Ground penetrating radar image registration method and device based on adaptive hyperbolic filtering

Abstract

The present application relates to a ground penetrating radar image registration method and device based on adaptive hyperbolic filtering. The method uses an adaptive hyperbolic filter to enhance the echo data obtained by real-time detection of the ground penetrating radar to obtain an enhanced image, obtains a target echo hyperbolic equation based on the ground penetrating radar target echo principle, constructs an adaptive hyperbolic filter based on the target echo hyperbolic equation and taking into account the change of underground dielectric constant, divides the pre-stored map according to the preset registration requirements to obtain multiple two-dimensional images, uses an adaptive hyperbolic filter to enhance each two-dimensional image and constructs a corresponding enhanced two-dimensional image set, and uses a cross-correlation matching method to perform similarity measurement between the enhanced image and each image in the enhanced two-dimensional image set to obtain an enhanced two-dimensional image that matches the enhanced image, thereby achieving image registration. The use of this method can improve matching accuracy and positioning accuracy.

Description

Technical Field

[0001] The present application relates to the field of ground penetrating radar navigation and positioning technology, and in particular to a ground penetrating radar image registration method and device based on adaptive hyperbolic filtering. Background Art

[0002] Ground Penetrating Radar (GPR) emits high-frequency electromagnetic waves to the ground and analyzes the received electromagnetic wave reflection signals to obtain underground information. The system is now widely used in underground target detection, road maintenance and other fields. With the development of the field of autonomous driving, the ground penetrating radar system provides a new research direction for the existing navigation and positioning system.

[0003] Ground Penetrating Radar (LGPR) is a new technology that uses ground penetrating radar echo data to determine the position information of a moving platform. This method is mainly different from existing vision and laser methods. It uses ground penetrating radar to align and locate underground feature data. Compared with the above-ground scene, the underground scene information changes less over time and can provide stable and reliable invariant features for positioning. It provides a supplement to the existing map-based positioning methods and enhances the existing positioning technology's resistance to common failure modes and robustness to environmental changes.

[0004] Ground penetrating radar positioning is a technology that relies on known maps for precise positioning. The underground geological layering structure and buried objects usually remain relatively stable. However, with the change of seasons and weather, the groundwater content in open environments (such as roads, etc.) may change, resulting in changes in the dielectric constant. The change in dielectric constant will directly affect the propagation speed of electromagnetic waves at the interface of the medium, resulting in differences in ground penetrating radar images collected at different times. Directly using cross-correlation as a similarity measure will result in a high degree of mismatch, which will challenge the performance of the system in specific time periods or climate change conditions, and may even affect the overall robustness of the system and the accuracy of positioning. Therefore, it is necessary to solve the mismatch problem caused by differences in ground penetrating radar images under different temperatures and humidities. Summary of the invention

[0005] Based on this, it is necessary to provide a ground penetrating radar image registration method, device, computer equipment and medium based on adaptive hyperbolic filtering that can improve matching accuracy and positioning accuracy in response to the above technical problems.

[0006] A ground penetrating radar image registration method based on adaptive hyperbolic filtering, the method comprising:

[0007] Acquiring echo data, wherein the echo data is detected by a ground penetrating radar in real time;

[0008] An adaptive hyperbolic filter is used to perform image enhancement on the echo data to obtain an enhanced image, wherein a target echo hyperbolic equation is obtained according to the target echo principle of a ground penetrating radar, and the adaptive hyperbolic filter is constructed based on the target echo hyperbolic equation and taking into account the change of underground dielectric constant;

[0009] The pre-stored map is divided into multiple two-dimensional images according to the preset registration requirements, each of the two-dimensional images is enhanced by using the adaptive hyperbolic filter to obtain an enhanced two-dimensional image, and a corresponding enhanced two-dimensional image set is constructed;

[0010] The enhanced image and each image in the enhanced two-dimensional image set are similarly measured by using a cross-correlation matching method to obtain an enhanced two-dimensional image that matches the enhanced image, thereby achieving image registration.

[0011] In one embodiment, before the echo data is image enhanced, the echo data is preprocessed using a mean value method.

[0012] In one embodiment, the adaptive hyperbolic filter is expressed as:

[0013] ;

[0014] in, ;

[0015] ;

[0016] In the above formula, Represents the time sampling sequence number, where Indicates the introduction of fluctuation factor, represents the speed of light, represents the dielectric constant of the underground medium, represents the sampling interval, represents the sampling time window, , ,filter The size is .

[0017] In one embodiment, when an adaptive hyperbolic filter is used for image enhancement, the adaptive hyperbolic filter is adaptively adjusted according to a time sampling sequence number, and image enhancement is performed by pixel-by-pixel enhancement.

[0018] In one embodiment, the enhanced image is represented as:

[0019] ;

[0020] In the above formula, represents the image to be enhanced, Indicates the vertical coordinate position of the pixel point. Indicates the horizontal coordinate position of the pixel.

[0021] In one embodiment, the registration requirements include:

[0022] Dividing the map into a plurality of two-dimensional images along the x direction of the driving trajectory;

[0023] Or, the array channel is divided into multiple two-dimensional images in the y direction.

[0024] In one embodiment, before registering the enhanced image:

[0025] estimating a new time delay according to the underground dielectric constant, and performing a time delay correction according to the new time delay;

[0026] Performing interpolation transformation on the enhanced image according to the corrected time delay to obtain a transformed enhanced image;

[0027] The transformed enhanced image is used for subsequent registration.

[0028] In one embodiment, the pre-stored map is a grid map composed of a plurality of A-scan data.

[0029] The present application also provides a ground penetrating radar image registration device based on adaptive hyperbolic filtering, the device comprising:

[0030] An echo data acquisition module is used to acquire echo data, wherein the echo data is acquired by real-time detection of a ground penetrating radar;

[0031] An image enhancement module, used for performing image enhancement on the echo data by using an adaptive hyperbolic filter to obtain an enhanced image, wherein a target echo hyperbolic equation is obtained according to the target echo principle of a ground penetrating radar, and the adaptive hyperbolic filter is constructed based on the target echo hyperbolic equation by considering the change of underground dielectric constant;

[0032] A map division module, used to divide the pre-stored map into multiple two-dimensional images according to the preset registration requirements, perform image enhancement on each two-dimensional image using the adaptive hyperbolic filter to obtain an enhanced two-dimensional image, and construct a corresponding enhanced two-dimensional image set;

[0033] The image registration module is used to measure the similarity between the enhanced image and each image in the enhanced two-dimensional image set by using the cross-correlation matching method to obtain an enhanced two-dimensional image matching the enhanced image, thereby realizing image registration.

[0034] A computer device comprises a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0035] Acquiring echo data, wherein the echo data is detected by a ground penetrating radar in real time;

[0036] An adaptive hyperbolic filter is used to perform image enhancement on the echo data to obtain an enhanced image, wherein a target echo hyperbolic equation is obtained according to the target echo principle of a ground penetrating radar, and the adaptive hyperbolic filter is constructed based on the target echo hyperbolic equation and taking into account the change of underground dielectric constant;

[0037] The pre-stored map is divided into multiple two-dimensional images according to the preset registration requirements, each of the two-dimensional images is enhanced by using the adaptive hyperbolic filter to obtain an enhanced two-dimensional image, and a corresponding enhanced two-dimensional image set is constructed;

[0038] The enhanced image and each image in the enhanced two-dimensional image set are similarly measured by using a cross-correlation matching method to obtain an enhanced two-dimensional image that matches the enhanced image, thereby achieving image registration.

[0039] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the following steps:

[0040] Acquiring echo data, wherein the echo data is detected by a ground penetrating radar in real time;

[0041] An adaptive hyperbolic filter is used to perform image enhancement on the echo data to obtain an enhanced image, wherein a target echo hyperbolic equation is obtained according to the target echo principle of a ground penetrating radar, and the adaptive hyperbolic filter is constructed based on the target echo hyperbolic equation and taking into account the change of underground dielectric constant;

[0042] The pre-stored map is divided into multiple two-dimensional images according to the preset registration requirements, each of the two-dimensional images is enhanced by using the adaptive hyperbolic filter to obtain an enhanced two-dimensional image, and a corresponding enhanced two-dimensional image set is constructed;

[0043] The enhanced image and each image in the enhanced two-dimensional image set are similarly measured by using a cross-correlation matching method to obtain an enhanced two-dimensional image that matches the enhanced image, thereby achieving image registration.

[0044] The above-mentioned ground penetrating radar image registration method and device based on adaptive hyperbolic filtering, by using an adaptive hyperbolic filter to enhance the echo data obtained by real-time detection of the ground penetrating radar, obtain an enhanced image, wherein the target echo hyperbolic equation is obtained according to the ground penetrating radar target echo principle, and the adaptive hyperbolic filter is constructed based on the target echo hyperbolic equation considering the change of underground dielectric constant, and the pre-stored map is divided according to the preset registration requirements to obtain multiple two-dimensional images, and the adaptive hyperbolic filter is also used to enhance each two-dimensional image and construct a corresponding enhanced two-dimensional image set, and the cross-correlation matching method is used to perform similarity measurement between the enhanced image and each image in the enhanced two-dimensional image set to obtain an enhanced two-dimensional image matching the enhanced image, thereby realizing image registration. The use of this method can improve the matching accuracy and positioning accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic diagram of a flow chart of a ground penetrating radar image registration method based on adaptive hyperbolic filtering in one embodiment;

[0046] Figure 2 A schematic diagram of the target echo principle of a ground penetrating radar in one embodiment;

[0047] Figure 3 A schematic diagram of the difference between ground penetrating radar images in sunny and rainy weather in one embodiment;

[0048] Figure 4 This is a schematic diagram of A-scan comparison for enhancement correction according to an embodiment, wherein: Figure 4 (a) represents the image before enhancement. Figure 4 (b) shows the enhanced and corrected image;

[0049] Figure 5 It is a structural block diagram of a ground penetrating radar image registration device based on adaptive hyperbolic filtering in one embodiment;

[0050] Figure 6 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0052] In the existing ground penetrating radar positioning technology, the image mismatch problem caused by the fluctuation of underground dielectric constant due to temperature and humidity changes, such as Figure 1As shown in FIG. 1 , a ground penetrating radar image registration method based on adaptive hyperbolic filtering is extracted to improve matching accuracy and positioning accuracy. The specific steps include:

[0053] Step S100, acquiring echo data, wherein the echo data is detected by a ground penetrating radar in real time.

[0054] Step S110, using an adaptive hyperbolic filter to perform image enhancement on the echo data to obtain an enhanced image, wherein a target echo hyperbolic equation is obtained according to the target echo principle of the ground penetrating radar, and an adaptive hyperbolic filter is constructed based on the target echo hyperbolic equation taking into account the change of underground dielectric constant.

[0055] Step S120, dividing the pre-stored map according to the preset registration requirements to obtain multiple two-dimensional images, using the adaptive hyperbolic filter to enhance each two-dimensional image to obtain an enhanced two-dimensional image, and constructing a corresponding enhanced two-dimensional image set.

[0056] Step S130, using a cross-correlation matching method to perform similarity measurement between the enhanced image and each two-dimensional image in the two-dimensional image set, to obtain an enhanced two-dimensional image that matches the enhanced image, thereby achieving image registration.

[0057] In this application, taking into account the problem of image mismatch caused by changes in temperature and humidity (i.e., weather influence) due to the underground dielectric constant, a filter that introduces changes in dielectric constant is proposed. By utilizing the filter to enhance the echo data and the original image, the mismatch problem caused by changes in dielectric constant (i.e., weather changes) is overcome.

[0058] Before explaining the present method, the construction of the pre-stored map in step S120 will be explained first, and the expression of the map will be introduced in the process to facilitate the subsequent understanding of the present method.

[0059] In this embodiment, the pre-stored map is a grid map composed of a plurality of A-scan data.

[0060] Specifically, ground penetrating radar is used to collect map data. Fixed interval triggering is used during data collection, and the sampling interval is recorded. , time window The ground penetrating radar positioning system for data collection also includes high-precision GPS, DMI, high-performance computers, etc.

[0061] Furthermore, the collected ground penetrating radar data is combined with high-precision GPS location tags to obtain a grid map The grid data consists of multiple A-scan data and is represented as:

[0062] (1)

[0063] In formula (1), x represents the direction of the ground penetrating radar, and y represents the direction of the ground penetrating radar array channel arrangement. Multiple A-scan stacks can obtain a ground penetrating radar image, and the image along the direction of travel can be expressed as:

[0064] (2)

[0065] The image along the array channel direction can be expressed as:

[0066] (3)

[0067] In formula (3), N represents the number of GPR time sampling points, M represents the number of sampling points in the moving direction, and P represents the number of GPR array channels.

[0068] In step S100, the acquired echo data is real-time data obtained by ground penetrating radar for underground detection, and the subsequent processed echo data is a section of echo data collected within a preset collection time. The current position information is obtained by continuously performing image registration on the echo data within the current collection time, thereby achieving real-time positioning.

[0069] Furthermore, before the echo data is enhanced, the mean method is used to preprocess it.

[0070] In step S110, the echo data is enhanced using a pre-built adaptive hyperbolic filter, which is constructed by first obtaining a target echo hyperbolic equation based on the ground penetrating radar target echo principle and then considering the change of underground dielectric constant based on the target echo hyperbolic equation.

[0071] In this embodiment, when constructing an adaptive hyperbolic filter, Figure 2 As shown in the figure, assuming that the underground medium is a single layer of uniform dispersion, the small target is analyzed as a point target, and the target delay can be determined. Horizontal position with antenna The relationship is expressed as:

[0072] (4)

[0073] The target echo hyperbola equation obtained by simplifying the above formula is expressed as:

[0074] (5)

[0075] In formula (5), .

[0076] Assuming that the point target position is known, the hyperbolic response of the GPR echo is only related to the propagation speed of the electromagnetic wave. When the semi-real axis a and semi-imaginary axis b of the hyperbola are used to initialize the hyperbola equation, the hyperbola equation is expressed as:

[0077] (6)

[0078] in, , ;

[0079] In formula (6), the propagation speed of electromagnetic waves in the medium is , represents the speed of light, Represents the dielectric constant of the medium.

[0080] Using ground penetrating radar detection, the hyperbolic response on the time domain image also needs to consider the sampling interval and sampling time window The influence of the hyperbolic parameters corresponding to the target response in the image can be expressed as:

[0081] , (7)

[0082] In formula (7), Indicates the target The time sampling sequence number corresponding to the location.

[0083] According to the hyperbolic parameters and The hyperbola equation corresponding to each position in the time domain image can be determined, but since the underground dielectric constant is unknown, the dielectric constant needs to be estimated.

[0084] In this embodiment, the dielectric constant can be estimated based on empirical values, or the dielectric constant can be estimated based on the velocity of the hyperbola in the ground penetrating radar image. .

[0085] Since precipitation and temperature changes will cause the underground dielectric constant to fluctuate, the fluctuation factor , the size of the fluctuation factor is positively correlated with the amount of precipitation, and two hyperbolic equations can be determined. According to the image domain data form, take the lower branch of the hyperbolic equation and translate its vertex to the origin of the coordinate axis, and two curve equations can be obtained:

[0086] (8)

[0087] (9)

[0088] In formula (8) and formula (9), Indicates the time sampling sequence number.

[0089] Furthermore, the extended hyperbola can be determined based on the two curve equations, that is, the adaptive hyperbola filter is expressed as:

[0090] (10)

[0091] in, ;

[0092] ;

[0093] In formula (10), Represents the time sampling sequence number, where Indicates the introduction of fluctuation factor, represents the speed of light, represents the dielectric constant of the underground medium, represents the sampling interval, represents the sampling time window, , ,filter The size is .

[0094] In this embodiment, since the hyperbolic response is related to time, the hyperbolic response is different at different times. When filtering or enhancing, the adaptive hyperbolic filter According to the time sampling sequence Perform adaptive adjustment and enhance the image by pixel-by-pixel enhancement .

[0095] Specifically, when using an adaptive hyperbolic filter When the echo data is filtered or enhanced, the process is expressed as:

[0096] (11)

[0097] In formula (11), Represents echo data, Indicates the vertical coordinate position of the pixel point. Indicates the horizontal coordinate position of the pixel

[0098] In step 120, when dividing the pre-stored map, the map may be divided into a plurality of two-dimensional images along the x direction of the driving trajectory according to the registration requirements. , or divided into multiple two-dimensional images according to the y direction of the array channel , and then use adaptive hyperbolic filter to enhance each two-dimensional image. The process is expressed as:

[0099] (12)

[0100] In formula (12), represents a two-dimensional image, Indicates the vertical coordinate position of the pixel point. Indicates the horizontal coordinate position of the pixel point. And constructs a corresponding enhanced two-dimensional image set based on each enhanced two-dimensional image.

[0101] The echo signal and the map are both filtered using an adaptive hyperbolic filter. After enhancement, the registration and positioning operation can achieve good results. When the underground dielectric constant changes greatly, such as Figure 3 As shown in the figure, it is a ground penetrating radar image of the same area in sunny and rainy weather. It can be seen from the image that the target fluctuates up and down, which is essentially the change of echo delay. That is to say, when the weather is more extreme and the rainfall is heavy, the underground dielectric constant will also change greatly, resulting in a large change in delay. In order to further improve the image registration accuracy in this scenario, before the enhanced image is registered: a new delay is estimated based on the underground dielectric constant, and a delay correction is performed based on the new delay, and then the enhanced image is interpolated according to the corrected delay to obtain a transformed enhanced image, and the transformed enhanced image is used for subsequent registration.

[0102] Specifically, according to The time calculation equation can get the new delay :

[0103] (13)

[0104] (14)

[0105] Furthermore, the experimental correction is expressed as:

[0106] (15)

[0107] At this time, the corrected sampling time is difficult to accurately project on the grid points. Therefore, it is necessary to interpolate the corrected data to obtain the enhanced image after the corresponding grid transformation. :

[0108] (16)

[0109] In step S130, the transformed enhanced query image, i.e. the transformed enhanced image In the enhanced map, the enhanced two-dimensional image In this embodiment, the cross-correlation matching method is used as the similarity metric, which is expressed as:

[0110] (17)

[0111] In formula (17), Indicates the time sampling number of the current image, Indicates the number of A-scans of the current image. The range of similarity is , the higher the value, the more similar the two images are. Searching for the position with the greatest similarity is the result of matching and positioning the real-time image on the map. After obtaining the matching two-dimensional image, the current moment positioning can be achieved based on the position information in the two-dimensional image.

[0112] In order to demonstrate the superiority of this method, registration and positioning verification was carried out on three simulation data sets and two measured data sets. Figure 4 The A-scan data comparison after the ground penetrating radar image enhancement and time correction is given. Figure 4 (a) is before correction, Figure 4 (b) After correction, it can be found that the A-scan data of sunny and rainy weather obtained by this method are more similar. Table 1 shows the accuracy of ground penetrating radar positioning on different data sets and compares it with the existing image processing methods. This method shows the best positioning accuracy. It can still ensure the accuracy of ground penetrating radar positioning when the underground temperature and humidity change, and improve the robustness of the ground penetrating radar positioning system.

[0113] Table 1 Comparison of positioning accuracy

[0114]

[0115] In the above-mentioned ground penetrating radar image registration method based on adaptive hyperbolic filtering, a ground penetrating radar image registration method based on adaptive hyperbolic filtering is provided for the problem of ground penetrating radar navigation and positioning. This method aims at the problem of image mismatching caused by the fluctuation of underground dielectric constant under different temperature and humidity. The typical hyperbolic features in the ground penetrating radar image are enhanced, an enhanced map library is constructed, and the real-time image collected by the motion platform is enhanced and time-delay corrected according to the change of dielectric constant. Similarity measurement is performed in the enhanced map library to achieve registration and positioning. The image mismatching caused by the fluctuation of dielectric constant is reduced, which provides an important guarantee for the realization of safe and reliable ground penetrating radar navigation and positioning.

[0116] It should be understood that although Figure 1 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 1 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0117] In one embodiment, Figure 5 As shown, a ground penetrating radar image registration device based on adaptive hyperbolic filtering is provided, comprising: an echo data obtaining module 200, an image enhancement module 210, a map division module 220 and an image registration module 230, wherein:

[0118] An echo data acquisition module 200 is used to acquire echo data, wherein the echo data is acquired by real-time detection of a ground penetrating radar;

[0119] An image enhancement module 210 is used to perform image enhancement on the echo data using an adaptive hyperbolic filter to obtain an enhanced image, wherein a target echo hyperbolic equation is obtained according to the target echo principle of the ground penetrating radar, and the adaptive hyperbolic filter is constructed based on the target echo hyperbolic equation taking into account the change of underground dielectric constant;

[0120] A map partitioning module 220 is used to partition the pre-stored map according to a preset registration requirement to obtain a plurality of two-dimensional images, perform image enhancement on each two-dimensional image using the adaptive hyperbolic filter to obtain an enhanced two-dimensional image, and construct a corresponding enhanced two-dimensional image set;

[0121] The image registration module 230 is used to measure the similarity between the enhanced image and each image in the enhanced two-dimensional image set by using a cross-correlation matching method to obtain an enhanced two-dimensional image that matches the enhanced image, thereby achieving image registration.

[0122] The specific definition of the ground penetrating radar image registration device based on adaptive hyperbolic filtering can be found in the above definition of the ground penetrating radar image registration method based on adaptive hyperbolic filtering, which will not be repeated here. Each module in the above-mentioned ground penetrating radar image registration device based on adaptive hyperbolic filtering can be implemented in whole or in part by software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory in the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0123] In one embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as follows: Figure 6As shown. The computer device includes a processor, a memory, a network interface and a database connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store map data. The network interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a ground penetrating radar image registration method based on adaptive hyperbolic filtering is implemented.

[0124] Those skilled in the art will understand that Figure 6 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0125] In one embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the following steps are implemented:

[0126] Acquiring echo data, wherein the echo data is detected by a ground penetrating radar in real time;

[0127] An adaptive hyperbolic filter is used to perform image enhancement on the echo data to obtain an enhanced image, wherein a target echo hyperbolic equation is obtained according to the target echo principle of a ground penetrating radar, and the adaptive hyperbolic filter is constructed based on the target echo hyperbolic equation and taking into account the change of underground dielectric constant;

[0128] The pre-stored map is divided into multiple two-dimensional images according to the preset registration requirements, each of the two-dimensional images is enhanced by using the adaptive hyperbolic filter to obtain an enhanced two-dimensional image, and a corresponding enhanced two-dimensional image set is constructed;

[0129] The enhanced image and each image in the enhanced two-dimensional image set are similarly measured by using a cross-correlation matching method to obtain an enhanced two-dimensional image that matches the enhanced image, thereby achieving image registration.

[0130] In one embodiment, a computer readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the following steps are implemented:

[0131] Acquiring echo data, wherein the echo data is detected by a ground penetrating radar in real time;

[0132] An adaptive hyperbolic filter is used to perform image enhancement on the echo data to obtain an enhanced image, wherein a target echo hyperbolic equation is obtained according to the target echo principle of a ground penetrating radar, and the adaptive hyperbolic filter is constructed based on the target echo hyperbolic equation and taking into account the change of underground dielectric constant;

[0133] The pre-stored map is divided into multiple two-dimensional images according to the preset registration requirements, each of the two-dimensional images is enhanced by using the adaptive hyperbolic filter to obtain an enhanced two-dimensional image, and a corresponding enhanced two-dimensional image set is constructed;

[0134] The enhanced image and each image in the enhanced two-dimensional image set are similarly measured by using a cross-correlation matching method to obtain an enhanced two-dimensional image that matches the enhanced image, thereby achieving image registration.

[0135] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0136] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0137] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A ground penetrating radar image registration method based on adaptive hyperbolic filtering, characterized in that: The method comprises: Acquiring echo data, wherein the echo data is detected by a ground penetrating radar in real time; An adaptive hyperbolic filter is used to enhance the echo data to obtain an enhanced image, wherein the target echo hyperbolic equation is obtained according to the target echo principle of the ground penetrating radar, and the adaptive hyperbolic filter is constructed based on the target echo hyperbolic equation and considering the change of underground dielectric constant, which is expressed as: ； in, ; ； In the above formula, Represents the time sampling sequence number, where Indicates the introduction of fluctuation factor, represents the speed of light, represents the dielectric constant of the underground medium, represents the sampling interval, represents the sampling time window, , ,filter The size is ; The pre-stored map is divided into multiple two-dimensional images according to the preset registration requirements, each of the two-dimensional images is enhanced by using the adaptive hyperbolic filter to obtain an enhanced two-dimensional image, and a corresponding enhanced two-dimensional image set is constructed; The enhanced image and each image in the enhanced two-dimensional image set are similarly measured by using a cross-correlation matching method to obtain an enhanced two-dimensional image that matches the enhanced image, thereby achieving image registration.

2. The ground penetrating radar image registration method according to claim 1, characterized in that: Before image enhancement is performed on the echo data, the echo data is preprocessed using a mean value method.

3. The ground penetrating radar image registration method according to claim 2, characterized in that: When an adaptive hyperbolic filter is used for image enhancement, the adaptive hyperbolic filter is adaptively adjusted according to the time sampling sequence number, and image enhancement is performed in a pixel-by-pixel enhancement manner.

4. The ground penetrating radar image registration method according to claim 3, characterized in that: The enhanced image is represented as: ； In the above formula, represents the image to be enhanced, Indicates the vertical coordinate position of the pixel point. Indicates the horizontal coordinate position of the pixel.

5. The ground penetrating radar image registration method according to claim 4, characterized in that: The registration requirements include: Dividing the map into a plurality of two-dimensional images along the x direction of the driving trajectory; Or, the array channel is divided into multiple two-dimensional images in the y direction.

6. The ground penetrating radar image registration method according to any one of claims 1 to 5, characterized in that: Before registering the enhanced image: estimating a new time delay according to the underground dielectric constant, and performing a time delay correction according to the new time delay; Performing interpolation transformation on the enhanced image according to the corrected time delay to obtain a transformed enhanced image; The transformed enhanced image is used for subsequent registration.

7. The ground penetrating radar image registration method according to claim 6, characterized in that: The pre-stored map is a grid map composed of multiple A-scan data.

8. A ground penetrating radar image registration device based on adaptive hyperbolic filtering, characterized in that: The device comprises: An echo data acquisition module is used to acquire echo data, wherein the echo data is acquired by real-time detection of a ground penetrating radar; The image enhancement module is used to perform image enhancement on the echo data using an adaptive hyperbolic filter to obtain an enhanced image, wherein the target echo hyperbolic equation is obtained according to the target echo principle of the ground penetrating radar, and the adaptive hyperbolic filter is constructed based on the target echo hyperbolic equation considering the change of underground dielectric constant, which is expressed as: ； in, ; ； In the above formula, Represents the time sampling sequence number, where Indicates the introduction of fluctuation factor, represents the speed of light, represents the dielectric constant of the underground medium, represents the sampling interval, represents the sampling time window, , ,filter The size is ; A map division module, used to divide the pre-stored map into multiple two-dimensional images according to the preset registration requirements, perform image enhancement on each two-dimensional image using the adaptive hyperbolic filter to obtain an enhanced two-dimensional image, and construct a corresponding enhanced two-dimensional image set; The image registration module is used to measure the similarity between the enhanced image and each image in the enhanced two-dimensional image set by using the cross-correlation matching method to obtain an enhanced two-dimensional image matching the enhanced image, thereby realizing image registration.

Images