SU851305A1 - Device for geoelectric prospecting - Google Patents

Description

The invention relates to geological exploration of ore deposits and can be used to identify signals that are a superposition of components of the same class. Geoelectromagnetic devices are known, based on constructing a useful signal and measuring received pulses, comprising a sensor, an input key, a strobe unit, a control unit, and a pulse recorder 1. The common drawbacks of such devices are low resolution, as well as low performance, associated with the need for a large number of additional calculations and growth using the pallet method. It is also known a device comprising in the measuring part a magnetic sensor, a measuring channel, an analog-digital converter, a computing device, a recorder, a synchronization and control unit, and a sensor of a reference signal (2). However, the resolution of the measurements performed by this device is low. It is also known a device for inductive electrical prospecting, comprising in the measuring part a magnetic induction sensor, an input key, a matched filter, a gating key, an integrator, and a recording device. With this device, the influence of fluctuation and coherent interference from surface deposits is reduced by introducing a filter matched in shape with the response of the geological object 31 under study. The disadvantages of this device are low resolution when separating signals from ore bodies, especially in areas with complex geoelectrical section, due to the fact that the matched filter does not allow to separate the signals of the same structure, as well as low performance and multichannel st in his execution. The purpose of the invention is to increase the productivity of exploration and resolution of the device. The goal is achieved in that a known device comprising a serially connected receiving sensor, an input key, a matched filter, a multiplier, an analog-to-digital converter, a computing device, a recorder, as well as a reference signal sensor and a control circuit connected to the input key, the computing device and an analog-digital converter, an exponentially increasing voltage driver, connected between the control circuit and a multiplier, is introduced, and a reference sensor is connected to the signal input of the computing device. In this case, the computing device contains a direct connected Fourier analyzer of a dividing unit and an inverse Fourier analyzer connected in series, the input of a direct Fourier analyzer is connected to the output of an analog-digital converter, the output of the inverse Fourier analyzer is connected to a recorder, and two inputs of the division unit with a control circuit and a reference signal sensor, respectively .

FIG. 1 shows a schematic diagram of the proposed device; in fig. 2 - stress diagrams, explaining the principle of its operation.

The device contains induction sensor 1, input key 2, matched filter 3, multiplier 4, exponentially increasing voltage shaper 5, analog-digital converter 6, computing device 7, forward Fourier analyzer 8, dividing unit 9, reference sensor 10 , reverse analysis of Fourier pp 11, control D2 and recorder 13,

The principle of operation of the device for geoelectromagnetic exploration is based on decomposing the components of the signal-response (transient) components in an anomalous parameter. In this case, the components in the superposition signal are assumed to be identical in structure with the useful signal from the ore anomaly, since fluctuation and coherent interference are suppressed by a matched filter that maximizes the signal-to-interference ratio with respect to random fluctuation and coherent interference, without changing the nature of the signals themselves , but only introduces a distortion, consisting in their uneven amplification.

The device works as follows.

The transient signal e (t) is complicated by interference (Fig. 2a) from the output of receiving sensor 1, via switch 2 is fed to the input of filter 3, which attenuates the influence of fluctuation and coherent interference (Fig. 2b) and is fed to one of inputs multiplier 4, the second input

which is supplied with an exponential increasing voltage (Fig. 2c) from the output of shaper 5, and the moment of unlocking the key 2 and the beginning of the formation of voltage U exp (x) by the shaper 5 are determined by the signals of the first and second outputs of the control circuit 12. The multiplied signal e (t) - exp (x) (Fig. 2 g) from the output of multiplier 4 is fed to the input of the analog-to-digital converter 6,

0 15 20 25 which quantizes the incoming signal through exponentially increasing time points, triggers clocking pulses (Fig. 2e) from the third output of control circuit 12, which ensures maximum removal to the formation from the most informative initial part of the transient process. The samples of the converter are fed to the Fourier analyzer 8, which over time X computes the Fourier coefficients of the process under study, for example, using the Fast Fourier Transform (FFT) method.

Then a pulse (Fig. 2e) from the fourth output of circuit 12 starts block 9, in which the current spectrum is divided by the Fourier spectrum of the reference signal stored by S in the operational memory of sensor 10 and the result of the division is transmitted to the reverse analyzer registers 11, which performs the reverse Fourier transform operation. For a time equal to twice; 1, at the time of calculating the Fourier coefficients, and the time required for performing the spectral division operation (Co-), the generalized transient spectrum (Fig. 2 g) is determined by the anomalous parameter. The resulting spectrum is output to the recorder 13, for which an oscilloscope, a digital printer or a recorder can be used.

The signal e (t) at the output of the filter

5 50 55 can be represented as

e (t) -Mc (c) Mn.2 (n ... t), W

where) is deterministic, integrable in a square

a function defining the structure of both the wanted signal and the interference;

Y.Np ,, c.P ni-ffecSMn "tude coefficients and

signal and interference information parameters. For a conducting ball anomaly, the function Z (ctt) can be written

0 65

2 (061 :,) 6otZ. (tbrr,) 2a (; t, O 4-fci, T, (2) m l

then the expression (1).

e (t)) (3)

And 1 according to the Laplace integral equation e (t) | z (ott) u (ot) dot Tet, 4 where and () is the generalized spectrum of the sum signal e (t) with respect to the anomalous parameterC-. Expression (4) is transformed in the convolution type equation E (x) JU (y) Z (xy) dy U (x) Z (and E (x) (x) exp (x) and (x) (-x) Z (x) Z exp (x)) exp (x) Therefore, according to expression (5), the signal e (t) decomposes into components of the form u (x) (E (x)} / F (Z (x}) 1 , (6.) where F is the operator of the Fur transform and (x) and (sb) exp (x) is the signal spectrum e (t); (ct) is the parameter. Thus, the proposed device allows to obtain at the output the generalized spectrum of the studied of the process according to the anomalous parameter L. The device solves the problem of increasing the resolution, and the data is interpreted in it automatically in the form of a generalized spectrum of the anomalous parameter, which, in turn, ensures the operability of the processing of measurement results.In the proposed device, the decomposition of the signal into its constituent components is represented as a generalized spectrum that determines c per measurement, which provides an increase in productivity. Moreover, the device is made single-channel, and its use does not require knowledge of a priori information about the magnitude of the anomalous parameter. Neo-SRO Formula 1. Geoelectromagnetic device containing serially connected receiving sensor, input key, matched filter, multiplier, analog-to-digital converter, computing device, recorder, as well as a reference signal sensor and control circuit connected to the input key, computing device and analog A digital converter, characterized in that, in order to increase the resolution and measurement performance, it is included in it between the control circuit and the multiplier an exponentially increasing voltage driver, and a reference signal sensor connected to the second signal input of the computing device. 2. A device according to claim 1, characterized in that the computing device comprises a sequentially connected direct Fourier analyzer, a division unit and a reverse Fourier analyzer, a direct analyzer input, Fourier is connected to the output of the analog-digital converter, the output of the reverse Fourier analyzer with a recorder, and the two other inputs of the dividing unit are with a control circuit and a reference signal sensor, respectively. Sources of information taken into account in the examination 1. A guide for the application of the method of transients in ore geophysics. Ed. F.M. Kamenetsky. L., Nedra, 1976, p. 53-67, 2. Canadian Patent 1007297, cl. 324-7, pub. 1977. 3. The author's certificate of the USSR 379903, cl. G 01 V 3/12, 1973 (pgtototip),

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Claims (2)

' Claim 1. A device for geoelectrical exploration, containing serially connected receiving sensor, input key, matched filter, multiplier, analog-to-digital converter, computing device, recorder, as well as a reference signal sensor and a control circuit connected to the input key, computing device, and analog-to-digital a converter, characterized in that, in order to increase the resolution and measurement performance, an exponential driver is included in it between the control circuit and the multiplier ialno-increasing voltage, as the reference signal sensor is connected to the second signal input Tel'nykh device. 2. The device according to π. 1, which consists in the fact that the body device contains a direct Fourier analyzer, a division unit and an inverse Fourier analyzer in series, the input of a direct Fourier analyzer is connected to the output of an analog-to-digital converter, the output of the inverse Fourier analyzer with a recorder / and the other two inputs of the division unit are a control circuit and a reference signal sensor, respectively.