IV.

The present invention involves the elimination of cable connections. A main station is at a known location with respect to a seismic prospect. Data acquisition units each with a seismometer entry channel and shot points are then placed throughout the seismic prospect as desired. The data acquisition units are then interrogated cyclically one after the other by the main station. In every data acquisition unit DAU another response code group is keyed in. The main station successively sends out an interrogation code group in the form of a data frame pulse group, on the one Series of channel synchronization pulses follows. As answer on each such data frame pulse group becomes the digital Representation of earth movement temporarily saved in each unit. Each data acquisition unit DAU counts channel pulses. When the number of channel synchronization pulses with the keyed-in response eode group on the data acquisition unit matches, then the data acquisition unit DAU responds by sending out an RF signal containing the stored Earth Movement Signal · represents.

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The present invention also includes the elimination of the surveying operation with the master station and a lift station at known locations with respect to a Coverage area while the data acquisition stations are are in unknown places. The slave station contains facilities by means of which it is able to check the time of arrival differences between each master station data frame pulse group and those sent out by the data acquisition unit DAU Can answer distance bits and store these time differences. The secondary station also speaks on Interrogation signal from the main station so that it goes to the main station for each data acquisition unit in chronological order Sends distance difference information.

The invention will now be explained by way of example with reference to the drawing. Show it:

Pig. 1 a seismic exploration arrangement, which is distributed over an outcrop area,

Pig. 2 is a block diagram of the main station 13 from FIG. 1,

Pig. 3 shows a time diagram of the processes taking place in the arrangement according to the invention;

Pig. 4 is a block diagram of a data acquisition unit DAU by Pig. 1,

Pig. 5 and 6 show a detailed circuit diagram of a control arrangement the data acquisition unit DAU from Pig. 4,

Pig. 7 and 8 a detailed circuit diagram of the amplifier, converter and shift register of Pig. 4 along with associated Control circuits,

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Pig. 9 the positional relationship between the 4 sheets of the drawing, on which Figures 5 to 8 are shown,

Fir. 10 is a detailed circuit diagram of a pulse generator and a preamplifier blanking circuit for driving a surface acoustic wave device in the invention Arrangement are suitable, and

FIG. 11 shows an arrangement at the secondary station 15 from FIG. 1.

In Fig. 1, a seismic exploration arrangement is schematically shown according to the invention. At selected locations, for example at shot point 10, seismic Generates impulses. The resulting seismic waves * migrate along sub-surface paths to below reflective horizons lying on the surface and back to the surface, where they are detected by the detector field 11, for example will. The seismic detected in this way Waves reach a data acquisition unit 12 (DAU) in the form of analog signals.

The D _a tenerfassungseinheit 12 is an RF transponder having means for performing analog-to-digital conversion of the D _e tektorfeld 11 detected seismic waves and thus 13 signals are sent to respond to a query broadcast by a master station 13, to this station, the correspond to the seismic data ascertained by the detector field 11. Accompanying data acquisition units DAU are arranged at selected points on a surface to be measured, as shown in FIG.

In the past, detector fields were, for example the detector field 11, via cable with a recording

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station 13 connected. During the recording, signals were multiplexed, from an analog representation to a implemented digital representation and then on a magnetic "tape saved. Furthermore, it was a completely normal process that the location of the shot point 10 and each location of the Detector fields, for example the detector field 11, measured exactly and both with regard to the azimuth angle and the Angles of elevation have been determined.

With the arrangement described here, the seismic data is sent to the main station 13 by Punk in real time. An RF secondary station 15 is preferably set up in the area 14 to be measured. By interrogating an HP channel 16 extending between the master station 13 and the data acquisition unit 12, not only is real-time seismic data collected, but range information is also acquired. Distance information is acquired from the slave station via channels 17 and 18. The distance data collected by the slave station 15 are then acquired by the master station 13 via the channel 18. The time of the shot, that is to say the time at which the seismic radiation is generated at the point of fire 10, is transmitted from the main station 13 via the channel 19. As a result of these processes, the data acquisition units, for example the data acquisition unit 12 with its associated detector field 11, can be attached anywhere in the entire area 14. You are then queried for the seismic data in real time, while information regarding the range is obtained at the same time. Triangulation calculations on the basis of the distance data acquired using the slave station 15 give the locations in terms of the azimuth angle.

In Pig. 2 is a block diagram of the master station. 13 dar-

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^ posed. A clock oscillator 20 is provided with an interval counter 21 connected «, the interval counter 21 is equipped with a control option via a line 21 a so that the rate at which the seismic data is to be sampled can be controlled. The outcome of the Interval counter 21 is connected to a pulse generator 22, and it is over.eine line 23 with a Counter 24 associated with a division ratio Ii. The pulse generator 22 generates an HP pulse with a duration under a microsecond. The impulse is dated with a Counter 21 generated certain pulse train. The sequence of the output pulses from the pulse generator 22 is shown in FIG.

In FIG. 3, the signal curve A1 contains a representation of a block 25 of pulses which are to be sent out by a data acquisition unit DAU as a response. The channel synchronization pulse 27 follows _a data frame pulse 26 at a predetermined interval. Twenty-two further channel synchronization pulses, for example the pulse 28, follow the channel synchronization pulse 27 at regular time intervals if 24 data acquisition units are used. Twenty-four channel sync pulses are generated between data frame pulse trains.

The signal curve A2 shows a data frame pulse train 26, 29, channel synchronization pulses 27, 28, 35c lying between the data frame pulse trains 26 and 29.

The data frame pulse trains 26 and 29 each contain 2 ¥ @ i pulses that are sent out immediately one after the other

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The signal run A3 indicates a sequence of pulses 26 ... 29, etc. The D _a tenrahmen pulse trains join pulse sequence removal cycle 30 a. Between the removal cycle pulse train 30 and the next following removal cycle pulse train 31 there are twenty-four data frame pulse trains. The removal cycle pulse trains 30 and 31 each consist of a group of three consecutive pulses.

In the arrangement of Pig. 2, channel sync pulses, frame and range pulse trains from the pulse generator 22 are applied to a surface acoustic wave device 31. The surface acoustic wave device 31 is used to spread each pulse with a duration of less than a microsecond from the generator 22 over a considerable band and to give the oscillation a clear course, which of a matching surface acoustic wave device at the stations 10, 12, 15 and so on from the main station 13 of I ¹ Ig. 1 removed to be determined. A preamplifier 32 and a power amplifier 33 then excite an antenna 34 via a transmit / receive switch 35. The Pig system described so far. Fig. 2 is a conventional HP channel except for the use of a surface acoustic wave device which has bandwidth spreading. results.

The system described so far forms the transmission section of the main station.

The main station is also with a receiving section equipped so that the information contained in the pulse train 25 of Fig. 3 can be received at the master station and can be saved. The receiving section contains the line 36 from the transmit / receive switch 35 leads to a preamplifier 37. The preamplifier 37

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is then to a receiving surface acoustic wave device which is the same as the surface acoustic wave device 31; however, the signal is applied to her so that it can is subjected to a mirror image treatment with respect to the signal treatment in the preamplifier 32. The output signal the surface wave device 38 is then a mixer 39, which is fed by a local oscillator 40. The output of the mixer 39 is fed to a hill curve detector 42 via an IF amplifier 41, so that this detector 42 is at its output e: xakt in the center of the pulse-shaped output of the surface acoustic wave device 38 generates a one microsecond pulse. The output pulse of the envelope detector 42 is then fed to a video amplifier 43, the output signal of which passes through a threshold value detector 44 to a demultiplexer 45 and from there to a data storage shift register 46. the seismic data signals appearing on the output line 47 leading to the demultiplexer 45 appear then on output lines 48.

There are many specialized ways of processing or using the data, once it is multiplexed are collected on line 47. The arrangement described here is based on the acquisition of seismic data and real-time distance data in multiplexed Form directed at a main station.

In Pig. 4 shows an embodiment of a data acquisition unit 12. The seismic detector field 11 must be connected to the input terminals 50 of a preamplifier 51, the output signal of which passes through a filter 52. The preamplifier 51 and the filter 52 are conventional structural units that are used in a seismic survey

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system manufactured, used and sold under the designation DFS I-DFS IV by Texas Instruments Incorporated of Dallas, Texas. The circuit arrangements leading away from the filter 52 comprise units for analog / digital conversion and transmission of the digital output of 2 ms or 4 ms samples of the seismic signal in real time, which are applied to terminals 50 in response to interrogation pulses from the main station In particular is a. Amplifier 53 is provided, which is equipped with a circuit 54 for automatic gain control. The output of the amplifier 53 is connected to an analog / digital converter 55, the output of which is connected via a channel 56 to a parallel load series shift register 57. A branch line 58 leads from the line 56 to a gain control generator. The gain control generator 59 is used to control the circuit 54 for automatic gain control. The gain control generator 59 is provided with an output line 60 which leads to the shift register 57. In this way, data present in the form of a word consisting of several bits are stored on the line 56 in the register 57 together with the gain exponent in the form of a group consisting of several bits and applied via the line 60. The content of the shift register 57 can then be output in a clock-controlled manner so that it is transmitted by the antenna 61. The channel between the shift register 57 and the antenna 61 contains a pulse generator 62 which generates a pulse with a duration of less than one microsecond for each binary value "1" in the shift register 57. The output signal of the pulse generator 62 is applied to a surface acoustic wave device 53, the output signal of which is in turn fed via a preamplifier 64 and a power amplifier 65 to a sending switch 66. The pulse generator 62 generates an RF pulse having a duration of less than one, Germ © 8 @ customer _p

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which is supplied to the surface acoustic wave device 53, so that the pulse is spread over time and with regard to its spectrum, so that this pulse with a "certain Identifier can be encoded while a relatively low one Transmission power per cycle of the bandwidth is made possible.

The query code groups received by a data acquisition unit pass from the antenna 61 via the transmit / receive switch 66 to an RF amplifier 67. The output signal of the RF amplifier 6? is applied to a surface acoustic wave device 68 which is similar to surface acoustic wave device 63 but is connected to time compress the received signal. The output signal of the surface acoustic wave device 68 is fed to a mixer 69, which is fed by a local oscillator 70, so that the output signal of the surface acoustic wave device 68 is converted to an intermediate frequency. The output signal of the mixer 69 arrives at an IF amplifier 71 and then to an envelope detector 72, the output signal of which arrives at a pulse shaper 75 via a video amplifier 73 and a threshold value detector 74. The pulse shaper 75 feeds a frame decoder 76, which supplies an input signal for a variable delay unit 77. The delay unit 77 applies clock pulses to the shift register 57 via a line 78. Channel numbers are preset manually via the lines 79 so that the clock line 80 leading to the shift register 57 is controlled. Clock pulses from the delay unit 77 are also fed to a status register 81. The status register © delivers Eingangsaignal for UEAs shift register 57 in the form of individual bits in time! © Ige over a circuit 82 _ö The input of the status register 81 is itmxg from a Saram @ 13L @ goTbildet 83 "the look besiehende for on di © Datenerfasiungseinheit Statusin - © i & © capacity sound 24 bits rar provides.

Each data acquisition unit DAU of FIG. 1 contains the transponder shown in FIG the analog data appearing at the connection terminals 50 in digital representation in the shift register 57 takes place. The stored data is then read from the shift register 57 and transmitted via the antenna 61 from each data acquisition unit DAU in response to from the Delay unit 77 decoded interrogation pulses from the Main station sent out.

FIGS. 5 to 8 arranged according to FIG. 9 show the main parts of the data acquisition unit DAU.

Figures 5 and 6 show parts of the circuit of Figure 4 including the pulse shaper 75, the frame decoder 76 and the variable delay unit leading to output line 80 of FIG. The input line 100 of FIG. 5 is the input line leading to pulse shaper 75. The circuit shown in FIGS. 5 and 6 is used to receive interrogation pulses from the main station, and it causes the generation of control pulses which read from the shift register 57 the data contained in it are stored at the time at which the interrogation pulse is received by the data acquisition unit.

As FIGS. 5 and 6 show, the interrogation input line 100 leads from the receiver channel to the input of an F] _ip-flop 101, which is used for pulse shaping as a monostable multivibrator. The output pulse of the flip-flop 101 appears on line 102, and it is supplied to an input of a UOR-S _c attitude 103rd Line 102 forms the output of flip-flop 101, which emits a signal negated with respect to the input signal on line 100. Line 104 carries an output signal with the same

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Polarity as on the line 100. The line 104 is connected to the Vore ins te Il β input of a flip-flop 105. The A _u sgangssignal of the flip-flop 105 appears on line 106 which is connected to the clock enable input of a 7-bit Binarzählers 107th The clock line 108 supplies the system clock at a frequency of 2.560 MHz.

One of the lines coming from the counter 107, the line 109, is connected to an input of a UAND circuit 110. The output of the HAIiD circuit 110 is connected to the second input of the ΪΓΟΕ circuit 103 via a line 111. The line 111 is also connected to the clear input of the flip-flop 105 via a HAHD circuit 112. The output of the HAHD circuit 112 is also connected to the clock enable terminal of a counter. The output line 114 of the counter 113 is connected to the second input of the HAHD circuit 110. The line 104 is connected to the T _a kteingang of the counter 113 is connected. The line 115 is connected to the release input of a decadic counter 107 and to the reset input of a binary counter 113 via the HOR circuit 115a and via a hegator 115b. The numbers 6 and 7 in the counter 107 designate output pulses 6 and 7, respectively, of the five-stage decadic counter 107. The counters 107, 113 and the flip-flop 105 can thus either from the output pulse 7 or from a signal via the HOR circuit and the hegator can be reset on line 115.

The output of the HOR circuit 103 is via an HOR circuit 120 of FIG. 6 at the input of a HOR circuit 121 having three inputs and at the clock input of one Flip-flops 120 connected. The flip-flops 101, 105 and 122, like the flip-flop 124, are D flip-flops.

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If a pulse appears at the output of the NOR circuit 120, then the leading edge of that pulse ensures that on line 125 coming from the Q output of the llip-flop 122 goes off, a low signal value lies. The line 125 is also connected to a second input of the ITOR circuit 121. The third entrance is from a The circuit to be described later supplies the indicates that an I.D. comparison has ended.

The B "OR circuit 121 is a seven-stage with the clock input Binary counter 126 connected. The binary counter 126 and the counter 128, which is also composed of seven stages are used with associated circuits to convert binary data at the output of the UOR circuit 121 into binary coded Transform decimal data when applied to a group of six exclusive OR circuits 131-138. The non-equivalence circuits 131 to 138 compare the BCD code group of the counters 126 and 128 with a preset one digitally entered BCD-I ♦ D. code group of Jagged encoder for manual entry of the code group are provided in each data acquisition unit DAU. the The output states of the thumbwheel switches appear on the Lines 141 through 148. It should be noted that for this purpose the bits with a weighting of one (1) for the terminal QL and A cht (8) from terminal Q. of counter 126 to exclusive OR circuits 131 and 134 and also to the NAND circuit 150 are created. The output of the NAND circuit 150 has one input of a three input NOR circuit 151 connected. The output of the NOR circuit 151 is connected to the clock input of the counter 128, and it is connected to the input of a NOR circuit 153 via a line 152. The exit the NOR circuit 153 is via an inverter 154 with the Reset terminal of counter 126 connected. The output of the NAND circuit 150 is via an inverter 155 at the Eaktöin ™

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connected to the output of the flip-flop 124. The flip-flop 124 is operated as a monostable toggle circuit, de- ' ren period is determined by a resistor 124a. The ^ output of flip-flop 124 is on a line 156 connected to the default input of flip-flop 122. The signal value on the line 125 is used to block an input into the NOR circuit 121 for the Duration of a! Act interval.

The output lines of the non-equivalence circuits 131 to 138 are connected to the inputs of the HOR circuits 160 and 161. The outputs of the NOR circuits 160 and 161 are connected to the inputs of a NAND circuit 162. The signal at the output of the NAND Circuit 162 has a high signal value at the output of the inverter 163 if and only if low signal values are present on all lines to the NOR circuits 160 and 161.

The output line 164 of the inverter 163 is connected to the third input line of the NOR circuits 121 and 151 are connected. This is used to keep the counting process in the To stop counters 126 and 128 when the signal value at the output of inverter 163 is high or true.

The inverter 163 is also connected to the clock input of a flip-flop 170, which is operated as a monostable multivibrator whose period is 1 ms and is determined by the resistor 161. The line 172 leads from the Q output of the flip-flop 170 to an input of a NAND circuit 173 ° Di® output line 174 leads to the clock @ ingangskl © mm @ H. of two register entries 175 and 176 of Figo I _{3 form} the elas Sehie ^ eregistes ¹ 57. The units 175 Wi & 176 are each ParalleHade serial shift registers with eight inputs. Di © Leitimg 174 is also with

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connected to the clock input of a 7-bit counter 177. the Circuit works so that a pulse with a high signal value and with one of the monostable multivibrator certain period on the line 174 appears when the output signal of the inverter 163 a has high or true value. ·

The trailing edge of each pulse on line 174 causes the Q ^ output appearing on line 178 in counter 177 to go high. Line 178 is also connected to the J input of a JK flip-flop 180. Such a pulse causes the state of flip-flop 180 to change. The Q output of flip-flop 180 is connected to the second input of NAKD circuit 173 via an IiAKD circuit 181 and via line 183. This causes the release of the at L _TION 182 appearing clock pulses for transmission over line 183 to the NAND circuit 173 and the line 174 for application to the shift register 57 of Fig. 7 as well as to the counter 177. On the Q ^ -A _u sgang of the counter 177 is also an inverter 190 connected. The inverter 190 is connected to a NAND circuit 191. The output of NAND circuit 191 appears on line 192.

The output line 192 is a reset line, the to the reset terminals of counters 107 and 113, to the reset terminal of the counter 128 to the reset terminal of the flip-flop 122 and to the second input of the NOR circuit 153 leads. Line 192 is also connected to the reset terminal of flip-flop 180. The outcome of the NAND attitude 162 is connected via line 194 to the reset terminal of counter 177 in order for it to be and the flip-flop 101 are reset.

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An initial reset line 193 is connected to the second input of the NAND circuit 191.

The seismic data from a sensor filter channel coming from the seismic detector array appears on line 200 from Pig. 8. The line 200 is connected to the inputs of two amplifiers 202 and 203 via a chopper 201. The amplifiers 202 and 203 have their A _u sgangen to the input of a summing amplifier 204 out. The chopper 201 and the amplifiers 202 ″ to 204 work together in such a way that they supply a square-wave output signal for a DC input signal. When a DC voltage of 5 volts occurs on line 200, a square-wave signal is generated at point 205, which extends from +5 volts to - 5 volts is sufficient. The signal curve is symmetrical with respect to the ground potential or the zero potential. The scanning speed of the seismic data is high, so that the input signal appears as a DC voltage signal for each scanning value and is chopped up to generate the scanning signal.

The chopper 201 is operated over a line 206 on which there is a signal representing a frequency which is equal to the frequency at which the signal on line 200 is to be sampled. Normally the sampling rate is either 2 ms or 4 ms. In the example described here, a sampling rate of 2 ms is used.

The output signal appearing at point 205 cycles through then actually 4 gain control stages. The first Stage contains a module 210, the second stage is from Module 211 is formed and the third stage consists of module 212. The modules 213 and 21.4 work together to

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Formation of the fourth gain control stage.

The gain control stages are via capacitors 220 coupled. The output of capacitor 220 leads to the switch arm of a gain control switch 221. A switch terminal connects directly to the input of module 210 tied together. The other switch terminal is across a voltage drop circuit connected to resistor 222 at this input.

The amplifier module 210 and the elements connected to it are selected so that in one position of the switch 221 the amplifier has a gain of 2 or a unity gain. In the other position of switch 221, the gain factor is 2, i.e. 2.

Such elements are attached to the S + ufe containing module 211

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connected that a gain of 2 or 2, that is, a unity gain or a gain by a factor of four results. The one containing module 212 Stage is equipped with such elements that there is a gain of 2 or 2, that is, a unity gain or a gain with the factor 16 results. The stage including modules 213 and 214 is with such Elements provided that have a gain of 2 or 2, i.e. a unity gain or a gain with a factor of 256 results.

By selected combinations of the S _c holder positions, such as switch 221, the circuitry between the output of capacitor 220 and output terminal 225 can be selectively controlled to have a gain of any power of two between 2 and 2 *. This gain can be selected by applying control states to the four input terminals A, B, C and D.

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The output of the variable gain amplifier is then fed to a sample and memory switch 228 through a damping resistor 227. When the switch 228 is connected to the capacitor 229, this capacitor 229 is charged so that the voltage across it follows the voltage applied. At the moment when the switch 228 'is opened by releasing the line 230, the voltage is set on the capacitor 229 and the input of an amplifier

240 supplied. The amplifier 240, with its input in parallel with capacitor 229 is a high impedance amplifier. It is used to attach to the terminal

241 to produce a unity gain output signal without the charge on capacitor 229 being removed.

The voltage at terminal 241 is then fed to amplifiers 242 and 246, which have a gain factor of one. D _a s output signal of the amplifier 242 may through a switch 243 to the signal input of an analog comparator circuit are fed to 244th The output signal of the amplifier 240 can also be fed to the comparison circuit 244 via a switch 245.

The amplifier 246 provides control of the comparison circuit. Its positive input is connected to terminal 241 and its negative input is connected to ground which serves as a reference point for the operation of amplifier 246. When the output of amplifier 240 is positive, switch 243 is turned on by amplifier 246 so that the comparison voltage applied to amplifier 244 is the output voltage of amplifier 242, that is, the inverted value of the voltage at terminal 241 since amplifier 242 has the gain factor - 1 .

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If the voltage at terminal 241 is negative, then the output signal of the S-expensive amplifier 246 is over an inverter 247 is applied to switch 245 to turn it on. In this pail it is on the voltage applied to the comparison circuit 244 determines the voltage at the terminal 241.

The comparison circuit 244 is supplied with a linearly increasing voltage via the input line 250, which occurs cyclically and repeats an increase rate which depends on the speed at which the line 200 is supplied Signal changes. How the repetition speed of the increasing voltage is controlled will be discussed later explained.

The voltage on line 250 is a voltage developed across capacitor 251 obtained by a reference voltage cell 252 is derived. The reference voltage cell 252 is connected to the input of an amplifier 253 Sawtooth generator 254 in connection. The sawtooth generator 254, the capacitor 251 and a control switch 255 constitute an integrator. When switch 255 is closed is, the voltage on capacitor 251 * is short-circuited so that capacitor 251 is discharged. When the switch 255 is open, a constant current from the sawtooth generator 254 is fed to the capacitor 251, what the creation of a sawtooth voltage running from positive to negative values on the line 250 has the consequence. This is the tension in the comparison posture 244 is compared with the voltage at terminal 241.

The output of the comparison circuit 244 is connected to a D flip-flop 261 via a line 260. Of the

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The Q output of the flip-flop 261 is connected to the switch 255 via a line 262. The ^ output is connected to an input of a NAND circuit 264 via a line 263. The second input of the NAND circuit 264 is fed via a clock line 266 so that during the time interval, in which V _{e is} the reference voltage on line rlauf lower than the voltage of the S _c holders 243 or 245 is a counter fed 275 clock pulses will. The content of the counter. 275 then represents in digital form the sampled values of the seismic analog voltage on line 200 at the time of sampling.

The analog voltage appearing on the line 200 is thus represented in a digital form of nine bits and a sign bit. This digital representation is stored in registers 175 and 176 (Fig. 7) stored · To achieve this conversion, the counter 275 is switched on when the Q output signal is on the line 263 from the flip-flop 261 assumes a high signal value. This will allow the passage of the clock pulses on line 266 through NAND circuit 264 and then Released via the line 277 to the clock input of the counter 275. The counter 275 stops counting the applied Clock pulses when flip-flop 261 reverses state. The time interval over which the counter 275 counts, is then dependent on the instantaneous amplitude of the analog signal on the line 200, as they do is sampled and stored in capacitor 229.

The counter 275 is triggered by control pulses on the line 277, which occur with the conversion speed of the seismic signals.

The content of counter 275 is written to the shift register

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175 and 176 depending on the control status on the NAITI) circuit 110 of FIG. 5 outgoing line 111 entered.

Registers 175 and 176 are each register with a capacity of eight bits.

The first two bits of register 176 are tied to a positive voltage, which means "always." have the state "1". The transmission of the first bit (the distance bit) from the data acquisition unit to a control station always forms the basis for measuring the distance between the data acquisition unit and the central station at the central station. The second bit (synchronization bit) is used to synchronize the main decoder to recover the transmitted data.

Bits 3 through 5 of register 176 are the bits for the Gain exponent. Bits 6 to 8 of the register

176 and bits 1 to 7 of register 175 are the output values of counter 275. Bit 8 of register 175 is a parity bit. Input line 513 of register 175 represents a status bit. That of twenty-four bits existing status word is sent by encoding one bit in chronological order with each data word will.

Unit 280 is a logic tree connected to the output lines of counter 275. The unit 280 is used together with the logic circuits 281, 282, 283 and 284 of the generation of a parity bit with the value "1" on output line 285 when an even number of ⁿ 1's "in all the internal bits between the input line 285 for Register 175 and the

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Distance bit is present in register 176. The gain control states on lines A "to D are generated by a gain control circuit 300 according to Pig. 7. This circuit samples the states of the two most significant bits of the digital data in counter 275 via NOR circuit 301. The two bits are sampled and if one has the binary value "1", then the circuit .300 causes the gain to be reduced. The binary values "0" at both inputs of the NOR circuit 301 indicate that the signal level applied to the gain-controlled amplifier section 210 to 214 is lower than a quarter The function of circuit 300 is to adjust the gain of amplifiers 210-214 so that the signal level is set at a level slightly below the quarter range point, and circuit 300 operates to provide rapid compression the gain, however, allows a controlled, longer gain period will. This is achieved using a counter 302. The counter 302 is connected via a line 303, which leads to an input of a NAND circuit 304, rbindung with the NOR circuit 301 in V _e. The line 303 is connected to an input of a NAND circuit 307 via an inverter 305 and a NAND circuit 306. The output of the NAND circuit 307 is connected to the clock input of the counter 302. The output of the NAND circuit 304 is connected to the reset input of the counter 302. The second input of the NAND circuit 307 is connected to the Q _Q output of the counter 302 via an inverter 310. The output of the NAND circuit 307 is also connected to the clock input of an up / down = via a line 311 ZMhlers 320 connected. The line 303 from the NOR circuit 301 is connected to the At & itrSrts / Atward control terminal of the counter 320.

Connections 321 of the counter 320 are optional

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connected to logic circuits 281 and 282 of the parity generator. The three least significant Lines 322 representing bits of counter 320 are connected to the three gain bit terminals of the Shift register 176 connected to keep them together with the digital code group of the seismic data sent from the data acquisition unit DAU to a main station will.

A NOR circuit 323 is on all four output lines 321 is connected and its output is connected to an input of a NOR circuit 324. The second entrance the NOR circuit 324 is output from a NAND circuit 325 supplied, which is connected at its input to the four lines 321, while its output via leads a negator. The output of NOR circuit 324 is connected to one input of a NOR circuit 326, the output of which is connected to the enable input of the counter 320 is. The second input of the NOR circuit 326 is with the line 303 and connected to the second input of the NAND circuit 304 and to an inverter 305. The second inputs of NAND circuits 304 and 306 are supplied by control line 327. The control line 327 comes from a port switching unit to be described.

Lines 321 are common to the gain control lines A to D, which lead to the gain control inputs of the amplifier section 210 to 214.

The signal on line 303 coming from the NAND circuit 301 leads to the up / down terminal of counter 320, determines whether the counter counts up or down, or doesn't count. When the signal on line 303 has a

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low value has that I _m pulses reach the Steuerleitufig 327 directly through the IiAND-Sehaltungen 306 and 307 to the clock input of the counter 320. When the signal on line 303 has a high value, then the pulses on the control line 327 are represented by the ! AND circuit 304 led to counter 302. The Z <= counter 302 then outputs an OFF transition signal a "b, which passes through the NAND circuit 307 to the clock input line 311 of the counter 320th An output pulse occurs at the counter 302 only when a predetermined A _n number of counts in Counter 302 has been reached, which means that it operates as a divider. In one embodiment of the arrangement described here, the counter 302 is a counter which emits an output signal for every 28 input pulses; it is therefore a divider with the division factor 128. This counter therefore determines the relationship between the gain compression rate and the gain expansion rate. The gain compression rate can be essentially instantaneous. The gain expansion rate is 1/128 the compression rate. In a typical arrangement, the compression rate was on the order of 24,000 dB per second, and the strain rate had a W _e rt on the order of 186 dB per second.

In the port circuit arrangement for controlling the system described so far, clock pulses on the line 266 made use of it. The clock pulses are entered with a frequency that in the present example 2.560 MHz and is preferably derived from a precisely controlled crystal oscillator.

The line 266 is connected to the clock input of the divider 266

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which consists of a 12-bit binary divider /. Line 266 is also connected to an input of NAND circuit 264.

The divider 268 provides output signals, four of which are used in the present port switching arrangement will. The first output signal appears on the line 269; it has a frequency of 160 kHz. The second output appears on line 401; it has a Frequency of 10 kHz. A third output appears on line 402 at a frequency of 5 kHz. the fourth output line 206 carries an output signal with it a frequency of 2.5 kHz. As mentioned above, leads the line 206 to the control input of the chopper 201. Thus, the voltage on the signal line 200 j'eT / eils sampled after 400 microseconds. Line 206 is also connected to one input of a NAND circuit 403. The second input of NAND circuit 403 is across the line 404 is connected to the flip-flop 270. The 10 kHz and 5 kHz lines 401 and 402, respectively, are marked with connected to the clock input or to the D input of the flip-flop 270, so that on the line 404 a pulse train which is phase shifted from the 5 kHz signal on line 402, but the same duration and has the same repetition frequency.

The output of the NAND circuit 403 is via a sampling and memory control line 230 connected to the clock input of a D flip-flop, which is a monostable multivibrator 405 is operated. Line 230 is also connected to the control terminal of switch 228 in the sample and memory circuit connected. It is also connected to the clock input of flip-flop 271. Finally she's over an inverter with the clock input of a flip-flop 406

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connected, which is operated as a monostable multivibrator.

The QA _u sgang of flip-flop 405 is connected via line 407 to one input of a NOR circuit 408th The output of the BOR circuit 408 is connected to the preset input of the flip-flop 271 via the line 409. The second input of the NOR circuit 408 is fed via the line 410 from the ^ output of a flip-flop. A line 412 leads to the preset input of the flip-flop 411? it is connected via line 412 with the (^ Q output of a flip-flop 413th D _e r Q output of flip-flop 271 is connected via line 414 to a second input of the HOR circuit 264th

The ^ output of the flip-flop 271 is with the help of the line 415 is connected to an input of a UOR circuit 416. The second input of the NOR circuit 416 is connected to the Q output of the flip-flop 406 via the line 417 fed.

The third input of the NOR circuit 264 is via the Line 263 supplied from the Q output of flip-flop 261. The line coming from the (^ output of flip-flop 415 is connected to the clock input of the flip-flop 261 and to the reset terminal of the counter 275.

How it works - Figures 5 to 8

The mode of operation of the incremental arrangement can be found on "bast with reference to the timing diagram of FIG to understand.

B®2? SignalT @ rlauf A1 gives channel synchronization impulses

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that are sent out within each data sampling interval. Channel synchronization pulses are thus in a sequence of 80 microseconds each "with a A "btas would occur in 2 milliseconds or in a sequence 160 microseconds "at a sample rate of 4 milliseconds repeated. In a system with twenty-four channels, the addressed channel responds in the interval between each pair of channel sync pulses with one seventeen bit word 25 represented by the data stored in shift registers 175 and 176 will.

The waveform A2 indicates a complete channel scan cycle in which every twenty-fifth channel synchronization pulse consists of two pulse groups 26 and 29. This double pulse transmission is a data frame synchronization. In each data frame, that is, between pulse groups 26 and 29, there are twenty-five channels scanned, that is, the twenty-four channels are being scanned is sampled for the seismic data, and an IT slave station is sampled for the data representing the distance between the main station, the lifting station and a data acquisition unit represent.

The signal course A3 gib-fc on a compressed time scale three pulse groups after every twenty-fifth Data frames are sent out. This gives a distance synchronization. That means that for every data frame only one distance word for a data acquisition unit DAU can be detected. Thus, all distance data are recorded requires twenty-four frames of data for every twenty-four data acquisition units. The distance fixest follow is used to synchronize the distance data. '

In Fig. 3, the pulse-shaped waveform A4 is a

509821/066 5

Square-wave clock pulse with a repetition frequency of 10 kHz, which is transmitted on line 401 from Pig. 7 occurs. The pulse waveform B shows the occurring on the line 402 of FIG. 7 5 kHz square pulse train "The pulse waveform C shows the Q-output of the flip-flops 27O _9, on the line 404 is present ο of the pulse waveform D is provided on the line 206 appearing control voltage, which has a repetition frequency of 2 ₉ 5 kHz and is fed to the chopper 201 «,

The pulse course E has a duration of 300 microseconds a high signal value followed by a low signal throw for 100 microseconds. The momentum ^ - course E 'gives the output line 230 (Fig. 7 and 8) the sampling and storage control voltage occurring in the UAITD circuit 403 an®

The pulse course F "preferably consists of pulses with a duration on the order of 1 microsecond immediately following the end of each 100 microsecond period of the Follow pulse curve E with a low signal value. This pulse train appears at the Q output of the flip-flop 404, and it is used to reset the A / D conversion line 263, so that the signal on line 263 goes high. If on line 263 a high Signal value is present, then there is also a high signal value on line 414, whereupon the clock pulses with the Frequency of 2.560 MHz on line 266 through NAND circuit 264 and through inverter 421 to the clock input of the counter 275 arrive. The line 277 is connected to the reset input of the counter 275, so that this when the NAND circuit 264 is triggered, reset whereby a new sequence of pulses in counter 275 begins.

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It should be noted that the signal curves A to j F illustrated operations in the arrangement described here run freely.

The waveform G shows the voltage at the output of NAND-S _c attitude 110 of Pig. 5. When this voltage goes low, it indicates that circuitry on line 100 has received and identified a sync pulse group from the master station. It should be noted that the output of the NAND circuit 110 is connected to the clock input of the flip-flop 413. The output of the flip-flop 413 is connected to the input of the flip-flop 411 via the line 412. The pulse on line 412 which is indicated by the waveform N, solves the synchronization for holding the A / DU _m-setting and storing the result in registers 175 and 176 from. Thus, when the signal profile G is received, the free-running arrangement shown by means of the signal profiles A to F is permanently synchronized with the transmission from the main station. The clock control signal H normally has a low signal level, and it picks up once every 2 milliseconds in accordance with the waveform F (pulses f 1, f2, f3, f4,. "...) and with the synchronization control signal 0, that is, when the signal level is low of the synchronization control signal 0. The signal Q is generated from the pulse waveform N and it appears on the line 410. The signal H appears at the output of the flip-flop 271, and it is based on the voltage on the line 409 set a high signal value.

The signal H maintains a high signal value for a period of time which varies as a function of the gain range is. In particular, the signal H remains at the high signal level until the two input signals of the NOR circuit 301

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assume the value zero.

Waveform J represents the voltage on line 422 that originates from the output of inverter 305. When the J signal from the inverter 305 is high at the time the E signal is high Assumes signal value, then "the signal curve -I remains at a high signal value» If, however, the for the pulse f4 of the signal curve F is present, in which the signal curve J has a, low signal value then the signal I is terminated as in step i2. The transition to the low signal value of the SignalVerlauf I indicates that the distance enhancement is ^ processes have ended and that the amplitude of the seismic signal applied by line 200 is less than a quarter of the scale range of the gain controlled amplifier.

The waveform K shows the voltage on line 263. This is a free running sgangssignal _u A. The length of the positive pulse in the signal curve K indicates the time for the duration of which the voltage on the capacitor 251 exceeds the signal voltage on the sampling and storage capacitor 229.

The waveform L represents the output signal of the NAND circuit 264, which is actually fed to the counter 275 for the period of time in which the waveform K has a high signal value. In Pig. 3 two groups L ^f and L ¹ 'are shown. In the circuit of Pig. 5 to 8, up to four such groups of clock pulses L ¹ , L ' ^{1 can be applied} to the counter 275. The A / D conversion is repeated up to four times as long as the distance amplifying operation is not completed _s, this means' to the two

509821/0665

Input signals of the HOR-S _c attitude 301 have the value zero.

The signal curve M shows the voltage on line 327, which proceeds from the KOR circuit 416. The pulses m1 and m2 are fed to the up / down counter 320, and they are used in gain adjustment, such as has been described above. The signal curve M is the same above as the signal curve 0 has been described.

The "signal curve P indicates the voltage on the line 417 from flip-flop 406 on; it is used to generate the signal curve M. That through the waveform P specified signal runs freely.

The analog portion of the circuit of Figures 5 through 8, particularly the chopper and gain control amplifiers contain circuit elements that operate between voltage levels - V, ground and + V. The logic diagram in the switching arrangement and the interrogation sections of the system only work between the voltage values - V and + V; they do not have mass as a reference.

In Fig. 10 is a circuit for that shown in Figs Surface acoustic wave devices (SWD) used. It becomes the together with the surface acoustic wave device 31 of Fig. 2 will be described. The circuit shown in Fig. 10 includes the pulse generator 22, in which a switching transistor 430 is connected to respond to an enable condition, that of the terminal 431 is fed when the control terminal 432 receives a transmission pulse. The transistors 433 and 434 serve to to feed the pulse generated in this way to a memory switching diode 435 and then to a coil 436. Everyone to the The output pulse applied to terminal 432 causes the build-up of a current in coil 436 to the memory switching diode

509821/0665

locks. The resulting inductive jump is then fed to the input matching circuit of the surface acoustic wave device 31 via the conductor 437. The input matching circuit contains an autotransformer 438 and a series coil 439 ₉ which leads to the terminals of the surface acoustic wave device 31 «. The output terminals of the surface acoustic wave device 31 lead via an autotransformer 440 to the input terminal 441 of a preamplifier.

When the memory switching diode blocks the current, cause the inductive jump fed to the surface acoustic wave device 31, the matching circuit with the autotransformer 438, the coil 439 and the components of the surface acoustic wave device to vibrate, causing several cycles a high-frequency output signal to terminal 441. In the embodiment described here, the surface acoustic wave device 31 and the associated circuit parts are tuned so that the system oscillates at a frequency of 168 MHz, so that the input line 441 several Cycles are fed. Surface acoustic wave device 31 is preferably a 100-bit matched phase shift filter with sixteen cycles per bit and with a center frequency of 168 MHz. The general structure of such devices is known. The surface acoustic wave device 31 consists of three matched transducers, which are deposited by deposition formed by aluminum electrodes in a creamy interlocking pattern on the surface of a quartz rod are. Transmit and receive input transducers at the ends of the rod consist of a pattern of eight interlocking linger pairs (fifteen interactions). A middle converter insists on the rod with a large output signal from a hundred groups of patterns, each with two pairs of fingers (three interactions), which are longitudinally opposite Sides of the quartz rod through long connecting tabs are connected in parallel. The problems between

509821 / oees

seeing the groups are equal to that of an acoustic Wave in the quartz rod in a path running through a bit period.

In such an arrangement, the input and the output of the surface acoustic wave device 31 are matched to 50 ohms with the aid of the autotransformers 438 and 440. The surface acoustic wave device 31 has an impedance of 2 Kib-ohms with a parallel capacitance of 3 pP for the transmit and receive transducers and an impedance of 258 ohms with a parallel capacitance of 43.5 pF for the output transducer when installed and attached. The coil 439, which is necessary so with the three p3? a resonance frequency of 168 MHz is created, has an inductance value of 270 nH. The inductance of the coil necessary to achieve resonance with a capacitor of 43.5 pi ¹

440 is 20.4 nH.

The preamplifier connected to input terminal 441 32 is a two-stage amplifier for that of the surface acoustic wave device 31 generated signal with spread spectrum from a level of -34 dBm to a level of OjO dBm is increased. The preamplifier 32 includes transistors 442 and 443. Into the circuit of the transistor 443 two blanking lines 444 and 445 are switched on, so that the operation of the output trans is tors 443 except during the duration of desired output signals from the surface acoustic wave device 31 can be blocked. This blanking also blocks the oscillation of the transmitter that is connected to the output terminal 446 connected amplifier circuits are harmful could be.

When the surface acoustic wave device .31 is pulse-fed appears preferably at the output terminal

441 only one of three resulting products. The three

509821/0685

Products contain a desired spectrum signal that is cross-coupled from the. Input pulse originates from the desired Output signal leads, as well as a signal generated by reflection of the acoustic wave from the end of the rod is generated and follows the desired signal. The blanking circuit only allows the desired signal, the Preamp 32 to cycle through. Thus, the blanking line 444 can be the base of the output transistor 443 of the preamplifier short-circuit to ground. Me voltage on line 445 keeps the correct emitter bias on Transistor 443 upright so that it can be turned back on quickly.

The circuit with the transistors 447 to 453 is used to supply the lines 444 and 445 with the blanking control pulses. The input signal is derived from terminal 432 via line 454. The transistors 447 and 448 form a monostable multivibrator which feeds a circuit of the same type via the line 455. The output signal of the second monostable multivibrator is fed to the base of the transistor 451, which is used to supply the blanking line 444 via the transistor 452 and the blanking line .455 via the transistor 453. The transistor 443 is switched on approximately one microsecond after the transmission pulse appearing on the line 454. It is switched off again after a time interval that depends on the time constants of the circuit containing the two flip-flops. During the period in which the transistor 443 is blocked, the voltage state on the line 445 controls the bias of the transistor 443 so that it can be switched on again quickly.

The power amplifier 33 of Fig * 2 has two units, namely a power amplifier with a power of 0.8 watts, to which a power amplifier with a

S09821 / OSSS

Performance of 32 Y / att follows. The RF power amplifier 33, the transmit / receive switch 34 and the antenna 35 are constructed according to the construction principles known in high frequency.

The surface acoustic wave device 38 in the receiving section of FIG. 2 is constructed in the same way as the surface acoustic wave device 31. In the transmitter section. Input and output ports of the surface acoustic wave device 38 are connected to the The output of the RF amplifier or the input of the converter 39 is adapted. In this embodiment the oscillator is there 40 emits an output signal with a frequency of 92 MHz, thus an output signal with a frequency at the converter of 76 MHz is generated, the .. then to the IF amplifier 41 and reaches the envelope detector 42.

Referring to Figure 2, pulses produce on the scan rate line 21a output pulses from the interval counter 21, which are fed to the pulse generator 22 every two milliseconds. The same pulses are transmitted via line 23 supplied to the counter 24, which via the line 24a data frame pulses with 1/24 of the repetition frequency of the signals on line 23 delivers. The counter 24 also delivers on the Line 24b is range data pulses at 1/24 of the repetition rate representing the pulses on line 24a. In response to every data frame pulse On line 24b, pulse generator 22 applies two pulses, such as pulses 26 of FIG. 3, to the surface acoustic wave device 31 at. The generator 22 conducts the surface acoustic wave device as a function of each pulse on the line 24a 31 three pulses 30 according to FIG. The applied to the surface acoustic wave device 31 Pulse is preferably a uanosecond pulse with a Duration on the order of 0.1 microseconds and it has a square envelope with respect to oscillation at 168 MHz. The output pulse of the surface acoustic wave device

509821/0665

31 then has a bandwidth in the order of magnitude of 10 MHz with a duration of 5 microseconds.

The two members of impulse group 26 and the. three members of impulse group 30 from Pig. 3 are on the order of 10 microseconds between their centers.

In Pig. 11 is the slave station 15 with an antenna 500 shown ^ via a transmit / receive switch 501 and a receiver 502 is connected to a first surface acoustic wave device 503. The surface acoustic wave device 503 is encoded to have the same code as the surface acoustic wave device 68th Pig. 4 in Has receiver section of the data acquisition unit. The output of the surface acoustic wave device 503 is connected to a TOTD gate 504 and to a counter 505. When a predetermined preset count occurs in counter 505 when counting pulses of the surface acoustic wave device 503 releases the UUD circuit 504 off the operation of a counter 506, which is fed with clock pulses from a clock unit 507. The outcome of the Receiver 502 is also connected to a second surface acoustic wave device 508. The surface acoustic wave device 508 is coded in the same way as the surface acoustic wave device 38 from Pig. 2. That means that in the surface acoustic wave device 503 contains code 1. The code 2 is contained in the surface acoustic wave device 508. The secondary station thus receives a pulse which it applies to the counter 506 via the line 509, so that this when receiving a transmission from a data acquisition unit the next following the transmission from the main station, which is the counter starts. In the counter 506, a counter reading is thus held that shows the difference in transit time between the transmission

509821/0665

transmission path 16 plus the transmission path 17 and the transmission path 18 by Pig. 1 plus a time constant corresponding to the response time of a data acquisition unit represents.

The counter reading stored in counter 506 is then displayed using of a load command on line 531 to a status shift register 512 transferred. The surface acoustic wave device 503 is also available with a lift station address decoder and control unit 515 connected together with the output of clock unit 507 via the UUD circuit 516 is connected to the clock input of the status shift register 512. The status shift register 512 is then connected via its output line 517 to a transmitter unit 518, which by means of the transmit / receive switch 501 is connected to the antenna 500. The lift station address decoding and control unit 515 is essentially the same as the decoding control unit with the non-equivalence splits 131 to 138 of Pig. 6 so that the main station the Slave station with regard to the status in the status shift register 512 can query recorded data.

The slave station contains a status sensor 520, which with the help of code lines 521 with the status shift register 512 is connected, so that in this register 512 such data that can be saved in addition to 'the in Counter 506 generated delay time difference data is desired. The time control at the main station based on the Results in distance bits in shift register 176 of FIG a measure of the length of the transmission path 16 from Pig. 1. A shift register comparable to status shift register 512 in each data acquisition unit is in Pig. 8 shown in the form of registers 512a, 512b and 512c, there are three contains separate shift registers which are connected in cascade.

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. - 38 -

The registers 512a, 512b, and 512c of FIG. 8 are supplied with status data from a unit 514, and this data is then passed to shift register 176 the status bit line 513 is supplied. The data in registers 512a, 512b and 512c of FIG. 8 preferably contain Status information such as the altitude of the data acquisition unit, the gain setting of the preamplifier, the setting of the filter for the separation of low frequencies, the setting of the Notch filter, the setting of the filter to cut off high frequencies, a low battery charge, the State of tension, etc.

Each sensing and coding unit 514 may contain conventional barometric pressure responsive device, which provides a display of the altitude of the data acquisition units involved. The query the data acquisition unit including its status register gives an indication of its altitude.

In the embodiment described herein, the arrangement includes well known and available from manufacturers Components according to the following list: Flip-Flops 101,105, 11Ob, RCA, Box 3200, Somerville, 122,124,170,261,270,271, N.J. 08876, D-Flip-Flop, 405,406,411 "Catalog No. CD-4013 A

Counter 107 RCA, decadic counter,

Catalog no. CD-4017 A

Counters 113, 320 RCA, Decadal Counters,

Catalog no. CD-4029 A

Counter 126, 177 RCA, binary counter, catalog

Ir. CD-4024 A

Flip-Flop 180 RCA, catalog no. CD 4027 A

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Shift registers 175, 176, 512a, 512b, 512c RCA, 8-bit asynchronous shift registers with parallel entry and serial edition, catalog Mr. CD-4021A

Parity generator 280

Counter 268, 275 Motorola Semiconductor Products, Inc., Box 20912, Phoenix, Ariz. 85036, Catalog no. MC-14531

ECA, meters with catalog no. CD-4040 A

Counter 302

ECA, 14-stage ripple counter, Catalog no. CD-4020 A

Switch 201, 221 ECA, triple two-channel switch, Catalog no. CD-4053

Computational amplifier 202, 203, 204, 210, 211, 212, 213, 214, 240

Eechen amplifier 242, 246, 253

Eechen amplifier 244 Pairchild Semiconductors, 313 Fairehild Dr, Mountain-View, California, Catalog No. U5B7776393

Siliconix, Inc., Santa Clara, California, Catalog No. 1144AP

Fairchild, catalog no. υ5ίΤ715393

Eechen amplifier 254 Fairchild, catalog no. U5B774O393

Switch 243, 245, ECA switch, catalog number, CD-4016

Resistor 227 Capacitor 229 1.2 kilo ohms
0.1 microfarads

A description of the S _c hußsteuerung and Zeitunter-

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Refraction transmission for the shot point ten is found in the Operation and Maintenance Manual for the Dinoseis seismic generator from Texas Instruments Incorporated, dated February 1966, reprinted July 1970.

Thus, with the aid of the arrangement according to the invention, seismic waves are generated at one shot point and at several Detector stations scanned. Interrogation pulses with spread are sent from an RF main station to the detector station Spectrum sent out. In response to this, coded pulses with spread spectrum are sent back to the main station, the samples correspond to the seismic waves; the impulses are then multi- ' plexed. The respective seismic signals are sampled at regular seismic data sampling intervals, the duration of which are selected based on the frequencies of the signals, so that the sample values reflect the time-amplitude changes of the signals. During normal mining operations the seismic data sampling intervals are typically 0.002 to 0.004 seconds. For the purpose of this present Let the expression "uniform seismic data sampling intervals" be used to describe intervals in the above To understand the order of magnitude. For signals with higher frequencies, shorter sampling intervals are desirable. For signals with lower frequencies, longer seismic data sampling intervals can be tolerated that the Still reflect time-amplitude changes in seismic signals with sufficient detail.

The invention has been described here in connection with specific exemplary embodiments, but is for the A person skilled in the art recognizes that within the scope of the invention there are still further modification possibilities.

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Claims (5)

Claims 1J Seismic Exploration Method, "where at Seismic waves are generated at a shot point, which are then transmitted to several seismic detector stations be determined, characterized in that from a main RF station, from the detector stations is removed, HP transmissions of digital code groups from all detector stations in a predetermined sequence in real time, with the digital code groups corresponding to the amplitudes of the detector stations correspond to detected seismic waves sampled at regular data sampling intervals, and that the code groups received at the master station are multiplexed. 2. The method according to claim 1, characterized in that the HP transmissions from pulses with spread Spectrum exist. 3. The method according to claim 1, characterized in that the sampling intervals in the range between 0.002 and 0.008 seconds. 4. The method according to claim 1, characterized in that digital code groups from an IT slave station to the Main station are transmitted, which represent the RF delay times over paths between the stations of which at least one leads over the detector stations. 5. The method according to claim 4, characterized in that at the main station digital runtime code groups 509821/0665 245 Ί 238 generated that-with the HP removal of each detector station correspond, and that runtime code groups are generated at the main station, which the HP removal from the main station to each of the detector stations and then to the lifting station. 6. The method according to claim 1, characterized in that the digital code groups from the detector stations also contain code information about the detector altitude. 7. A method for seismic exploration, in which seismic waves are generated at a shot point, which be determined at several detector stations, characterized in that from a main station to the detector stations polling pulses with a spread spectrum are transmitted and that from the detector stations to the master station successively spread spectrum pulses are sent, the samples correspond to the seismic waves sampled after receiving an interrogation pulse from the main station will. 8. The method according to claim 7, characterized in that the interrogation pulses with uniform seismic data sampling intervals be sent out. 9. The method according to claim 7, characterized in that each detector station in each interval with the Duration between 0.002 and 0.008 seconds an interrogation pulse processed. 10. Arrangement for seismic exploration in which at Seismic waves are generated at a shot point, which are detected at several seismic detector stations 509821/0865 are characterized by an HP main station, the is attached away from the detector stations and an HP transmission of digital code groups from all detector stations in a predetermined sequence and in real time guaranteed, these code groups amplitudes of the seismic detected at the detector stations Correspond to waves occurring in uniform data sampling- * Intervals are sampled and that means for multiplexing those received at the master station Code groups are provided. 11. Arrangement according to claim 10, characterized in that that the main HP station and the seismic detector stations have RF channels with surface acoustic wave devices for generating pulse transmissions with spread Spectrum included between them. 12. Arrangement according to claim 10, characterized in that that time control devices are provided in the main station, the digital code groups from the detector stations with sampling intervals in the range of 0.002 to 0.008 seconds. 13. Arrangement according to claim 10, characterized in that that a lifting station is provided, which send digital code groups to the main station, which the HP transit times correspond on paths between the stations, at least one of which leads via the detector stations. 14. The arrangement according to claim 10, characterized in that a sensor device is provided which has a detector height code group generated, and that scanning devices at the detector stations height information in the contain digital code groups from the detector stations. 509821 / 068B 245-238 15 · Arrangement for seismic exploration with devices for generating seismic waves at a shot point and with devices for determining the resulting seismic waves at several detector stations, characterized by means for transmitting spread spectrum interrogation pulses from a master station to the detector stations and devices that depend on the interrogation pulses one after the other from the Detector stations send out spread spectrum pulses to the main station, the samples of the seismic Waves correspond to the receipt of an interrogation pulse can be scanned by the main station. 16. Arrangement according to claim 15, characterized in that that time control devices enable the transmission of the interrogation pulses at regular data sampling intervals. 17. Arrangement for seismic survey, marked by data acquisition units for acquiring seismic data at each of a plurality of detector stations, one of the master station remote from the data acquisition units, a slave stations remote from the data acquisition units and from the master station, devices for transmitting Channel sync pulses with spread spectrum from the master station, facilities in all data acquisition units for receiving and compressing the synchronization pulses, Pulse generating devices which, depending on the compressed pulses, generate enable a sampling pulse sequence, the first bit of which has a warning signal value, memory devices at the lifting station, depending on the synchronization pulses Save time-out signal that the time-out between the reception of a synchronization pulse from the master station at the slave station and the reception of the bit with the true signal value from the data acquisition unit 509821/0665 sent, and transmission facilities at the sub-station, which depends on a predetermined synchronization pulse send the timing signal from the master station to the master station. 18. Arrangement for collecting seismic data, characterized by (a) a main RF station near a seismic prospect; (b) data acquisition units, one at each of several seismic detector stations in the Ggbiet is attached and a saved, you has its own identification code (I.D.), (c) seismic detector devices so attached to the "data acquisition units." are connected to provide them with analog seismic signals corresponding to the earth's movement supply at each of the stations, (d) Devices in each of the data acquisition units which convert the analog signal into a binary one as a function of commands Convert and save code group, (e) an RF transmitter at the master station for generating these commands, with a first spectrum spreading code device each of the pulse commands is provided over an HP spectrum during the coding of its HF transmission spreads, (f) a receiver in each of the data acquisition units for receiving and initially compressing each of the commands in mirror image relation to the spreading at the main station, 509821/0 685 (g) a comparison device in each of the data acquisition units to trigger the transmission of binary seismic data code groups from a unit when a predetermined one Relationship between the identification code group for this unit and a pulse from the master station is present, (h) an HP transmitter in each of the units with a second spectrum spreading device for each pulse in the Data code group and (i) a receiver in the master station for receiving and similar compression of all pulses received by the units in mirror image relation to their spread "in the units. 19. Method of seismic exploration, "in which at one Shot point seismic waves are generated, characterized in that the amplitudes of successive samples of the seismic waves, which are generated at several detector stations at different distances from the point of fire appear after their generation, are converted into digital code groups and that the code groups from all detector stations can be transmitted sequentially and in real time to a main station via a point connection. 20. The method according to claim 19, characterized in that ^c that the digital code groups are sent from the detector stations with sampling intervals of about 4 milliseconds one after the other to the main station. 21. Method of collecting seismic data from a seismic prospect characterized by (a) being at a known location with respect to the area an IT substation is set up, 509821/0665 (Id) that at each of several unknown places in data acquisition units are set up in the area, which scan the earth's movement and convert it into a digital representation, (c) that in the data acquisition units and in the slave station a different response code group is set in each case, (d) that from a main station at a related to the Area known point periodically an HP plague signal is sent out with a spread spectrum, to the one Sequence of channel synchronization pulses follows, (e) that for each of the data acquisition units the binary representation of the earth's movement as a function of the reception each of the plague signals is recorded, (f) that at each of the data acquisition units and at the Slave station the channel synchronization pulses following each pest signal to be received and counted, (g) that the number of channel synchronization pulses in each of the data acquisition units and in the lifting station is counted, (h) that the decoded number is compared with the response code groups, (i) that depending on a match between of the decoded number and the response code groups, the plague signal as HP spread spectrum pulses from each Data acquisition unit is sent out, whereupon a similar transmission of a signal from the slave station takes place, the the transit time from the main station to the data acquisition unit, 509821/0665 to a slave station and back to the master station, and (j) that the master station receives that of the data acquisition units and responses received from the lift station to one common data channel multiplexed. 22. Method of collecting seismic data from a seismic Prospecting area, characterized (a) that data acquisition units are set up at each of several unknown locations in the area, which the Scan earth movement and convert it into a digital representation, (b) that one in each of the data acquisition units. different Response code group is set. (c) that are transmitted from a master station in a known location with respect to the area data frame pulse signals, each followed by a sequence of channel synchronization pulses, (d) that in each of the data acquisition units a digital The representation of the earth's movement in relation to the time of the reception of each of the data frame pulse signals is stored, (e) that at each of the data acquisition units the synchronization pulses to be received and counted, (f) that for each data acquisition unit the number of Synchronization pulses are decoded, (g) that the decoded number with the response code groups 509821/066 5 is compared and (h) that depending on a match between of the decoded number and the response code group, the stored signal is sent out by each data acquisition unit will.. 23. Arrangement for the acquisition of seismic data from one seismic prospect in which data acquisition units are each installed at several locations in the area, with the data acquisition units sensing the earth's movement and convert it into a digital representation, characterized by (a) Means for setting a unique identification code group in each of the data acquisition units, (b) a main station for periodic transmission of a data frame signal on the spaced apart Channel synchronization pulses follow, (<j) facilities in each of the data acquisition units for Generating the digital representation of the earth's movement as a function of the reception of each of the data frame signals, (d) facilities in each of the data acquisition units for Receiving and plaguing the number of synchronization impulses, which follow each data frame signal, (e) comparison means in each data acquisition unit to compare the number with the identification code group, (f) broadcast facilities that are dependent on a match between the identification code group and the 509821/0665 number broadcast the digital representation from each of the data acquisition units, and (g) multiplexing means in the master station for multiplexing those received from the data acquisition units Answers in a common data channel. 24. Arrangement according to claim 23, characterized in that that free-running scanning devices are provided in each data acquisition unit, which the signal amplitude of the seismic signal sample, digitally encode and a gain code group for the sample several Times in every interval between consecutive frames of data generate ignaleη. 25. The arrangement according to claim 24, characterized in that between each detector and responder one Analog signal amplifier and an analog-digital converter are inserted and that provided in the analog channel Devices for automatic gain control respond to changes in the digitally coded sample value in such a way that that the amplitude range of the signals applied to the converter is limited and a corresponding change in the gain code group caused. 26. The arrangement according to claim 23, characterized in that devices are provided with each digital Representation of earthmoving generate, store and create a digital reinforcement code group for each representation send out. 27. An arrangement according to claim 23, characterized gekeimzeichnet, that means are provided with every _s digital representation of the E _r d "bewegimg a digital code group Statue generate and send _o 509821 / OBBS 28. Arrangement according to claim 27, characterized in that that devices are provided which measure the altitude and convert it into the digital status code group. 29. Arrangement for collecting seismic data, marked by (a) a main station, (Td) Transmitting devices for transmitting a sequence of HF channel synchronization pulses with a spread spectrum between two members of a group of data frame pulses, (c) multiple seismic data acquisition units, at locations remote from the main station, (d) a counting device in each data acquisition unit, which depends on each data frame pulse train and on each channel synchronization pulse a count of the number the near sync pulses received after each data frame pulse train triggers (e) input devices on each of the data acquisition units for inputting an identification code group, (f) comparison means for comparing the output signals the payment device in each data acquisition unit with their identification code group, (g) transmission devices, which are dependent on a predetermined Relationship between the output of the counting device and the identification code group to the master station send out a digital code group that shows the instantaneous value of the seismic signal at the time of transmission represents the data frame pulse train, and 509821/066 5 (h) means in the master station for receiving and storing the code group from the data acquisition units in the order that they are stored in the units Identification code groups. 30. RF transponder device for analog signals from an amplifier with a step-shaped automatic gain control, characterized by an RF receiver with input response devices for receiving a RF transmission and a related sampling and conversion of the analog signal into a digital data code group consisting of several bits, means for converting the gain value of the amplifier into a gain code group consisting of several bits with each of the samples of the analog signal, a serial output shift register for storing the data and gain code groups, a storage device for storing an identification code group consisting of a plurality of bits, a storage device for Store a multi-bit channel sync code group and an HP sending device with a logic arrangement including a comparator for enabling an RF transmission of the data and gain code groups from the register if the identification code group and the synchronization code group match. 31. Arrangement according to claim 30, characterized in that scanning and converting devices several groups of data and gain code groups between successive ones Generate actuations of the responders and that the responders with selected code groups for each of several groups to be associated. 32. Arrangement according to claim 31, characterized in that 509821/0665 that a timing device for the sampling and conversion devices works freely and independently of the sync seode groups. 33 ·. Arrangement according to claim 31, characterized in that that code generating devices are provided for generating a status code group and that control devices part of the status code group in the shift register with the data and gain code groups for transmission together. - 34. Arrangement according to claim 33, characterized in that that means for measuring the altitude of the transponder, the means for generating the status code group contain. · 35. Arrangement for seismic surveying, characterized by (a) several data acquisition units, each with a punk responder and a seismic detector, each unit at one of a plurality of spaced apart units seismic detector stations in a seismic prospect. it is appropriate (b) a master radio station in or near the prospect and (c) Means in the data acquisition units and in the main station for interrogation and successive polling the radio transponder in real time through the main station so that these digital samples of analog signals detects and stores that are scanned by the detector stations with a fixed sampling interval, the duration of which is dependent is selected from the frequencies of the signals, whereby the sampling values the temporal amplitude changes of the signals reproduce. 509821/0665 36. Order according to. Claim 35, characterized in that that each of the seismic signals from the detector stations are digitally encoded and with A "b tag tint in the Order of magnitude of 4 milliseconds in the associated responder is stored and that counting devices are coded in the responders so that they transmit the transmission from the responders in a predetermined call sequence depending on interrogation signals from the main station release. 37 · Arrangement according to claim 35, characterized in that each responder contains free-running devices, the multiple consecutive time samples of each seismic signal within each polling interval in implement a digital code group and that transmission facilities depending on an interrogation signal from the main station, send out a sample per interrogation interval from each responder. 38. Arrangement according to claim 35, characterized in that each responder includes means which sense the seismic signal samples and convert them into a digital format at a speed which is high in comparison with the response speed, and that A _n twortgeber-Signalverstärlcungseinrichtungen are provided, which depend on successive conversions of the seismic signal samples are changed with amplitudes lying outside predetermined limits. 39. A method for seismic exploration, characterized in that that at a seismic detector station at high speed successive digital data code groups are generated, the successive time-amplitude samples of seismic waves arriving at the detector station represent that for each digital 509821/0665 Data code group a digital gain code group is generated and that in equal time intervals that comprise several of the digital code groups to one An HP pulse code group is sent to the main station, which represents one of the digital scan code groups and its associated gain code group. 40. A method for acquiring seismic data from a seismic prospect, characterized in that (a) that at each of several locations in the area data acquisition units that record the earth's movement and convert it into a digital representation Implement movement (b) that in each of the data acquisition units a '.unique Identification code group is entered, (c) that a data frame signal is periodically received from a master station is sent out, followed by channel synchronization pulses that are spaced apart from each other, (d) that in each of the data acquisition units the digital Representation of the earth's movement is generated depending on the reception of each of the data frame signals, (e) that in each data acquisition unit the on each Receive data frame signal following synchronization pulses and be determined in their number, (f) that, for each D _a tenerfassungseinheit the number is compared with the identification code groups, (g) that the digital representation of the earth's movement is dependent on a match between the identification 5 0 9821/0665 code group and the number of each data acquisition unit is sent out and (h) that the data coming from the data acquisition units responses received from the master station are multiplexed into a common data channel. 41. Arrangement for the continuous acquisition of analog data, marked by (a) a main station, (b) means see Zvi for transmitting a sequence of RF channel synchronization pulses spread spectrum each pair of members of a G _r oup data frame pulses, (c) multiple data acquisition units on from the main station remote places, (d) counting devices in each of the data acquisition units, which depends on each data frame pulse train and each channel synchronization pulse a count of Number of received after each data frame pulse train Trigger channel synchronization pulses, (e) means in each of the data acquisition units for entering an identification code group, (f) comparison means for comparing the output signal the counting devices on each data acquisition unit with their identification code group, (g) transmission devices, which are dependent on a predetermined Relationship between the output of the counting device and the identification code group to the main 509821/0665 sending station a digital code group that _u represents the A genblickswert of the seismic signal at the time of transmission of the data frame pulse train and (h) facilities in-the main station for receiving and Storing the code group from the data acquisition units in the order of those stored in the units Identification code groups. 5 0 9821/0665