JPH0799396B2 - Buried object exploration equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention radiates radio waves from the ground to gas pipes, water pipes, various cables, etc. buried in the ground and receives their echoes. The present invention relates to an underground buried object exploration apparatus for measuring the position (including depth) of the underground buried object based on the display of the received echo on a display.

[Conventional technology]

Conventionally, a transmitter mounted on a mobile dolly emits radio waves toward the ground, and a reflected wave from an underground buried object corresponding thereto is received by a receiver mounted on the mobile dolly, and the reflected wave propagates to the ground. There is known a radar-type underground buried object exploration device that detects the position depth of the buried object.

In this underground buried object exploration device of the radar system, if the round-trip propagation time is Δt0 and the depth to the buried object from which the radio wave is reflected is Z, The position of the underground buried object in the depth direction is detected by performing the following calculation.

In this case, the radio wave propagation velocity v _g changes depending on the relative permittivity ε _re of soil, and when the radio wave propagation velocity in vacuum is c, It is known that the relationship becomes.

Therefore, in order to accurately detect the depth D0 of the underground buried object, it is necessary to confirm the relative permittivity εre of the soil in advance.

Therefore, the propagation velocity vg is estimated by the estimated value of the specific induction rate εre for each soil type such as sandy land, farmland, etc., and the depth of the underground buried object is detected by the estimated propagation velocity (Photoelectric Manufacturing
There is a KSD3AM underground exploration device). In addition, a method has been proposed in which soil is actually collected and the relative permittivity εre is measured, and the depth of the underground buried object is detected by the measured value (24th
SICE Academic Lecture 1505 "Research on Underground Exploration Radar-Part 2").

[Problems to be Solved by the Invention]

However, in the former case of estimating the relative permittivity εre, ε
Let Δvg be the variation of vg with respect to the variation Δre of re
From equation (2) Therefore, if the estimation error of εre is ± 20%,
The vg error is ± 10%, and as a result, the depth detection error is also ± 10%, and there is a problem that sufficient exploration accuracy cannot be obtained.

On the other hand, with the latter method that actually measures εre, the accuracy is good, but since a relative dielectric constant measuring device must be prepared separately, the economic burden increases and the ground surface is such as asphalt. When it is covered with, there is a problem that the soil cannot be collected and the use is limited.

In this case, the propagation velocity vg due to the reflected wave from the underground buried object
The method of estimating the depth and detecting the depth Z based on the estimated value is the “Ground Radar System” (June 1986).
VoL.J66-B.No.6.P716-720), this method can detect the position of underground buried objects under asphalt, but it requires complicated calculations such as matrix calculation. Since it needs to be performed, there is a problem that it takes time to obtain a detection result.

An object of the present invention is to provide an underground buried object exploration apparatus capable of detecting the position of an underground buried object with high accuracy and a simple configuration in a short time.

[Means for Solving the Problem] Therefore, in the first invention of the present invention, an echo image of the underground buried object is displayed using the buried object exploration apparatus as parameters in the depth direction of the underground buried object and the moving direction of the moving carriage. Display means to
According to the signal intensity of the echo image on the display means, the echo image is formed in a hyperbolic shape based on the propagation time of the reflected wave obtained when the mobile carriage is moved a certain distance while emitting radio waves from the transmitter. First means for displaying the echo image in hue or lightness, and a hyperbolic pseudo echo image is formed, and the central portion and the contour portion of the pseudo echo image are displayed in different hues or lightness on the display means. Second
Means for moving the display position of the pseudo echo image and inputting information for matching the apex position and the spread of the opening with the echo image of the underground buried object to the second means. And a fourth means for calculating the propagation velocity of the radio wave in the ground based on the information indicating the apex position of the pseudo echo image and the spread of the opening when the two displayed echo images coincide with each other. The position of the underground buried object at an arbitrary point is detected based on the value of the propagation velocity calculated by the means.

According to the second aspect of the present invention, the buried object exploration device is used as a parameter for the depth direction of the underground buried object and the moving direction of the moving carriage to display an echo image of the buried object and a radio wave from the transmitter. While forming a hyperbolic echo image based on the propagation time of the reflected wave obtained when the moving carriage is moved by a full distance while emitting, with the hue or brightness according to the signal intensity of the echo image on the display means. A first means for displaying the echo image; a hyperbolic pseudo echo image for displaying the echo image in a hue different from the hue used for displaying the echo image on the display means. And means for inputting to the second means information for moving the display position of the pseudo echo image so that the vertex position and the spread of the opening coincide with the echo image of the underground buried object.
And a fourth means for calculating the propagation velocity of the radio wave in the ground based on the information indicating the apex position of the pseudo echo image and the spread of the opening when the two displayed echo images match. The position of the underground buried object at an arbitrary point is detected based on the value of the propagation velocity calculated by the fourth means.

[Work]

That is, in the first aspect of the present invention, when radio waves are emitted at a plurality of points on the ground surface above the underground buried object, a hyperbolic echo image produces a signal intensity (echo) based on the information on the propagation time of the reflected wave at each point. It is displayed with good visibility on the display means by color classification or brightness classification according to the level).

Then, the hyperbola of the echo image is specified by superimposing the pseudo echo image on this hyperbolic echo image (this is called the curve fitting method). The contour portion is color-coded or lightness-classified with different hues or luminosity, and the center portion and the contour portion are discriminated and displayed on the display means. By performing such color coding or lightness classification, when the color or lightness used in the pseudo echo image and the color or lightness on the display means (a clogging, a color or lightness representing a hyperbolic echo image) match. Even if there is, the same pseudo echo image can be visually recognized on the display means in the color or the lightness that does not match.

Therefore, it is possible to perform the overlaying operation without always losing sight of the pseudo echo image on the display means, without causing a defitting error (overlaying error in the curve fitting method), and accurately. The hyperbolic echo image and the pseudo echo image can be matched.

In this way, if the two echo images are overlapped, the apex position of the echo image and the spread of the opening are determined based on the information of the pseudo echo image. The radio wave propagation speed vg can be calculated. Then, if vg can be calculated, the position of the underground buried object can be calculated based on the relationship with the information on the propagation time at any position.

Further, in the second invention of the present invention, as in the case of the first invention, the hyperbolic echo image is displayed on the display means with good visibility by color coding or lightness classification according to the signal intensity (echo level). To be done.

Then, the echo image and the pseudo echo image are superposed by the curve fitting method to identify the hyperbola of the echo image. In this case, the pseudo echo image is used to display the echo image of the hyperbola. The echo image is displayed in a color different from the existing color (the color that is the basis of the brightness when displayed).

By thus displaying different colors, the superimposing operation can be performed without always losing sight of the pseudo echo image on the display means. Therefore, the two echo images can be accurately superimposed without causing a fitting error.

If the two echo images overlap in this way, the radio wave propagation velocity Vg in the ground and the position of the underground buried object can be calculated easily and easily in the same manner.

In any case, in the present invention, since the pseudo echo image is displayed on the display means with good visibility, it is possible to perform the overlaying operation with high accuracy, and finally to position the underground buried object with high accuracy. It can be calculated. Further, the calculation of this position can be easily and easily performed based on the information of the pseudo echo image at the time of the superposition.

(Embodiment) FIG. 1 is a block diagram showing an embodiment of the present invention, which is roughly composed of a moving carriage 1 and a main body 2. The moving carriage 1 has a transmitter 10 and an antenna 11 which emit radio waves toward the buried object 3 in the ground, a receiver 12 and a receiving antenna 13 which receive reflected waves from the buried object 3, and the moving carriage 1 has a unit distance. The distance sensor 14 generates one pulse each time it moves. In addition, the main body 2 includes an arithmetic unit 20 that forms an echo image of the buried object 3 based on the pulse signal from the distance sensor 14 and the reflected wave signal received by the receiver 12, and a display that displays the formed echo image. It is composed of a device 21.

FIG. 2 is a plan view showing the details of the display surface of the display device 21, in which a hyperbolic echo image 4 of the buried object 3 and a pseudo echo image 5 (Q indicates this apex mark) described later are displayed on the display surface. Both the first display unit 210 for displaying, the second display unit 211 for displaying the image of the position movement switch for moving the horizontal and vertical display positions of the pseudo echo image 5 by the pressing operation, and both hyperbolas of the pseudo echo image 5. A third display unit 212 for displaying an image of a spread information input switch for changing the spread of the opening by a pressing operation is provided, and a transparent touch panel (not shown) for detecting the pressing operation position on the entire display surface. ) Is attached, and the operation of the position movement switch and the spread information input switch is detected by this touch panel.

FIG. 3 shows a configuration for displaying the echo image 4 on the display unit 210. The trigger circuit 110 is a circuit that oscillates a trigger pulse at regular intervals. The required radar pulse is generated and amplified in synchronism with the oscillation of and the power is supplied to the transmitting antenna 11. The transmission antenna 11 emits radio waves toward the ground along with such power supply.

On the other hand, the reflected signal received via the receiving antenna 13 is received by the receiving circuit 12 '. This received signal (reflected echo)
Is amplified by the Rf amplifier 115 and then converted into a predetermined low frequency signal through the Rf / Lf (high frequency / low frequency) conversion circuit 120.

The reception signal thus converted into the low frequency signal is sampled and quantized by the A / D conversion circuit 130 and converted into a digital signal. The output of the A / D conversion circuit 130 is applied to the display memory writing control circuit 170.

On the other hand, the trigger signal generated from the trigger circuit 110 is applied to the transmission circuit 10 'and at the same time, the Rf / Lf conversion circuit 120
Is also input to and converted into a low frequency signal together with the received signal amplified through the Rf amplifier 115. The trigger signal converted to this low frequency is the vertical sync signal generation circuit 140.
And is used to form a vertical synchronization signal that indicates vertical coordinates when a two-dimensional cross-sectional image of the target is displayed. The vertical synchronization signal thus formed and output is also added to the display memory writing control circuit 170.

Further, the distance sensor 14 outputs one pulse each time the apparatus of this embodiment moves a predetermined distance as the apparatus of this embodiment moves. The output pulse of the sensor 14, that is, the distance measurement signal is input to the horizontal synchronization signal generation circuit 160 to form a horizontal synchronization signal that indicates horizontal coordinates when a two-dimensional sectional image of the target is displayed. Used. The horizontal synchronizing signal formed and output by the horizontal synchronizing signal generating circuit 160 is also applied to the display memory writing control circuit 170.

In this way, the display memory write control circuit 170 receives the information corresponding to the two-dimensional coordinates generated through the vertical synchronizing signal generating circuit 140 and the horizontal synchronizing signal generating circuit 160, and the
The received signal data from the D conversion circuit 130 will be input respectively.

The display memory writing control circuit 170 is a circuit that controls writing of the received signal data into the display memory 171 based on the vertical synchronizing signal and the horizontal synchronizing signal. That is, the display memory writing control circuit 170 successively converts the coordinate values obtained corresponding to the vertical synchronizing signal and the horizontal synchronizing signal into the address values of the display memory 171 and receives them from the A / D converting circuit 130. It operates so as to write the signal data to the corresponding address of the display memory 171.

The display memory 171 is composed of, for example, a RAM, and the brightness information (gradation change information) corresponding to the value of the data of the received signal corresponds to each pixel on the display unit 210 as pixel information. It is a memory that is stored and read with N bits.

Similarly, the graphic memory 172 is also a memory configured by, for example, a RAM and capable of writing and reading data indicating a pseudo echo image. The graphic memory 172 corresponds to each pixel on the display unit 210 and indicates the pseudo echo image. Value data is stored as pixel information.

For example, FIG. 9A shows this graphic memory 172.
FIG. 3 is a conceptual enlarged view showing a part of the data content of the pseudo echo image stored in FIG. 1, in which the central portion 5'a of the pseudo echo image 5'and its contour portion 5'b have different data values "1", " It is stored so as to be "0".

The movement of the pseudo echo image stored in the graphic memory 172 on the display screen is performed by a command from a microprocessor (not shown) based on the operation of the position movement switch and the spread information input switch.

The X-sync Y-sync signal generation circuit 173 includes the display memory 171.
And a circuit for reading the contents of the graphic memory 172 and generating sync signals V and H in the X and Y directions for displaying the contents on the display unit 210, which will be described later. The sync signals V and H are read. As the timing pulse of
It is added to the display memory 171 and the graphic memory 172, and is also added to the display unit 210 as a timing signal for scanning drive of the CRT of the display unit 210.

The display clock generation circuit 174 is a circuit that generates the clock of the X synchronization Y synchronization signal generation circuit 173.

The D / A conversion circuit 175 converts the pixel information corresponding to each pixel read from the display memory 171 into an analog signal, and the signal is added to the weighting circuit 176.

The weighting circuit 176 is a circuit for weighting each color signal R (red), G (green), B (blue) to the pixel information read from the display memory 171, and an amplifier Ra for weighting each color. , Ga, Ba,
The gains of these amplifiers are adjusted so that colorless signals (that is, black and white gradation signals) are output.

Therefore, the contents stored in the display memory 171 are expressed as a white / black single color display on the display unit 210, and the echo image is displayed by dividing the brightness according to the intensity change of the received signal.

On the other hand, the weighting circuit 177 is a circuit for weighting each color signal (R, G, B) to the pixel information read from the graphic memory 172, and an amplifier Rb, Gb, for weighting each color R, G, B, The amplifier is composed of Bb, and the gains of these amplifiers are adjusted so that an achromatic signal (that is, a black and white gradation signal) is output.

Therefore, the content stored in the graphic memory 172 is represented as a white / black single color display on the display unit 210, and the central portion of the pseudo echo image is white and the contour portion of the pseudo echo image is black. And the contour portion is displayed with different brightness divisions.

The adder circuit 178 adds the output signals of the weighting circuits 176 and 177 for each color signal and outputs the result.
Signals R, G, and B obtained by adding the output signals of b, the amplifiers Ga, Gb, and the amplifiers Ba, Bb are added to the display unit 210.

The display unit 210 includes a CRT and displays the contents of the display memory 171 and the graphic memory 172, that is, an echo image and a pseudo echo image on the CRT based on the synchronization signals V, H and the signals R, G, B. It is a device that operates so as to operate (see FIG. 2).

In the above-mentioned configuration, when radio waves are emitted from the transmitter 10 while moving the movable carriage 1 on the ground surface, the echo image 4 of the buried object 3 becomes a hyperbolic shape as shown in FIG. 4 (a).

That is, as shown in FIG. 4 (a), the coordinate axis of the distance when the moving carriage 1 moves on the ground surface is X, the coordinate axis indicating the distance in the depth direction toward the ground is Z, and the buried object 3 is If it is assumed that the transmitting and receiving antennas 11 and 13 are located at the point (C ₀ , Z ₀ ) indicated by the point C, and the transmitting and receiving antennas 11 and 13 are located at the point B directly above the point C,
The buried object 3 can be observed as an echo image at a depth (Z ₀ ) corresponding to the distance BC between the points B and C.

On the other hand, since the transmission radio wave has a spread in its propagation method, the echo image of the buried object 3 is observed even when the transmission / reception antennas 11 and 13 move to a point A which is deviated leftward from directly above the point C. be able to. The echo image in this case is the point ▲ ▼
The distance between them corresponds to a point D having a depth equal to {(x−x ₀ ) ² + Z ₀ ² } ^1/2 . Therefore, the locus of the point D (X, Z) when the moving carriage 1 is moved, that is, the echo image 4 of the buried object 3 is Z = ▲ ▼ = {(x−x ₀ ) ² + Z ₀ ² } ^1/2 = ▲ ▼: It becomes a hyperbolic shape represented by (4).

On the other hand, the radio waves emitted from the transmitting antenna 11 are received by the receiving antenna.
Between the echo delay time t until it is received by 13 and the radio wave propagation velocity VG and the depth Z of the buried object 3, Have a relationship.

Therefore, according to the equations (4) and (5), The relationship is established. However, t ₀ is the transmission wave propagation time at point B, and t, vg are unknowns.

On the other hand, in the echo image 4 of the buried object 3 displayed on the display unit 210 of the display device 21, the horizontal axis is the distance axis x of the truck 1 and the vertical axis is the time axis t, as shown in FIG. 4 (b). Is. That is, the echo image of the buried object 3 is displayed by converting the distance axis Z in the depth direction into the time axis t.

Here, the A / D converted output of the received wave shown in FIG. 5 (a) has a digital waveform as shown in FIG. 5 (b), and this digital waveform is white / white depending on the signal level as described above. The display image on the display unit 210 is actually as shown in FIG.

That is, in FIG. 4 (b), the hyperbola indicated by the alternate long and short dash line corresponds to the leading edge portion F '(see FIG. 5 (b)) of the reflection echo 4, and the hyperbola 4P indicated by hatching indicates the reflection. The portion corresponding to the peak portion P ₁ (see FIG. 5 (b)) of the echo 4 and the hyperbola shown by stippling indicate that another gradation level portion P ₂ (fifth portion) adjacent to the peak portion P ₁ Figure (b)
The echo image 4 is displayed with the brightness divided so that each of these gradation regions can be distinguished from other gradation regions.

It should be noted that, even in the other gradation portions of the digital waveform of FIG. 5B, the gradation regions are correspondingly displayed on the display unit 210 while being divided into luminosity, but the description will be given here. For simplicity, it is not shown in FIG. 4 (b).

By the way, the gradation area indicated by the above-mentioned alternate long and short dash line (front line F ′)
Is a region that is confused with the background because the signal level is 0, and is difficult to visually recognize on the display screen. In the gradation region 4P (peak portion P ₁ ) indicated by hatching, the signal level corresponds to the maximum amplitude. Therefore, the display image of gradation change has a noticeable gradation of all white, which is a region that is very easy to visually recognize.

Therefore, in this apparatus, the pseudo echo image 5 is superimposed on the echo image 4.

The operation of superimposing the pseudo echo images 5 will be described below.

First, as shown in FIG. 6A, the pseudo echo image 5 having a predetermined spread is displayed at an arbitrary position on the display unit 210, and the position of the vertex mark Q and the spread coefficient α are displayed on the display unit. The switch images of 211 and 212 are changed by the pressing operation and superposed on the echo image 4. At this time, the pseudo echo image 5 has the following relationship in the x · t coordinate system: {(x−x ₀ ) ² + (α · t0) ² } ^1/2 α · t (7) If it is, the above (6)
The following relationship is established by comparing the equation and the coefficient of the equation (7).

vg = 2α (8) Here, (x0, t0) is the vertex coordinates of the pseudo-hyperbola 5 (the coordinates of the vertex mark Q). And this Q coordinate is displayed on the display 21
The increase / decrease is instructed and determined by the switch image of 1.
Further, α is a factor of the spread of the opening of the pseudo echo image 5, so that when the spread is increased, α is increased.
Further, when it is made smaller, the display unit 212 is set so that α becomes smaller.
It can be changed by pressing the switch image displayed on.

Therefore, as shown in FIG. 6B, when the echo image 4 and the pseudo echo image 5 overlap each other, the coordinates of the vertex position of the echo image 4 are set to the coordinates (x0, t) of the vertex mark Q of the pseudo echo image 5.
0) can be obtained. Further, the spread of the hyperbolic opening forming the echo image 4 can also be obtained by the spread value α of the pseudo echo image 5. As a result, vg (radio wave propagation velocity) is obtained by the equation (8), and this vg and t0
(Echo delay time at the point B directly above the buried object 3) is calculated by substituting it into the equation (5) to calculate the vertex position coordinates of the echo image 4 of the buried object 3, that is, the depth Z. be able to.

The echo image 4 of the buried object 3 is the reception wave (Fig. 7) at the receiver 12 from the rising timing of the transmission trigger (Fig. 7 (a)) or the transmission wave (Fig. 7 (b)) of the transmitter 10. (C))
It is displayed at the position on the t-axis that corresponds to the time Δt0 until the rising timing of, but when superimposing the pseudo echo image 5, it is possible that the brightness of the echo image 5 has not sufficiently changed at the rising timing of the received wave. Since it can be considered, it is better to superimpose the pseudo echo image 5 above the echo image 4 as shown in FIG.

As described above, the two echo images are superposed. During the superimposing operation, the pseudo echo image 5 is displayed with the central portion and the contour portion thereof having different lightness levels of white and black, respectively, as described above. There is.

Therefore, during the above operation, as shown in FIG.
For example, when the pseudo echo image 5 intersects the echo image 4, the lightness of the gradation area 4P indicating the peak portion of the echo image 4 at the intersection G coincides with the lightness of the central portion 5a of the pseudo echo image 5 ( Even if both are shown by hatching), the brightness of the same gradation area 4P and the brightness of the contour portion 5b of the pseudo echo image 5 do not match (black solid with respect to hatching). Superimposition can be done without losing sight. Even in the portion H where the echo image 4 does not exist, even if one of the two types of brightness representing the pseudo echo image 5 matches the brightness of the background, the other brightness matches the brightness of the background. Therefore, the moving operation can be performed without losing the pseudo echo image 5. In this way, the pseudo echo image 5 is always displayed on the display screen with good visibility during the fitting operation, so that the operator can be accurately superposed without being tired.

However, when the data value representing the pseudo echo image 50 'is stored in the graphic memory 172 without distinction between the central portion and the contour portion as shown in FIG. 9B, for example,
In the display screen, for example, as shown in FIG. 11 (b), the brightness of the gradation area 40P showing the peak portion of the echo image 40 at the intersection G'of the two echo images coincides with the brightness of the pseudo echo image 50 (both. The brightness indicated by the hatching) occurs, and the relevant pseudo echo image 50 is lost. Also,
Even in the portion H'where the echo image 40 does not exist, the brightness representing the pseudo echo image 50 and the brightness of the background match, and the pseudo echo image 50 is lost. Therefore,
The pseudo echo image 50 during the fitting operation is less likely to be visually recognized on the display screen, the operator is likely to be tired, and the accuracy of superposition deteriorates. Compared to such a case, the pseudo echo image 5 is divided into three layers of brightness as described above, so that the visibility and the overlay accuracy can be improved.

As described above, according to the embodiment, the position of the echo image of the underground buried object and the spread of the hyperbolic opening are detected by superimposing the pseudo echo images, and the radio wave propagation in the soil is based on the detected value. Since the speed is calculated to detect the position of the underground buried object, the structure of the device can be made simpler and less expensive than the conventional one, and the position can be detected with high accuracy and in a short time. Moreover, since the pseudo echo image is configured to be displayed by distinguishing the center portion and the contour portion thereof, the pseudo echo image 5 is displayed with good visibility. Therefore, the operator can perform the superimposing operation of the two echo images without fatigue, and the superimposing can be performed with high accuracy.

In the embodiment, both the echo image 4 and the pseudo echo image 5 are displayed by brightness, but it goes without saying that they can be displayed by color.

In this case, the weighting circuit 176 is replaced by the display memory 171.
Is read out and input, a color signal (that is, a gradation signal of hue) corresponding to the value of each data is output, and the weighting circuit 177 is set to the content of the graphic memory 172. Is read out and input, two kinds of color signals according to the value of each binary data may be output.

Therefore, the pseudo echo image 5 is displayed on the display screen in two different color classifications such as "red" at the center and "blue" at the contour.

Also in this case, since the hue of the pseudo echo image 5 is displayed with good visibility without being integrated with the echo image 4 or the hue of the background, the superposition can be performed with high accuracy as in the case of dividing the brightness.

Further, in the embodiment, the graphic memory 172 has the shape shown in FIG.
Although it is memorized in Fig. 10 (a) or 10
Of course, it is possible to implement the memory as shown in FIG. In short, the content stored in the graphic memory 172 is arbitrary as long as the center portion and the contour portion of the pseudo echo image are well constructed and can be identified and displayed on the display screen.

As described above, in addition to displaying the pseudo echo image in the three-layer state according to the brightness or the hue, the pseudo echo image can be displayed with good visibility as follows.

That is, the pseudo echo image is displayed in a hue other than the hue used for displaying the reflected echo image.

For example, the gain of each amplifier Ra, Ga, Ba of the weighting circuit 176 is adjusted so that an achromatic signal, that is, a black and white gradation signal is output, and each amplifier Rb, Gb of the weighting circuit 177, The gain of Bb is adjusted so that a signal having a certain hue is output.

Then, on the display screen, the echo image or the background is displayed as a white / black grayscale image having no hue, while the pseudo echo image is displayed as, for example, a "red" image having a certain hue. Incidentally, in this case, as the storage content of the graphic memory 172, data such that the pseudo echo image is represented in a single layer as shown in FIG. 9B may be stored.

In this way, the pseudo echo image is visually recognized by being distinguished from other colors, that is, in this case, an achromatic color on the display screen. Of course, the reflected echo image and the background are displayed in different colors. In such a case, it is of course possible to obtain the same effect by configuring the device so that the pseudo echo image can be displayed in a different hue not used for this display.

Further, in the embodiment, the position and spread of the pseudo echo image 5 are changed by the operation of the touch panel, but it can be appropriately replaced with a mechanical contact switch or various input means such as a keyboard and a joystick.

On the other hand, although the pseudo echo image is formed by the equation (7), the spread of the hyperbola also changes when t0 changes in the equation (7). However, if the following method is used, only the parallel movement in the vertical direction (time axis direction) can be performed without changing the spread of the hyperbola.

For simplicity, both sides of the equation (7) are shown as squared here. That is, (x−x0) ² + (α · t0) ² = (α · t) ² (9) is an equation equivalent to the equation (7).

Here, deforming it as α · t0 = d, t1 = 0, the ^{(x-x0) 2 + D} 2 α 2 · (t-t 1) 2 ...... (10). Therefore, with respect to the operation of the position movement switch, when “↑” is operated …… t1 ← t1−M When “↓” is operated …… t1 ← t1 + M When “←” is operated …… x0 ← x0−N When “→” is operated …… As x0 ← x0 + N, t1, x0 is updated with the increase / decrease value M, N, and when the spread information input switch is operated, “← →” is operated. If α ← α + F (α) t0 ← t0 + t1 t1 ← 0 D ← α ・ t0, then when "→ ←" is operated, α ← α + F (α) t0 ← t0 + t1 t1 ← 0 D ← α ・If the pseudo echo image 5 is formed as t0, only the parallel movement in the vertical direction can be performed without changing the spread. In addition,
F (α) is a function value defined with α.

〔The invention's effect〕

As described above, in the present invention, the position of the echo image of the underground buried object and the hyperbolic opening spread are detected by superimposing the pseudo echo images, and the radio wave propagation velocity of the soil based on the detected value. Since the position of the buried object is calculated by calculating, the need for measuring the relative permittivity of the soil is eliminated, and the structure can be made inexpensive, and the position of the buried object under the asphalt can also be determined. It can be detected accurately. Furthermore, since the estimated location of the relative permittivity of soil is not used, there is no position detection error due to an estimation error, and highly accurate position detection can be performed. Further, since a complicated calculation such as matrix calculation is not performed, the position detection result can be obtained in a short time.

Further, since the pseudo echo image is displayed on the display screen with good visibility, the operator can perform the overlapping operation without getting tired.

Therefore, it is possible to perform the overlay with high accuracy without causing an overlay error (fitting error).

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a plan view showing details of a display screen of a display device, FIG. 3 is a block diagram showing a configuration example of a drive circuit of a display device, and FIG. (A) is an explanatory view for explaining that the echo image becomes hyperbolic, FIG. 4 (b) is a conceptual view showing an actual display screen, (5)
The figure is a time chart showing A / D conversion processing output of received radio waves (received signals), and FIGS. 6 (a) and 6 (b) are explanations for performing an operation of superimposing a pseudo echo image on an echo image of a buried object. 7 and 8 are time charts showing the time relationship between the transmitted wave and the received wave, FIG. 8 is an explanatory view showing the positional relationship when the pseudo echo image is superimposed on the buried object echo image, FIG. 9 (a),
(B) and FIGS. 10 (a) and (b) are conceptual views illustrating a part of the contents stored in the graphic memory shown in FIG. 3, and FIGS. 11 (a) and (b) are display views. It is an enlarged view which shows notionally an opposite echo image and a pseudo echo image on a screen. 1 ... Mobile trolley, 2 ... Main body, 3 ... Buried object, 4 ...
Echo image, 5 ... Pseudo echo image, 10 ... Transmitter, 12 ...
Receiver, 20 ... Computing device, 21 ... Display device.

Claims (2)

[Claims] 1. A receiver mounted on a mobile truck receives a reflected wave of an underground radio wave of a radio wave emitted from a transmitter mounted on the mobile truck toward the ground, and the underground buried object is received according to a propagation time of the reflected wave. In a radar-based buried object exploration device that detects the position of the underground buried object, a display unit that displays an echo image of the underground buried object as parameters in the depth direction of the underground buried object and the moving direction of the moving carriage, and the radio wave from the transmitter The echo image in the form of a hyperbola is formed based on the propagation time of the reflected wave obtained when the movable carriage is moved by a certain distance while being emitted, and the hue or brightness according to the signal intensity of the echo image is displayed on the display means. A first means for displaying an echo image; and a second means for forming a hyperbolic pseudo echo image so that the display means displays the central portion and the contour portion of the pseudo echo image in different hues or intensities. A third means for inputting to the second means information for moving the display position of the pseudo echo image so as to match the vertex position and the spread of the opening with the echo image of the underground buried object; And a fourth means for calculating the propagation velocity of the radio wave in the ground based on the information indicating the apex position of the pseudo echo image and the spread of the opening when the two echo images are matched with each other. An embedded object exploration device characterized in that the position of an underground underground object at an arbitrary point is detected based on the calculated propagation velocity value. 2. A receiver mounted on a mobile truck receives a reflected wave of an underground radio wave of a radio wave emitted from a transmitter mounted on the mobile truck toward the ground, and the underground buried object is received according to a propagation time of the reflected wave. In a radar-based buried object exploration device that detects the position of the underground buried object, a display unit that displays an echo image of the underground buried object as parameters in the depth direction of the underground buried object and the moving direction of the moving carriage, and the radio wave from the transmitter The echo image in the form of a hyperbola is formed based on the propagation time of the reflected wave obtained when the movable carriage is moved by a certain distance while being emitted, and the hue or brightness according to the signal intensity of the echo image is displayed on the display means. First means for displaying an echo image, and a pseudo-echo image having a hue or lightness different from the hue or lightness used for displaying the echo image on the display means by forming a hyperbolic pseudo-echo image Second means for displaying and information for moving the display position of the pseudo echo image so that the vertex position and the spread of the opening coincide with the echo image of the underground buried object are input to the second means. A third means, and a fourth means for calculating the propagation velocity of the radio wave in the ground based on the information indicating the apex position of the pseudo echo image and the spread of the opening when the two displayed echo images match. The buried object exploration apparatus is characterized in that the position of the underground buried object at an arbitrary point is detected based on the value of the propagation velocity calculated by the fourth means.