Discrete imaging method and device of ground penetrating radar system, terminal equipment and storage medium

Abstract

The invention discloses a discrete imaging method and device for a ground penetrating radar system, terminal equipment and a storage medium, and relates to the technical field of detection radar imaging, and the method comprises the steps: obtaining a plurality of antennas of a common midpoint antenna array, and carrying out the integration and superposition of initial signals collected at different collection points in a detection region, generating a discrete signal of each antenna pair on each acquisition point, and determining the two-way travel time and the inclination factor of a detection target detected by each antenna pair at each acquisition point according to the discrete signal, and carrying out migration integration according to the coordinate position of each acquisition point, the discrete signal of each antenna pair, the two-way travel time of the corresponding detection target and the inclination factor, generating a two-dimensional imaging result of the depth profile of each acquisition point, and finally splicing the two-dimensional imaging results of the acquisition points to obtain the depth profile of the detection target. And generating an underground three-dimensional model of the detection area. Therefore, the problem that the underground imaging result of the existing handheld radar ground penetrating system is not ideal can be effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of detection radar imaging, and particularly relates to a discrete imaging method, device, terminal device and storage medium for a ground penetrating radar system. Background Art

[0002] Ground Penetrating Radar (GPR) is a widely studied technology aimed at improving the efficiency of underground detection. For situations where remote collection of measurement data is required, such as detecting buried ground wires. Currently, the mainly applied ground penetrating radar systems are vehicle-mounted GPR systems and hand-held GPR systems. The vehicle-mounted GPR system has the advantages of high detection efficiency and good detection effect in broad and flat terrains. It mainly constructs a regular grid according to the detection area, then determines the measurement points according to the planning of the regular grid, and uses transmitting and receiving antennas at each measurement point to record the time delay and amplitude information between the transmitted signal and the received echo signal. Through migration imaging algorithms, the reflected signals are accurately located to the underground detection substances, and finally, underground imaging is performed through a velocity model and post-processing.

[0003] The hand-held GPR system is more suitable for underground detection work in mountainous areas and other terrains with complex terrains where vehicle-mounted GPR systems cannot enter. The operator manipulates the sensor or holds the sensor to move and observe along the survey line. However, when the terrain of the detection area is too complex, the sensor cannot move along the survey line, and the observation positions are random. If the data at random observation positions is interpolated into a regular grid, the underground imaging result will not be ideal. Summary of the Invention

[0004] Embodiments of the present invention provide a discrete imaging method, device, terminal device and storage medium for a ground penetrating radar system, effectively solving the problem that the underground imaging result of the current hand-held radar ground penetrating system is not ideal.

[0005] An embodiment of the present invention provides a discrete imaging method for a ground penetrating radar system, including:

[0006] Obtaining initial signals collected by a plurality of antenna pairs of a common midpoint antenna array at different acquisition points in a detection area, and the coordinate position of each acquisition point;

[0007] For each acquisition point, integrating and superimposing the plurality of initial signals collected by each antenna pair to generate discrete signals of each antenna pair at each acquisition point;

[0008] Based on the discrete signals, determine the two-way travel time and the tilt factor of the detection target detected by each antenna pair at each acquisition point; wherein, the two-way travel time is the time required for the transmitted signal of the transmitting antenna in the antenna pair to reach the detection target and then be reflected by the detection target to the corresponding receiving antenna; the tilt factor is the cosine value of the angle between the signal propagation direction and the vertical axis;

[0009] Perform migration integration based on the coordinate positions of each acquisition point, the discrete signals of each antenna pair, the two-way travel time of the corresponding detection target, and the tilt factor to generate a two-dimensional imaging result of the depth profile of each acquisition point;

[0010] According to the coordinate positions of the acquisition points, splice the two-dimensional imaging results of each acquisition point to generate a three-dimensional underground model of the detection area.

[0011] Further, for each acquisition point, integrating and superimposing a plurality of initial signals collected by each antenna pair to generate discrete signals of each antenna pair at each acquisition point, including:

[0012] Traverse the acquisition points and calculate the signal-to-noise ratio of the initial signals collected by each antenna pair under the currently traversed target acquisition point;

[0013] Generate target weights for each initial signal according to the signal-to-noise ratio;

[0014] Integrate the initial signals of each antenna pair according to the initial signals collected by each antenna pair and the corresponding target weights to generate discrete signals of each antenna pair at the target acquisition point;

[0015] When the traversal is completed, generate discrete signals of each antenna pair at all acquisition points.

[0016] Further, the performing migration integration based on the coordinate positions of each acquisition point, the discrete signals of each antenna pair, the two-way travel time of the corresponding detection target, and the tilt factor to generate a two-dimensional imaging result of the depth profile of each acquisition point includes:

[0017] Calculate the wave field value of the detection target detected by each antenna pair at each acquisition point according to the following formula:

[0018]

[0019] wherein, p out (x0,y0,z0) is the wave field value of the detection target (x0,y0,z0), Δx is the first distance between the acquisition point and the detection target on the x-axis, Δy is the second distance between the acquisition point and the detection target on the y-axis, cosθ is the tilt factor, vr is the spherical spreading factor for correcting the signal amplitude, Pin (x, y, t) is the input data set constructed from the position coordinates (x, y) of the acquisition point and the two-way travel time t;

[0020] Generate a two-dimensional imaging result corresponding to the depth profile of the acquisition point according to the wave field value.

[0021] Further, splicing the two-dimensional imaging results of each acquisition point according to the coordinate position of the acquisition point to generate an underground three-dimensional model of the detection area, including:

[0022] Perform median filtering on each of the two-dimensional imaging results to generate a plane to be spliced;

[0023] Using the Kriging interpolation algorithm, map each of the planes to be spliced into a preset three-dimensional space according to the coordinate position of the acquisition point and the three-dimensional coordinates of the corresponding detection target to generate an initial three-dimensional model;

[0024] Scan the initial three-dimensional model to determine the unknown areas in the detection area that have not been detected;

[0025] Use an extrapolation algorithm to fill the unknown areas to generate an underground three-dimensional model of the detection area.

[0026] Another embodiment of the present invention provides a discrete imaging device for a ground penetrating radar system, which is characterized by including:

[0027] A signal acquisition module for acquiring the initial signals collected by several antenna pairs of a common midpoint antenna array at different acquisition points in the detection area, and the coordinate position of each acquisition point;

[0028] A signal superposition module for integrating and superposing the several initial signals collected by each antenna pair for each acquisition point to generate discrete signals of each antenna pair at each acquisition point;

[0029] A signal processing module for determining the two-way travel time and tilt factor of the detection target detected by each antenna pair at each acquisition point according to the discrete signals; wherein, the two-way travel time is the time required for the transmitted signal of the transmitting antenna in the antenna pair to reach the detection target and then the detection target reflects the transmitted signal to the corresponding receiving antenna; the tilt factor is the cosine value of the angle between the signal propagation direction and the vertical axis;

[0030] A two-dimensional imaging module for performing migration integration according to the coordinate position of each acquisition point, the discrete signals of each antenna pair, the corresponding two-way travel time of the detection target, and the tilt factor to generate a two-dimensional imaging result of the depth profile of each acquisition point;

[0031] A three-dimensional imaging module, which is used to splice the two-dimensional imaging results of each acquisition point according to the coordinate positions of the acquisition points, and generate an underground three-dimensional model of the detection area.

[0032] Further, for each acquisition point, the signal superposition module integrates and superimposes a plurality of initial signals collected by each antenna pair to generate discrete signals of each antenna pair at each acquisition point, including:

[0033] Traverse the acquisition points, and calculate the signal-to-noise ratio of the initial signals collected by each antenna pair under the currently traversed target acquisition point;

[0034] Generate target weights for each of the initial signals according to the signal-to-noise ratio;

[0035] Integrate the initial signals of each antenna pair according to the initial signals collected by each antenna pair and the corresponding target weights, and generate discrete signals of each antenna pair at the target acquisition point;

[0036] When the traversal is completed, generate discrete signals of each antenna pair at all acquisition points.

[0037] Further, the two-dimensional imaging module performs migration integration according to the coordinate position of each acquisition point, the discrete signals of each antenna pair, the two-way travel time of the corresponding detection target, and the tilt factor, and generates a two-dimensional imaging result of the depth profile of each acquisition point, including:

[0038] Calculate the wave field values of the detection targets detected by each antenna pair at each acquisition point according to the following formula:

[0039]

[0040] where p out (x0, y0, z0) is the wave field value of the detection target (x0, y0, z0), Δx is the first distance between the acquisition point and the detection target on the x-axis, Δy is the second distance between the acquisition point and the detection target on the y-axis, cosθ is the tilt factor, vr is the spherical spreading factor used to correct the signal amplitude, P in (x, y, t) is the input data set constructed by the position coordinates (x, y) of the acquisition point and the two-way travel time t;

[0041] Generate a two-dimensional imaging result corresponding to the depth profile of the acquisition point according to the wave field value.

[0042] Further, the three-dimensional imaging module splices the two-dimensional imaging results of each acquisition point according to the coordinate positions of the acquisition points, and generates an underground three-dimensional model of the detection area, including:

[0043] Perform median filtering on each of the two-dimensional imaging results to generate a plane to be stitched;

[0044] Using the Kriging interpolation algorithm, map each of the planes to be stitched into a preset three-dimensional space according to the coordinate positions of the acquisition points and the three-dimensional coordinates of the corresponding detection targets to generate an initial three-dimensional model;

[0045] Scan the initial three-dimensional model to determine the unknown areas in the detection area that have not been detected;

[0046] Use the extrapolation algorithm to fill the unknown areas to generate the underground three-dimensional model of the detection area.

[0047] Another embodiment of the present invention provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements a discrete imaging method of a ground penetrating radar system as described in any one of the above embodiments.

[0048] Another embodiment of the present invention provides a storage medium, which includes a stored computer program. When the computer program runs, it controls the device where the storage medium is located to execute a discrete imaging method of a ground penetrating radar system as described in any one of the above embodiments.

[0049] By implementing the present invention, the following beneficial effects are achieved:

[0050] The present invention discloses a discrete imaging method, device, terminal device and storage medium for a ground penetrating radar system. The method integrates and superimposes the initial signals collected by a plurality of antenna pairs of a common midpoint antenna array at different acquisition points in a detection area to generate discrete signals of each antenna pair at each acquisition point. According to the discrete signals, the two-way travel time and tilt factor of the detection target detected by each antenna pair at each acquisition point are determined. Migration integration is performed based on the coordinate position of each acquisition point, the discrete signals of each antenna pair, the corresponding two-way travel time of the detection target, and the tilt factor to generate a two-dimensional imaging result of the depth profile of each acquisition point. Finally, the two-dimensional imaging results of each acquisition point are stitched together to generate an underground three-dimensional model of the detection area. It can be understood that the present invention uses a common midpoint antenna array composed of a plurality of antenna pairs arranged linearly with different spacings to detect the detection area, enabling subsequent construction of a two-dimensional imaging result of the underground depth profile corresponding to the acquisition points, without the need to pre-construct a regular grid and move along a preset detection route. Finally, directly based on the coordinates of the acquisition points, the two-dimensional imaging structures are stitched together to generate an underground three-dimensional model, overcoming the problem of inaccurate imaging caused by the randomness of the observation position at present. Therefore, the present invention effectively improves the underground imaging quality of a handheld GPR system in complex terrain areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 FIG. 6 is a schematic flowchart of a discrete imaging method for a ground penetrating radar system according to an embodiment of the present invention.

[0052] Figure 2 FIG. 10 is a schematic structural diagram of a discrete imaging device for a ground penetrating radar system according to an embodiment of the present invention.

[0053] Figure 3 FIG. 14 is a schematic structural diagram of a common midpoint antenna array according to an embodiment of the present invention. DETAILED DESCRIPTION

[0054] To make the objectives, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments in the present application belong to the scope of protection of the present application.

[0055] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terms used herein are for the purpose of describing specific embodiments only and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above description of the drawings are intended to cover non-exclusive inclusion.

[0056] In the description of the embodiments of this application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity, specific order or primary-secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "a plurality" is more than two, unless otherwise specifically defined.

[0057] Referring to "embodiments" herein means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of this application. The phrase does not necessarily refer to the same embodiment at various positions in the specification, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0058] In the description of the embodiments of this application, the term "and / or" is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B, which can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after.

[0059] In the description of the embodiments of this application, the terms "a plurality" and "several" both refer to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0060] In the description of the embodiments of this application, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can also be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of this application can be understood according to specific circumstances.

[0061] See Figure 1, to solve the problem that the underground imaging result of the current hand-held radar ground penetration system is not ideal, a discrete imaging method of a ground penetrating radar system provided by an embodiment of the present invention includes:

[0062] S1. Obtain the initial signals collected by several antenna pairs of a common midpoint antenna array at different acquisition points in the detection area, and the coordinate position of each acquisition point;

[0063] In a preferred embodiment of the present invention, as Figure 3 shown, the antennas in the common midpoint antenna array are linearly arranged. Each antenna pair is composed of a transmitting antenna and a receiving antenna, and the distances between the transmitting antennas and the receiving antennas of each antenna pair are different. In this embodiment, three pairs of Vivaldi antenna configurations are used to form a symmetric CMP (common midpoint) antenna array, that is Figure 3 the three groups of antenna pairs A, A’, B, B’, C, C’ shown in. It should be noted that it is not only applicable to three pairs of antennas, but also applicable to more pairs of antennas. However, three pairs are preferred because it can well demonstrate the advantages of the method while maintaining a simple structure. In each antenna pair, one is responsible for transmitting signals and the other is used for receiving signals; therefore, three received signals can be collected as initial signals in each measurement to form a multi-offset CMP data set. It should be further noted that, to avoid signal interference between antenna pairs, each antenna pair uses different channels for communication, or staggers the transceiver times of each antenna pair to ensure the quality of the initial signals.

[0064] S2. For each acquisition point, integrate and superimpose the several initial signals collected by each antenna pair to generate the discrete signals of each antenna pair at each acquisition point;

[0065] Preferably, the step of integrating and superimposing the several initial signals collected by each antenna pair for each acquisition point to generate the discrete signals of each antenna pair at each acquisition point includes:

[0066] S21. Traverse the acquisition points, and calculate the signal-to-noise ratio of the initial signals collected by each antenna pair under the currently traversed target acquisition point;

[0067] S22. Generate the target weights of each initial signal according to the signal-to-noise ratio;

[0068] S23. Integrate the initial signals of each antenna pair according to the initial signals collected by each antenna pair and the corresponding target weights to generate the discrete signals of each antenna pair at the target acquisition point;

[0069] S24. When the traversal is completed, generate the discrete signals of each antenna pair at all acquisition points.

[0070] In a preferred embodiment of the present invention, to improve the measurement accuracy, at each acquisition point, multiple measurements are performed. Each time a measurement is taken, an initial signal of each antenna pair is obtained. By superimposing a number of initial signals of the same antenna pair, the effective signal can be enhanced and the noise can be suppressed. Further, in this embodiment, weights are assigned to each initial signal according to the signal-to-noise ratio of each initial signal. The higher the signal-to-noise ratio, the greater the assigned weight. It should be noted that the sum of the weights of a number of initial signals of an antenna pair is equal to 1.

[0071] S3. According to the discrete signals, determine the two-way travel time and the tilt factor of the detection target detected by each antenna pair at each acquisition point; wherein, the two-way travel time is the time required for the transmission signal of the transmitting antenna in the antenna pair to reach the detection target and then for the detection target to reflect the transmission signal to the corresponding receiving antenna; the tilt factor is the cosine value of the angle between the signal propagation direction and the vertical axis.

[0072] In a preferred embodiment of the present invention, according to the soil in the detection area, determine the propagation speed of the electromagnetic wave signal in this detection area. Then, according to the average transmission time and the average reception time of a number of initial signals corresponding to each discrete signal, determine the two-way travel time. Further, according to the reception directions of a number of initial signals corresponding to each discrete signal, determine the tilt factor.

[0073] S4. Perform migration integration according to the coordinate position of each acquisition point, the discrete signals of each antenna pair, the two-way travel time of the corresponding detection target, and the tilt factor, and generate a two-dimensional imaging result of the depth profile of each acquisition point.

[0074] Preferably, the performing migration integration according to the coordinate position of each acquisition point, the discrete signals of each antenna pair, the two-way travel time of the corresponding detection target, and the tilt factor, and generating a two-dimensional imaging result of the depth profile of each acquisition point includes:

[0075] S41. According to the following formula, calculate the wave field value of the detection target detected by each antenna pair at each acquisition point:

[0076]

[0077] where p out (x0, y0, z0) is the wave field value of the detection target (x0, y0, z0), Δx is the first distance between the acquisition point and the detection target on the x-axis, Δy is the second distance between the acquisition point and the detection target on the y-axis, cosθ is the tilt factor, vr is the spherical spreading factor for correcting the signal amplitude, P in (x, y, t) is the input data set constructed by the position coordinates (x, y) of the acquisition point and the two-way travel time t.

[0078] S42. Generate a two-dimensional imaging result corresponding to the depth profile of the acquisition points based on the wave field values.

[0079] In a preferred embodiment of the present invention, the Kirchhoff migration integral is used to determine the following formula:

[0080]

[0081] Among them, the two-way travel time t is calculated according to the following formula:

[0082]

[0083] Among them, A is the observation aperture, that is, the set of spatial positions of all transmitting-receiving antenna pairs participating in imaging, v is the propagation speed of the electromagnetic wave signal in this detection area. is the distance between the detection target and the acquisition point, t0 is the preset time reference, that is, the theoretical shortest time for the transmitted signal to be reflected to the receiving antenna after reaching a specific underground position (detection target). It is set based on the straight-line propagation path of the signal in the underground medium. θ is the angle between the propagation direction and the vertical axis. Cosine θ is the tilt factor or directivity factor, which describes the angular dependence of the amplitude. vr is the spherical spreading factor, and the time derivative is the wavelet shaping factor, which produces a 90-degree phase shift and adjustment of the amplitude spectrum. Integrating according to the above formula gives:

[0084]

[0085] S5. According to the coordinate positions of the acquisition points, splice the two-dimensional imaging results of each acquisition point to generate an underground three-dimensional model of the detection area.

[0086] Preferably, the step of splicing the two-dimensional imaging results of each acquisition point according to the coordinate positions of the acquisition points to generate an underground three-dimensional model of the detection area includes:

[0087] S51. Perform median filtering on each of the two-dimensional imaging results to generate a plane to be spliced;

[0088] S52. Use the Kriging interpolation algorithm to map each of the planes to be spliced into a preset three-dimensional space according to the coordinate positions of the acquisition points and the three-dimensional coordinates of the corresponding detection targets to generate an initial three-dimensional model;

[0089] S53. Scan the initial three-dimensional model to determine the unknown areas in the detection area that have not been detected;

[0090] S54. Use the extrapolation algorithm to fill the unknown areas to generate an underground three-dimensional model of the detection area.

[0091] In a preferred embodiment of the present invention, the local coordinate systems of each plane to be spliced are converted into a preset unified global coordinate system to unify the position references of all planes. If there is positioning drift, the ICP (Iterative Closest Point) algorithm is used for point cloud registration to correct the trajectory deviation. According to the coordinates of each acquisition point, the detection path is determined. According to the detection path, an interpolation algorithm such as inverse distance weighted interpolation (IDW) or Kriging interpolation is used to fill the discrete two-dimensional profile data into a regular three-dimensional space. For multiple profile data in the overlapping area, weighted average (such as assigning weights based on signal-to-noise ratio) or maximum value projection is used to eliminate redundancy and enhance the effective signal. The depth axes (Z direction) of each two-dimensional profile are aligned to construct a three-dimensional volume data matrix V(x, y, z). If the depth sampling intervals are inconsistent, linear interpolation is used to unify them into a fixed step size (such as 0.1 meter). For areas not covered by the scanning path, an extrapolation algorithm (such as wave equation continuation) is used, and finally morphological closing operations (such as dilation + erosion) are used to smooth the data boundary and reduce jagged artifacts to generate the underground three-dimensional model of the detection area.

[0092] This embodiment provides a discrete imaging method for a ground penetrating radar system. By integrating and superimposing the initial signals collected by several antenna pairs of a common midpoint antenna array at different acquisition points in the detection area, discrete signals of each antenna pair at each acquisition point are generated. According to the discrete signals, the two-way travel time and tilt factor of the detection target detected by each antenna pair at each acquisition point are determined. Migration integration is performed based on the coordinate position of each acquisition point, the discrete signals of each antenna pair, the corresponding two-way travel time and tilt factor of the detection target to generate a two-dimensional imaging result of the depth profile at each acquisition point. Finally, the two-dimensional imaging results of each acquisition point are spliced to generate the underground three-dimensional model of the detection area. This embodiment uses a common midpoint antenna array composed of several antenna pairs arranged linearly with different spacings to detect the detection area, enabling subsequent construction of a two-dimensional imaging result of the underground depth profile corresponding to the acquisition points, without the need to pre-construct a regular grid and move along a preset detection route. Finally, directly based on the coordinates of the acquisition points, the two-dimensional imaging structures are spliced to generate an underground three-dimensional model, overcoming the problem of inaccurate imaging caused by the randomness of the observation position at present. Therefore, this embodiment effectively improves the underground imaging quality of the handheld GPR system in complex terrain areas.

[0093] See Figure 2 , which is a schematic structural diagram of a discrete imaging device for a ground penetrating radar system provided by an embodiment of the present invention, includes:

[0094] A signal acquisition module for acquiring the initial signals collected by several antenna pairs of a common midpoint antenna array at different acquisition points in the detection area, as well as the coordinate position of each acquisition point;

[0095] A signal superposition module, which is used to integrate and superpose a plurality of initial signals collected by each antenna pair for each acquisition point to generate discrete signals of each antenna pair at each acquisition point;

[0096] A signal processing module, which is used to determine the two-way travel time and tilt factor of the detection target detected by each antenna pair at each acquisition point according to the discrete signals; wherein, the two-way travel time is the time required for the transmitted signal of the transmitting antenna in the antenna pair to reach the detection target and then be reflected by the detection target to the corresponding receiving antenna; the tilt factor is the cosine value of the angle between the signal propagation direction and the vertical axis;

[0097] A two-dimensional imaging module, which is used to perform migration integration according to the coordinate position of each acquisition point, the discrete signals of each antenna pair, the two-way travel time of the corresponding detection target, and the tilt factor to generate a two-dimensional imaging result of the depth profile of each acquisition point;

[0098] A three-dimensional imaging module, which is used to splice the two-dimensional imaging results of each acquisition point according to the coordinate position of the acquisition point to generate an underground three-dimensional model of the detection area.

[0099] Preferably, the signal superposition module integrates and superposes a plurality of initial signals collected by each antenna pair for each acquisition point to generate discrete signals of each antenna pair at each acquisition point, including:

[0100] Traverse the acquisition points, and calculate the signal-to-noise ratio of the initial signals collected by each antenna pair under the currently traversed target acquisition point;

[0101] Generate target weights for each of the initial signals according to the signal-to-noise ratio;

[0102] Integrate the initial signals of each antenna pair according to the initial signals collected by each antenna pair and the corresponding target weights to generate discrete signals of each antenna pair at the target acquisition point;

[0103] When the traversal is completed, generate discrete signals of each antenna pair at all acquisition points.

[0104] Preferably, the two-dimensional imaging module performs migration integration according to the coordinate position of each acquisition point, the discrete signals of each antenna pair, the two-way travel time of the corresponding detection target, and the tilt factor to generate a two-dimensional imaging result of the depth profile of each acquisition point, including:

[0105] Calculate the wave field value of the detection target detected by each antenna pair at each acquisition point according to the following formula:

[0106]

[0107] Among them, p out (x0, y0, z0) is the wave field value of the detection target (x0, y0, z0), Δx is the first distance between the acquisition point and the detection target on the x-axis, Δy is the second distance between the acquisition point and the detection target on the y-axis, cosθ is the tilt factor, vr is the spherical spreading factor used to correct the signal amplitude, P in (x, y, t) is the input data set constructed by the position coordinates (x, y) of the acquisition point and the two-way travel time t;

[0108] According to the wave field value, a two-dimensional imaging result corresponding to the depth profile of the acquisition point is generated.

[0109] Preferably, the three-dimensional imaging module splices the two-dimensional imaging results of each acquisition point according to the coordinate position of the acquisition point to generate an underground three-dimensional model of the detection area, including:

[0110] Perform median filtering on each of the two-dimensional imaging results to generate a plane to be spliced;

[0111] Using the Kriging interpolation algorithm, according to the coordinate position of the acquisition point and the three-dimensional coordinates of the corresponding detection target, map each of the planes to be spliced into a preset three-dimensional space to generate an initial three-dimensional model;

[0112] Scan the initial three-dimensional model to determine the unknown areas in the detection area that have not been detected;

[0113] Use an extrapolation algorithm to fill the unknown areas to generate an underground three-dimensional model of the detection area.

[0114] It should be noted that the device embodiments described above are only illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. In addition, in the attached drawings of the device embodiments provided by the present invention, the connection relationship between the modules indicates that they have a communication connection, which can be specifically implemented as one or more communication buses or signal lines. Those of ordinary skill in the art can understand and implement without creative work.

[0115] Those skilled in the art can clearly understand that for the sake of convenience and brevity, the specific working process of the device described above can refer to the corresponding process in the foregoing method embodiment, and will not be repeated here.

[0116] Another preferred embodiment of the present invention provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, a discrete imaging method of a ground penetrating radar system as described in any one of the above embodiments is implemented.

[0117] The terminal device may be a computing device such as a desktop computer, a notebook, a palm computer, and a cloud server. The terminal device may include, but is not limited to, a processor and a memory.

[0118] The so-called processor may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The processor is the control center of the terminal device, and connects various parts of the entire terminal device through various interfaces and lines.

[0119] The memory may be used to store the computer program. The processor realizes various functions of the terminal device by running or executing the computer program stored in the memory and calling the data stored in the memory. The memory may mainly include a program storage area and a data storage area. Among them, the program storage area may store an operating system, application programs required for at least one function, etc.; the data storage area may store data created according to the use of the mobile phone, etc. In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, at least one magnetic disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0120] Another preferred embodiment of the present invention provides a storage medium, which is a computer-readable storage medium, and the computer program is stored in the computer-readable storage medium. When the computer program is executed by a processor, the steps of the above-mentioned various method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in the form of source code, object code, executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electrical carrier signal, telecommunication signal, and software distribution medium, etc.

[0121] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present invention.

Claims

1. A discrete imaging method for a ground penetrating radar system, characterized in that, Including: Obtaining initial signals collected by a number of antenna pairs of a common midpoint antenna array at different acquisition points in a detection area, and the coordinate position of each said acquisition point; For each acquisition point, integrating and superimposing the several initial signals collected by each said antenna pair to generate discrete signals of each antenna pair at each acquisition point; According to the discrete signals, determining the two-way travel time and tilt factor of the detection target detected by each said antenna pair at each acquisition point; wherein, the two-way travel time is the time required for the transmitted signal of the transmitting antenna in the antenna pair to reach the detection target and then be reflected by the detection target to the corresponding receiving antenna; the tilt factor is the cosine value of the angle between the signal propagation direction and the vertical axis; Performing migration integration according to the coordinate position of each said acquisition point, the discrete signals of each antenna pair, the corresponding two-way travel time of the detection target, and the tilt factor to generate a two-dimensional imaging result of the depth profile of each said acquisition point; According to the coordinate positions of the acquisition points, splicing the two-dimensional imaging results of each acquisition point to generate an underground three-dimensional model of the detection area.

2. The discrete imaging method of a ground penetrating radar system according to claim 1, characterized in that, The step of, for each acquisition point, integrating and superimposing the several initial signals collected by each said antenna pair to generate discrete signals of each antenna pair at each acquisition point includes: Traversing the acquisition points and calculating the signal-to-noise ratio of the initial signals collected by each antenna pair under the currently traversed target acquisition point; Generating target weights of each said initial signal according to the signal-to-noise ratio; Integrating the initial signals of each antenna pair according to the initial signals collected by each antenna pair and the corresponding target weights to generate discrete signals of each antenna pair at the target acquisition point; When the traversal is completed, generating discrete signals of each antenna pair at all acquisition points.

3. The discrete imaging method of a ground penetrating radar system according to claim 2, characterized in that, The step of performing migration integration according to the coordinate position of each said acquisition point, the discrete signals of each antenna pair, the corresponding two-way travel time of the detection target, and the tilt factor to generate a two-dimensional imaging result of the depth profile of each said acquisition point includes: Calculating the wave field value of the detection target detected by each said antenna pair at each acquisition point according to the following formula: where p out (x0, y0, z0) is the wave field value of the detection target (x0, y0, z0), Δx is the first distance between the acquisition point and the detection target on the x-axis, Δy is the second distance between the acquisition point and the detection target on the y-axis, cosθ is the tilt factor, vr is the spherical spreading factor used to correct the signal amplitude, P in (x, y, t) is the input data set constructed by the position coordinates (x, y) of the acquisition point and the two-way travel time t, and A is the observation aperture formed by the set of spatial positions of all antenna pairs; Generating a two-dimensional imaging result corresponding to the depth profile of the acquisition point according to the wave field value.

4. The discrete imaging method of a ground penetrating radar system according to claim 3, characterized in that, The step of splicing the two-dimensional imaging results of each acquisition point according to the coordinate positions of the acquisition points to generate an underground three-dimensional model of the detection area includes: Performing median filtering processing on each said two-dimensional imaging result to generate a plane to be spliced; Using the Kriging interpolation algorithm, mapping each said plane to be spliced into a preset three-dimensional space according to the coordinate positions of the acquisition points and the three-dimensional coordinates of the corresponding detection target to generate an initial three-dimensional model; Scanning the initial three-dimensional model to determine unknown areas in the detection area that have not been detected; Using an extrapolation algorithm to fill the unknown areas to generate an underground three-dimensional model of the detection area.

5. A discrete imaging device for a ground penetrating radar system, characterized in that, Including: A signal acquisition module, configured to acquire initial signals collected by a number of antenna pairs of a common midpoint antenna array at different acquisition points in a detection area, and the coordinate position of each said acquisition point; A signal superposition module, which is used to integrate and superpose a plurality of initial signals collected by each antenna pair for each acquisition point, and generate discrete signals of each antenna pair at each acquisition point; A signal processing module, which is used to determine the two-way travel time and tilt factor of the detection target detected by each antenna pair at each acquisition point according to the discrete signals; wherein, the two-way travel time is the time required for the transmitted signal of the transmitting antenna in the antenna pair to reach the detection target and then be reflected by the detection target to the corresponding receiving antenna; the tilt factor is the cosine value of the angle between the signal propagation direction and the vertical axis; A two-dimensional imaging module, which is used to perform migration integration according to the coordinate position of each acquisition point, the discrete signals of each antenna pair, the two-way travel time of the corresponding detection target, and the tilt factor, and generate a two-dimensional imaging result of the depth profile of each acquisition point; A three-dimensional imaging module, which is used to splice the two-dimensional imaging results of each acquisition point according to the coordinate position of the acquisition point, and generate an underground three-dimensional model of the detection area.

6. The discrete imaging device of a ground penetrating radar system according to claim 5, characterized in that, The signal superposition module, for each acquisition point, integrates and superposes a plurality of initial signals collected by each antenna pair, and generates discrete signals of each antenna pair at each acquisition point, including: Traverse the acquisition points, and calculate the signal-to-noise ratio of the initial signals collected by each antenna pair under the currently traversed target acquisition point; Generate target weights for each of the initial signals according to the signal-to-noise ratio; Integrate the initial signals of each antenna pair according to the initial signals collected by each antenna pair and the corresponding target weights, and generate discrete signals of each antenna pair at the target acquisition point; When the traversal is completed, generate discrete signals of each antenna pair at all acquisition points.

7. The discrete imaging device of a ground penetrating radar system according to claim 6, characterized in that, The two-dimensional imaging module, which performs migration integration according to the coordinate position of each acquisition point, the discrete signals of each antenna pair, the two-way travel time of the corresponding detection target, and the tilt factor, and generates a two-dimensional imaging result of the depth profile of each acquisition point, including: Calculate the wave field value of the detection target detected by each antenna pair at each acquisition point according to the following formula: where p out (x0, y0, z0) is the wave field value of the detection target (x0, y0, z0), Δx is the first distance between the acquisition point and the detection target on the x-axis, Δy is the second distance between the acquisition point and the detection target on the y-axis, cosθ is the tilt factor, vr is the spherical spreading factor used to correct the signal amplitude, P in (x, y, t) is the input data set constructed by the position coordinates (x, y) of the acquisition point and the two-way travel time t, and A is the observation aperture formed by the set of spatial positions of all antenna pairs; Generate a two-dimensional imaging result corresponding to the depth profile of the acquisition point according to the wave field value.

8. The discrete imaging device of a ground penetrating radar system according to claim 7, characterized in that, The three-dimensional imaging module, which splices the two-dimensional imaging results of each acquisition point according to the coordinate position of the acquisition point, and generates an underground three-dimensional model of the detection area, including: Perform median filtering on each of the two-dimensional imaging results to generate a plane to be spliced; Adopt the Kriging interpolation algorithm, and map each of the planes to be spliced into a preset three-dimensional space according to the coordinate position of the acquisition point and the three-dimensional coordinates of the corresponding detection target, and generate an initial three-dimensional model; Scan the initial three-dimensional model to determine unknown areas in the detection area that have not been detected; Fill the unknown areas by using an extrapolation algorithm to generate an underground three-dimensional model of the detection area.

9. A terminal device, characterized in that, It includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements a discrete imaging method of a ground penetrating radar system as described in any one of claims 1 to 4.

10. A storage medium, characterized in that, The storage medium includes a stored computer program, wherein when the computer program runs, it controls the device where the storage medium is located to execute a discrete imaging method of a ground penetrating radar system according to any one of claims 1 to 4.

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