JP2000258546A - Propagation signal processing method and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the method and device of propagation signal processing that can easily discriminate a true vibration source and a reflection point when propagation is made at a plurality of propagation speeds without being affected by the level fluctuation of a reception signal in an individual and a mixture. SOLUTION: When a vibration source S of a propagation signal being propagated in a medium and a reflection point Q are to be detected, the propagation signal is received by a plurality of receivers R1, R2,... Rn, and the reception signal is converted to digital quantity by an A/D converter 9, is compared with a fixed slice level by a quantization part 13, and is quantified, thus eliminating influence due to the loss of propagation, and allowing each propagation speed to be subjected to overlapping processing by an overlapped processing part 15. A reflection position judgment part 17 multiplies or adds the result that has been subjected to the overlapping processing by or to each propagation speed, and a coincidence position is detected as the true vibration source S or the reflection point Q.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a propagation signal processing method and apparatus, and more particularly, to a propagation signal processing for detecting a vibration source or a reflection point from a propagation signal oscillated from a vibration source and propagated in a medium. A method and an apparatus therefor.

[0002]

2. Description of the Related Art When a part of a mixture such as an individual and soil is vibrated, an elastic wave propagates through a medium. At this time, the propagating wave is attenuated by absorption, scattering, etc., depending on the propagation distance and medium,
A longitudinal wave, a transverse wave, a surface wave, and the like propagate with different propagation losses and different propagation speeds.

Conventionally, as shown in FIG. 11, a vibration source S and at least one vibration receiving point R are opposed to each other in a medium such as soil, or as shown in FIG. At S, the medium is vibrated, and a wave reflected from a reflection point Q such as an object or a layer in the medium is received at a reception point R.

Now, in the case shown in FIG.
When the vibration is received by the plurality of geophones R1 to Rn from the vibration source S, the propagation time Tn to the n-th geophone is Tn =
Hn / V.

[0005] Here, Hn represents the distance to the geophone, and V represents the propagation velocity.

[0006] As shown in FIG. 12, when the vibrations emitted from the vibration source S and reflected by the reflector Q in the medium are received by the plurality of vibration receivers R1 to Rn, The propagation time Ti to the i-th geophone is

## EQU1 ## Ti = [√ (H ² + Xk ² ) + √ ｛H ² + (Xi
−Xk) ² ｝] / V to obtain the position of the source S and the position of the reflection point Q. H is the distance between the line connecting the transducer and the receiver, Xi:
Distance between transmitter and receiver, Xk: distance between transmitter and reflection point (perpendicular to H)

[0007]

However, in such a conventional technique, the propagation wave in the medium is affected by the propagation loss, the state of the reflector, and the like. It is necessary to compensate for propagation attenuation by using in parallel according to

At this time, when an elastic wave propagates through a medium, a plurality of propagation waves (for example, longitudinal waves, transverse waves, etc.) having a plurality of propagation velocities are generated. Therefore, the propagation velocities of these waves are estimated. However, since a specific wave is limited and processed in a certain measurement range after being artificially identified, there is a problem that experience is required and stable analysis is difficult.

In addition, when there are a large number of vibration sources S and targets, there is a problem that experience is required to artificially identify a received signal, and a true signal may be erroneously recognized. Further, there is a problem that the reflection level of the target object and the like may not be low enough to be supplemented with respect to the surroundings.

An object of the present invention has been made by paying attention to the conventional technology as described above, and is not affected by the fluctuation of the level of a received signal in an individual or a mixture, and when the signal is propagated at a plurality of propagation speeds. An object of the present invention is to provide a propagated signal processing method and a propagated signal processing device that can easily determine a true source and a reflection point.

[0011]

According to a first aspect of the present invention, there is provided a method for processing a propagated signal, comprising the steps of: In the propagation signal processing method for detecting the propagation signal, the propagation signal is received by a plurality of geophones, the received signal is quantized with respect to a certain slice level, and the relative position between the receiving point and the epicenter or the reflection point is overlapped. Processing to detect a true source position or a reflection position.

Therefore, when detecting the source and the reflection point of the propagation signal propagating in the medium, the propagation signal is received by a plurality of receivers, and the received signal is converted into a slice level (the threshold value) of a certain level. ) To eliminate the effect of the propagation loss by quantization and superimpose it to detect the true source position or reflection position.

According to a second aspect of the invention, there is provided a propagated signal processing method according to the first aspect, wherein when signals having different propagation speeds are superimposed, the signals are processed at the respective propagation speeds, and each signal is processed at the same receiving point. It is characterized by having a function of, by multiplying or adding signals from a plurality of geophones, signals obtained by matching propagation waves having different propagation speeds to be true information.

Therefore, when a propagation signal is received at a plurality of propagation speeds, the signal is read out for each propagation speed and multiplied or added by each propagation signal at the same receiving point,
The matched position is detected as a true source or a reflection point.

According to a third aspect of the present invention, a propagation signal processing apparatus detects a distance from a propagation signal oscillated from a vibration source and propagates in a medium to a vibration source or a reflection point, and determines a position of the vibration source or the reflection point. A plurality of geophones arranged at a plurality of locations for receiving the propagation signal, and an A for digitizing the geophone signal received by the geophone.
A / D converter, a quantization unit for quantizing the received signal digitized by the A / D converter with respect to a constant slice level, and a relative position between the received point and a source or reflection point. And a superposition processing unit for detecting a true source position or a reflection position by superposition processing.

Therefore, when detecting the source or reflection point of a propagation signal propagating in a medium, the propagation signal is received by a plurality of receivers, and the received signal is converted into a digital signal by an A / D converter. , And quantize by a quantizer to compare with a certain level of slice level to eliminate the effects of propagation loss.The superposition processor superposes this to determine the true source position or reflection position. To detect.

According to a fourth aspect of the present invention, there is provided the propagated signal processing apparatus according to the third aspect, wherein the propagated signal is transmitted at each of the propagation speeds when the propagation signal is propagated with a plurality of propagation speeds. A reflection position determination unit that detects a position where propagation waves of different propagation velocities match by multiplying or adding a plurality of received signals for each of the same received points to determine a true vibration source or a reflection point. It is characterized by having.

Therefore, when a propagation signal is received at a plurality of propagation velocities, the superposition processing unit performs processing on each of the propagation velocities, and the reflection position determination unit multiplies each propagation signal for each same reception point. Or, by addition, the coincident position is detected as a true source or a reflection point.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings.

A method for discriminating a signal propagated through a medium at a plurality of propagation speeds will be described. For simplicity, a case where there is one receiving point and two kinds of propagation speeds will be described first.

Referring to FIG. 2A, the vibration wave emitted from the vibration source S propagates from the vibration source S to the vibration receiving point R. Alternatively, as shown in FIG. 2B, the source S → reflected object Q →
Propagation to the receiving point R.

Now, let the propagation speeds be V1 and V2, and V1> V
Assuming that 2, the waveform received at the receiving point R is represented as shown in FIG. 3A when the propagation time T is represented on the horizontal axis. Here, T1 is the time reached at the propagation speed V1,
In addition, T2 indicates the time of arrival at the propagation speed V2.
Therefore, T1 <T2.

FIG. 3B shows a received signal that has been subjected to effective quantization when the received signal level fluctuates greatly or the level of the target signal is lower than the surroundings.

When the received waves as shown in FIGS. 3A and 3B are read with respect to the propagation velocities V1 and V2, and the propagation distance L is displayed on the horizontal axis, it is shown in FIG. 4 (A) and FIG. 3 (B)
4B is as shown in FIG. 4B.

[0025]

(Equation 2) And a relative relationship as shown in FIGS. 4A and 4B is obtained.

That is, reading is performed at V ₁ and V ₂ , respectively, and t ₁
V ₁ =, t ₂ V ₂ is the true position.

Next, when the signal read in FIGS. 4A and 4B is multiplied by L, the result is as shown in FIGS. 5A and 5B.

Therefore, by performing the processing described above, it is possible to select the propagation speed without artificial judgment or propagation speed.
The true distance L from the vibration source S (or the reflection point Q) to the vibration receiving point R can be easily obtained.

In the above description, the case where there are two types of propagation speeds V1 and V2 has been described. However, even if there are three or more types of propagation speeds, as a result of processing at each propagation speed, the target object matches. What you do is the position of the true target.

Next, a case where the number of sources S and the number of reflection points Q are larger will be described. Also in this case, a large number of sources S and reflection points Q can be obtained by determining each signal.

That is, as shown in FIGS. 6 and 7, the vibration wave generated from the vibration
When the vibrations received by the geophones R1, R2,... arranged at i are shown with the propagation time T on the horizontal axis, the waveform is as shown in FIG.

If there is a vibration source S or a reflector Q under the receiver Rn in FIG. 7, the echo is received by the receiver Rn earliest. That is, the propagation time Tn is: Tn = {H ² + (Xn−Xk) ² } / V in the case of FIG.

## EQU3 ## Tn = [Ｘ (H ² + Xk ² ) + √ ｛H ² + (Xi
−Xk) ² ｝] / V. From this, binarization (quantization) at a slice level (also referred to as a threshold value) e in order to eliminate the influence of the propagation loss is as shown in FIG. 9, and the received signal is not affected by the propagation loss. From this, when the direct distance H from the vibration receiving point to the vibration source S or the reflection point Q is obtained, H = {T ² · V ² − (Xi−Xk) ² } in the case of FIG. ,

H = √ [T ² · V ² + Xi · (2Xk−Xi) ·
{Xi · (2Xk−Xi) / T ² / V ² +2} −4X
k ² ] / 2. Here, Xk is the horizontal distance between the source S or the reflection point Q and the reference point, Xi is the distance between the receiver Ri and the source S, V
Represents the propagation speed.

As a result, as shown in FIG. 10, the received signals are arranged at the same depth, and R1, R2,.
The position of the distance H where the received signals of Rn,... Coincide with each other can be obtained. Similarly, when Xk is changed, R1, R
A point where the echoes of 2,... Rn,.

That is, as shown in FIG. 6 and FIG. 7, high-precision measurement is possible by receiving vibrations with a large number of vibration receivers R,. Becomes

Next, with reference to FIG. 1, a description will be given of a propagated signal processing device 1 for performing the above-described processing. The propagation signal processing device 1 has a CPU 3 serving as a central processing unit having an input unit 5 of a keyboard for inputting data such as a slice level and an output unit 7 of a CRT for displaying various information.

Further, the CPU 3 includes the respective geophones R1, R
2, an A / D converter 9 for converting a received signal transmitted from Rn into a digital amount is connected. Also, CPU
3, a memory 11 for storing various data, a quantization 13 based on a designated slice level as a reference, and a superposition processing unit 15 for superposing data are connected.

In the case where the data is composed of several propagation speeds, the superposition processing unit 15 processes the data for several propagation speeds, and outputs a plurality of vibrations at the same vibration receiving point. A reflection position determination unit 17 is connected which detects a position where propagation waves of different propagation velocities coincide by multiplying or adding signals to determine a true source or a reflection point.

With the above configuration, each of the geophones R1, R2,.
Rn receives the received signal, and converts the received signal into an A / D signal.
The converter 9 converts the data into a digital value and stores it in the memory 11. The data, which is a digital quantity stored in the memory 11, is reduced by the quantization unit 13 using quantization software using a designated threshold level (slice level) in order to reduce the influence of level fluctuation. And quantize. The superimposition processing unit 15 that corrects the quantized data at the relative position with respect to each of the geophone receiver data and performs an addition process is processed using the superimposition processing software.

The superposition processing section 15 performs superposition processing at the propagation speed of each wave, and stores each result in the memory 11.
This processing result is read out by the reflection position determination unit 17 for each result and multiplied to obtain a remaining reflection point, and erases data serving as a virtual image.

Based on the above results, a superposition calculation process is performed at the propagation speed of each wave, the results are multiplied, and the remaining reflection points are set as true reflection positions, so that a large number of waves (propagation speed) are generated. Measurement in a medium such as a soil layer becomes easy. Further, the distance and position of a point caused by an earthquake, ground deformation, or the like can be easily obtained.

It should be noted that the present invention is not limited to the above-described embodiment of the present invention, but by making appropriate changes,
It can be implemented in other aspects.

[0042]

As described above, in the propagated signal processing method according to the first aspect of the present invention, a plurality of geophones are used when detecting the source and reflection point of a propagated signal propagating in a medium. The propagation signal is received and the received signal is quantized by comparing it with a certain level of slice level, so that the effects of propagation loss can be eliminated. And it is possible to easily determine the true vibration source and the reflection point without artificially discriminating when transmitting at a plurality of propagation speeds.

In the propagated signal processing method according to the second aspect of the present invention, when a propagated signal is received at a plurality of propagated speeds, each propagated speed is processed, and the processed results are multiplied or added to match. Since the position is detected as a true source or a reflection point, the true source or the reflection point can be easily determined without being artificially identified.

In the propagation signal processing device according to the third aspect of the invention, when detecting a vibration source or a reflection point from a propagation signal propagating in a medium, the propagation signal is received by a plurality of vibration receivers. The signal is converted into a digital quantity by an A / D converter, compared with a fixed slice level by a quantization unit, quantized, and then subjected to a polymerization process by a polymerization processing unit. It is not affected by level fluctuation, and it is possible to easily determine the true source or reflection point without artificially identifying when propagating at multiple propagation speeds. Can be detected.

In the propagation signal processing apparatus according to the fourth aspect, when a propagation signal is received at a plurality of propagation speeds, the superposition processing unit processes each of the propagation speeds, and the processing result is used as a reflection position determination unit. Are multiplied or added, and the coincident position is detected as a true source or a reflection point, so that the true source or the reflection point can be easily determined without being artificially identified.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a propagation signal processing device according to the present invention.

FIG. 2A is an explanatory diagram illustrating a positional relationship between a vibration source and a geophone, and FIG. 2B is an explanatory diagram illustrating a positional relationship between a vibration source, a reflection point, and a geophone.

FIG. 3A is a graph showing a received waveform, and FIG.
Is a quantized graph.

FIG. 4A is a graph showing received waveforms of signals having different propagation speeds, and FIG. 4B is a quantized graph.

5A is a graph showing a waveform of a signal subjected to a polymerization process, and FIG. 5B is a quantized graph thereof.

FIG. 6 is an explanatory diagram showing a positional relationship between a vibration source and a plurality of geophones.

FIG. 7 is an explanatory diagram showing a positional relationship between a vibration source, a reflection point, and a plurality of geophones.

FIG. 8 is a graph showing a waveform of a received signal from each receiver.

FIG. 9 is a graph obtained by quantizing the waveform of FIG. 8;

FIG. 10 is a graph showing the calculated depth position of the reflection point.

FIG. 11 is an explanatory diagram showing a positional relationship between a vibration source and a geophone.

FIG. 12 is an explanatory diagram showing a positional relationship among a vibration source, a reflection point, and a geophone.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Propagation signal processing apparatus 9 A / D converter 13 Quantization part 15 Superposition processing part 17 Reflection position determination part Q Reflection point R Geophone S S source V Propagation velocity

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hisako Koizumi 1-13-8 Matsugaoka, Moriya-cho, Kitasoma-gun, Ibaraki F-term (reference) 5J083 AA02 AB12 AC07 AC12 AC17 AD04 AE06 BA01 BE10 BE19 CA01 EB02

Claims (4)

[Claims] 1. A propagation signal processing method for detecting a vibration source or a reflection point from a propagation signal oscillated from a vibration source and propagated in a medium, wherein the propagation signal is received by a plurality of geophones, and Quantifying a slice level at a certain level, superimposing the relative position between the received point and the epicenter or reflection point, and detecting the true epicenter or reflection position. . 2. When signals having different propagation speeds are superimposed, the signals are processed at the respective propagation speeds and multiplied or added by the signals of a plurality of geophones at the same receiving point, thereby having different propagation speeds. 2. The propagation signal processing method according to claim 1, wherein a signal whose propagation wave coincides is regarded as true information. 3. A distance from a propagation signal oscillated from a vibration source and propagated in a medium to the vibration source or a reflection point is detected.
A propagation signal processing device for detecting the position of a vibration source or a reflection point, comprising: a plurality of geophones arranged at a plurality of locations for receiving the propagation signals; A D converter, a quantization unit for quantizing the received signal digitized by the A / D converter with respect to a predetermined slice level, and superimposing a relative position between the received point and a vibration source or a reflection point. And a superposition processing unit for processing to detect a true source position or a reflection position. 4. When the propagation signal is superimposed and propagated at a plurality of propagation speeds, the signal is processed at each propagation speed, and a plurality of received signals are multiplied or added at the same receiving point to obtain different signals. 4. The propagation signal processing apparatus according to claim 3, further comprising a reflection position determination unit that detects a position where the propagation waves having the same propagation velocity coincide with each other and sets the position as a true source or a reflection point.