KR20000024666A - Detection apparatus for the survey of buried structures by used gpr system - Google Patents

Abstract

PURPOSE: An apparatus for detecting underground buried substance using GPR system is provided to manufacture the GPR(ground penetration radar) of better performance, to improve work efficiency through unification and to ensure the safety of the piping with the development of economical and simplified GPR. CONSTITUTION: A main console(100) controls the whole system, also records and stores a signal transmitted from a receiver(300), and transmits files to a PC necessary for processing. The main console(100) determines several variables, such as initial time at which the signal is recorded, the digital sampling distance of receiving signal, whole time range at which the signal is recorded, stacking time, etc, necessary for the probing. A display part(400) converts the acquired pulse file into the image. A transmission cable is in charge of the file transmission between the main console(100) and the transmitter and receiver(200,300).

Description

Underground buried surface detection device using zipal system {DETECTION APPARATUS FOR THE SURVEY OF BURIED STRUCTURES BY USED GPR SYSTEM}

The present invention relates to an underground landfill detection device, and more particularly, underground landfill using a ground penetration radar (GPR), which can compensate for the disadvantages of the pipe locator of the prior art. It relates to a detection device.

In the basement of our residence, there are numerous underground structures such as gas pipes, water and sewage pipes, oil pipes, communication and power cable pipes, various ducts and storage tanks. Accordingly, safety accidents associated with underground facilities are frequent. This trend is also expected to continue to increase in the future. Therefore, careful management and maintenance of these underground facilities is urgent.

In Korea, the high-pressure pipe network of 10 ~ 70㎏ / ㎠ operates over 1,300 km as of the end of 1997 and is expected to reach 2,000 km within a few years. Due to the nature of the high-pressure pipes, large-scale accidents such as the Ahyeon-dong accident in 1994 occur, which requires thorough management and safety measures.

There are various factors that can cause the safety of the pipe, but among them, 1) pipe breakage by other construction (excavator, drilling machine), 2) pipe deformation due to ground subsidence or flow, 3) subway or other underground The three major hazards are electrical corrosion caused by vagus currents from the facility.

In order to establish countermeasures, it is essential to first identify the exact location of the pipe. In order to reduce the risk of other constructions, it is best to identify and notify the exact location of the gas piping when permitting before construction. In addition, accurate positioning of the pipe is essential to know the amount of deformation due to settlement or flow of the pipe.

Currently, the following methods are mainly used to locate the pipes.

1) The surface of stone is installed at the critical point (pipe section, before and after crossing).

2) Place plumbing signs directly above the plumbing or on the side road shoulders.

3) Use pipe locator.

The use of paving stones is ineffective because the installation intervals between the paving stones are too long and sometimes out of the original position, and the signing method does not indicate the exact position of the pipes, but it indicates the presence of high-pressure pipes around. to be.

The method of using a pipe locator is the most commonly used method, which has the advantage of being relatively accurate and simple. However, the accuracy of the pipe locator is greatly reduced due to interference in the place where the pipe is complicated.

One of the methods that can compensate for the disadvantages of the pipe locator is a method using the GPR.

GPR is a device that detects various structures and layers in the ground using high frequency electromagnetic wave and received signal processing method to detect the position of the object. It was originally used for the purpose of physics exploration and recently applied to underground pipe detection. It was.

However, such a conventional GPR is complicated in equipment configuration and requires considerable experience and proficiency to accurately analyze the detection results, and the detection results are very sensitive depending on the properties of the soil. It is a difficult situation.

In other words, as described above, the conventional GPR, despite its precision, has a disadvantage that the detection result depends largely on the electrical properties of the soil, and that a considerable amount of skill is required for the analysis of the detection result and that it is an expensive equipment. It is difficult to spread a wide range. In addition, it is composed of a main console (transmission console), a transmission antenna, a portable PC, a cable (cable), etc., takes up a considerable amount of space during work and is inefficient in terms of maintenance.

Accordingly, the present invention has been made to solve the above-mentioned problems, and the object of the present invention is to compare the principles, advantages and disadvantages of the prior art, establish a best underground landfill detection technique, and improve the performance of the GPR. It is to provide underground underground site detection device using GPR system that secures the pipes by improving and improving the work efficiency through the small size integration and developing and distributing the economical and simplified GPR with greatly reduced cost.

1 is a block diagram of the underground buried land detection device using a GPR system of the present invention.

2 is a control block diagram of FIG. 1 in more detail.

Figure 3 is a side perspective view of a cart equipped with the present invention.

4 is a perspective view of FIG.

5 is a view showing a basic method of obtaining a cross-sectional image of the underground buried of the present invention.

6 shows a method of shaping an image of the invention.

7 is a view showing a detection result of the present invention.

8 is a diagram showing the results when the gas is probed in the longitudinal direction of the pipe;

9 is a view showing the principle of measuring the depth of embedding according to the present invention.

10 is a view showing the detection results when using an antenna having a center frequency of 100 MHz and a center frequency of 50 MHz, respectively.

Fig. 11 shows the waveform of an ideal pulse of a circuit using a diode and its circuit diagram.

12 is a waveform diagram of an output pulse of a circuit using a diode.

13 is a waveform diagram obtained by a circuit and an experiment using an avalanche transistor;

14 is a detailed circuit diagram of a pulse transmission circuit of the present invention.

15 is a detailed circuit diagram of a pulse generator of the present invention.

16 is a view comparing the shapes of the output pulses of the monopulse method and the dual pulse method.

17 shows the directivity characteristics of a dipole antenna.

18 shows resonance characteristics of a dipole antenna.

19 is a waveform diagram of a received signal.

20 is a detailed circuit diagram of a reception preamplifier of the present invention.

21 is a detailed circuit diagram showing a transmitting antenna of the present invention.

Fig. 22 is a detailed circuit diagram showing a receiving antenna of the present invention.

Figure 23 is a block diagram depicting another embodiment of the present invention.

<Explanation of symbols for main parts of the drawings>

100: control device 110: receiving preamplifier

120: A / D converter 130: pulse generator

140: pulse transmission circuit 150: CPU

160: receiving signal storage unit 200: transmitting antenna

300: receiving antenna 400: display unit

500: power supply unit 600: communication unit

700: Internet Server 800: Cart

810: lower cart 820: handle

830 moving wheels 900 transmission line

Characteristic of the underground buried surface detection device using the GPR system according to the present invention for achieving the above object, the PC required for indoor data processing by controlling the entire system, recording and storing the signal transmitted from the receiving antenna It is responsible for transmitting data to the controller.It is necessary for the exploration such as the first time the signal is recorded by the control device, the digital sampling interval of the received signal as the analog signal, the total time range in which the signal is recorded, and the stacking frequency. Determining various variables, generating and amplifying pulses suitable for the determined variables, amplifying them, radiating them through a transmitting antenna, amplifying and recording signals received through a receiving antenna, and sampling intervals and sampling intervals per trace. A controller for determining the number; A transmitting and receiving antenna for emitting a pulse generated by the control device and receiving a signal reflected from the buried object after passing through the medium; A display unit for realizing the pulse data acquired by the control device as an image, and displaying a sectional view of a higher resolution by applying various implementation colors to a high-resolution screen for the processed data; A transmission line made of a coaxial cable or an optical cable to perform data transmission between the control device and the transmitting and receiving antennas, and to transmit a radar wave and receive a reflected wave in a minimum noise state; And a power supply unit for supplying driving power to each of the units, using a DC power source to reduce the generation of high-quality pulses and noise as a necessary power for generation of electromagnetic pulses and transmission and reception of data.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

The present invention radiates electromagnetic waves in the frequency range of about 1 to 1800 MHz from the transmitter to the ground, and is reflected at the interface between the underground media (for example, the buried structure and soil contact) having different electrical characteristics. It is a non-destructive detection equipment that collects and records the electromagnetic waves returning to the ground and analyzes the image and structure of underground buried materials through data processing and analysis process by PC.

Figure 1 is a block diagram of the underground buried land detection device using the GPR system of the present invention. FIG. 2 is a control block diagram showing FIG. 1 in more detail, FIG. 3 is a side perspective view of a cart equipped with the present invention, and FIG. 4 is a perspective view of FIG.

As shown, the present invention is composed of a control device 100, a transmitting antenna 200, a receiving antenna 300, a display unit 400, a power supply unit 500 and a transmission line 900.

The main control unit 100 controls the entire system, and records and stores a signal transmitted from the reception antenna 300 to transmit data to a PC necessary for data processing indoors. In particular, the controller 100 determines various variables required for the exploration, such as the initial time at which the signal is recorded, the digital sampling interval of the received signal, which is an analog signal, the total time range at which the signal is recorded, and the stacking frequency. After generating and amplifying a transmission and reception pulse suitable for the determined variable, the radiation is transmitted through the transmission antenna 200, and the signal received through the reception antenna 300 is amplified and recorded. In addition, the sampling interval and the number and sampling intervals per trace are determined.

Transmitter and receiver antenna (200) (300) is the most essential part of the GPR to emit a pulse generated from the control device 100 and receives the signal reflected back from the buried object after passing through the medium Is a device that uses different antennas depending on the emission frequency selected to match the exploration limit depth.

The display unit 400 is an apparatus for implementing the acquired pulse data as an image, and may display a sectional view of higher resolution by applying various implementation colors to a high resolution screen on the processed data.

The transmission line 900 is responsible for data transmission between the control device 100 and the transmission and reception antennas 200 and 300. The transmission line 900 receives the transmission of the radar wave and the reception of the reflected wave in the lowest noise state. It is preferable to use a coaxial cable or an optical cable in charge of the transmission function.

The power supply unit 500 preferably uses a DC power source in order to reduce the generation of high-quality pulses and noise as the necessary power for the generation of electromagnetic pulses and the transmission and reception of data.

The control device (100) comprises: transmitting means for generating a pulse of ultra wide bandwidth through a pulse generator (130) and a pulse transmitting circuit (140); A reception preamplifier (110) for amplifying a signal input from the reception antenna (300); An A / D converter 120 for converting an analog signal amplified by the reception preamplifier 110 into a digital signal; And a CPU 150 for controlling the entire system, collecting raw data, and measuring propagation time from transmission to reception.

In addition, the present invention, as shown in Figure 3 and 4, the control device 100, the transmitting antenna 200, the receiving antenna 300, the display unit 400, the power supply unit 500 and the transmission line 900 ) Is loaded on a cart 800 provided with a moving wheel 830 and a handle 820 to reduce mobility of the worker because of improved mobility.

Transmitting and receiving antennas 200 and 300 are installed in the lower cart 810 in order to minimize the transmission and reception signal (signal) loss, close to the surface and attached to the front, back so that electromagnetic waves are not lost in the air, light weight and workability good.

In addition, since the power supply unit 500 can be driven by a lightweight battery, the power supply unit 500 can be recharged, and battery replacement is easy. The display unit 400, which can display the information of the device to help the operator to quickly and smoothly detect, is made of a CRT monitor or LCD panel and has high resolution and high contrast ratio for sufficient reading even in direct sunlight in the open air. Have

If described with reference to the accompanying drawings, the principle of the present invention configured as follows. First, the electromagnetic wave emitted from the transmitting antenna 200 propagates in the medium and detects a wave reflected after hitting an object, and measures the distance between the object and the transmitter from the flight time and propagation speed of the electromagnetic wave.

However, in the case of underground media, since the radar is physically non-homogeneous than the air propagated, it is difficult to easily find information such as radar. In other words, due to the physical heterogeneity, the signal reflected from the basement contains a lot of noise, which is difficult to read. Therefore, the exploration data must go through appropriate processing.

Basic method for obtaining a cross-sectional image of the underground buried material using the present invention is as shown in FIG. In FIG. 5, (a) shows transmission and reception of electromagnetic waves, and (b) shows acquired pulse data.

As illustrated, a radio transmitter (XMIT) and a receiver form a pair of transmit / receive antennas 200 and 300 to be in contact with each other on the ground. The signal emitted from the transmitter penetrates a short distance into the ground. Radio waves, which propagate underground, will reflect when they collide with other materials with nearby soil and electrical properties. For example, signals are reflected from buried pipes and underground voids. The signal reflected from the underground object (radio signal) arrives after a short time after being emitted as shown in FIG.

FIG. 6 is a view illustrating a method of shaping an image of the present invention, in which a pulse echo reflected from a buried object is generally shaped on a display unit 400 such as a PC screen so that an observer can easily recognize the image. The radar moves on the ground at regular intervals as shown in Fig. 6 (a) (1 → 2 → 3), so that a new echo is drawn next to the previous echo as in Fig. 6 (b). This pulse pattern is continuously output on the screen of the PC. When a sufficient amount of signal is detected in this way, the operator can see the echo pattern on the screen and recognize that there is an object buried underground.

The above detection results are shown in the form of a hyperbola when the reflected pulses of the lower part of FIG. 7 (b) are connected. When the pipe is buried underground as shown in (a) of FIG. 7, when the buried object is located in front of the transmitting / receiving antennas 200 and 300 when it is detected across the pipe, the emitted echo is reflected back to the object. It will take some time to come.

This time is gradually reduced as the transmit and receive antennas 200 and 300 approach the object. If there are antennas 200 and 300 directly above the buried object, the echo reflection time is the shortest. Afterwards, the time for the reflected wave to reach the receiving antenna 300 increases as the buried object passes again. This results in a hyperbola. Experienced workers can see that this is a small object, such as a pipe. Different patterns appear depending on the type of buried structure. For example, a cuboid storage tank buried underground would appear as a flat curve with both ends of the echo curve descending downwards.

However, if the probe in the longitudinal direction of the pipe result will be as shown in FIG. That is, since the distance between the transmission and reception antennas 200 and 300 and the pipe are always the same, when the pulse of the received reflected wave is followed, it appears as a straight line. The problem is that the same results occur under different conditions. For example, assuming that an area is divided into two layers, such as a clay / bedrock layer, the detection result is shown as a straight line as shown in FIG. 8 even at the boundary of the two layers. It cannot be said that it is buried. Therefore, when burying the buried pipe, it should be detected across the pipe.

Buried depth measurement principle according to the present invention is as shown in FIG. In other words, it is not easy to determine the depth of burial if you do not have some information about the surrounding soil. In principle, the GPR system measures the emission / arrival time of electromagnetic waves and pulses very accurately. In other words, if the moving speed of the electromagnetic wave in the soil is known, the depth of embedding can be calculated because the time between the transmitted pulse and the reflected pulse of FIG. 9 (b) is known. Therefore, the embedding depth is displayed on the image appearing on the PC through such a process.

However, the speed of the radar signal varies sensitively with the soil type. In the air, radar waves propagate at a rate of 297,600 km / sec. However, in the soil, the speed is very sensitive to the moisture content, porosity, etc. of the soil. Therefore, empirically knowing the electrical characteristics, electrical conductivity and dielectric constant (dielectric constant) of the soil, or if there is a buried object that knows the depth of embedding, it is possible to accurately correct the depth of embedding measured by GPR detection. Therefore, soil information is essential for accurate depth measurement through GPR. Table 1 shows the propagation characteristics of electromagnetic waves according to the general soil types.

material Dielectric constant Speed (m / ㎱) Attenuation Coefficient (㏈ / m) air One 0.30 0 distilled water 80 0.033 0.002 fresh water 80 0.033 0.1 sea water 80 0.01 1000 dry sand 3 ~ 5 0.15 0.01 saturated snad 20-30 0.06 0.03-0.3 limestone 4 ~ 8 0.12 0.4 ~ 1 silt 5-30 0.09 1-100 clay 5-40 0.07 1-100 granite 4 ~ 6 0.13 0.01 ~ 1 dry salt 5 ~ 6 0.13 0.01 ~ 1 ice 3 ~ 4 0.16 0.01

On the other hand, one of the most important variables in GPR survey is the selection of operating frequency. Appropriate frequency selection can determine whether or not exploration is successful. Frequency selection may be made by clearly defining the subject to be explored. This means that field exploration should be carried out prior to the survey.

Considerations for frequency selection include geological conditions of the site, surface obstructions, electrical characteristics of the soil, and depth of burial of the object. The most important factor in dual frequency selection is the depth of detection, because the higher the frequency, the lower the detection depth. Therefore, the frequency should be appropriately selected according to the depth and size of the target.

FIG. 10 is a detection result when an antenna having a center frequency of 100 MHz and a center frequency of 50 MHz is used, respectively. As can be seen, the information about the deep-depth buried material is relatively detailed when the low-frequency antenna of 50 MHz is used according to the depth of the object to be explored, and the information about the deep-depth buried material is used when the 100 MHz antenna is used. It can be seen that.

In addition, Table 2 below shows the approximate detectable depth according to the center frequency.

Depth (m) Center frequency (MHz) 0.5 1,000 1.0 500 2.0 200 7.0 100 10.0 50 30.0 25 50.0 10

When detecting the depth of gas pipelines, antennas with a center frequency of 225 MHz are mainly used.In addition, 400 MHz antennas are also used for the detection of other pipelines having a lower depth of field than gas pipelines at points where several pipes intersect. Although it is used, since the depth of embedding of a general gas pipe is about 2m, it is most preferable to use an antenna having a center frequency of about 200 MHz in the present invention.

In addition, a time window means how long a data is to be received, which is related to the depth of burial of the object to be detected. That is, the data must be received for a sufficient time more than the time when the electromagnetic wave propagates to the buried object and then returns again. This is also closely related to the propagation rate of electromagnetic waves in the soil. Therefore, when selecting the time window, it is necessary to know information about the electrical properties of the soil as well as the depth of embedding of the object.

Sampling interval (Sampling interval) means how much time interval to collect the reflected waveform to return, the value varies depending on the center frequency of the antenna used in general. The two variables are preferably used according to the frequency of the most suitable values according to the type of the transmit and receive antennas (200, 300).

In addition, if the electrical conductivity of the soil is high, the propagation of electromagnetic waves becomes difficult. In general, if the cell conductivity is 0.01Ω ^-1 · cm ^-1 or more, it is considered difficult to detect GPR. Therefore, it is essential to understand or predict the electrical characteristics of the area to be detected before the detection in advance. In Table 3 below, the media were classified according to their electrical conductivity.

Exploration conditions Electrical Conductivity (σ) (Ω ^-1 · cm ^-1 ) medium good σ <10 ^-7 Air, Dry Granite, Dry Limestone, Concrete, Asphalt Not bad 10 ^-7 <σ <10 ^-2 fresh water, ice, snow, sand, sit, dry clay, basalt Bad σ> 10 ^-2 Wet clay, wet basalt, sea water, thaw

Next, the operation of the present invention through the features of the respective components constituting the present invention will be described in more detail.

In the transmission means composed of the pulse transmission circuit 140 and the pulse generator 130 of the GPR, ultra wide bandwidth pulses are generated. Therefore, as a core GPR manufacturing technology, ultra-wide bandwidth pulse reproduction technology must be possessed. This pulse must meet the specification of 100 volts or more with a width of 5 ms with a standing time of approximately 300 ms. This standard corresponds to a throughput of 300 kHz / kHz based on the test standard used to indicate the specification of semiconductor components. It is realized by existing semiconductor components using general oscillation, amplification, modulation, and demodulation techniques. This is impossible. Therefore, in the present invention, hundreds of experiments were repeated, and the ultra wide bandwidth pulse of the desired purpose was reproduced. It is divided into two main categories as follows.

First, since a diode is used, it can be observed that a step recovery operation generally occurs in a power rectifying diode. This is important for this study and is not intended to be a diode characteristic. Therefore, it does not define that step recovery occurs in the diode specification. The most important specification of a diode is TRR. Next are TS and TR. Therefore, it is generally impossible to determine the step recovery operation of an untested diode. The staff recovery diode D is hereinafter referred to as SRD. 11 shows a waveform of an ideal pulse and a circuit diagram thereof.

The illustrated circuit generates a sharp waveform pulse using a low voltage SRD (D), the diode D of which is biased forward by a direct current through two inductors L1 and L2. Initially, SRD (D) suppresses the flow of electrons and holes. At this time, when the input pulse reaches the diode (D) provides a path of high conductivity through the diode (D). Thus, the output voltage reaches the input voltage, the charged voltage drops rapidly and the barrier of charge immediately recovers. The circuit is then opened and the output voltage drops to zero.

In this experiment, the circuit was evaluated under the following conditions.

Vmax = 300V (IR = 6A)

Vbias = Adjusted to find the optimal output waveform

R = 50 W

L = 200 mH

C = 0.1 mF

If the reflected wave of the transmission line is not minimized, the expected standing time / pulse width is not guaranteed. The shape of the output pulse is as shown in FIG.

Secondly, in the case of using an avalanche transistor, Fig. 13 is a waveform obtained by a circuit and an experiment using an avalanche transistor. An avalanche bias voltage of 140V is applied to the collector of Q1 via the R3-C1 network. Q1 is 75 volts. At this time, if C1 is charged to a sufficiently high voltage, the balance of Q1 is broken and as a result, a very fast granular pulse is generated by C1. Subsequently, C1 is discharged via R4, and the voltage decreases rapidly, and at the same time, the breakdown phenomenon of Q1 is immediately restored. C1 is recharged through R3 until Q1 is again debalanced. This phenomenon is repeated about 200,000 times / second.

The voltage of the pulse obtained here is about 55V and the width is about 4-5 kV. The time of granulation and arrival is about 1 ms. Q1 should choose a transistor with the balanced characteristics. However, the characteristics and specifications are not guaranteed by the manufacturer.

However, unspecified results of sampling and testing dozens of transistors show overall satisfactory characteristics. To satisfy the output voltage of 50-60V, it is necessary to adjust the value of C1 between 2-10mA. In order to obtain good results from this circuit, it is necessary to design the ground diagram of the substrate to be suitable for high speed characteristics.

As a result of evaluating the above two circuits, both of them could satisfy the basic standard of this experiment, but it was judged that it is more efficient to use the balanced transistor method which is easier to control. On the other hand, in the present invention, it is more preferable to adopt a bipolar method in which the above circuit is used in two up-down symmetry, that is, a method in which two pulses are generated at the same time in order to make a stronger transmission pulse.

An embodiment of the circuit described above is illustrated in FIGS. 14 and 15. FIG. 14 is a detailed circuit diagram of the pulse transmission circuit of the present invention, FIG. 15 is a detailed circuit diagram of the pulse generator of the present invention, and FIG. 16 is a view comparing the shapes of the output pulses of the monopulse type and the dual pulse type.

The dipole antennas 200 and 300 for transmission and reception of the present invention are as follows. In general, in the high frequency region, a horn antenna or a planar array type antenna is used. However, in the range of the 225 MHz band aimed at by the present invention, a dipole type antenna is applied.

Dipole antennas have various problems such as low directivity, antenna ringing, unstable characteristic impedance, undesired frequency spread, and mechanical enlargement.However, the use of resistive termination reduces antenna resonance, It is possible to increase antenna directivity by adopting a reflector, to reduce unnecessary frequency spread by appropriate use of a buffer, and to reduce its size and weight.

17 and 18 show the characteristics investigation record of the dipole antenna for this improvement experiment. Here, FIG. 17 shows directivity characteristics of the dipole antenna, and FIG. 18 shows ringing characteristics of the dipole antenna.

Regarding the reception preamplifier 110 of the present invention, the circular shape of the received reflection wave is theoretically shown in FIG. 19. In practice, however, it is common to detect undesired signals such as unnecessary frequency bands, noise, echo, resonance waves, images, etc., which are much more complicated. Therefore, it is necessary to remove them using an appropriate band pass filter and amplify the noise to the required level without noise in order to obtain desired information. In the present invention, a reception preamplifier 110 capable of amplifying up to 90 DB as necessary through the wideband high frequency amplifier NE5205 is implemented, and an embodiment of the circuit is shown in FIG. 20.

In addition, a signal input from the reception antenna 300 and amplified by the reception preamplifier 110 is converted into a digital signal by an analog-to-digital conversion A / D converter 120, and the CPU 150 transmits the signal. The propagation time from reception to reception is measured. This requires measurement techniques for very short time periods (nanoseconds or picoseconds as needed) and the latest technology used in high-speed digital storage oscilloscopes. 21 and 22 are detailed circuit diagrams of the transmitting antenna 200 and the receiving antenna 300 according to the present invention.

On the other hand, as described above, the structure of the GPR of the present invention is very complicated. That is, the transmit and receive antennas 200 and 300 which are in close contact with the ground surface and are responsible for transmitting and receiving, the field transmitting circuit 140 and the pulse generating unit 130 generating pulses of an ultra wide band, control the transmission output and adjust the receiving frequency. Provides the operating power of all devices including a CPU (150) for analysis and a transmission / reception cable (900) of several tens of meters for an interface, a control analysis and collection of field data operation, a PC (not shown), and storage. It is composed of a power supply unit 500, etc., very complicated wiring is required, and due to physical problems such as the configuration of many devices (Device), the daily detection speed is expected to be approximately 1km / Day.

The electrical problem is that the daily detection distance is limited by the capacity of the battery because the operation is supplied from the battery. Since the current consumption of the pulse transmitting circuit 140, the pulse generator 130, and the transmitting and receiving antennas 200 and 300 generating ultra wide band pulses is large, it is desirable to always prepare a heavy power supply and proceed with the detection. .

In addition, when multiple devices are mounted on a single device, there is a possibility of many malfunctions due to noise between the devices due to the ultra-wideband pulse. In order to eliminate the malfunction caused by the noise, each device must be separately mounted on a structure capable of filtering noise as in the present invention, and an integrated mechanism cart having a structure in which a spare battery of weight can be mounted. 800 is preferred. As a result, the preparation of the site was greatly improved due to the integration of the equipment (site preparation, interface for each module), the site was easily detected and the equipment was moved, and the spare battery could be installed to provide physical and electrical elements. The detection speed is 4km / day.

In addition, the present invention further includes a separate reception signal storage unit 160 to store the collected raw data for use in the CPU 150 in a sufficient amount of static memory, and the CPU 150 as necessary It saves the raw data that is sent at the request and collected at high speed.

In addition, since the CPU 150 must use an extremely short (nano or picosecond) electromagnetic wave pulse as the transmission wave, the received signals are input by combining a delayed signal and a reduced signal of the transmission signal. However, these received signals have distance information on targets at a certain location but do not have direction information. Therefore, the detection result is generally in the form of hyperbola, and even if high resolution image processing operation is performed, it reconstructs the reflection of the reflected pulse according to the depth information of the medium to be explored into distance information to reproduce in a faint form and experience of the probe In addition, the fact that the information about the object to be detected is inferred and interpreted through various detection results.

This makes it hard to tell which one is being probed when there is a medium similar to the one being underground. For example, if gas pipes and other pipes are adjacent to each other in parallel, it can be seen that the two pipes pass simultaneously, but it is not easy to distinguish the types of pipes without knowing the preliminary information about the pipe position.

Therefore, in the present invention, when the target passes quickly through one target while transmitting to the medium evenly side by side from the antenna 200, 300 using a plurality of transmit and receive antennas 200, 300 so as to accurately find the direction of the target. The reverberation of the pulses will appear as several hyperbolas in space and time. In this case, it is judged that one target can be easily found by taking the vertices of several hyperbolas. If the echoes of these pulses are processed by a suitable algorithm and the continuous transmit / receive pulses are arranged, a visual effect close to 3D can be obtained. Therefore, it is possible to acquire information on the exact buried object.

In addition, the practical use of the present invention and the acquisition of three-dimensional image to the antenna spacing and resolution, analysis of the signal conversion, curling of the echo pulse, separation of the combined pulse, removal of the background signal, compensation of the transmission loss and correction of signal directivity The research should continue.

FIG. 23 is a block diagram illustrating another embodiment of the present invention. In the configuration of the transmitting and receiving antennas 200 and 300 and the control device 100, the communication unit 600 and the Internet server 700 are shown in FIG. Configure more. Therefore, the transmitting and receiving antennas 200 and 300 transmit the high frequency electromagnetic wave pulses generated by the control device 100 and also receive the received signal reflected back from the target object. As described above, the transmission / reception frequency is selected differently according to the depth of the probe and the size of the probe.

The control device 100 controls the entire system and processes the data by recording and storing the measured signal. The control apparatus 100 determines various variables required for the exploration such as the first time the received signal is recorded, the digital sampling interval of the received signal which is an analog signal, the total time range in which the signal is recorded, the number of stackings, and the like. Generate and transmit and receive pulses that are suitable for amplifying and radiating through the transmitting antenna 200, and amplifies and records the signal received through the receiving antenna 300. In addition, sampling intervals and number of sampling intervals per trace are determined.

In addition, the communication unit 600 is a part having a function of supporting the connection of the control device 100 and the Internet server 700. The apparatus of the present invention can be controlled via the Internet, and the measurement data is transmitted to the client via the Internet in real time. The main function is to connect the RS232 communication function of the control device 100 and the TCP / IP function of the Internet server 700, and serves as a network bridge capable of supporting the SNMP protocol.

Therefore, it is possible to remotely manage and control GPR, which is a measurement equipment, by using the SNMP protocol and Java's applet technology on the Internet, and to control the specific GPR remotely, and the measurement data from the specific GPR is real-time. To the client.

Therefore, as described above, according to the underground buried material detecting apparatus using the GPR system according to the present invention, because it is loaded on the cart (cart), the mobility is improved in the characteristics of the equipment to reduce the fatigue of the operator. The antenna is installed at the bottom of the cart in order to minimize the transmission and reception signal (signal) loss is attached to the front and back in close contact with the surface, the electromagnetic wave is not lost to the air, the weight is light and workability is good. Since it can be driven by a lightweight battery, recharging is possible and battery replacement is easy. The display device that can display the information of the device to help the operator to quickly and smoothly detect is made of a CRT monitor or LCD panel, and has a high resolution and high contrast ratio for sufficient reading even in direct sunlight in the open air. The raw data collected in the field work can be stored in a reliable mass storage device and can be re-read. Therefore, more accurate image analysis and composition can be performed in the office (laboratory) after the work. In addition, it is possible to remotely manage and control GPR, which is a measurement equipment, by using the SNMP protocol and Java's applet technology on the Internet, and to remotely control a specific GPR, and to measure data from a specific GPR in real time. There are various effects such as being delivered to the client.

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes are intended to fall within the scope of the claims set forth.

Claims (10)

It controls the whole system, records and stores the signal transmitted from the receiving antenna 300, and transmits the data to the PC necessary for data processing indoors, the first time the signal is recorded in the control device 100 Determining various variables such as time, digital sampling interval of analog signal, total time range in which signal is recorded, stacking frequency, etc., and amplifying by generating transmit / receive pulse suitable for the determined variable. A control device (100) that radiates through the transmit antenna (200), amplifies and records the signal received through the receive antenna (300), and determines sampling intervals and the number and number of sampling intervals per trace; Transmitting and receiving antennas (200) (300) for radiating pulses generated by the control device (100) and receiving signals returned from the buried object after passing through the medium; A display unit 400 for implementing a pulse data obtained by the control apparatus 100 as an image, and displaying a cross-sectional view of a higher resolution by applying various implementation colors to a high-resolution screen for the processed data; Coaxial cable or optical cable is responsible for data transmission between the control device 100 and the transmitting and receiving antennas 200 and 300, and is responsible for transmitting the transmission of the radar wave and the reception of the reflected wave in the lowest noise state. Transmission line 900; And a power supply unit 500 for supplying driving power to each of the units, using a DC power supply to reduce the generation of high-quality pulses and noise as the necessary power for the generation of electromagnetic pulses and the transmission and reception of data. Underground deposit detection device using system. According to claim 1, The control device 100, the transmitting antenna 200, the receiving antenna 300, the display unit 400, the power supply unit 500 and the transmission line 900 to the moving wheel 830 and the handle ( 820 is mounted on a cart 800 provided with the transmitting and receiving antennas 200 and 300 are installed in the lower cart 810 in order to minimize the transmission and reception signal (signal) loss is in close contact with the front surface , Underground attachment detection device using the GPR system, characterized in that the electromagnetic wave is not lost to the air by attaching to the back. The method of claim 1, wherein the transmitting antenna (200) uses a dipole antenna, the underground site using the GPR system, characterized in that for using an antenna of about 200MHz. The apparatus of claim 1, wherein the control device (100) comprises: transmitting means for generating a pulse of ultra wide bandwidth through a pulse generator (130) and a pulse transmitting circuit (140); A reception preamplifier (110) for amplifying a signal input from the reception antenna (300); An A / D converter 120 for converting an analog signal amplified by the reception preamplifier 110 into a digital signal; And a CPU 150 for controlling the entire system, collecting raw data, and measuring a propagation time from transmission to reception. The method of claim 4, wherein the transmitting means generates a sharp waveform pulse by using a low voltage step recovery diode, wherein the diode D is forward biased by a DC current through two inductors L1 and L2. Initially, SRD (D) suppresses the flow of electrons and holes, and when the input pulse reaches the diode (D), it provides a high conductivity path through the diode (D), and the output voltage reaches the input voltage. The underground deposit detection device using a GPR system, characterized in that the different charged voltage drops rapidly and the charge barrier immediately recovers, and the circuit is opened and the output voltage drops to zero. 5. The apparatus of claim 4, wherein the transmitting means is configured using an avalanche transistor, wherein an avalanche bias voltage of 140 V is applied to the collector of Q1 via the R3-C1 network, and Q1 maintains 75 volts, At this time, if C1 is charged to a sufficiently high voltage, the balance of Q1 is broken, and as a result, a very fast granular pulse is generated by C1. Then, C1 is discharged via R4, and the voltage is rapidly attenuated, and at the same time, breakdown of Q1. The phenomenon is also immediately recovered, and C1 is a underground buried probe using a GPR system, characterized in that configured to be recharged through the R3 until the destruction of avalanche. [5] The apparatus of claim 4, wherein the reception preamplifier (110) is configured to amplify up to 90 DB as necessary through the wideband high frequency amplifier NE5205. 5. The apparatus of claim 4, further comprising a reception signal storage unit 160 to store the collected raw data in a sufficient amount of static memory for use by the CPU 150, Underground burial detection device using a GPR system characterized in that to quickly store the raw data sent by the request and collected at a high speed. The method of claim 1, wherein a plurality of transmit and receive antennas (200, 300) are configured to transmit the same side by side from the antennas (200, 300) to the medium while quickly passing through the target of one point, the echo of the received pulse is space Underground facilities detection device using a GPR system characterized in that it appears as a number of hyperbolas with respect to time and to take the vertices of these hyperbolas to find one target. According to claim 1, further comprising a communication unit 600 for supporting the connection of the control device 100 and the Internet server 700, the device can be controlled through the Internet, the measurement data is via the Internet in real time Underground installation detection device using a GPR system, characterized in that configured to be delivered to the client to enable remote management and control measurement.