Abnormal body directional detection method and device based on borehole radar

Abstract

The invention discloses an anomalous body directional detection method and device based on a borehole radar, and belongs to the technical field of borehole radar detection, and the method comprises the steps: obtaining a plurality of azimuth angles of the borehole radar during testing, and a radar image map corresponding to each azimuth angle; determining the electromagnetic wave propagation velocity of the space where the anomalous body is located based on the radar images, and performing migration imaging on each radar image based on the electromagnetic wave propagation velocity to obtain a plurality of migration images; and determining a plurality of maximum reflection energies of the plurality of offset images, and performing weighted calculation on the plurality of azimuth angles through the plurality of maximum reflection energies to determine a target azimuth angle of the anomalous body. By taking the maximum reflection energy of the offset image as a reference quantity, weighting calculation is carried out on a plurality of azimuth angles corresponding to the radar image map, and the target azimuth angle of the anomalous body can be accurately determined.

Description

Technical Field

[0001] The present invention relates to the technical field of borehole radar detection, and in particular to a method and device for directional detection of anomalies based on borehole radar. Background Art

[0002] Borehole radar is a geophysical method that transmits and receives high-frequency electromagnetic waves within a borehole, processes and analyzes the reflected and transmitted waves, and obtains geological information. Its key difference from ground-based radar is its ability to approach anomalies to a certain extent, overcoming the shortcoming of ground-based radar, which is limited to near-surface detection due to its shallow detection depth. Drilling is currently the most widely used method in karst exploration, providing intuitive and accurate identification of the lithology and development of unfavorable geological bodies beneath the borehole. However, drilling costs are relatively high, and the limited number of holes drilled makes it difficult to achieve comprehensive regional coverage. Furthermore, drilling results are only a snapshot of a single hole, unable to fully understand the geological conditions surrounding the borehole. Borehole radar, based on existing boreholes, can obtain geological information within a certain radius of the borehole. It offers advantages such as a wide detection range, low cost, and high efficiency, and holds broad application prospects in the detection of unfavorable geological bodies such as karst, faults, and fracture zones.

[0003] The transmitting and receiving antennas of traditional borehole radar are generally omnidirectional antennas, so they can only determine the depth of the anomaly and the distance from the borehole, but cannot determine the angle of the anomaly's location. However, in many projects, we need to know not only the depth of the anomaly and the distance from the borehole, but also the precise direction of the anomaly.

[0004] Therefore, in the process of borehole radar detection in the prior art, there is a problem that the target azimuth angle of the abnormal body cannot be determined. Summary of the Invention

[0005] In view of this, it is necessary to provide a method and device for directional detection of anomalies based on borehole radar to solve the problem in the prior art that the target azimuth of the anomaly cannot be determined during borehole radar detection.

[0006] In order to solve the above problems, in a first aspect, the present invention provides a method for directional detection of anomalies based on borehole radar, comprising: Obtain multiple azimuths of the borehole radar during testing, as well as the radar image corresponding to each azimuth; Determining the electromagnetic wave propagation speed in the space where the abnormal body is located based on the radar image, and performing offset imaging on each of the radar image based on the electromagnetic wave propagation speed to obtain a plurality of offset images; A plurality of maximum reflection energies of the plurality of offset images are determined, and a target azimuth angle of the abnormal body is determined by performing weighted calculation on the plurality of azimuth angles according to the plurality of maximum reflection energies.

[0007] In some possible implementations, determining the electromagnetic wave propagation velocity in the space where the anomaly is located based on the radar image, and performing offset imaging on each of the radar image based on the electromagnetic wave propagation velocity to obtain multiple offset images includes: Selecting a hyperbolic characteristic region of the radar image, and determining the electromagnetic wave propagation speed in the space where the abnormal body is located based on the length and time relationship of the hyperbolic characteristic region; Performing offset imaging on each of the radar image images based on the electromagnetic wave propagation speed to obtain a plurality of offset images of the radar image images; An energy mean of the offset image is calculated based on the electromagnetic wave propagation speed, and the offset image is binarized based on the energy mean to obtain a binarized image of the radar image.

[0008] In some possible implementations, selecting a hyperbolic characteristic region of the radar image and determining the electromagnetic wave propagation speed in the space where the abnormal object is located based on the length and time relationship of the hyperbolic characteristic region includes: Obtaining a first time when the borehole radar detects the anomaly at a first position, and a second time and a third time when the borehole radar detects the anomaly based on a second position and a third position, respectively, wherein the first position refers to the position where the borehole radar most quickly detects the vertex of the hyperbolic characteristic region; The electromagnetic wave propagation speed in the space where the abnormal object is located is determined by calculating the Pythagorean theorem according to the first position, the second position, the third position, the first time, the second time, and the third time.

[0009] In some possible implementations, the calculation formula for the electromagnetic wave propagation speed is:

[0010] in, is the electromagnetic wave propagation speed, is the first position, is the second position, is the third position, For the first time, For the second time, is the third time.

[0011] In some possible implementations, performing offset imaging on each radar image based on the electromagnetic wave propagation speed to obtain multiple offset images of the radar image includes: Constructing a coordinate system and mapping the radar image onto a plane where the horizontal and vertical axes of the coordinate system are located; Performing a two-dimensional Fourier transform on the radar image in the horizontal and vertical directions to obtain a two-dimensional Fourier transform result; The two-dimensional Fourier transform result is sequentially subjected to vertical axis extension and inverse Fourier transform processing, and the vertical coordinate is set to zero to obtain the offset image.

[0012] In some possible implementations, after performing offset imaging on each of the radar images based on the electromagnetic wave propagation speed to obtain a plurality of offset images, the method further includes: Obtaining an energy mean of the offset image, and determining an energy threshold according to a preset threshold coefficient and the energy mean; The pixels of the offset image are binarized based on the energy threshold to obtain the binarized image of the radar image.

[0013] In some possible implementations, after obtaining the offset image of the radar image, the method further includes: Performing speed scanning detection on the space where the abnormal body is located based on different preset electromagnetic wave propagation speeds to obtain corresponding multiple detection radar image maps; Determining a plurality of detection binary images of the plurality of detection radar image maps; The focusing indexes of the detection binary image corresponding to different preset electromagnetic wave propagation velocities are calculated, and the preset electromagnetic wave propagation velocity corresponding to the minimum focusing index is determined as the target electromagnetic wave propagation velocity.

[0014] In some possible implementations, calculating the target azimuth of the anomaly according to the maximum reflected energy and the azimuth includes: Determining the weight of the azimuth angle according to the maximum reflected energy, and determining the target azimuth angle of the anomaly according to a target azimuth angle calculation formula; The target azimuth angle calculation formula is:

[0015] is the target azimuth, For the i The azimuth angle, For the i The maximum reflected energy, Indicates summation.

[0016] In some possible implementations, obtaining multiple azimuths of the borehole radar during testing, and a radar image corresponding to each azimuth, includes: placing the borehole radar equipped with multiple antennas in the borehole, and determining an initial azimuth angle of each receiving antenna; The direction of the drilling is used as the moving direction of the drilling radar equipped with multiple antennas, and the rotation angle of the drilling radar equipped with multiple antennas at any drilling distance and radar data of each receiving antenna are obtained; Correcting the actual azimuth angle corresponding to the radar data according to the rotation angle to obtain target radar data at any drilling distance based on the initial azimuth angle; The target radar data is converted into the radar image, and the azimuth angle corresponding to the radar image is determined according to the initial azimuth angle.

[0017] In a second aspect, the present invention further provides a device for directional detection of anomalies based on borehole radar, comprising: The parameter acquisition module is used to obtain multiple azimuth angles of the borehole radar during testing, as well as the radar image corresponding to each azimuth angle; an offset image acquisition module, configured to determine the electromagnetic wave propagation velocity in the space where the abnormal body is located based on the radar image, and to perform offset imaging on each of the radar image based on the electromagnetic wave propagation velocity to obtain a plurality of offset images; The abnormal body orientation module is used to determine a plurality of maximum reflection energies of the plurality of offset images, and perform weighted calculation on the plurality of azimuths by using the plurality of maximum reflection energies to determine a target azimuth of the abnormal body.

[0018] The beneficial effects of adopting the above embodiment are as follows: the present invention provides a method for directional detection of anomalies based on borehole radar, which can effectively ensure the reliability of offset imaging and obtain concise and clear information about the anomaly by determining the electromagnetic wave propagation speed in the space where the anomaly is located based on the radar image; by using the maximum reflection energy of the offset image as a reference amount and performing weighted calculation on multiple azimuths corresponding to the radar image, the target azimuth of the anomaly can be accurately determined. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic flow chart of an embodiment of a method for directional detection of anomalies based on borehole radar provided by the present invention; Figure 2 The invention provides the acquisition of azimuth and radar image Figure 1 Schematic diagram of the process of the embodiment; Figure 3 A schematic structural diagram of an embodiment of a borehole radar equipped with a single-transmit-multiple-receive antenna provided by the present invention; Figure 4 A schematic structural diagram of an embodiment of a vertical hole drilling radar test provided by the present invention; Figure 5 A schematic structural diagram of an embodiment of a horizontal hole drilling radar test provided by the present invention; Figure 6 A schematic diagram of a process for obtaining an offset image of a radar image according to an embodiment of the present invention; Figure 7 A schematic diagram of the results of an embodiment of a hyperbolic characteristic region provided by the present invention; Figure 8 A schematic diagram of a process for obtaining an offset image of a radar image according to another embodiment of the present invention; Figure 9 A result comparison diagram of a radar image and a migration image according to an embodiment of the present invention; Figure 10 A comparison diagram of the results of an embodiment of an offset image and a binarized image provided by the present invention; Figure 11 A schematic diagram of a flow chart of an embodiment of determining a target electromagnetic wave propagation velocity provided by the present invention; Figure 12 Schematic diagram of the results of migration imaging and binarization imaging in an embodiment of the present invention when the wave velocity is correct, the wave velocity is too small, and the wave velocity is too large; Figure 13 This is a structural block diagram of an embodiment of the abnormal body directional detection device based on borehole radar provided by the present invention. DETAILED DESCRIPTION

[0020] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0021] It should be understood that the schematic drawings are not drawn to scale. The flowcharts used in the present invention illustrate operations implemented according to some embodiments of the present invention. It should be understood that the operations of the flowcharts can be implemented out of sequence, and steps that have no logical contextual relationship can be reversed in order or implemented simultaneously. In addition, those skilled in the art, guided by the content of the present invention, can add one or more other operations to the flowcharts or remove one or more operations from the flowcharts. Some of the block diagrams shown in the accompanying drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in the form of software, or in one or more hardware modules or integrated circuits, or in different networks and / or processor systems and / or microcontroller systems.

[0022] The terms "first" and "second" in the embodiments of the present invention are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a technical feature designated as "first" or "second" may explicitly or implicitly include at least one such feature.

[0023] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute a separate or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0024] In order to solve the problem in the prior art that the target azimuth of an anomaly cannot be determined during borehole radar detection, the present invention provides a method and device for directional detection of anomalies based on borehole radar, which are described in detail below.

[0025] like Figure 1 As shown, Figure 1 A schematic flow chart of an embodiment of a method for directional detection of anomalies based on borehole radar provided by the present invention includes: S101: Acquire multiple azimuths of the borehole radar during testing, and a radar image corresponding to each azimuth; In some embodiments of the present invention, the azimuth angle refers to the azimuth angle of the receiving antenna of the borehole radar during testing. When the transmitting antenna transmits signals in all directions, the receiving antenna only receives signals at a certain fixed angle at a time during the process of receiving signals, and then converts the received signals into radar images. In other words, each radar image has a corresponding fixed azimuth angle of the received signal.

[0026] S102: determining the electromagnetic wave propagation velocity in the space where the anomaly is located based on the radar image, and performing offset imaging on each radar image based on the electromagnetic wave propagation velocity to obtain multiple offset images; In some embodiments of the present invention, the abnormal body generally includes geological structures or features such as faults, karst fissure zones, aquifers, igneous rock intrusion zones, and coal thickness variation zones.

[0027] S103: Determine a plurality of maximum reflection energies of the plurality of offset images, and perform weighted calculation on a plurality of azimuths using the plurality of maximum reflection energies to determine a target azimuth of the abnormal body.

[0028] It should be noted that the azimuth refers to the angle of the receiving antenna. The azimuth can be defined as horizontal longitude, or customized as needed. Horizontal longitude is the angle formed by rotating the north direction line at a certain point clockwise to the target direction line.

[0029] The target azimuth refers to the azimuth corresponding to the direction of the anomaly. Based on the target azimuth, the angle of the anomaly relative to the borehole can be accurately determined. Combined with the distance information obtained by measurement, the anomaly can be located.

[0030] In this embodiment, by determining the electromagnetic wave propagation speed in the space where the anomaly is located based on the radar image, and performing offset imaging on each radar image based on the electromagnetic wave propagation speed, the reliability of the offset imaging can be effectively guaranteed, and concise and clear information about the anomaly can be obtained; by using the maximum reflection energy of the offset image as a reference amount and performing weighted calculation on multiple azimuths corresponding to the radar image, the target azimuth of the anomaly can be accurately determined.

[0031] In some embodiments of the present invention, in S101, in order to obtain multiple azimuths of the borehole radar during testing, and the radar image corresponding to each azimuth, such as Figure 2 As shown, Figure 2 The invention provides the acquisition of azimuth and radar image Figure 1 The schematic flow diagram of the embodiment includes: S201: placing a borehole radar equipped with multiple transmitting antennas in a borehole and determining an initial azimuth angle of each receiving antenna; In some embodiments of the present invention, a borehole radar configured with a single transmit and multiple receive antennas includes multiple receiving antennas, such as Figure 3 As shown, Figure 3 A schematic diagram of the structure of an embodiment of a borehole radar equipped with a single-transmitting, multi-receiving antenna provided by the present invention. The "single-transmitting" antenna refers to an omnidirectional transmitting antenna that emits electromagnetic waves in a 360-degree angle; the "multi-receiving" antenna refers to multiple (usually 3 or 4) directional receiving antennas. Each receiving antenna is equipped with shielding partitions on both sides and can only receive electromagnetic wave signals within a certain angle range directly in front of it. The azimuth of the geological anomaly can be interpreted based on the signal characteristics of each receiving antenna.

[0032] In addition, the cap is used to prevent water and dust and protect the probe connection joint; the fixed bearing is used to fix the various components of the probe; the metal shell is used to protect the internal components of the probe; the non-metallic shell is placed on the outside of the transmitting and receiving antennas and will not shield the electromagnetic wave signals; the electronic compass is used to record the azimuth of the probe; the main control board controls the start and stop of the transmitting antenna and stores the electronic compass and receiving antenna data; the battery is used to power the various components of the probe; and the shielding partition is used to isolate electromagnetic waves.

[0033] In actual use, you can choose one transmit and three receive antennas or one transmit and four receive antennas according to actual needs, and there is no restriction here.

[0034] It should be noted that each receiving antenna corresponds to an azimuth angle, and during the test, each receiving antenna can obtain a radar image. Therefore, the azimuth angles, receiving antennas, and radar images are one-to-one corresponding, and their numbers are exactly the same.

[0035] S202: Using the drilling direction as the movement direction of the borehole radar equipped with multiple antennas, obtaining the rotation angle of the borehole radar equipped with multiple antennas at any drilling distance and radar data of each receiving antenna; S203: Correcting the actual azimuth angle corresponding to the radar data according to the rotation angle to obtain target radar data at any drilling distance based on the initial azimuth angle; In some embodiments of the present invention, since the borehole radar may rotate during the test, causing the collected radar data to be inconsistent with the initial azimuth, in order to ensure the reliability of the radar data, it is necessary to correct the actual azimuth corresponding to the radar data at each test position, that is, any borehole distance, to ensure that the obtained target radar data is completely consistent with the initial azimuth.

[0036] S204: Convert the target radar data into a radar image, and determine the azimuth angle corresponding to the radar image according to the initial azimuth angle.

[0037] During the test, the borehole radar used is a single-hole test, which can be used for vertical drilling, horizontal drilling, and even inclined drilling, without limitation.

[0038] In order to ensure the intuitive display of the position relationship of the borehole radar during the test, such as Figure 4 As shown, Figure 4 This is a structural diagram of an embodiment of the vertical hole drilling radar test provided by the present invention, as shown in FIG. Figure 5 As shown, Figure 5 This is a structural schematic diagram of an embodiment of the horizontal hole drilling radar test provided by the present invention.

[0039] A borehole radar primarily consists of a main control unit, a radar probe, a probe cable, a pulley counter, a pulley counter cable, and a tripod. The main control unit records the pulley counter data, thereby determining the vertical and horizontal position of the radar probe and, therefore, the drilling distance. The radar probe is a multi-receiver device, equipped with multiple receiving antennas, capable of acquiring signals from the transmitting antenna from multiple angles, thereby generating reliable radar data.

[0040] In particular, the main control machine can also output a radar image corresponding to the radar data according to actual needs, or can also send the radar data to other data processing modules to obtain the corresponding radar image.

[0041] During the borehole radar test, as the radar probe moves, the pulley counter records the probe movement information, the electronic compass records the probe's azimuth information, the omnidirectional transmitting antenna transmits electromagnetic waves 360 degrees, and multiple receiving antennas receive electromagnetic wave signals in real time. Finally, the main control machine saves the probe's movement distance, azimuth angle, and received electromagnetic wave information. Among them, based on the pulley counter data and the electronic compass data, the azimuth angles of multiple receiving antennas during the test are corrected. For example, at the beginning of data collection, i The initial azimuth angle of the receiving antenna is , the radar probe moves in the hole x After the distance, the rotation occurs, and the rotation angle is recorded as , then the receiving antenna is x The corrected azimuth at the distance is .

[0042] In some embodiments of the present invention, in S102, in order to perform offset imaging on the radar image, a plurality of offset images are obtained, such as Figure 6 As shown, Figure 6 A schematic diagram of a process for obtaining an offset image of a radar image provided by the present invention includes: S601: Selecting a hyperbolic characteristic region of the radar image, and determining the electromagnetic wave propagation speed in the space where the anomaly is located based on the length and time relationship of the hyperbolic characteristic region; S602: Performing offset imaging on each radar image based on the electromagnetic wave propagation speed to obtain a plurality of offset images of the radar image.

[0043] In this embodiment, the area where the anomaly exists is determined by selecting a hyperbolic characteristic area of the radar image, and the electromagnetic wave propagation speed in the space where the anomaly exists is determined by performing data analysis on the length and time of this area, thereby ensuring the standardization of the offset image obtained by offset imaging.

[0044] In some embodiments of the present invention, in S601, in order to select a hyperbolic characteristic area of the radar image and determine the electromagnetic wave propagation speed in the space where the anomaly is located based on the length and time relationship of the hyperbolic characteristic area, first, the first time when the borehole radar detects the anomaly at the first position, and the second time and third time when the borehole radar detects the anomaly based on the second position and the third position respectively are obtained, where the first position refers to the position where the borehole radar detects the vertex of the hyperbolic characteristic area most quickly; then, based on the first position, the second position, the third position, the first time, the second time, the third time, the Pythagorean theorem is used to calculate the electromagnetic wave propagation speed in the space where the anomaly is located.

[0045] like Figure 7 As shown, Figure 7 This is a schematic diagram of the results of an embodiment of the hyperbolic feature area provided by the present invention, wherein the hyperbolic feature area refers to an area with obvious hyperbolic features selected in the radar image, and the hyperbolic vertex and two reflection points are manually added, and the vertex coordinates are marked as , the coordinates of the two reflection points are marked as , The burial depth of the abnormal body is h , due to system delay and vacuum delay, there is an error between the time of picking up the point and the real time, which is recorded as , then the electromagnetic wave propagation speed The derivation process is as follows: Abnormal body burial depth h Equal to speed When traveling one way The product of , that is: (1) h , and signal arrival point The moving paths are the side lengths of the right triangle, satisfying: (2) Substituting formula (1) into formula (2) and shifting the terms, we can obtain: (3) Depend on Similarly, we can get: (4) Using formula (3)-formula (4) we can eliminate , and sorting can be obtained: (5) in, is the propagation speed of electromagnetic waves, For the first position, For the second position, For the third position, For the first time, For the second time, For the third time.

[0046] In this embodiment, by performing data calculation on the hyperbola characteristic region, the propagation speed of electromagnetic waves in the space where the abnormal body is located is estimated, thus preparing for subsequent data processing.

[0047] In some embodiments of the present invention, in S602, in order to perform offset imaging on each radar image based on the propagation speed of electromagnetic waves, a plurality of offset images of the radar image are obtained, such as Figure 8 As shown, Figure 8 A schematic diagram of a process for obtaining an offset image of a radar image according to another embodiment of the present invention includes: S801: Construct a coordinate system and map the radar image onto the plane where the horizontal and vertical axes of the coordinate system are located; S802: Performing a two-dimensional Fourier transform on the radar image in the horizontal and vertical directions to obtain a two-dimensional Fourier transform result; S803: Performing vertical axis extension and inverse Fourier transform processing on the two-dimensional Fourier transform results in sequence, and setting the vertical coordinate to zero to obtain an offset image.

[0048] It should be noted that the horizontal axis generally refers to the horizontal distance direction of the borehole radar. The larger the horizontal coordinate, the greater the distance from the borehole; the vertical axis generally refers to the time direction. The larger the vertical coordinate, the greater the time difference from the initial acquisition time; the vertical axis generally refers to the borehole depth direction. The larger the vertical coordinate, the greater the corresponding borehole depth value.

[0049] Furthermore, in order to intuitively demonstrate the effect of migration imaging, Figure 9 As shown, Figure 9 This is a comparison diagram of the results of the radar image and the offset image provided by the present invention. Obviously, there is a clear hyperbolic feature area in the radar image, and the offset image can intuitively show the location and approximate range of the anomaly.

[0050] In a specific embodiment, taking horizontal drilling as an example (vertical drilling is similar, in data processing x and z Direction swapping), borehole radar data migration imaging is carried out based on the frequency wavenumber method. The main steps of migration imaging are as follows: (1) Borehole radar data exist x and t The two-dimensional Fourier transform of the direction is obtained ,in, (6) (2) Yes Extend in the z direction and get ,in, (7) (3) Yes Perform a two-dimensional inverse Fourier transform to obtain ,in, (8) (4) and Substitute into formula (8) and take , get the migration imaging result ,in, (9) In formula (6) to formula (9) is the original wave train data of radar, for The two-dimensional Fourier transform result of x is the horizontal distance coordinate, z is the vertical depth coordinate, t is the sampling time, is the angular frequency, v is the propagation speed of electromagnetic waves, and They are x Direction and z The wave number in the direction.

[0051] In some embodiments of the present invention, after obtaining the offset image, it is necessary to convert it into a binary image in order to intuitively determine the energy relationship.

[0052] In order to obtain the energy mean of the migration image based on the propagation speed of electromagnetic waves, and perform binarization imaging on the migration image based on the energy mean to obtain a binarized image of the radar image, first, the energy mean of the migration image is obtained, and the energy threshold is determined according to a preset threshold coefficient and the energy mean; then, the pixels of the migration image are binarized based on the energy threshold to obtain a binarized image of the radar image.

[0053] In a specific embodiment, the offset image is usually messy, and the binarization threshold coefficient is set , shielding weak energy background areas, highlighting strong energy reflection areas, simplifying radar image morphology, and improving anomaly recognition accuracy, such as Figure 10 As shown, Figure 10 This is a comparison diagram of the results of the offset image and the binarized image provided by the present invention. The main process of binarizing the offset image is as follows: (1) Calculating speedv The energy mean of the offset image under ,in M , N They are x and z Number of discrete sampling points in direction: (10) (2) Make point-by-point judgment on the offset image. If the amplitude of the point is greater than or equal to , then it is set to 1, otherwise it is set to 0, and the binary image is recorded as : (11) In some embodiments of the present invention, after obtaining the binary image, in order to improve the reliability of the electromagnetic wave propagation speed, the electromagnetic wave propagation speed can also be accurately solved. Specifically, Figure 11 As shown, Figure 11 A schematic flow chart of an embodiment of determining a target electromagnetic wave propagation velocity provided by the present invention includes: S1101: Performing speed scanning detection on the space where the abnormal object is located based on different preset electromagnetic wave propagation speeds to obtain corresponding multiple detection radar image maps; S1102: Determine multiple detection binary images of multiple detection radar image maps; S1103: Calculating the focus indexes of the detection binary image corresponding to different preset electromagnetic wave propagation velocities, and determining the preset electromagnetic wave propagation velocity corresponding to the minimum focus index as the target electromagnetic wave propagation velocity.

[0054] In some embodiments of the present invention, offset imaging requires a preset electromagnetic wave propagation velocity. Improperly preset velocity settings can result in poor imaging. When anomalies require precise location, the medium velocity can be accurately estimated based on velocity scanning, image binarization, and image focus determination. The specific steps are as follows: (1) Set the speed scanning interval and speed scanning interval, take a certain section of radar image as the research object, and perform offset imaging processing on each speed value; (2) Set the binarization threshold , perform binary imaging on the migration imaging results of each velocity; (3) Calculate the focusing index of the binary image at each speed v :

[0055] (4) Within the speed scanning range, the speed corresponding to the minimum image focus index is the optimal speed.

[0056] like Figure 12 As shown, Figure 12Schematic diagram of the results of the offset imaging and binarization imaging of an embodiment of the present invention when the wave velocity is correct, the wave velocity is too small, and the wave velocity is too large. It can be seen that the focusing index when the preset wave velocity is correct Much smaller than the focusing index when the wave speed is set improperly.

[0057] In some embodiments of the present invention, in S103, after obtaining the offset image, it is necessary to determine multiple maximum reflection energies of multiple offset images, and perform weighted calculation on multiple azimuths using the multiple maximum reflection energies to determine the target azimuth of the anomaly.

[0058] Specifically, the weight of the azimuth angle is determined according to the maximum reflected energy, and the target azimuth angle of the anomaly is determined according to the target azimuth angle calculation formula; The target azimuth angle calculation formula is:

[0059] is the target azimuth, For the i Azimuth, For the i The maximum reflected energy, Indicates summation.

[0060] In order to better implement the abnormal body directional detection method based on borehole radar in the embodiment of the present invention, the embodiment of the present invention also provides an abnormal body directional detection device based on borehole radar, such as Figure 13 As shown, Figure 13 This is a structural block diagram of an embodiment of an abnormal body directional detection device based on borehole radar provided by the present invention. The abnormal body directional detection device based on borehole radar 1300 includes: The parameter acquisition module 1301 is used to obtain multiple azimuth angles of the borehole radar during testing, and the radar image corresponding to each azimuth angle; The offset image acquisition module 1302 is used to determine the electromagnetic wave propagation speed of the space where the abnormal body is located based on the radar image, and perform offset imaging on each radar image based on the electromagnetic wave propagation speed to obtain multiple offset images; The abnormal body orientation module 1303 is used to determine multiple maximum reflection energies of multiple offset images, and perform weighted calculation on multiple azimuths by the multiple maximum reflection energies to determine the target azimuth of the abnormal body.

[0061] An embodiment of the present invention also provides a computer-readable storage medium, which is used to store computer-readable programs or instructions. When the program or instructions are executed by a processor, it can implement the steps or functions of the anomaly directional detection method based on borehole radar provided in the above-mentioned method embodiments.

[0062] Those skilled in the art will appreciate that all or part of the process flow of the above-described method embodiment can be implemented by instructing related hardware (such as a processor, controller, etc.) through a computer program, and the computer program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a magnetic disk, an optical disk, a read-only memory, or a random access memory.

[0063] The above is a detailed introduction to the method and device for directional detection of anomalies based on borehole radar provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for technical personnel in this field, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A method for directional detection of anomalies based on borehole radar, characterized in that: include: Obtain multiple azimuths of the borehole radar during testing, as well as the radar image corresponding to each azimuth; Determining the electromagnetic wave propagation speed in the space where the abnormal body is located based on the radar image, and performing offset imaging on each of the radar image based on the electromagnetic wave propagation speed to obtain a plurality of offset images; A plurality of maximum reflection energies of the plurality of offset images are determined, and a target azimuth angle of the abnormal body is determined by performing weighted calculation on the plurality of azimuth angles according to the plurality of maximum reflection energies.

2. The method for directional detection of anomalies based on borehole radar according to claim 1, characterized in that: Determining the electromagnetic wave propagation speed of the space where the abnormal body is located based on the radar image, and performing offset imaging on each of the radar image based on the electromagnetic wave propagation speed to obtain multiple offset images, including: Selecting a hyperbolic characteristic region of the radar image, and determining the electromagnetic wave propagation speed in the space where the abnormal body is located based on the length and time relationship of the hyperbolic characteristic region; Each of the radar image images is subjected to offset imaging based on the electromagnetic wave propagation speed to obtain a plurality of offset images of the radar image images.

3. The method for directional detection of anomalies based on borehole radar according to claim 2, characterized in that: The step of selecting a hyperbolic characteristic region of the radar image and determining the electromagnetic wave propagation speed in the space where the abnormal body is located based on the length and time relationship of the hyperbolic characteristic region includes: Obtaining a first time when the borehole radar detects the anomaly at a first position, and a second time and a third time when the borehole radar detects the anomaly based on a second position and a third position, respectively, wherein the first position refers to the position where the borehole radar most quickly detects the vertex of the hyperbolic characteristic region; The electromagnetic wave propagation speed in the space where the abnormal object is located is determined by calculating the Pythagorean theorem according to the first position, the second position, the third position, the first time, the second time, and the third time.

4. The method for directional detection of anomalies based on borehole radar according to claim 3, characterized in that: The calculation formula for the electromagnetic wave propagation speed is: in, is the electromagnetic wave propagation speed, is the first position, is the second position, is the third position, For the first time, For the second time, is the third time.

5. The method for directional detection of anomalies based on borehole radar according to claim 2, characterized in that: The performing offset imaging on each of the radar image images based on the electromagnetic wave propagation speed to obtain a plurality of offset images of the radar image images includes: Constructing a coordinate system and mapping the radar image onto a plane where the horizontal and vertical axes of the coordinate system are located; Performing a two-dimensional Fourier transform on the radar image in the horizontal and vertical directions to obtain a two-dimensional Fourier transform result; The two-dimensional Fourier transform result is sequentially subjected to vertical axis extension and inverse Fourier transform processing, and the vertical coordinate is set to zero to obtain the offset image.

6. The method for directional detection of anomalies based on borehole radar according to claim 1, characterized in that: After performing offset imaging on each of the radar images based on the electromagnetic wave propagation speed to obtain a plurality of offset images, the method further includes: Obtaining an energy mean of the offset image, and determining an energy threshold according to a preset threshold coefficient and the energy mean; The pixels of the offset image are binarized based on the energy threshold to obtain a binarized image of the radar image.

7. The method for directional detection of anomalies based on borehole radar according to claim 6, characterized in that: After obtaining the binarized image of the radar image, the method further includes: Performing speed scanning detection on the space where the abnormal body is located based on different preset electromagnetic wave propagation speeds to obtain corresponding multiple detection radar image maps; Determining a plurality of detection binary images of the plurality of detection radar image maps; The focusing indexes of the detection binary image corresponding to different preset electromagnetic wave propagation velocities are calculated, and the preset electromagnetic wave propagation velocity corresponding to the minimum focusing index is determined as the target electromagnetic wave propagation velocity.

8. The method for directional detection of anomalies based on borehole radar according to claim 1, characterized in that: The determining the target azimuth angle of the abnormal body by weighted calculation of the multiple azimuth angles using the multiple maximum reflected energies includes: Determining the weight of the azimuth angle according to the maximum reflected energy, and determining the target azimuth angle of the anomaly according to a target azimuth angle calculation formula; The target azimuth angle calculation formula is: is the target azimuth, For the i The azimuth angle, For the i The maximum reflected energy, Indicates summation.

9. The method for directional detection of anomalies based on borehole radar according to claim 1, characterized in that: The method of obtaining multiple azimuths of the borehole radar during testing and the radar image corresponding to each azimuth includes: placing a borehole radar equipped with multiple antennas in the borehole, and determining an initial azimuth angle of each receiving antenna; The direction of the drilling is used as the moving direction of the drilling radar equipped with multiple antennas, and the rotation angle of the drilling radar equipped with multiple antennas at any drilling distance and radar data of each receiving antenna are obtained; Correcting the actual azimuth angle corresponding to the radar data according to the rotation angle to obtain target radar data at any drilling distance based on the initial azimuth angle; The target radar data is converted into the radar image, and the azimuth angle corresponding to the radar image is determined according to the initial azimuth angle.

10. A device for detecting abnormal bodies based on borehole radar, characterized in that: include: The parameter acquisition module is used to obtain multiple azimuth angles of the borehole radar during testing, as well as the radar image corresponding to each azimuth angle; an offset image acquisition module, configured to determine the electromagnetic wave propagation velocity in the space where the abnormal body is located based on the radar image, and to perform offset imaging on each of the radar image based on the electromagnetic wave propagation velocity to obtain a plurality of offset images; The abnormal body orientation module is used to determine a plurality of maximum reflection energies of the plurality of offset images, and perform weighted calculation on the plurality of azimuths by using the plurality of maximum reflection energies to determine a target azimuth of the abnormal body.

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