CN102590869B - Artificial field source frequency domain electrical prospecting method and prospecting system - Google Patents
Artificial field source frequency domain electrical prospecting method and prospecting system Download PDFInfo
- Publication number
- CN102590869B CN102590869B CN201210073322XA CN201210073322A CN102590869B CN 102590869 B CN102590869 B CN 102590869B CN 201210073322X A CN201210073322X A CN 201210073322XA CN 201210073322 A CN201210073322 A CN 201210073322A CN 102590869 B CN102590869 B CN 102590869B
- Authority
- CN
- China
- Prior art keywords
- signal
- frequency
- circuit
- waveform
- random
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Abstract
Provided are an artificial field source frequency domain electrical prospecting method and a prospecting system. A series of waveform current signals fed into the underground serve as artificial excitation sources, the frequency of the waveform current signals changes randomly, and the randomness of the frequency change of the waveform current signals is similar to the randomness of white noise. Simultaneously, waveforms of sent signals and waveforms of received signals are recorded synchronously. According to the principle of signal correlation, interference signals with correlation of the sent signals and the received signals as zero can be removed by means of the correlation of the sent signals and the received signals, information required by geological prospecting can be obtained, and the signal-to-noise ratio of geological prospecting signals and the resolution ratio of the geological prospecting are improved. The prospecting system applying the prospecting method mainly comprises a transmitter and a receiver, wherein the transmitter is used for transmitting random square-wave or bell-wave signals within a whole preset frequency range by one time, the receiver is used for receiving the random square-wave or bell-wave signals with geoelectric information transmitted by the transmitter, and a global position system (GPS) is utilized to perform synchronous control between the transmitter and the receiver. The artificial field source frequency domain electrical prospecting method and the prospecting system are suitable for prospecting of China's multiple mountain mineral deposits.
Description
Technical field
The present invention relates to a kind of exploration geophysics method, particularly a kind of artificial random field source frequency domain electrical prospecting method and detection system.
Background technology
Frequency domain electro-prospecting is explored as one of important means of geologic prospecting, mainly studies the variation of the earth complex apparent resistivity with the signal frequency, and the ultimate principle of its depth measurement can be summed up as electromagnetic " kelvin effect " simply.When electromagnetic wave can be with to some extent through the ground telecommunications breath on stratum in underground when transmission, and the electromagnetic wave of different frequency is different in the degree of depth of underground propagation, and the detection stratum that frequency is higher is more shallow, and the detection stratum that frequency is lower is darker.Frequency domain electro-prospecting is having application very widely aspect the resource explorations such as the underground metal mineral reserves of searching, distribution of water resources, coal, oil gas.Frequency domain electro-prospecting relatively more commonly used mainly contains at present: frequency variation method, odd harmonic method, double frequency current method, controllable source the earth audio frequency method (CSAMT), frequency sounding method, a
nSequence pseudo random signal electrical method etc.What at present the various frequency fields of domestic and international application swashed that electricity and electromagnetic method all adopt is the square wave excitation field source, measurement be one or more in the earth complex apparent resistivity spectral amplitude, phase spectrum (or real spectrum and empty composing).
For frequency domain electro-prospecting, what we mainly paid close attention to is the response of the earth for the different frequency supply waveform, thereby the ideal field source signal of frequency field exploration should have the characteristics such as wide frequency range, harmonic component is abundant, harmonic energy is evenly distributed.
At present the external frequency variation method that adopts is a frequency, the measurement one by one of a frequency, and not only work efficiency is lower, and, due to the uncertainty of external interference, causes its measuring accuracy also to be difficult to improve, and particularly when survey frequency was more or less the same, error was larger.Domestic have the method that adopts the different pulse of the software control a series of frequencies of emission to measure, but its frequency be progressively from high to low or from low to high rule change, still belong to the category of frequency variation method in essence from it, can't overcome its intrinsic shortcoming.Also have in addition to adopt and first measure external disturbance, the method that rear refinement frequency is measured, although to a certain degree improved work efficiency, but due to external world's existence of uncertain variation interference in time,, such as factors such as temperature, humidity and other ground electrical interference, make its measuring accuracy be greatly affected.
Shortcoming for frequency variation method, people have proposed again the method for test odd, although can measure simultaneously a plurality of frequencies, because the frequency difference of its survey frequency is fixed, and, along with its strength of current of rising of overtone order constantly reduces, can't guarantee the measuring accuracy of higher hamonic wave.
The double frequency current method is the electric current that two amplitudes equate, one high and one low frequency is different to be synthesized the double frequency electric current by certain phase relation feed underground, obtain simultaneously once the ground telecommunications breath of two frequencies, although, two kinds of methods have had certain improvement, but it is still not high that it measures efficiency, once can only measure two frequencies.
a
nSequence pseudo random signal electrical method is the mathematical principle according to pseudo random signal coding, with-1,0 and 1 three code element represent respectively electric current I=-I, 0, I,, with the electric current of n different frequency, be combined as the resultant current that contains n main frequency composition, feeds simultaneously underground.Once observation can be from the response of n different frequency of underground extraction.This method is a plurality of frequency contents because detectable signal contains, and can measure simultaneously, have improved to a certain extent work efficiency.With 2
nPseudo random signal is example, and the predominant frequency that contains in its field source electric current is by 2
nStepping, the number of predominant frequency are 3,5,7 ... 157 ... Deng.According to the principle of frequency sounding, the uncontinuity of detectable signal frequency can cause the discontinuous of the geology detecting degree of depth, and resolution is lower, and then affects the effect of geology detecting; In addition, overlap with a certain frequency in detectable signal when outer signals or near the time, very easily affect the result of detection of whole waveform.For this reason, when adopting this method to survey, people have to strengthen the power of surveying emission, to improve the signal to noise ratio (S/N ratio) that receives signal.But the increasing of power causes the growth at double of its volume and weight, is unfavorable for the exploration in open-air and mountain area.
Comprehensive the above frequency domain electro-prospecting, its excitation field source signal is square-wave signal, with it, carries out geological exploration, and turn off delay time is short, the signal rising and falling edges linearity is good, and its harmonic components content is more, and these all are conducive to carry out the analysis of the electric data in ground.But above frequency domain electro-prospecting is because its field source signal frequency is less, waveform is single, for avoiding extraneous and various interference own, have to adopt the method that improves the instrument transmitted power to improve the signal to noise ratio (S/N ratio) that receives signal, improve detection resolution to reach, deepen the purpose of investigation depth, but the increasing of power must cause the raising of detecting devices cost and the increase of volume, and the heaviness of equipment will reduce the efficiency of detection.In addition, consider that how Mineral Resources in China is hidden in the complex-terrains such as mountain area deeply, also is unfavorable for transportation and the use of this main equipment.
Summary of the invention
In order to overcome the shortcoming of above-mentioned prior art frequency domain electro-prospecting technology, the present invention proposes a kind of artificial field source frequency domain electrical prospecting method and exploration system.
The present invention is based on the ultimate principle of frequency sounding, as artificial excitation's field source, the randomness of described waveform current signal frequency change is similar to white noise by the waveform current signal to a series of frequency accidentals variations of underground infeed.While synchronous recording transmitted signal and reception signal, the principle of basis signal correlativity, according to transmitted signal and the characteristic that receives signal correction, removal and transmitted signal and reception signal correlation are 0 undesired signal, and then improve the signal to noise ratio (S/N ratio) of geology detecting signal and the resolution of subsurface investigation.
The step of the inventive method is as follows:
1) the waveform current signal that changes to a series of frequency accidentals of underground infeed is as artificial excitation's field source, simultaneously the information such as the frequency that transmits of record, amplitude, phase place.
Due to extraneous and the uncertain variation in time of the electromagnetic interference (EMI) of instrument own, the present invention adopts random waveform electric current as the correlativity of artificial excitation's field source with reduction detectable signal and undesired signal, its waveform frequency can cover whole frequency band, can repeat to produce, repeatedly observation.In this waveform electric current, the amplitude of each frequency is about the same, phase place is continuous, dutycycle is adjustable, transmit frequency range can preset, randomness and the white noise of its frequency change are suitable, be set with in detection process and stop sending the waveform current time, so that the calibration of sending and receiving waveform phase.Based on the characteristic that sends the power frequency random variation, field source signal frequency content is continuous in whole frequency band, its frequency spectrum is continuous, measured depth of stratum is also continuous when surveying like this, improved the resolution of subsurface investigation, and because detectable signal and undesired signal correlativity are 0, the principle of basis signal correlativity, removal and transmitted signal correlativity are 0 undesired signal, just can effectively evade the ground electrical interference, improve the signal to noise ratio (S/N ratio) that receives signal, obtain detectable signal accurately.
2) receive the also surface em ripple signal of acquisition and recording process earth-layer propagation at distance artificial excitation field source number meter in the scope of tens of kilometers, the acquisition and recording of this reception signal is to synchronize and carry out with the acquisition and recording of transmitted signal.
3) according to the signal correlation principle, the transmitted signal of acquisition and recording is relevant to receiving between signal, and due to the randomness of detectable signal frequency change, incoherent between transmitted signal and external interference signal, just can remove the impact of undesired signal by the correlation operation between transmitted signal and reception signal like this, obtain our the needed useful signal that contains ground telecommunications breath.The related operation formula of signal is as follows:
R
zf(t)＝Z(t)＊f(t)＝(f(t)*e(t)*K(t)+n(t))＊f(t)＝R
ff(t)*e(t)*K(t)+R
nf(t) (1)
In formula: * represents correlation operation, and * represents convolution algorithm;
Z (t) is for receiving signal, Z (t)=f (t) * e (t) * K (t)+n (t); F (t) is transmitted signal; E (t) is the earth response; K (t), for the detection instrument response, can directly measure; N (t) is extraneous uncertain noises.R
zf(t) be the cross correlation function of Z (t) and f (t), R
ff(t) be the autocorrelation function of f (t), R
nf(t) be the cross correlation function of n (t) and f (t), wherein, R
zf(t), R
ff(t), R
KT (t) can directly calculate, R
nf(t) uncorrelated with detectable signal due to undesired signal, therefore be 0.Just can obtain the earth response e (t) according to the inverse operation of correlation operation like this.
Consider that field source detectable signal commonly used at present is square-wave signal, the time that rise and fall change is very short, and the sampling in sending and receiving signal high-low level conversion time section just becomes very important.Sample frequency is low, is unfavorable for synchronous between signal, very easily loses useful information; And the raising sample frequency can strengthen again the complicacy of instrument and the data volume of collection, is unfavorable for operation and the processing of the data in later stage that instrument is safe and reliable.Be directed to this, the invention allows for and adopt random bells as detectable signal.The rising of bells signal and decline time delay are long, in the situation that adopt same waveform sampling rate, bells is surveyed more difficult loss useful information.
The exploration system of application the inventive method mainly comprises transmitter and receiver.
Transmitter is used for sending random square wave or the bells current signal in the predeterminated frequency scope, the frequency that transmitter sends waveform is random variation, randomness and white noise are suitable, variation range has covered whole frequency band, and this transmission waveform is periodic in the transmitting time section, and the sign that wave period finishes is the zero waveform signal of pre-set timing.Be conducive to send so on the one hand the record of waveform, be convenient on the other hand send, receive between waveform and carry out phase alignment and later stage waveform processing.Transmitter adopts the electrode emission, mainly comprises power supply circuit, signal generation unit, signal synchronization unit, signals collecting memory circuit and holding circuit.Power supply circuit adopts accumulator or small generator,, through boosting, power supply is provided for after rectifying and wave-filtering whole system of transmitters.The signal generation unit, also can be for the stratum specific single-frequency square wave of output or the bells signal paid close attention to for generation of needed random square wave and bells signal.Signal synchronization unit adopts GPS, relies on the universal time pps pulse per second signal of GPS to carry out synchronously transmitter and receiver, starts to receive signal when sending random square wave or bells signal; The signals collecting memory circuit is connected on the signal generation unit, is used for the waveform signal that the storage of when signal is launched non-volatile recording and big data quantity is launched.Holding circuit is connected on the signal generation unit, and transmitter is carried out overcurrent and under-voltage protection.
Receiver is used for receiving, recording and store random square wave or the bells signal with ground telecommunications breath that transmitter sends, and can disposablely receive simultaneously all transmitted signals in whole predeterminated frequency scope, and it is carried out precise acquisition and storage.Receiver adopts electrode to receive signal.Receiver mainly comprises power circuit, impedance matching circuit, signal filter circuit, signal amplification circuit, signals collecting memory circuit, signal synchronization circuit and data processing unit.Power circuit provides power supply for whole receiver.Impedance matching circuit is used for the earth is carried out impedance matching, is convenient to signal and receives, and it is connected on electrode by long lead.Signal on receiving electrode after impedance matching circuit output, is carried out filtering and amplifies and process it by signal filter circuit and signal amplification circuit.After the signals collecting memory circuit is connected to signal amplification circuit, signal synchronization circuit is connected on the signals collecting memory circuit, after the signals collecting memory circuit receives synchronizing signal from signal synchronization circuit, start the signal after amplifying is gathered and analog to digital conversion, then be stored in jumbo storer.Data processing unit, namely high performance computing machine is connected on the signals collecting memory circuit of receiver, reads the reception signal of storage and carry out the data in later stage and process from mass storage.Receiver can adopt many groups to receive, and increases work efficiency.
The frequency range of the random waveform signal that adopts in the present invention is: 0.001Hz～65535Hz, also can select a certain frequency range wherein to survey in real work.
The present invention is different from present the frequency domain electro-prospecting exploration take square wave as field source of generally application, and adopt random square wave and bells signal to survey, have wide frequency range, survey the characteristics such as frequency is close, frequency spectrum is continuous, detection efficiency is high, convenient, flexible, and bells detectable signal used rises and descends comparatively slow, sampling rate during signal intensity is easy to just can reach requirement, useful information while more being not easy to the lossing signal variation, can greatly improve the resolution of subsurface investigation.In the methods of the invention, the random variation of observation and frequency in the same period of a plurality of frequencies, can reduce the correlativity of signal and interference, effectively evade the impact of the factor of the times to time change such as environment temperature and humidity, extraneous ground electricity and atmospherics on observed result, need not improve the transmitted power of instrument and just can improve the signal to noise ratio (S/N ratio) that receives signal, improve confidence level and the validity of observed result.In addition, in conjunction with present existing various active source frequency domain electro-prospecting method of exploration: as controllable source the earth audio frequency method (CSAMT), frequency sounding method, double frequency current method, a
nSequence pseudo random signal electrical method etc., utilize its advantage, after random square wave that receiving end will receive or bells signal discrete become digital signal to send to computing machine to carry out digital filtering, carry out again a plurality of Period Superpositions, the contour accuracy floating-point computing of computer iterations, also can further improve the signal to noise ratio (S/N ratio) of observation signal.Adopt like this multiple technologies means to substitute the original raising system transmitted power that adopts to improve the method for observation signal signal to noise ratio (S/N ratio), both avoided power to improve equipment and the device problem of bringing, can reduce device volume again, be convenient to loading and unloading and transportation, be more suitable for China's many mountain areas mineral reserve and stock the exploration of situation.
Description of drawings
Fig. 1 the present invention sends dynamo-electric functional-block diagram;
Fig. 2 the present invention receives dynamo-electric functional-block diagram;
Fig. 3 FPGA internal module schematic diagram;
Fig. 4 pulse-width modulation waveform figure;
Fig. 5 transmitter main circuit schematic diagram;
The random square-wave signal schematic diagram of Fig. 6;
The random bells signal schematic representation of Fig. 7;
The amplitude frequency diagram of Fig. 8 random waveform.
Embodiment
The invention will be further described below in conjunction with the drawings and specific embodiments.
The survey system of application frequency domain electro-prospecting of the present invention is comprised of transmitter and receiver two parts, and exploration system input impedance 〉=40M Ω adopts GPS to carry out synchro control between transmitter and receiver.
Described transmitter principle as shown in Figure 1.Described transmitter comprises power supply circuit, signal generation unit, signal synchronization unit, signals collecting memory circuit and holding circuit.Power supply circuit is given whole transmitter power supply, and the signal generation unit is divided into random waveform generator, PWM modulating unit, isolated drive circuit, switching tube circuit, filtering circuit, and they are sequentially connected.The control end of transmitter and gps signal lock unit are connected on the random waveform generator of signal generation unit, and control end produces the control signal of random waveform generator, and signal synchronization unit adopts the output of GPS synchro control random signal and the reception of signal.The random waveform generator produces needed random square wave and bells, this random waveform transfers to the PWM modulating unit and carries out the PWM modulation, be converted to pulse waveform, as driving signal after the isolated drive circuit isolation, flow to the work of switching tube drives switching tube, it is underground that the switching tube circuit produces a series of high voltages under the driving that drives signal, the pulse waveform of electric current changes the needed random current waveform infeed of geology detecting again into after the filtering circuit filtering greatly.Current foldback circuit in holding circuit and undervoltage detection circuit are connected to the signal generation unit to whole transmitter on the switching tube circuit and carry out overcurrent and under-voltage protection, and the signals collecting memory circuit is connected on filtering circuit the random signal that sends is gathered and is stored in the middle of jumbo storer.
Described receiver principle as shown in Figure 2.Described receiver comprises power circuit, impedance matching circuit, signal filter circuit, signal amplification circuit, signals collecting memory circuit, signal synchronization circuit and data processing unit.Power circuit is given whole receiver system power supply.after impedance matching circuit is connected in receiver electrode M, N, the coupling of the earth impedance while realizing measuring, signal filter circuit comprises trap circuit and high pass and low-pass filter circuit, the input end of trap circuit is connected with the output terminal of impedance matching circuit, the input end of high pass and low-pass filter circuit is connected with the output terminal of trap circuit, the input end of signal amplification circuit is connected with the output terminal of high pass and low-pass filter circuit, the signals collecting memory circuit comprises A/D sample conversion circuit and storage unit, the input end of A/D sample conversion circuit is connected with the output terminal of signal amplification circuit, the input end of storage unit is connected with the output terminal of A/D sample conversion circuit, data processing unit is connected with the storer of storage unit.The signal pass order that receives is: impedance matching circuit, trap circuit, high pass and low-pass filter circuit, signal amplification circuit, A/D sample conversion circuit, storage unit, data processing unit.The 50Hz that the trap circuit filtering interfering is larger, 150Hz signal, high pass and low-pass filter circuit are realized high pass and the low-pass filtering to signal, signal amplification circuit carries out magnification at high multiple to filtered signal, simulating signal after A/D sample conversion circuit will amplify is carried out after high speed analog-to-digital conversion flowing to storage unit and is carried out large capacity storage, data processing unit reading out data and carry out data and process from storer.The function switch circuit is connecting high pass and low-pass filter circuit and signal amplification circuit, realizes the selection of circuit parameter under different frequency and enlargement factor.The gps signal lock unit is connecting A/D sample conversion circuit, realizes sending random signal and receives synchronizeing between random signal.Under-voltage protecting circuit is connected on data processing unit, and by the achieve a butt joint under-voltage protection of receipts machine of this unit.
Described exploration system adopts random square wave and bells signal, and it is to have the signal of equal randomness with white noise signal within the whole cycle, be in the present embodiment with field programmable gate array (referred to as: FPGA) produce.The FPGA system adopts the CYCLONE II family chip EP2C8Q208C8 chip of altera corp as acp chip, and EPCS16 is as its configuring chip, and the operation of whole FPGA system is controlled by the external control end.The internal module that FPGA produces random waveform mainly comprises: random frequency generation module, waveform adjusting module, random waveform memory module, PWM adjusting module, the module connection layout as shown in Figure 3.The outside connection: described external control end connects the waveform adjusting module to be realized sending the control of random waveform frequency range, wave form; The GPS synchronizing signal connects the random waveform memory module, synchronizeing between controlling its output and signal receiving; The PWM adjusting module connects isolated drive circuit, and its output is worked as the drive switching tube.The inner connection: random frequency generation module, waveform adjusting module, random waveform memory module, PWM adjusting module are linked in sequence.Wherein, the random frequency generation module is for generation of the frequency number of random variation, after the waveform adjusting module, with the frequency number adjusted and Waveform Control information conveyance to the random waveform memory module, when the GPS synchronizing signal is come temporarily according to frequency number and control information output random waveform, consider that continuous signal is difficult to amplify, adopt the PWM adjusting module to carry out width modulation to random signal and be transformed into switching value and amplified by switching tube, improved energy utilization efficiency.The frequency number of random variation can be produced by various random sequence generators, here be to realize with linear feedback shift register (LFSR) technology, by the PWM module to signal carry out after width modulation waveform as shown in Figure 4, wherein dashed curve is wherein one section of the front random signal of modulation, and the solid line pulse waveform is signal after the modulation of this section random signal.
Figure 5 shows that the operating circuit of transmitter.Power acquisition 12V accumulator wherein; F is overcurrent protection; in main circuit, switching tube adopts IGBT; 4-1 for boosting, current rectifying and wave filtering circuit; 4-2 is random signal generator and isolated drive circuit, and for generation of the driving signal of IGBT, inductance L and capacitor C 1, C2 have formed filtering circuit jointly; be used for level and smooth current signal and the filtering high frequency interference that sends, R
LFor the impedance of the earth, Rc is sample resistance, and 4-3 is signal acquisition circuit and undervoltage detection circuit.As shown in Figure 6 and Figure 7, Fig. 8 is the amplitude frequency diagram of random waveform to the schematic diagram of transmitter transmitted signal, can find out that its frequency spectrum and white noise are similar, and frequency spectrum is continuous, according to the stratum of its detection of principle of frequency sounding, is also continuous, and detection resolution is high.
Described transmitter and receiver are all established two frequency ranges of high and low frequency, and low frequency is 0.1Hz～102.4Hz, and high frequency is 100Hz～1024Hz, can select according to actual needs.After the selection of carrying out high frequency or low frequency, transmitter and receiver also can carry out for selected frequency range the selection of high-frequency circuit and low-frequency channel parameter.
The signals collecting memory circuit of described exploration system needs at a high speed, high-resolution A/D sampling, and the suggestion A/D converter is more than 16, and the data storage needs jumbo storer, the comprising transmitted signal and receive the data of signal of the long-time section of storage., take the 100kHz data acquisition as example, comprise that at least the two paths of signals collection data of 10 hours of sending and receiving signal are: 16 * 100000 * 60 * 60 * 10=5.76 * 10
10(bit) ≈ 6.71 (G), so suggestion memory span 〉=10G.
The waveform current signal that the signal generation unit of described survey system produces a series of frequency accidentals variations feeds underground, receiver arrives all transmitted signals in the whole predeterminated frequency scope of disposable reception in the scope of tens of kilometers at distance artificial excitation field source number meter, simultaneously transmitted signal and reception signal are carried out the synchronous acquisition storage, according to the signal correlation principle, to receive signal and transmitted signal and carry out correlation operation, the computing formula of correlation operation is as follows:
R
zf(t)＝Z(t)＊f(t)＝(f(t)*e(t)*K(t)+n(t))＊f(t)＝R
ff(t)*e(t)*K(t)+R
nf(t)
In formula: * represents correlation operation, and * represents convolution algorithm;
Z (t) is for receiving signal, Z (t)=f (t) * e (t) * K (t)+n (t); F (t) is transmitted signal; E (t) is the earth response; K (t) is the detection instrument response; N (t) is extraneous uncertain noises; R
zf(t) be the cross correlation function of Z (t) and f (t), R
ff(t) be the autocorrelation function of f (t), R
nf(t) be the cross correlation function of n (t) and f (t); Undesired signal and transmitted signal are uncorrelated, R
nf(t) be 0, removal and transmitted signal correlativity are 0 undesired signal, obtain required ground telecommunications breath.
Claims (7)
1. artificial field source frequency domain electrical prospecting method, it is characterized in that: described method of exploration by the waveform current signal that changes to a series of frequency accidentals of underground infeed as artificial excitation's field source, and at distance artificial excitation field source number meter, arrive in the scope of tens of kilometers the surface em ripple signal that receives through earth-layer propagation, while synchronous recording transmitted signal and reception signal, the principle of basis signal correlativity, according to transmitted signal and reception signal correction characteristic, removal and transmitted signal correlativity are 0 undesired signal, obtain the needed information of geology detecting;
Described waveform current signal is square wave or bells electric current, and the randomness of described waveform current signal frequency change is similar to white noise; The waveform frequency of described waveform current signal covers whole frequency band, frequency content in whole frequency band continuously, and the characteristic of frequency random variation while having the waveform current emission; In described waveform current signal, the amplitude of each frequency is suitable, phase place is continuous, and dutycycle is adjustable, and transmit frequency range can preset.
2. artificial field according to claim 1 source frequency domain electrical prospecting method, is characterized in that: be set with and stop sending the waveform current time in the exploration process, so that the calibration of sending and receiving waveform phase.
3. artificial field according to claim 1 source frequency domain electrical prospecting method, it is characterized in that: the low-limit frequency of described square wave and bells electric current is 0.001Hz, highest frequency is 65535Hz, and transmission frequency is a certain frequency range in 0.001Hz～65535Hz.
4. the survey system of application rights requirement 1 a described method, comprise transmitter and receiver, it is characterized in that:
Described transmitter is used for sending random square wave or the bells current signal in the predeterminated frequency scope, and transmitted signal is gathered and stores; Described transmitter adopts the electrode transmitted signal; Described transmitter comprises: power supply circuit, signal generation unit, signal synchronization unit and signals collecting memory circuit and holding circuit; Power supply circuit provides power supply for described transmitter; The signal generation unit is for generation of described random square wave or bells signal, and can be for the stratum specific single-frequency square wave of output or the bells signal paid close attention to; Signal synchronization unit adopts GPS, relies on the universal time pps pulse per second signal of GPS to carry out synchronously transmitter and receiver, receives signal when sending random square wave or bells signal; The signals collecting memory circuit is connected on the signal generation unit, is used for the waveform signal that the storage of when signal is launched non-volatile recording and big data quantity is launched; Holding circuit is carried out overcurrent and under-voltage protection to transmitter;
Described receiver is used for random square wave or the bells signal with ground telecommunications breath that reception, record and storage transmitter send; Described receiver adopts electrode to receive signal, comprises power circuit, impedance matching circuit, signal synchronization circuit, signal filter circuit, signal amplification circuit, signals collecting memory circuit and data processing unit; Power circuit provides power supply to receiver, and impedance matching circuit is connected on electrode by long lead, is used for the earth is carried out impedance matching; Signal synchronization circuit adopts GPS synchro control transmitter and receiver; Signal filter circuit and signal amplification circuit carry out filtering and amplify and process the signal that receives; After the signals collecting memory circuit is connected to signal amplification circuit, the signal after amplifying is gathered and analog to digital conversion and storage; Data processing unit is connected on the signals collecting memory circuit of receiver, the transmitted signal of storage is carried out data with the reception signal process.
5. survey system according to claim 4, it is characterized in that: described transmitter and receiver are all established two transmit frequency ranges of high and low frequency, and low frequency is 0.001Hz～102.3Hz, and high frequency is 100Hz～65535Hz.
6. survey system according to claim 4, it is characterized in that: described survey system adopts on-site programmable gate array FPGA to produce described random square wave and bells signal in conjunction with switching tube circuit and filtering circuit, and the FPGA internal module comprises: random frequency generation module, waveform adjusting module, random waveform memory module and PWM adjusting module; Random frequency generation module, waveform adjusting module, random waveform memory module, PWM adjusting module are linked in sequence; Wherein, the random frequency generation module designs with random sequence generator, produce the frequency number of random variation, the waveform adjusting module is adjusted frequency and the Waveform Control information of output waveform, the random waveform that the random waveform memory module needs according to the frequency number of adjusting and Waveform Control information output, the PWM adjusting module carries out width modulation to random signal and is transformed into switching value and flows to the switching tube circuit and amplify, and filtering circuit carries out smothing filtering to signal after being connected to the switching tube circuit.
7. survey system according to claim 4, it is characterized in that: the waveform current signal that the signal generation unit of described survey system produces a series of frequency accidentals variations feeds underground, receiver arrives all transmitted signals in the whole predeterminated frequency scope of disposable reception in the scope of tens of kilometers at distance artificial excitation field source number meter, simultaneously transmitted signal and reception signal are carried out the synchronous acquisition storage,, according to the signal correlation principle, will receive signal and transmitted signal and carry out correlation operation:
R
zf(t)=Z(t)＊f(t)=(f(t)*e(t)*K(t)+n(t))＊f(t)=R
ff(t)*e(t)*K(t)+R
nf(t)
In formula: * represents correlation operation, and * represents convolution algorithm;
Z (t) is for receiving signal, Z (t)=f (t) * e (t) * K (t)+n (t); F (t) is transmitted signal; E (t) is the earth response; K (t) is the detection instrument response; N (t) is extraneous uncertain noises; R
zf(t) be the cross correlation function of Z (t) and f (t), R
ff(t) be the autocorrelation function of f (t), R
nf(t) be the cross correlation function of n (t) and f (t); Undesired signal and transmitted signal are uncorrelated, R
nf(t) be 0, removal and transmitted signal correlativity are 0 undesired signal, obtain required ground telecommunications breath.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210073322XA CN102590869B (en) | 2012-03-19 | 2012-03-19 | Artificial field source frequency domain electrical prospecting method and prospecting system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210073322XA CN102590869B (en) | 2012-03-19 | 2012-03-19 | Artificial field source frequency domain electrical prospecting method and prospecting system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102590869A CN102590869A (en) | 2012-07-18 |
| CN102590869B true CN102590869B (en) | 2013-11-13 |
Family
ID=46479776
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210073322XA Active CN102590869B (en) | 2012-03-19 | 2012-03-19 | Artificial field source frequency domain electrical prospecting method and prospecting system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102590869B (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BR112015008132A8 (en) * | 2012-10-12 | 2018-01-02 | Geotech Airborne Ltd | ELECTROMAGNETIC RECEPTION SYSTEM FOR GEOPHYSICAL SCANNING AND METHOD FOR CALIBRATION OF AN ELECTROMAGNETIC RECEPTION SYSTEM FOR GEOPHYSICAL SCANNING |
| CN103091717B (en) * | 2013-01-09 | 2015-10-21 | 中国科学院电工研究所 | A kind of electromagnetic exploration method receiving and dispatching automatic synchronization frequency conversion |
| CN104597506B (en) * | 2015-01-26 | 2017-03-29 | 吉林大学 | The air-ground electromagnetic exploration method of frequency domain |
| CN105866844A (en) * | 2016-06-12 | 2016-08-17 | 何继善 | Device and method for measuring whole region measuring current source frequency domain electric field horizontal x component |
| CN106549683B (en) * | 2016-11-01 | 2019-04-02 | 国网山西省电力公司电力科学研究院 | A kind of spread spectrum coding detectable signal emission system |
| CN108071385B (en) * | 2016-11-17 | 2021-03-16 | 中国石油化工股份有限公司 | Method and circuit for measuring electromagnetic wave resistivity amplitude ratio and phase difference while drilling |
| CN110031901A (en) * | 2019-03-20 | 2019-07-19 | 武汉捷探科技有限公司 | One kind deepening electric prospecting system and a kind of investigation method |
| CN112162323B (en) * | 2020-09-28 | 2024-03-08 | 长春工程学院 | Underground bad geological survey method and system based on artificial field source frequency domain electrical method |
| CN113031079B (en) * | 2021-04-21 | 2023-10-03 | 中南大学 | New power excitation method based on frequency division power method |
| CN114839688B (en) * | 2022-05-06 | 2023-05-12 | 甘肃煤田地质局一四九队 | Electromagnetic prospecting transmitter control device and method |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2512339B2 (en) * | 1990-07-24 | 1996-07-03 | 日本鋼管株式会社 | Underground radar tomography device |
| JPH08684A (en) * | 1994-06-16 | 1996-01-09 | Tabuchi Kazuhisa | Gynecological medical examination stand |
| CN1199175A (en) * | 1997-05-13 | 1998-11-18 | 中南工业大学 | Pseudo-random three-frequency excitation method to distinguish mineral abnormality from carbon abnormality |
| US7526413B2 (en) * | 2001-01-31 | 2009-04-28 | Exxonmobil Upstream Research Company | Volumetric laminated sand analysis |
| CN102053278B (en) * | 2010-09-09 | 2011-10-26 | 天津英驰勘探技术有限公司 | Electrical prospecting method and measuring device |
-
2012
- 2012-03-19 CN CN201210073322XA patent/CN102590869B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN102590869A (en) | 2012-07-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102590869B (en) | Artificial field source frequency domain electrical prospecting method and prospecting system | |
| CN102053280B (en) | Nuclear magnetic resonance ground water detection system with reference coils and detection method | |
| CN102183792B (en) | Artificial source frequency domain electromagnetic sounding device and measurement method | |
| CN103823244B (en) | Magnetic resonance three-component noise removing device and noise removing method | |
| CN103091717B (en) | A kind of electromagnetic exploration method receiving and dispatching automatic synchronization frequency conversion | |
| CN102096111B (en) | Transmitting-receiving antenna separation type nuclear magnetic resonance water exploring device and water exploring method | |
| CN101397907B (en) | Method and apparatus for eliminating directly coupling signal of induction logging tool | |
| CN104597506A (en) | Frequency domain ground-to-air electromagnetic prospecting method | |
| CN102288625A (en) | Channel concrete lining nondestructive testing system | |
| CN1945358B (en) | High precision measuring method for deep resource based on natural electric field idealization and detecting instrument | |
| CN110187394B (en) | Method and device for acquiring formation resistivity anisotropy by double-field source electromagnetic sounding method | |
| CN104481519A (en) | Cross-well electromagnetic well logging signal emission electronic system | |
| CN106383364A (en) | Pseudo-random frequency-sweeping nuclear magnetic resonance detection instrument | |
| CN103207413A (en) | Electrical prospecting device and system | |
| CN102073061B (en) | Ground microphone information high-density recording system using digital ground microphone | |
| CN103884920A (en) | Automatic frequency sweeping inductance measuring meter and measuring method | |
| CN104122594A (en) | Multi-parameter extraction data processing method of time domain induced polarization full-waveform sampling | |
| CN112285786A (en) | Method for improving exploration depth based on ultrahigh-density electrical method equipment | |
| CN103412338A (en) | Pseudo-random code electrical instrument | |
| CN104459802B (en) | Emission device for electrical prospecting system | |
| CN212255732U (en) | Time-frequency electromagnetic data acquisition device based on extremely-low-frequency electromagnetic source | |
| CN203759264U (en) | Nuclear magnetic resonance bipolarity superposition de-noising device based on power frequency full cycle | |
| Hornbostel et al. | Waveform design for electroseismic exploration | |
| CN104453868A (en) | Induction logging instrument transmitting signal synthesizing device, induction logging instrument transmitting signal synthesizing method and induction logging method | |
| CN208334669U (en) | A kind of radio underground electro magnetic wave perradiator |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |