WO2002031537A1 - Procede pour etalonner la permittivite relative d'un detecteur electromagnetique et detecteur electromagnetique - Google Patents

Procede pour etalonner la permittivite relative d'un detecteur electromagnetique et detecteur electromagnetique Download PDF

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Publication number
WO2002031537A1
WO2002031537A1 PCT/JP2001/007328 JP0107328W WO0231537A1 WO 2002031537 A1 WO2002031537 A1 WO 2002031537A1 JP 0107328 W JP0107328 W JP 0107328W WO 0231537 A1 WO0231537 A1 WO 0231537A1
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WIPO (PCT)
Prior art keywords
signal
relative permittivity
period
electromagnetic wave
analysis
Prior art date
Application number
PCT/JP2001/007328
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English (en)
Japanese (ja)
Inventor
Masahiro Fujiwara
Original Assignee
Cos Co., Ltd.
Priority date (The priority date 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 date listed.)
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Publication date
Application filed by Cos Co., Ltd. filed Critical Cos Co., Ltd.
Priority to JP2002534869A priority Critical patent/JP3511026B2/ja
Priority to AU2001293352A priority patent/AU2001293352A1/en
Publication of WO2002031537A1 publication Critical patent/WO2002031537A1/fr

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
    • G01V3/00—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation
    • G01V3/15—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation specially adapted for use during transport, e.g. by a person, vehicle or boat
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/88—Radar or analogous systems specially adapted for specific applications
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/04—Display arrangements
    • G01S7/06—Cathode-ray tube displays or other two dimensional or three-dimensional displays
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/04—Display arrangements
    • G01S7/06—Cathode-ray tube displays or other two dimensional or three-dimensional displays
    • G01S7/062—Cathode-ray tube displays or other two dimensional or three-dimensional displays in which different colours are used
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/04—Display arrangements
    • G01S7/06—Cathode-ray tube displays or other two dimensional or three-dimensional displays
    • G01S7/10—Providing two-dimensional and co-ordinated display of distance and direction
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/88—Radar or analogous systems specially adapted for specific applications
    • G01S13/885—Radar or analogous systems specially adapted for specific applications for ground probing

Definitions

  • the present invention relates to a method for calibrating the relative permittivity of an electromagnetic wave probe and an electromagnetic wave probe, and more particularly, to a novel technique capable of accurately and easily calibrating a relative permittivity at an exploration site.
  • Electromagnetic wave probes that radiate electromagnetic waves from antennas and receive and analyze reflected waves from objects have been developed and used for exploration of buried objects such as buried pipes and land mines.
  • Such an electromagnetic wave probe radiates high-frequency electromagnetic waves from the antenna at predetermined intervals and receives and analyzes the reflected waves to determine the distance to the object and determine the physical properties of the object that has passed the electromagnetic wave. The non-destructive measurement of the object to be explored.
  • the spacecraft can display the search results in various modes. For example, as shown in FIG. 11, one received signal at a certain search position can be displayed as a received waveform on a screen with the horizontal axis representing the time axis and the vertical axis representing the amplitude axis.
  • the received signals at a plurality of search positions at predetermined intervals in the horizontal direction of the search target are stored and held, and predetermined signal processing is performed on the plurality of received signals, whereby the vertical axis represents the depth and the horizontal axis represents the depth.
  • a two-dimensional cross-sectional image (or pulse echo image) of the search target at the search position (the number of scans) is generated, and this cross-sectional image can be displayed as shown in FIG.
  • the above signal processing can be exemplified by pulse compression processing (pulse co-immediate response process) and synthetic aperture processing (synthetic aperture process).
  • pulse compression processing pulse co-immediate response process
  • synthetic aperture processing synthetic aperture process
  • a specific point (for example, the first peak point of the amplitude) P of the surface wave P in the received signal shown in FIG. As the receiving start point, and the received receiving start point P.
  • the automatic tracking circuit fluctuates due to ambient temperature fluctuations and variations in circuit members, which causes fluctuations in the tracking zone, and the measurement results vary even though the products have the same specifications. Had a problem.
  • a broadband transmission electromagnetic wave is reflected at various points at various points in the medium at various phase points, and a reception wave is formed by a composite wave of this large number of reflected waves.
  • It can be correlated with the relative permittivity and specific resistance of the medium.
  • the relative permittivity of the medium could not be measured by analyzing only a single received waveform observed at a specific measurement point on the ground surface.
  • the inventor of the present invention has made the transmission wave band extremely narrow (for example, a band of about 20 MHz at a center frequency of 1 GHz) and radiated in a pulse shape, and reflected a strong narrow-band electromagnetic wave.
  • a wave with a receiving antenna and detecting this detection signal with a new detection circuit, it has been found that a predetermined correlation occurs between the period of the received waveform and the relative permittivity of the medium. That is, the pulse-shaped narrow-band electromagnetic wave has a propagation speed and an attenuation rate according to the relative permittivity of the medium during the propagation in the medium.
  • reflected waves are generated at all points in the medium, and a received wave is formed by combining the multiple reflected waves.
  • each reflected wave is received by the receiving antenna on the ground.
  • a predetermined phase shift occurs in the reflected wave according to the relative dielectric constant of the medium.
  • the received waveform composed of the multiple reflected waves includes a signal component corresponding to the average relative permittivity at each depth of the search target.
  • the periodic force S of each phase of this received waveform changes according to the average permittivity at each depth of the target to be searched, and the noise component of each phase of the received wave changes at each depth in the target to be searched. It corresponds to the average dielectric constant. Therefore, based on these signal components, it is possible to observe a change in the dielectric constant at each depth in the object to be searched.
  • the present invention has been proposed in view of such circumstances, and in an electromagnetic wave probe capable of observing the dielectric constant at each depth of a search target in a received waveform, calibration of relative permittivity is facilitated prior to the search.
  • An object of the present invention is to provide a method for calibrating the relative permittivity of an electromagnetic wave probe that can be performed.
  • Another object of the present invention which is proposed at the same time, is to provide an electromagnetic wave probe that can effectively perform the relative dielectric constant calibration method. Disclosure of the invention
  • the relative dielectric constant calibration method of the present invention proposed to achieve the above object is based on a transmission antenna that radiates an electromagnetic wave, a reception antenna that receives a reflected wave of the radiated electromagnetic wave, and a detection signal of the reception antenna. And a signal processing unit that processes the received signal and outputs an analysis signal.
  • the signal processing unit converts the received signal into an analysis signal having a different signal period by frequency conversion.
  • the setting means is adjusted so as to match a predetermined reference time according to the rate.
  • the present invention is suitably applied to an electromagnetic wave probe in which the average relative permittivity at each depth in the search target and the average period of each phase of the signal waveform for analysis have a predetermined correlation. More preferably, a signal processing circuit that generates an analysis signal waveform in which the average period of each phase of the analysis signal waveform is substantially proportional to the square root of the average relative permittivity at each depth in the search target It is good to use for an electromagnetic wave probe equipped with. Further, the present invention can be suitably applied to a device that radiates pulsed electromagnetic waves in a narrow band by optimizing a transmission antenna and a transmission circuit.
  • the receiving unit can be mainly configured by a high-frequency circuit, and the main function of the receiving unit can be to detect a reflected wave, and is an output signal of the receiving unit.
  • the reception signal is preferably in the KHz band to the tens of MHz band.
  • the receiving unit and the signal processing unit may be configured as a circuit on another substrate, or may be configured as an integrated circuit on the same substrate.
  • the frequency conversion in the present invention is a general term for the process of equivalently changing the frequency by changing the correspondence between the analysis signal and the time axis, and changing the analysis signal itself in the time axis direction. It includes all processes and processes that change the unit time of the time axis.
  • the signal for analysis is an analog signal
  • the signal for analysis is frequency-converted by a frequency conversion circuit such as a double balanced mixer. Can be converted.
  • the analysis signal is represented by a set of digital data obtained by AD-converting the received signal, the digital data group is assumed to have been sampled at a timing different from the actual sampling timing. By handling (in other words, by changing the unit time between each sampling data), the frequency of the analysis signal is converted.
  • the frequency conversion constant setting means may have an appropriate configuration.
  • the setting means may include a variable resistor provided in the circuit.
  • the cycle adjusting means is constituted by a microcomputer that operates based on a predetermined program
  • the setting means includes a rewritable memory and a data rewritable memory. It can be composed of a program to be rewritten and input means such as a switch for data input.
  • Calibration of the relative permittivity in the spacecraft refers to associating the signal cycle of the received signal in the medium having the relative permittivity with the time axis.
  • the relative permittivity of the medium and the propagation speed of electromagnetic waves in the air are C.
  • the following relationship is generally established between the electromagnetic wave propagation distance (depth) D and the time t. That is, the propagation distance (depth) can be obtained by calculating the propagation time.
  • each signal of the analysis signal will be displayed when the relative permittivity is not calibrated. Even if there is a correlation between the period for each phase and the time axis on the screen, there is no reference, so for example, an analysis signal including the surface reflected wave and the reflected wave from the buried object is displayed on the screen. In this case, the waveform shape can be determined, but the distance (depth) to the buried object is determined based on the time between the surface reflected wave and the object reflected wave. I can't ask.
  • the relative permittivity cannot be specified for the received signal having a different period, and physical property analysis cannot be performed.
  • the reference time for signal processing is not determined, there is no correspondence between the period of the signal for analysis and the time axis in the signal processing unit.
  • the arbitrary point of the analysis signal waveform displayed on the screen can be obtained.
  • the propagation time between them can be obtained from the time axis.
  • the period of the analysis signal in the signal processing unit can be correlated with the time axis, and signal processing can be performed based on the calibrated time axis.
  • the setting means of the period adjustment unit is adjusted and set so that the period of the analysis signal (period of the surface reflected wave) when the electromagnetic wave is radiated to the air coincides with the reference time. Yes, this creates an equivalently calibrated state with a medium of reference relative permittivity.
  • the period of the analysis signal in the fluctuating state coincides with the reference time.
  • Calibration is performed as follows. As a result, as long as the temperature and the like do not fluctuate rapidly, the fluctuation error between the cycles according to the relative permittivity in the analysis signal is canceled out, and the measurement with less error can be performed.
  • the calibration is performed using the signal for analysis of airborne radiation, the effect of the dielectric on the transmitting antenna can be eliminated as much as possible, and more accurate calibration can be performed.
  • the surface reflected wave at the time of air-to-air radiation is based on the first reflection by the electromagnetic wave radiated from the transmitting antenna. Includes firing.
  • the signal processing unit is configured to generate and output an analysis signal having a predetermined relationship between the period and the relative permittivity based on the received signals having different periods according to the relative permittivity of the medium. be able to.
  • An electromagnetic wave passing through a medium having a different relative permittivity causes a change in propagation speed according to the passing medium, and accordingly, a received signal undergoes a frequency change (periodic change) according to the relative permittivity of the medium.
  • the correlation between the period of the analysis signal and the relative permittivity is clarified, and the average relative permittivity at each depth is calculated based on the analysis signal, and based on the calculated average relative permittivity. Depth analysis can be performed easily.
  • the present invention is a method for deriving a reference time in the relative dielectric constant calibration method of the present invention, which radiates an electromagnetic wave from a transmitting antenna toward a reference dielectric having a predetermined relative dielectric constant and a calibration distance.
  • the setting means is adjusted so that the time between the reflected wave at the reference dielectric surface and the calibration distance included in the analysis signal coincides with the time when the electromagnetic wave propagates through the calibration distance in the reference dielectric.
  • the period of the analysis signal when anti-air radiation is performed from the antenna is determined as a reference time.
  • the time for the electromagnetic wave to propagate through the calibration distance in the reference dielectric refers to the time for the electromagnetic wave to reciprocate between the surface of the reference dielectric and the calibration distance.
  • the above-described calibration method of the present invention uses the reference time obtained in this manner.
  • the frequency of the analysis signal during air-to-air radiation is measured.
  • the superior idea of the present invention can be recognized in that the period is used as a reference time for calibration.
  • the present invention proposes a transmitting antenna that radiates an electromagnetic wave, a receiving antenna that receives a reflected wave of the radiated electromagnetic wave, a receiving unit that generates a receiving signal based on a detection signal of the receiving antenna, A signal processing unit that processes the received signal and outputs an analysis signal; a storage unit that stores measurement condition data including a reference relative permittivity value; and an arithmetic unit.
  • the setting means is configured to match a cycle of the analysis signal when the electromagnetic wave is radiated from the transmitting antenna to the air with a reference time predetermined according to a reference relative permittivity. It can be configured to be adjustable. Further, the signal processing unit generates a received signal in the exploration as an analysis signal calibrated in accordance with the relative permittivity, and the arithmetic unit determines the analysis signal based on the measurement condition data stored in the storage unit. It is possible to adopt a configuration in which the analysis data subjected to the above calculation is generated.
  • the above-described method of calibrating the relative permittivity can be used in this electromagnetic wave probe.
  • the processing unit By calibrating the relative permittivity by optimizing the predetermined circuit constants of the signal processing unit, etc., the correspondence between the analysis signal and the time axis in the relative permittivity is calibrated.
  • the processing unit generates and outputs an analysis signal obtained by performing a period adjustment process on the received signal according to the setting of the setting unit.
  • the period of the analysis signal has a certain relationship with the relative permittivity of a medium such as the underground.
  • the generated analysis signal is sent to the calculation means, and necessary calculation is performed based on the measurement condition data stored in the storage means to generate analysis data necessary for displaying a search result or the like.
  • the measurement condition data includes data such as an arithmetic processing program to be added to the analysis signal in accordance with the reference relative permittivity value and the search result display mode.
  • the signal processing unit is the same as the electromagnetic wave probe for performing the relative dielectric constant calibration method.
  • a configuration may be employed in which an analysis signal having a predetermined relationship between the period and the relative permittivity is generated and output.
  • FIG. 1 is a block diagram showing a configuration of a main part of an electromagnetic wave probe according to an embodiment of the present invention.
  • FIG. 2 is an explanatory diagram showing a sampling state of a received signal in a medium having a low relative dielectric constant.
  • FIG. 3 is an explanatory diagram showing a sampling state of a received signal in a medium having a high relative dielectric constant.
  • FIG. 4 is an explanatory diagram showing a procedure for calibrating the relative permittivity of the present invention using the indicator of the spacecraft shown in FIG.
  • Fig. 5 is a front view showing the reference dielectric (dried masa).
  • FIG. 6 is an explanatory diagram showing a procedure for matching calibration distances based on an analysis signal in a reference dielectric.
  • FIG. 7 is an explanatory diagram showing a procedure for making the period of the surface reflected wave of the analysis signal at the time of antiaircraft radiation coincide with the reference time.
  • FIG. 8 is an explanatory diagram showing a procedure for matching the calibration distances shown in FIG. 6 by performing surface wave processing.
  • FIG. 9 is a front view showing a reference dielectric (epoxy resin).
  • FIG. 10 is an explanatory diagram showing a procedure for matching calibration distances based on an analysis signal in a reference dielectric.
  • FIG. 11 is an explanatory diagram of a conventional tracking zone in an analysis signal.
  • FIG. 12 is an explanatory diagram illustrating a change that occurs in a cross-sectional image due to a change in a tracking zone.
  • the time axis corresponding to the received signal is adjusted by the setting means of the cycle adjusting unit.
  • the correspondence between the received signal and the time axis is calibrated, and as a result, an analysis signal obtained by performing frequency conversion on the received signal can be generated.
  • the received signal itself can be subjected to frequency conversion (period conversion) by the period adjustment unit according to the setting of the setting means, and thereby the correspondence between the received signal and the time axis can be obtained.
  • a calibrated analysis signal can be generated.
  • the transmission signal radiated from the transmission antenna and the detection signal of the reception antenna belong to the microwave band of several hundred MHz to approximately 1 GHz.
  • a series of processes of generating a reception signal by repeating sampling a predetermined number of times while gradually shifting a sampling point of a reception antenna detection signal repeatedly received at a predetermined period is performed by a reception unit. It can also be configured.
  • peak value hold or average value hold is performed while sampling the amplitude of the reception antenna detection signal that is repeatedly received.
  • envelope value detection By performing envelope value detection on the average value, it is possible to generate a reception signal suitable for signal processing in which the frequency is reduced with respect to the original reception antenna detection signal, at the reception unit. Then, the generated received signal can be subjected to period adjustment for calibration in the signal processing unit.
  • a pulse control signal including a triangular wave signal (sawtooth wave) for sampling is output from the pulse controller, and the received signal can be sampled by this control signal. Further, by varying the rise time of the triangular wave signal in the control signal in conjunction with the potential change amount ( ⁇ ) of the detection signal, the relative dielectric constant of the medium is large and the period of the received signal is relatively large. The received waveform can be observed over a long time width (observation window), and when the relative permittivity of the medium is small and the period of the received signal is small, the received waveform can be observed over a relatively short time width (observation window).
  • a diode bridge for example, a Schottky barrier diode
  • a diode bridge for example, a Schottky barrier diode
  • the response characteristic of the diode and the frequency characteristic are compared.
  • the analysis signal that has passed through the medium having the different relative permittivity exhibits different periods according to the relative permittivity.
  • a correction data table indicating the relationship between the cycle of the analysis signal and the real time is created in advance by measurement, and the correction cycle corresponding to the cycle is converted to obtain the time (depth) from the analysis signal. ) Can be requested.
  • the predetermined relationship between the period of the received signal and the real time is obtained. It is also possible to generate and output an analysis signal that has been subjected to signal processing so as to have it.
  • the time for the electromagnetic wave to propagate through the calibration distance in the reference dielectric refers to the time for the electromagnetic wave to reciprocate between the surface of the reference dielectric and the calibration distance.
  • Electromagnetic Only calibration distance D in a reference dielectric having a dielectric constant epsilon r of the reference time t required for round trip propagation is expressed by the following equation. However, the propagation speed of electromagnetic waves in the atmosphere. . And
  • the time between the reflected wave on the reference dielectric surface and the reflected wave at the calibration distance is made to coincide with the propagation time t required for the calibration distance D. Adjust the setting means. Thereby, the correspondence between the analysis signal and the time axis in the signal processing unit is calibrated.
  • the reference time is determined by performing anti-air radiation and determining the period of the reflected wave.
  • the state calibrated with the reference relative permittivity can be equivalently reproduced by simply matching the period when anti-air radiation is performed with this reference time.
  • Derivation of the reference time can be performed by the user of the electromagnetic wave probe, but requires a large-scale reference dielectric. Therefore, the derivation of the reference time is basically performed by the manufacturer that provides the spacecraft, and the reference time must be specified for each antenna that can be replaced with the spacecraft and attached to the user. Thus, the user can accurately and easily calibrate the relative permittivity.
  • “dry dry soil” with a relative permittivity of 12 and a calibration distance of 50 cm is inexpensive and practical, but a medium having another relative permittivity is used as the reference dielectric. May be used. Masato is a conglomerate made of weathered granite.
  • the calibration distance (calibration time) is measured in “dry masa soil”. By confirming that this measured value is within the predetermined error range, it is possible to manage the specific dielectric constant of “dried masa”.
  • a dry mason earth is placed inside a box made of wood or the like.
  • the period T of an electromagnetic wave passing through a medium is the relative permittivity of the medium, and the propagation speed C of electromagnetic waves in the atmosphere. , And, using the frequency f of the electromagnetic wave.
  • the period in a medium with a relative dielectric constant of 12 is about 1/2 times the period in a medium with a relative dielectric constant of 45, and the received signal has a frequency variation (period) corresponding to the relative dielectric constant of the medium. Fluctuation).
  • the signal processing unit can generate an analysis signal obtained by performing signal processing on the received signal so that the following relationship is established. That is, it is possible to generate an analysis signal having a linearity between the analysis signal and the square root of the relative permittivity.
  • the electromagnetic wave probe 1 includes an antenna unit ⁇ , a signal processing unit 10, a calculation unit 11, a storage unit 12, and a display unit 13.
  • the antenna unit AT has a transmitting antenna radiating an electromagnetic wave at a predetermined cycle and a receiving antenna R receiving a reflected wave of the radiated electromagnetic wave adjacently and integrally housed therein.
  • the signal processing unit 10 includes a transmission unit 10b for supplying a pulse and a bias voltage to the transmission antenna T, and a reception unit 10c for performing necessary preprocessing on the detection signal captured by the reception antenna R. And a period adjustment unit 10d that generates an analysis signal obtained by performing a period adjustment by frequency conversion on the reception signal transmitted from the reception unit 10c, and a frequency conversion constant of the period adjustment unit 10d. And setting means 10 e for variably setting. Each component of the signal processing unit 10 is connected to the signal processing circuit 10a. It operates in response to necessary control signals.
  • the arithmetic means 11 performs digital processing, has an analog-to-digital converter, and has a function of converting an analog analysis signal transmitted from the signal processor 10 into digital data. Then, it generates analysis data obtained by performing an arithmetic process based on the measurement condition data stored in the storage means 12 on the analysis signal transmitted from the cycle adjusting unit 10d.
  • analysis data is generated by performing the corresponding arithmetic processing on the analysis signal, and the search result is displayed based on the generated analysis data.
  • the display unit 13 receives the analysis data subjected to the arithmetic processing transmitted from the arithmetic means 11 and performs a display control on the display controller 13a, and a display signal outputted from the display controller 13a.
  • the display 13 includes a display 13b that performs display based on the display 13b, and a display adjustment unit 13c that adjusts the display position of the display 13b.
  • the cycle adjusting unit 10d receives the analog reception signal transmitted from the reception unit 10c, and changes the cycle of the reception signal according to the setting of the setting unit 10e to thereby adjust the time axis. Perform an operation to change the correspondence.
  • these adjustment processes are performed mainly by analog processing. That is, the analysis signal output from the period adjustment unit 10d is displayed on the display unit 13 via the arithmetic unit 11, and the semi-fixed resistor (not shown) of the setting unit 10e is adjusted. Thus, the sweep speed in the time axis direction of the analysis signal is changed to adjust the period, that is, to calibrate the relative dielectric constant.
  • the search is mainly performed in a medium having a relative dielectric constant of approximately 3 to 50, and is used for analysis having linearity between the square root of the relative dielectric constant and the period of the received signal. Requires a signal. Further, since the frequency of the received signal is approximately 500 01.5 GHz, it is difficult to directly perform signal processing on the received signal.
  • the frequency of the received signal is adjusted prior to the processing of the cycle adjusting unit 10d.
  • the receiving unit 10c performs pre-processing for reducing the wave number and obtaining an analysis signal having a period corresponding to the relative permittivity of the passing medium.
  • the non-linear part of the frequency characteristic and the ON characteristic of the Schottky diode (hereinafter referred to as SBD) is positively combined and used, so that the relative permittivity of the medium and the period can be reduced.
  • An analysis signal having a predetermined relationship is output beforehand.
  • the peak value hold or the average value hold is performed while sampling the reception signal at each time interval according to the slope (mV / ⁇ t) of the output level V with respect to the reception signal time t according to the characteristics of the SBD.
  • an operation of repeating a series of processes for generating a frequency-reduced analysis signal is performed.
  • the period of the received signal is short, the period of the generated analysis signal having a reduced frequency is also short, and if the period of the received signal is long, the period of the generated analysis signal is also long. Can be pre-processed.
  • the control signal transmitted from the signal processing circuit 10a of the signal processing unit 10 is received by the receiving unit 10c, and the received signal is generated by analog processing. It is also possible to generate signals.
  • an electromagnetic wave is radiated from the transmitting antenna T to the air, and the analysis signal received by the receiving antenna R and generated by the signal processing unit 10 is displayed on the display 13b as shown in FIG.
  • the setting means 10e is adjusted so that the period of the surface reflected wave Wo in the analysis signal coincides with a predetermined reference time t according to the reference relative permittivity. As a result, the period of the analysis signal in the reference relative permittivity is correlated with the time axis, and the calibration of the relative permittivity is completed.
  • the frequency conversion of the received signal received by the receiving antenna R is thereafter performed by the period adjusting unit 10d according to the setting of the setting unit 10e.
  • An analysis signal to which is applied is generated, and an exploration analysis process is performed using the analysis signal obtained by performing an arithmetic process on the generated analysis signal by the arithmetic unit 11.
  • the period of the analysis signal displayed on the display 13 b is associated with the time axis, and the signal processing unit 10 The time standard in signal processing becomes clear.
  • the relative permittivity of the received signal in a medium having a different relative permittivity is determined.
  • An analysis signal having a period substantially proportional to the square root is generated.
  • the arithmetic means 11 performs processing necessary for displaying the search result on the analysis signal, generates the analysis data, and sends it to the display unit 13 I do.
  • the receiving unit 10c generates an analysis signal having a period substantially proportional to the square root of the relative permittivity, but the receiving unit 10c reduces the frequency of the analysis signal. It is also possible to generate analysis data having a period substantially proportional to the square root of the relative permittivity in the arithmetic means 11.
  • the relative permittivity calibration method of the present invention it is possible to easily carry out the method by simply matching the cycle of the analysis signal at the time of anti-air radiation with the reference time without using a special device. However, accurate exploration can be performed.
  • the time required for the electromagnetic wave to propagate through the calibration distance at the reference relative permittivity (round-trip propagation time of the calibration distance) t is calculated in advance.
  • Figure 6 shows the analysis signal W, which is the surface reflected wave W. And the reflected wave W 1 at the calibration distance d (50 cm).
  • the setting means 10 e of the period adjuster 10 d is adjusted so that the value is equal to the propagation time t of the calibration distance. This completes the calibration of the relative permittivity at the relative dielectric constant of 12; that is, the calibration of the period and the time axis of the analysis signal W is completed.
  • the airborne radiation is performed with the relative permittivity calibrated in this way, and the reference time t can be obtained by reading the period t of the surface reflected wave of the analysis signal from the time axis as shown in FIG.
  • the signal processing circuit 10a extracts the difference signal component between the analysis signals W by using a surface wave process (the probe 1 has By applying the surface wave processing mode, the starting point can be easily grasped.
  • the difference signal component subjected to the surface wave processing is displayed as an analysis signal W ', and the position of the calibration distance d of the reference dielectric 20 (the lower surface of the reference dielectric 20) A metal plate or the like is brought into contact with and separated from the surface.
  • the analysis signal W 'at this time the reflected wave W1' is displayed as a variable element, so that the starting point can be easily grasped. Therefore, the surface reflected wave W.
  • the calibration can be easily performed.
  • the reference time serving as the basis for the calibration of the relative dielectric constant can be easily derived by the inexpensive reference dielectric 20 using “dried masa” or the like.
  • the reference dielectric 20 is provided by the manufacturer of the spacecraft 1, there is no need to provide it on the user side. The user can perform reliable calibration simply by specifying the reference time in the instruction manual, etc. .
  • Fig. 10 shows the analysis signal W, which is the surface reflected wave W. And the reflected wave W1 at the calibration distance (50 cm).
  • the setting means 10e of the period adjuster 10d is adjusted so that the time t is equal to the propagation time t of the calibration distance.
  • the relative permittivity at the relative permittivity of 4.0 is calibrated, that is, the cycle and the time axis of the analysis signal W are calibrated.
  • the antenna AT of the detector 1 is abutted to radiate an electromagnetic wave, and the received signal is displayed on the display 13b as an analysis signal.
  • the analysis signal W includes the surface reflected wave W as shown in FIG. And the reflected wave W1 at the calibration distance (50 cm).
  • This surface reflected wave W. T between the reflected wave and W1. Is read from the time axis, and an error from the propagation time t of the calibration distance when the relative dielectric constant is 12 is determined.If the error is within a predetermined range, it is assumed that the relative dielectric constant of the reference dielectric 20 is maintained. I do.
  • the surface reflected wave W included in the analysis signal may be adjusted to move the analysis signal to a position where the time can be easily read.
  • the signal processing unit 10 and the arithmetic unit 11 are shown as different configurations.However, the arithmetic unit 11 has a configuration using a common CPU with the signal processing circuit 10a of the signal processing unit 10. It is also possible. Further, it is also possible to digitize the processing of the cycle adjusting unit 10d and the setting unit 10e.
  • the method of measuring the relative permittivity can include the following steps (a) to (d). '
  • Relative permittivity (measurement cycle time Z reference cycle time) Steps to obtain from 2 X reference calibration relative permittivity (this relative permittivity is the average value for each section).
  • the dielectric constant (relative permittivity) obtained in this way is classified by a color bar and displayed as a permittivity distribution map in the depth direction of the stratum.
  • the state inside, the dielectric constant, the stratum, and the like can be determined.
  • By placing a cursor on the color bar and searching the analyzed section distance it is possible to simultaneously observe the average dielectric constant of the section, the total depth, etc., greatly simplifying electromagnetic wave exploration and improving functionality be able to.
  • the period of the analysis signal based on the received signal obtained by the anti-air radiation coincides with the reference time without requiring any special device.
  • Calibration at a predetermined relative permittivity can be performed immediately by just doing so, and workability at the exploration site can be improved and precise exploration can be performed. Further, according to the method of deriving the reference time of the present invention, which is also proposed at the same time, it is possible to easily obtain the reference time using the reference dielectric.
  • the relative permittivity calibration method of the present invention can be effectively implemented.

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  • Engineering & Computer Science (AREA)
  • Remote Sensing (AREA)
  • Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • Geology (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geophysics (AREA)
  • Electromagnetism (AREA)
  • Radar Systems Or Details Thereof (AREA)
  • Geophysics And Detection Of Objects (AREA)

Abstract

La présente invention concerne un procédé pour étalonner aisément la permittivité relative d'un détecteur électromagnétique avant toute détection, ainsi qu'un détecteur électromagnétique permettant la mise en oeuvre dudit procédé d'étalonnage de permittivité relative. Ledit détecteur électromagnétique (1) comprend une antenne d'émission (T), qui permet d'émettre une onde électromagnétique, une antenne de réception (R), qui permet de recevoir une onde réfléchie de l'onde électromagnétique émise, une unité de réception, qui permet de produire un signal de réception en réponse à un signal de détection issu de l'antenne de réception (R), ainsi qu'une unité de traitement de signal (10), qui permet de traiter le signal de réception et de produire un signal d'analyse. L'unité de traitement de signal (10) présente une partie de réglage de période (10d), qui permet de convertir le signal de réception en signal d'analyse présentant une période de signal différente, par conversion de fréquence. La partie de réglage de période (10d) comprend un système de réglage (10e), tel qu'un condensateur à capacité variable, qui permet de régler une constante de conversion de fréquence. Ce système de réglage (10e) est réglé de façon que, lorsqu'une onde électromagnétique est émise dans l'air depuis l'antenne d'émission (T), la période du signal d'analyse puisse correspondre au temps de référence t, qui est prédéfini en fonction d'une permittivité relative de référence.
PCT/JP2001/007328 2000-10-12 2001-08-27 Procede pour etalonner la permittivite relative d'un detecteur electromagnetique et detecteur electromagnetique WO2002031537A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP2002534869A JP3511026B2 (ja) 2000-10-12 2001-08-27 電磁波探査機の比誘電率校正方法および電磁波探査機
AU2001293352A AU2001293352A1 (en) 2000-10-12 2001-08-27 Method for calibrating relative permittivity of electromagnetic detector and electromagnetic detector

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US10074127B2 (en) 2002-04-17 2018-09-11 Ebay Inc. Generating a recommendation

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JP2018068850A (ja) * 2016-11-02 2018-05-10 国際化工株式会社 樹脂製食器の製造方法

Citations (4)

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Publication number Priority date Publication date Assignee Title
JPH01282490A (ja) * 1988-05-06 1989-11-14 Koden Electron Co Ltd 土中の誘電率計測機能を具備した地中探査装置
JPH0886881A (ja) * 1994-09-16 1996-04-02 Mitsui Eng & Shipbuild Co Ltd 地中埋設物探査装置
JP2000147111A (ja) * 1998-11-05 2000-05-26 Meisei Electric Co Ltd 地中埋設物探知装置及び地中埋設物探知方法
JP2000221266A (ja) * 1998-11-24 2000-08-11 Osaka Gas Co Ltd ３次元ボクセルデ―タ表示方法及び装置

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01282490A (ja) * 1988-05-06 1989-11-14 Koden Electron Co Ltd 土中の誘電率計測機能を具備した地中探査装置
JPH0886881A (ja) * 1994-09-16 1996-04-02 Mitsui Eng & Shipbuild Co Ltd 地中埋設物探査装置
JP2000147111A (ja) * 1998-11-05 2000-05-26 Meisei Electric Co Ltd 地中埋設物探知装置及び地中埋設物探知方法
JP2000221266A (ja) * 1998-11-24 2000-08-11 Osaka Gas Co Ltd ３次元ボクセルデ―タ表示方法及び装置

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10074127B2 (en) 2002-04-17 2018-09-11 Ebay Inc. Generating a recommendation

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