JP3232344B2 - Real-time detection of buried objects - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting an object buried in the ground or in a structure using electromagnetic waves, and more particularly, to a method for detecting a set of a transmitting antenna and a receiving antenna by using a ground surface or a structure. The present invention relates to a buried object detection method for notifying a measurer of the presence of a buried object in real time using a buzzer, a sound, a lamp, or the like without measuring a moving distance of an antenna when moving the object along a surface.

[0002]

2. Description of the Related Art FIG. 9 is a block diagram of an apparatus for detecting an underground buried object by using an electromagnetic wave method. In the figure, a pulse having a time width of several nsec is transmitted from a transmitter 1 to a transmission antenna 2, and this pulse signal is converted into an electromagnetic wave by the transmission antenna 2 and radiated into the ground. The radiated electromagnetic wave propagates through the ground, and is reflected at a location having different electrical properties from the surrounding medium. The reflected electromagnetic wave is transmitted to the receiving antenna 3
And converted into an electric signal by the receiver 4. In the actual measurement, the antennas 2 and 3 are moved in the direction of the arrow in the figure. Then, the above-described transmission and reception processes are performed at specified time intervals (for example, every 1 second), and a plurality of received signals are recorded. The plurality of received signals are color-modulated by the arithmetic unit 6 for each magnitude of the amplitude value, and then arranged two-dimensionally to form an observation pattern of an underground section.

FIG. 10 is a diagram showing an underground cross-section observation pattern formed in this way. In the figure, a time position where the absolute value of the amplitude value of the received signal is equal to or greater than a specified value is indicated by a “diagonal line”.
Other time positions are indicated by "white". Here, the pattern 21 corresponds to a group of reflected waves from the ground surface. Since the electromagnetic wave radiated from the antenna spreads at a certain angle, the reflected wave group from the buried pipe has a hyperbolic shape as shown in a pattern 31 in FIG. The actual position of the buried pipe corresponds to the apex of the hyperbola of the pattern 31. Therefore, the buried pipe 30 can be detected by recognizing the hyperbolic shape in the underground section observation pattern. Here, patterns 22, 32, and 33
Is constituted by a group of reflected waves generated by a ringing phenomenon in which a reflected wave from the buried pipe 30 is further reflected. Therefore, these shapes are similar to the patterns 21 and 31.

Conventionally, as a method of recognizing the hyperbolic shape, there has been proposed a method of notifying an operator of the presence of a buried object by a buzzer or the like without measuring an antenna moving distance, such as a synthetic aperture method and a Hough transform. . According to this proposal, the reflected wave is received not at every movement distance of the antenna but at certain time intervals, and the amplitude value of the time position at which the amplitude value of the received signal is locally maximum and the amplitude value of the time position at which the amplitude is minimum are determined. Each,
The amplitude values at time positions other than “1” and “−1” are normalized to “0”. Then, such normalization is performed for two consecutively received signals, and the relationship between coordinates whose standard value is “1” or “−1” is checked. Here, the change in the propagation time between the coordinates determined to be relevant is calculated, and the result is added and stored in the added value data map. When the value stored at that time is equal to or greater than the specified value SH, the buzzer 7 sounds and the display unit 8 performs a blinking operation such as a lamp to notify the operator of the presence of the buried object.

FIG. 11A shows only the coordinate positions where the added value is equal to or greater than the specified value SH in the added value data map. As shown in the figure, the line drawing pattern 310 composed of the reflected wave group from the buried pipe 30 included in the underground section observation pattern was successfully recognized, and as a result, FIG. As shown in the figure, the buzzer 7 and the like were successfully sounded near the buried position of the tube 30 while moving the antenna.

[0006]

However, in such a conventional buried object detection device, noise whose propagation time gradually decreases in accordance with the moving direction of the antenna, in particular, FIG.
As shown in a pattern 41 shown in FIG. 1, there is a problem that a gentle noise in the horizontal direction is erroneously recognized as an embedded object. Further, in order to process the waveform patterns 32 and 33 shown in FIG. 10 that are multiplexly observed by the ringing phenomenon such that the reflected wave once reflected by the buried object is further reflected, as a reflected wave from each buried object, There has been a problem that false alarms such as the buzzer sounding several times at different volume levels occur.

Further, in order to remove noise having a gentle shape in the horizontal direction such as the pattern 41 described above, usually, a difference operation is performed between signal components at the same propagation time position of two reflected waves measured at intervals of a fixed distance. In order to perform this difference processing, it is necessary to measure the moving distance of the antenna.However, in a place where the ground surface is soft, the moving distance cannot be measured accurately by an encoder built into the antenna axle. Therefore, there is a problem that this kind of noise cannot be sufficiently removed because the difference processing cannot be applied. Therefore, the present invention avoids recognizing a noise whose propagation time becomes gradually shorter as the antenna moves in the direction of movement of the antenna as a buried object. The purpose is to prevent false alarms.

[0008]

SUMMARY OF THE INVENTION In order to solve such a problem, the present invention provides a step of receiving a reflected wave at certain time intervals while moving an antenna, and calculating a differential value of the received signal. The amplitude of the received signal at the time position where the differential value is zero is "1" when the sign of the amplitude of the received signal at the time position is positive, and "-1" when the sign is negative.
And a step of normalizing the amplitude value of the other time position to “0”, and a standard value map which is a map of data in which the standardized results of two continuously received signals are two-dimensionally arranged. And “1” and “−1” indicating the first line data which is the standard value of the received signal received first.
Examining the relationship between each coordinate having the following values and each coordinate of the second line data, which is the standard value of the received signal received next; and the electromagnetic wave on each coordinate in the set of coordinates determined to be related Storing the difference value of the propagation time and storing the difference value as the coordinates of the additional value map having the same coordinate system as the standard value map, comprising the steps of: Subsequently, coordinates having a value other than “0” in the second line data on the addition value map and having the maximum propagation time are defined as starting point coordinates X,
A search step of searching for a coordinate Y having a value other than “0” within a predetermined time from the start point coordinate X in a direction in which the propagation time becomes shorter, and in the case where the coordinate Y exists in the search step,
Only when the signs of the origin coordinate XK and the coordinate YK on the standard value map corresponding to the origin coordinate X and the coordinate Y on the addition value map are different signs, the sum of the value of the origin coordinate X and the value of the coordinate Y is calculated, An adding step of storing the total value in a coordinate Y; and a repeating step of repeatedly executing a searching step and an adding step for each coordinate of the second line data with the coordinate Y as a starting point coordinate X, while moving the antenna. And a notifying step of notifying when the value stored in the addition value map exceeds a prescribed value, and detecting the buried object.

Further, in the search step, a predetermined time for searching for the coordinate Y in the direction in which the propagation time becomes shorter from the starting point coordinate X is set to a time near the pulse width of the electromagnetic wave to be transmitted.

[0010]

Therefore, according to the present invention, since an addition value map is created by adding an emphasis step, noise having a gentle shape in the horizontal direction can be removed. That is, by performing a process of close-up of a waveform involving multiple reflections, it is possible to remove a noise that cannot be realized unless a difference process is conventionally performed. Further, even if the reflection image from the buried object is observed multiple times due to the ringing phenomenon, the calculation is performed so that only the first waveform having the shortest propagation time is emphasized. If this is the case, only the first waveform will be generated, so that it is possible to prevent a buzzer having a different volume from sounding several times.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. 1 and 2 are flowcharts showing the operation of the device shown in FIG. 9 to which the method for detecting a buried object in real time according to the present invention is applied, and FIG. 3 shows the amplitude of the received signal being "1", "-".
FIG. 4 is an explanatory diagram for explaining normalization to “1” and “0”.
FIG. 5 is a standard value data map in which standardized received signals are arranged two-dimensionally, FIG. 5 is an additional value data map for storing a difference in propagation time between coordinates determined to be relevant, and FIG. FIG. 6 is a diagram showing a positional relationship between coordinates having a value equal to or greater than a certain standard value SH in the added value data map of FIG. 5 and buzzer sounding.

Referring to FIGS. 3 to 6, FIGS.
The detailed operation of the present invention will be described with reference to the flowchart of FIG. In describing this operation, a buried object detection device shown in FIG. 9 will be used, and a buried pipe 30 buried in the ground will be described as an example of the buried object. That is, a pulse having a time width of several nsec is transmitted from the transmitter 1 shown in FIG.
The pulse signal is transmitted to the transmission antenna 2 installed at 0, and is converted into an electromagnetic wave by the transmission antenna 2 and radiated into the ground. The emitted electromagnetic wave propagates in the ground and is reflected by the buried pipe 30. In step STEP 1 of FIG. 1, the reflected electromagnetic wave is received by the receiving antenna 3 installed on the ground surface 20 according to the timing sent from the time counter 5, converted into an electric signal by the receiver 4, and calculated by the calculation unit 6. I do. FIG. 3A shows an example of a received signal converted into an electric signal by the receiver 4 (referred to as a received signal f (1)). This example shows a digitized example.

Next, in step STEP2, the amplitude value of the received signal is normalized to "1", "-1", and "0". That is, the amplitude values at the time positions where the amplitude value of the received signal is locally maximum and minimum are normalized to “1” and “−1”, respectively, and the amplitude values at other time positions are normalized to “0”. . At this time, in order to remove the influence of noise, when the absolute value of the original amplitude value is smaller than the specified value B, the amplitude value is set to “0” at all time positions. FIG. 3B shows the normalized result. Next, in step STEP3, the received signal f (2) is obtained as in step STEP1, and in step STEP4, the received signal f (2) is standardized as in step STEP2.

In step STEP5, a standard value data map in which the standardized results of the two received signals f (1) and f (2) continuously received are two-dimensionally arranged is created. For example, FIG. 3C shows a standard value data map for the standardized signal of FIG. 3B. As shown in the figure, the mesh portions represented by two types of patterns are “1” and “−”.
1 "respectively.

For convenience of explanation, FIG. 4 shows a standard value data map of 14 received signals. In FIG. 4, the Y axis is in the propagation time direction, and each cell is a sampling point of the received signal. Y axis numbers 1, 2, ...,
Reference numeral 19 denotes the coordinates of each sampling point, and one cell corresponds to 2 nsec. On the other hand, the X axis indicates the antenna moving direction, and the numbers 1, 2,..., 14 of the X axis indicate the coordinates of each received waveform. Here, assuming that the timing sent from the time counter 5 is 1 second, each received waveform is received every second. Therefore, the sampling point group whose X-axis is 4 in FIG. 4 is a signal received 4 seconds after the start of reception, and also corresponds to a signal received directly above the buried pipe 30.

In this embodiment, as two received signals f (1) and f (2) continuously received, a coordinate group (1, j) having an X-axis coordinate of 1, and j = 1 to 19, , And a coordinate group (2, j) in which the X-axis coordinate is 2 and j = 1 to 19, and the coordinates “1” and “−1” of these coordinate groups are described below. The tracking and addition processing of the line drawing shown is performed. In FIG. 4, description will be made by taking as an example the coordinates (1, 12) whose standard value is “1”. As shown in FIG. 4, attention is focused on a range of a specified value S1 (hereinafter, a search range) around a coordinate (2, 12) located at the same propagation time position as the coordinate (1, 12). If there are coordinates having the same standard value “1” as the coordinates (1, 12) in the search range, it is determined that both are related. Therefore, in this case, it is determined that the coordinates (1, 12) and the coordinates (2, 11) are related. This process is performed for all the coordinates where the X axis is 1 and the standard values are “1” and “−1”. As a result, in FIG. 4, the coordinates (1, 2) and (2, 2), the coordinates (1, 4) and (2, 4), and the coordinate (1,
12) and (2,11), and coordinates (1,16) and (2,11)
15) is determined to be relevant, and it is determined that the coordinates (1, 18) are not relevant. Such a process is referred to as a line drawing tracking process.

Next, in step STEP6, the following processing is performed for each set of coordinates determined to be relevant to the line image tracking processing. Here, the coordinates (1, 12) and (2,
This will be described using the set 11). Propagation time coordinate (1, 12) T ₁₂ and the difference value of the propagation time T ₁₁ of the coordinates _{(2,11) (T 12 -T 11} ) to calculate the (T ₁₂ -T in this embodiment ₁₁ =
2 nsec). Next, an added value data map having the same coordinate system as in FIG. 4 is created as shown in FIG. Here, for example, it is defined that the coordinates (2, 11) in FIG. 4 and the coordinates (2, 11) in FIG. 5 are respectively in the same coordinate system. Then, the coordinates (2, 1) of the added value data map in the same coordinate system as the coordinates (2, 11) of the standard value data map
1) stores the difference value (T ₁₂ −T ₁₁ ). At this time, if a value other than 0 exists at the coordinates (1, 12) of the added value data map, the value of the coordinates (2, 11) and the value of the coordinates (1, 12) of the added value data map are changed. The sum is calculated, and the value of the sum is calculated again at the coordinates (2,
11). The values shown in the cells of FIG. 5 are stored values.

Next, in step STEP7, it is determined whether or not the above processing has been performed for all sets of coordinates determined to be relevant. Here, the coordinates (1,
2) and (2,2), and coordinates (1,4) and (2,2)
Since the difference between the propagation times in the set 4) is 0, the values stored at the coordinates (2, 2) and (2, 4) in FIG. 5 are 0. Next, in step STEP8, coordinates (2, j) where the X-axis of the addition value data map is 2 and j = 1 to 19 are coordinates having values other than 0 and coordinates (2 , A) (in this embodiment, a =
15). Hereinafter, the coordinates (2, a) are referred to as starting point coordinates.

Next, in steps STEP9 and STEP10 and steps STEP11 to STEP13 in FIG. 2, the following processing is performed. That is, step ST
In EP9, at the coordinates (2, j) where the X-axis of the addition value data map is 2, j = 1 to 19, the value has a value other than 0 in the direction in which the propagation time decreases from the origin coordinates, and A search is made for the coordinates (2, b) existing within a certain range S2. In the present embodiment, S2 = 8 nsec. Further, in the present embodiment, as shown in FIG.
There is a coordinate (2, 11) having a value other than 0 in ec.

Therefore, as in this embodiment, the specified range 8n
When there are coordinates (2, b) having a value other than 0 within sec, and a standard value in the same coordinate system as the coordinates (2, a) and (2, b) of the added value data map If the signs of the values of the coordinates (2, a) and (2, b) of the data map are different, for example, “−1” and “1”, and if YES is determined in step STEP11 of FIG. In step 12, the coordinates (2,
The sum of the values of a) and the coordinates (2, b) is calculated. Then, it is stored at the coordinates (2, b) of the added value data map.
Such processing is hereinafter referred to as hyperbolic enhancement processing.
Thereafter, at coordinates (2, j) where the X-axis of the addition value data map is 2 and j = 1 to 19, all coordinates having values other than 0 are subjected to hyperbolic enhancement processing. It is determined in step STEP14 whether or not the operation has been completed.

In the case where there are coordinates (2, b) having a value other than 0 within the specified range 8 nsec, the coordinates (2, a), (2, b) of the added value data map are used.
Coordinates of the standard value data map (2,
If the signs of the values of a) and (2, b) match, for example, “1” and “1”, the process proceeds to step STEP14 without performing the hyperbolic enhancement process. Also, coordinates (2, 2) having a value other than 0 within a specified range 8 nsec.
If b) does not exist, the search is continued beyond the specified range in step STEP13 until coordinates (2, c) having a value other than 0 are detected. And coordinates (2, c)
Is detected, the process proceeds to step STEP14.

Here, the size of the prescribed range S2 is determined by the pulse width λ of the pulse used. Also,
The vibration period of the vibration waveform generated by the ringing phenomenon in which the reflected wave reflected by the buried pipe 30 is reflected again is also determined by the pulse width λ used. Therefore, multiple reflection portions on the standard value data map, for example, FIG.
The interval in the propagation time direction between the line drawing patterns 310 and 320 in (a) becomes equal to a value near the pulse width. That is, the search range S2 corresponds to a value near the pulse width λ. This prevents addition of other unnecessary noise components in step STEP12.

In the multiple reflected wave image generated by ringing, a pattern adjacent in the propagation time direction, for example, FIG.
0 and patterns 32 and 33 and patterns 32 and 33
Have opposite signs. Therefore, the result of the normalization is, for example, the coordinates (2, 15) and (2, 11) in FIG.
Have different signs such as "1" and "-1". Therefore, before performing addition in step STEP12, step STE
At P11, the coordinates (2, a), (2,
It is determined whether the sign of the standard value of the coordinates (2, a) and (2, b) of the standard value data map in the same coordinate system as that of b) is different, for example, “1” and “−1”. Confirm.
If they are different, it can be understood that the coordinates (2, a) and (2, b) are the coordinates corresponding to the multiple reflection patterns 31 and 32, respectively, and the hyperbolic enhancement processing is executed.
Thereby, it is further prevented that other unnecessary noise components are added in step STEP12.

Next, steps STEP14 and STEP14
At 15, the following processing is executed. That is, coordinates (2, j) where the X axis of the addition value data map is 2, j = 1 to 19,
In, for all coordinates having a value other than 0,
It is determined in step STEP whether or not hyperbolic enhancement processing has been performed.
The determination is made at 14. If the processing has not been completed, the flow returns to step STEP 9 in FIG. 1 with the coordinates (2, b) or the coordinates (2, c) of the added value data map as starting coordinates in step STEP 15. If the processing has been completed, the process proceeds to step STEP16.

In step STEP16, the coordinates (2, j) where the X axis of the added value data map is 2 and j = 1 to 1
If the maximum added value of No. 9 is equal to or greater than the specified value SH, a buzzer sounds at a frequency changed according to the value of the added value. FIG. 7 is a diagram showing the relationship between the value of the added value data map and the buzzer sound frequency. Subsequently, in step STEP17, it is determined whether or not the measurement has been completed. If the measurement has not been completed, the process returns to step STEP3 in FIG. 1 to receive the reflected wave again. In the present embodiment, as shown in FIG. 4, the description is made using the standard value data map for the 14 received signals. However, in actuality, the processing is performed in parallel with the movement of the antenna. Only two received signals that are continuously received are targeted. Therefore, step STE
Before shifting to P3, the following processing is performed in step STEP.
Perform at 18.

That is, the values of the coordinates (2, j) and j = 1 to 19 of the added value data map whose X-axis is 2 are now converted to the coordinates (1, 1) of the added value data map whose X-axis is 1. j), j =
1 to 19 are stored for each Y-axis coordinate. That is, A
(1, j) = A (2, j), j = 1 to 19 are performed. Here, A (i, j), i = 1,2 is the coordinates (i, j),
i = 1,2. Thereafter, the values of the coordinates (2, j), j = 1 to 19, of the added value data map whose X axis is 2 are deleted. That is, A (2, j) = 0, j = 1 to 19,
And Then, the process proceeds to step STEP3 to receive the reception signal again. At this time, the received signal received again is referred to as f (2), and the received signal received immediately before f (2) is referred to as f (1). Received signals f (1), f
For (2), all the steps shown in the flowcharts of FIGS. 1 and 2 are executed. As a result of repeating steps STEP3 to STEP16 while moving the antenna in this manner, as shown by coordinates (4, 9) in FIG.
For example, the added value of the hyperbolic vertex coordinates increases.

Here, the advantages of the hyperbolic enhancement process executed in steps STEP8 to STEP15 will be described below with reference to FIGS. FIG. 5 is an added value data map obtained by the conventional technique. Assuming that the prescribed value relating to the buzzer sound is 5, there are a total of four coordinates having a value greater than 5. That is, the coordinates (4, 9) representing the true propagation time to the buried pipe, the coordinates (4, 13) that are the ringing components thereof, and the vertex of the pattern whose propagation time gradually decreases in the horizontal direction. The coordinates are (13, 10) and (14, 10). Therefore,
In the stage of FIG. 5, the buzzer sounds at the coordinates (13, 10) and (14, 10), and the position of the buried pipe is erroneously recognized. On the other hand, if hyperbolic enhancement processing as shown in FIG. 6 is performed, the vertex coordinates (4, 4) of the hyperbola having multiple reflections
The added value in 9) increases. Therefore, if the specified value SH relating to the buzzer sound is set to be larger than that of the related art (SH = 15 in the present embodiment), only the coordinates (4, 9) can be recognized.

FIG. 8 shows actual measurement results. FIG. 8 (a)
Is an addition value data map displaying only coordinates having a value equal to or greater than the specified value SH. In the prior art shown in FIG. 11A, the line drawing patterns 320, 330 and 410 could not be removed, but in the present embodiment, only the line drawing pattern 310 is extracted as shown in FIG. Successful. Therefore, as shown in FIG. 8B, the buzzer can be sounded only near the top of the buried pipe,
It is possible to accurately notify the operator of the presence of the buried pipe.

As described above, the following various advantages can be obtained by using the present embedded object detection method. That is, even if there is a reflection image that is continuous in the horizontal direction like the reflected wave from the stratum interface and the propagation time gradually increases and decreases in the horizontal direction, it is buried in the underground section observation pattern. It can be distinguished from a tube. Further, even if multiple reflection images from the buried pipe are observed due to the ringing phenomenon, the number of times the buzzer sounds at each antenna position is one, so that it is easy to recognize the horizontal position of the buried pipe.

Therefore, since the above-mentioned advantages can be expected, the present invention is particularly effective for measurement in a place that is dangerous for the operator to measure or a place where the state of the antenna moving surface is bad. That is, for example, by inserting an antenna into a digging trench while digging with a digging machine such as a backbow in road construction, it is possible to easily detect a buried object that cannot be detected by measurement from the ground surface. Therefore, it is possible to prevent a buried object damage accident caused by the excavating machine.

[0031]

As described above, according to the present invention, when an embedded object is detected, an emphasis step is added to create an added value map. It is possible to remove a noise having a gentle shape in the horizontal direction, which was possible. Further, even if the reflection image from the buried object is observed multiple times due to the ringing phenomenon, the calculation is performed so that only the first waveform having the shortest propagation time is emphasized. For example, only the first waveform can be extracted, and as a result, it is possible to prevent a buzzer having a different volume from sounding several times.
Therefore, it is possible to provide a detection method for notifying the presence of a buried object at a position closer to the buried position, and it is not necessary for an operator to detect the buried object.

[Brief description of the drawings]

FIG. 1 is a flowchart showing an operation of a buried object detection device to which the present invention is applied.

FIG. 2 is a flowchart showing the operation of the buried object detection device.

FIG. 3 is an explanatory diagram showing an example of normalization of a received signal.

FIG. 4 is a diagram showing a standard value data map.

FIG. 5 is a diagram showing an addition value data map.

FIG. 6 is a diagram illustrating an example of a case where hyperbolic enhancement processing is performed on an addition value data map;

FIG. 7 is a diagram showing a relationship between a value of an addition value map and a buzzer sound frequency.

FIG. 8 is a diagram illustrating a situation in which a buzzer sounds at an added value coordinate equal to or greater than a specified value.

FIG. 9 is a block diagram of a buried object detection device.

FIG. 10 is a diagram showing an underground section observation pattern.

FIG. 11 is a diagram showing a relationship between an addition value coordinate based on a conventional addition value data map and a sounding state of a buzzer.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Transmitter, 2 ... Transmission antenna, 3 ... Reception antenna, 4
... Receiver, 5 ... Time counter, 6 ... Calculation unit, 7 ... Buzzer, 8 ... Display unit, 30 ... Buried pipe.

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Junichi Masuda 1-1-6 Uchisaiwai-cho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (56) References JP-A-4-184185 (JP, A) JP-A-Hei JP-A-3-261888 (JP, A) JP-A-3-289587 (JP, A) JP-A-1-180487 (JP, A) JP-A-61-271484 (JP, A) JP-A-1-280278 (JP, A A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G01V 3/12 G01S 7/02 G01S 7/32 G01S 13/88

Claims (2)

(57) [Claims] 1. An electromagnetic wave transmitted from an antenna installed on a ground surface or a structure surface to a ground surface or a structure surface, and an electromagnetic wave reflected from an object existing in the ground or a structure is received again by the antenna. In the method of detecting a buried object for detecting an object existing in the ground or in a structure, a step of receiving a reflected wave at certain time intervals while moving an antenna to obtain a received signal; A value is calculated and the amplitude of the received signal at the time position where the differential value is zero is set to “1” when the sign of the amplitude of the received signal at the time position is positive, and “−1” when the sign is negative. Normalizing the amplitude values at other time positions to “0”; and a standard value map, which is a map of data obtained by two-dimensionally arranging the standardized results of two consecutively received signals. Create The respective coordinates having the values of "1" and "-1" indicating the first line data which is the standard value of the first received signal and the second line data which is the standard value of the next received signal A relevance determining step of examining the relationship with each coordinate of the coordinates, and calculating a difference in the propagation time of the electromagnetic wave on each coordinate in the set of coordinates determined to be relevant in the relevancy determining step, and calculating the difference value. A storing step of storing the coordinates of the additional value map having the same coordinate system as the standard value map; and a value other than “0” in the second line data on the additional value map, and the propagation time is maximized. A search step of searching for a coordinate Y having a value other than “0” within a predetermined time in a direction in which the propagation time is shorter from the start coordinate X, where the coordinates Y are coordinates; In this case, the values of the origin coordinates X and the coordinates Y are different only when the signs of the origin coordinates XK and the coordinates YK on the standard value map corresponding to the origin coordinates X and the coordinates Y on the addition value map are different signs. Calculating the total value of the second line data, and repeatedly executing the search step and the adding step for each coordinate of the second line data, using the coordinate Y as a starting point coordinate X. And repeatedly executing the emphasizing step consisting of moving the antenna, and a notifying step of notifying when the value stored in the addition value map exceeds a prescribed value. How to detect. 2. The method for detecting a buried object in real time according to claim 1, wherein in the searching step, a predetermined time for searching for a coordinate Y from the starting point coordinate X in a direction in which a propagation time becomes shorter is determined by a pulse width of an electromagnetic wave to be transmitted. A method for detecting a buried object in real time, wherein the method is set near the time corresponding to the time.