Magnetic anomaly acceleration calculation method, device, equipment and medium

Abstract

The invention relates to the technical field of magnetic exploration, and provides a magnetic anomaly acceleration calculation method and device, equipment and a medium, and the method comprises the steps: determining a target region and the observation height of the target region; constructing a target area model containing the anomalous body model, and performing grid division on the target area model containing the anomalous body model; setting the magnetic susceptibility of each grid unit in each layer of anomalous body model for anomalous body models in the target area model after grid division, and calculating the magnetization intensity of each grid unit; calculating a contribution kernel function coefficient of each grid unit in each layer of anomalous body model to an observation height magnetic field by adopting a compression storage strategy, and further obtaining a kernel function coefficient matrix of each layer of anomalous body model; and realizing fast convolution of the kernel function coefficient matrix and the magnetization intensity by adopting fast Fourier transform to obtain an abnormal magnetic field value at the observation height. On the premise of ensuring the calculation precision and reducing the memory consumption, the efficiency of the magnetic anomaly forward calculation is greatly improved.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of magnetic prospecting, and in particular to a method, device, equipment and medium for accelerating the calculation of magnetic anomalies. Background Technique

[0002] Magnetic prospecting has been widely used to solve various geological problems due to its advantages such as low cost, high efficiency, environmental friendliness, and large coverage. In actual field observations, geological bodies with a much larger scale in the strike direction than in the direction perpendicular to the strike are usually approximated by two-dimensional bodies that extend infinitely along the strike. This can greatly reduce the memory and calculation time required for calculations, and correspondingly, inversion is easier to achieve.

[0003] In the magnetic anomaly numerical simulation method, the literature (Wu, L., Tian, G. High-precision Fourier forward modeling of potential fields. Geophysics, 2014, 79(5): G59 - G68.) proposed a Gauss-FFT method for numerical simulation of magnetic anomalies of two-dimensional bodies in the frequency domain. This method can well overcome the boundary oscillation effect problem of the traditional fast Fourier transform and greatly improve the accuracy of numerical simulation. However, as the number of Gauss points increases, its computational amount increases exponentially, and the error is relatively large when calculating the magnetic anomalies inside the abnormal body. The literature (Jeshvaghani, M. S., Darijani, M. Two-dimensional geomagnetic forward modeling using adaptive finite element method and investigation of the topographic effect. Journal of Applied Geophysics, 2014, 105, 169 - 179.) realized the numerical simulation of magnetic anomalies of two-dimensional bodies under complex models and undulating terrain conditions by using the method of unstructured grid meshing. This method can appropriately encrypt the grid at the boundary of the complex model to improve the simulation accuracy. However, as the number of grid nodes increases, the formed large sparse matrix is large, resulting in a long calculation time.

[0004] The existing traditional magnetic anomaly numerical simulation has problems of poor applicability to complex forms with arbitrary geometric shapes and arbitrary magnetic susceptibility distributions and low calculation efficiency. Therefore, it is necessary to study a numerical simulation method for the magnetic field of two-dimensional bodies that is efficient and has good applicability to any complex geological body, and to solve the deficiencies of traditional methods. Summary of the Invention

[0005] Aiming at the technical problems existing in the prior art, the present invention proposes a magnetic anomaly acceleration calculation method, device, equipment and medium, which has good applicability to complex geological bodies with arbitrary geometric shapes and arbitrary susceptibility distributions, and can greatly improve the efficiency and accuracy of magnetic anomaly forward calculation on the premise of ensuring the calculation accuracy of the magnetic field value of complex geological bodies and reducing memory consumption.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows: On the one hand, the present invention provides a magnetic anomaly acceleration calculation method, including the following steps: Determine the target area of magnetic method geological exploration and the observation height of the target area, where the target area contains abnormal bodies; Construct a target area model including an abnormal body model, and perform grid division on the target area model including the abnormal body model; For the abnormal body model in the target area model after grid division, set the magnetic susceptibility of each grid unit in each layer of the abnormal body model, and calculate the magnetization intensity of each grid unit; Adopt a compressed storage strategy to calculate the contribution kernel function coefficients of each grid unit in each layer of the abnormal body model to the magnetic field at the observation height, and then obtain the kernel function coefficient matrix of each layer of the abnormal body model; Use the fast Fourier transform to achieve the fast convolution of the kernel function coefficient matrix and the magnetization intensity, and obtain the abnormal magnetic field value at the observation height.

[0007] Further, use rectangular grids to perform grid division on the target area model including the abnormal body model, and discretize the target area and the abnormal body model in the target area into multiple rectangular grid units; among them, the number of rectangular grid units discretized along the x and z directions of the target area are respectively 、 pieces, and the number of rectangular grid units discretized along the x and z directions of the abnormal body model are respectively 、 pieces.

[0008] Further, setting the magnetic susceptibility of each grid unit in each layer of the abnormal body model includes: setting the magnetic susceptibility value of each rectangular grid unit according to the geometric shape and susceptibility distribution of the abnormal body model, and the magnetic susceptibility of each rectangular grid unit is a constant value, and the magnetic susceptibility values of different rectangular grid units are different, so as to describe a complex abnormal body model with arbitrary geometric shape and arbitrary susceptibility distribution.

[0009] Further, for the abnormal body model in the target area model after grid division, setting the magnetic susceptibility of each grid unit in each layer of the abnormal body model and calculating the magnetization intensity of each grid unit includes: According to the Earth's main magnetic field model, calculate the Earth's main magnetic field for each rectangular grid cell in each layer of the anomaly body model; Calculate the magnetization intensity of each rectangular grid cell based on the Earth's main magnetic field of each rectangular grid cell and the magnetic susceptibility of each rectangular grid cell.

[0010] Furthermore, adopt a compressed storage strategy to calculate the contribution kernel function coefficients of each grid cell in each layer of the anomaly body model to the magnetic field at the observation height, and then obtain the kernel function coefficient matrix of each layer of the anomaly body model, including: For the set observation height , the contribution kernel function coefficients of each grid cell in the -th layer of the anomaly body model to the magnetic field at the observation height are calculated by the following formula: ; ; where and represent the horizontal and vertical contribution kernel function coefficients of the -th grid cell in the -th layer of the anomaly body model to the magnetic field at the observation height; , , , , represent the coordinates of the rectangular grid cell numbered , ; ; ; represents the vacuum permeability, Δ x , Δ z respectively represent the intervals between the centers of the rectangular grid cells in the horizontal and vertical directions; Based on the contribution kernel function coefficients of each grid cell in each layer of the anomaly body model to the magnetic field at the observation height, obtain the kernel function coefficient matrix of each layer of the anomaly body model.

[0011] Furthermore, use the fast Fourier transform to achieve the fast convolution of the kernel function coefficient matrix and the magnetization intensity, and obtain the abnormal magnetic field value at the observation height: ; ; In the formula, and represent the horizontal magnetic field value and the vertical abnormal magnetic field value of the target area at the observation height, and represent the Fourier transform pair, and respectively represent the The kernel function coefficient matrices in the horizontal and vertical directions of the layer anomaly body model and respectively represent the horizontal magnetization intensity matrix composed of the horizontal magnetization intensities of each rectangular grid unit of the layer anomaly body model and the vertical magnetization intensity matrix composed of the vertical magnetization intensities of each rectangular grid unit of the layer anomaly body model; represents extracting the first elements of the matrix, that is, the anomaly magnetic field values at the observation height.

[0012] On the other hand, a magnetic anomaly acceleration calculation device is provided, including: The first module is used to determine the target area of the magnetic method geological exploration and the observation height of the target area, and the target area contains anomaly bodies; The second module is used to construct a target area model including an anomaly body model and perform grid division on the target area model including the anomaly body model; The third module is used to set the magnetic susceptibility of each grid unit in each layer of the anomaly body model in the grid-divided target area model and calculate the magnetization intensity of each grid unit; The fourth module is used to calculate the contribution kernel function coefficients of each grid unit in each layer of the anomaly body model to the magnetic field at the observation height by adopting a compressed storage strategy, and then obtain the kernel function coefficient matrix of each layer of the anomaly body model; The fifth module is used to implement the fast convolution of the kernel function coefficient matrix and the magnetization intensity by using the fast Fourier transform to obtain the anomaly magnetic field values at the observation height.

[0013] Furthermore, in the fourth module, calculating the contribution kernel function coefficients of each grid unit in each layer of the anomaly body model to the magnetic field at the observation height by adopting a compressed storage strategy, and then obtaining the kernel function coefficient matrix of each layer of the anomaly body model, includes: For the set observation height , the contribution kernel function coefficients of each grid unit in the layer anomaly body model to the magnetic field at the observation height are calculated by the following formula: ; ; where, the numbers of rectangular grid units in the target area discretized along the x and z directions are respectively , respectively, and the numbers of rectangular grid units in the anomaly body model discretized along the x and z directions are respectively , respectively, and Indicates the horizontal and vertical direction contribution kernel function coefficients of the th grid cell in the layer anomaly body model to the magnetic field at the observation height; , , , , represents the coordinates of the rectangular grid cell numbered ; represents the coordinates of the rectangular grid cell numbered in the x direction at the observation height ; ; ; ; represents the vacuum permeability, Δ x and Δ z respectively represent the intervals between the centers of the rectangular grid cells in the horizontal and vertical directions; The kernel function coefficient matrix of each layer anomaly body model is obtained based on the contribution kernel function coefficients of each grid cell in each layer anomaly body model to the magnetic field at the observation height.

[0014] On the other hand, the present invention provides a computer device, including a memory and a processor, the memory stores a computer program, and when the processor executes the computer program, the steps of the above-mentioned magnetic anomaly acceleration calculation method are realized.

[0015] On the other hand, the present invention provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above-mentioned magnetic anomaly acceleration calculation method are realized.

[0016] On the other hand, the present invention provides a computer program product, the computer program product is stored on a computer-readable storage medium, and includes computer instructions, and when the computer instructions are run by a processor, the computer device realizes the steps of the above-mentioned magnetic anomaly acceleration calculation method.

[0017] Compared with the prior art, the technical effects of the present invention are: This method uses the analytical method to calculate the kernel function coefficient matrix, which can effectively ensure the calculation accuracy.

[0018] This method adopts a compressed storage strategy and only needs to calculate the kernel function coefficients related to the grid cells in the anomaly body model, reducing the calculation and storage of the kernel function coefficient matrix of the corresponding layer, reducing the memory requirement and the calculation amount, improving the calculation efficiency on the premise of ensuring the accuracy of the calculation analytical formula, and effectively improving the calculation speed without losing any accuracy. The present invention has good applicability for calculating complex anomaly bodies with arbitrary geometric shapes and arbitrary susceptibility distributions. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0020] Figure 1 Flowchart of the magnetic anomaly acceleration calculation method proposed for an embodiment; Figure 2 Result diagram of the horizontal component of the ground magnetic field calculated by the magnetic anomaly acceleration calculation method proposed based on the present invention for an embodiment; Figure 3 Result diagram of the horizontal component of the ground magnetic field directly calculated based on the analytical solution for an embodiment; Figure 4 Relative error result diagram of the horizontal component of the magnetic field calculated by the magnetic anomaly acceleration calculation method proposed based on the present invention and the magnetic field calculated based on the analytical solution for an embodiment; Figure 5 Result diagram of the vertical component of the ground magnetic field calculated by the magnetic anomaly acceleration calculation method proposed based on the present invention for an embodiment; Figure 6 Result diagram of the vertical component of the ground magnetic field directly calculated based on the analytical solution for an embodiment; Figure 7 Relative error result diagram of the vertical component of the magnetic field calculated by the magnetic anomaly acceleration calculation method proposed based on the present invention and the magnetic field calculated based on the analytical solution for an embodiment. Specific embodiments

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0022] An embodiment provides a forward magnetic field acceleration method, including: Determine the target area of magnetic method geological exploration and the observation height of the target area, where the target area contains abnormal bodies; Construct a target area model including an abnormal body model, and perform grid division on the target area model including the abnormal body model; For the abnormal body model in the target area model after grid division, set the magnetic susceptibility of each grid unit in each layer of the abnormal body model, and calculate the magnetization intensity of each grid unit; Adopt a compressed storage strategy to calculate the contribution kernel function coefficients of each grid cell in the abnormal body models of each layer to the magnetic field at the observed height, and then obtain the kernel function coefficient matrix of the abnormal body models of each layer; Use the fast Fourier transform to achieve the fast convolution of the kernel function coefficient matrix and the magnetization intensity, and obtain the abnormal magnetic field value at the observed height.

[0023] Among them, the abnormal body described in the present invention can be a complex geological body with any geometric shape and any magnetic susceptibility distribution.

[0024] Construct a target area containing the abnormal body model according to the size of the abnormal body, and construct a corresponding target area model containing the abnormal body model according to the target area and the size of the abnormal body. Use rectangular grids to divide the target area model containing the abnormal body model, and discretize the target area and the abnormal body model within the target area into multiple rectangular grid cells. Among them, the number of rectangular grid cells discretized along the x and z directions of the target area is 、 respectively, and the number of rectangular grid cells discretized along the x and z directions of the abnormal body model is 、 respectively.

[0025] Next, set the magnetic susceptibility of each grid cell in each layer of the abnormal body model, including: setting the magnetic susceptibility value of each rectangular grid cell according to the geometric shape and magnetic susceptibility distribution of the abnormal body model, and the magnetic susceptibility of each rectangular grid cell is a constant value, and the magnetic susceptibility values of different rectangular grid cells are different, so as to describe a complex abnormal body model with any geometric shape and any magnetic susceptibility distribution.

[0026] For the abnormal body model in the target area model after grid division in the present invention, set the magnetic susceptibility of each grid cell in each layer of the abnormal body model, and calculate the magnetization intensity of each grid cell according to the magnetic susceptibility of each grid cell in each layer of the abnormal body model, including the following steps: Calculate the main magnetic field of the earth in each rectangular grid cell of each layer of the abnormal body model according to the main magnetic field model of the earth ; ; represents the coordinates of the rectangular grid cell numbered in the abnormal body model, represents the main magnetic field of the earth of the rectangular grid cell numbered in the -th layer of the abnormal body model. and respectively represent the main magnetic field of the earth of the rectangular grid cell numbered in the of the Earth's main magnetic field in rectangular grid cells x (horizontal direction), z (vertical direction) component, representing the local magnetic dip angle.

[0027] Calculate the magnetization intensity at each rectangular grid cell according to the Earth's main magnetic field and the magnetic susceptibility of each rectangular grid cell in each layer of anomaly models ; ; wherein, represents the magnetic susceptibility value of the rectangular grid cell numbered in the anomaly model; , respectively represent the horizontal direction and vertical direction components of the magnetization intensity at the rectangular grid cell numbered in the x anomaly model of the z layer.

[0028] The horizontal magnetization intensity matrix composed of the horizontal magnetization intensities of each rectangular grid cell in the anomaly model of the layer, and the vertical magnetization intensity matrix composed of the vertical magnetization intensities of each rectangular grid cell in the anomaly model of the layer.

[0029] The present invention adopts a compressed storage strategy to calculate the contribution kernel function coefficients of each grid cell in each layer of anomaly models to the magnetic field at the observation height, and then obtains the kernel function coefficient matrix of each layer of anomaly models, including: For a set observation height , the contribution kernel function coefficients of each grid cell in the anomaly model of the layer to the magnetic field at the observation height are calculated by the following formula: ; wherein, and respectively represent the horizontal direction contribution kernel function coefficient and the vertical direction contribution kernel function coefficient of the th grid cell in the anomaly model of the layer to the magnetic field at the observation height; , , , represents the coordinates of the rectangular grid cell numbered ​ Indicates the observation height The rectangular grid cell coordinates numbered in the x - direction above ; ; ; ; Indicates the vacuum permeability, Δ x , Δ z respectively represent the intervals between the centers of the rectangular grid cells in the horizontal and vertical directions. The above formula reduces the calculation of the arctangent function and the cotangent function, and improves the calculation efficiency on the premise of ensuring the calculation accuracy of the analytical formula.

[0030] Based on the contribution kernel function coefficients of each grid cell in each layer of the anomaly body model to the magnetic field at the observation height, the kernel function coefficient matrix of each layer of the anomaly body model is obtained.

[0031] The magnetic susceptibility of each discrete grid cell is a constant. Therefore, the integral of each grid cell can derive its analytical formula, and the calculation accuracy is high. Secondly, when the method of the present invention calculates the contribution value of the n -th layer anomaly body model to the magnetic field at the observation height, it only needs to calculate the contribution kernel function coefficients of each grid cell in the anomaly body model to the magnetic field at the observation height. This means that the size of the kernel function coefficient matrix of each layer of the anomaly body model can be the same or different, and it is all related to the discretization situation of the anomaly body model. When the number of grid cells divided in a certain layer of the anomaly body model is small, it means that the contribution kernel function coefficients to be calculated will also decrease, so that the calculation speed can be effectively improved.

[0032] Finally, the fast Fourier transform is used to realize the fast convolution of the kernel function coefficient matrix and the magnetization intensity, and the anomalous magnetic field value at the observation height is obtained: ; ; In the formula, and represent the horizontal - direction magnetic field value and the vertical - direction anomalous magnetic field value of the target area at the observation height, and represent the Fourier transform pair, and respectively represent the horizontal - direction and vertical - direction kernel function coefficient matrices of the -th layer anomaly body model, and respectively represent the horizontal - direction magnetization intensity matrix composed of the horizontal - direction magnetization intensities of each rectangular grid cell of the -th layer anomaly body model and the vertical - direction magnetization intensity matrix composed of the vertical - direction magnetization intensities of each rectangular grid cell of the -th layer anomaly body model; Indicates extracting the first elements of the matrix, i.e., the abnormal magnetic field values at the observation heights.

[0033] In one embodiment, a magnetic anomaly acceleration calculation device is provided, including: A first module for determining the target area of magnetic method geological exploration and the observation height of the target area, where the target area contains abnormal bodies; A second module for constructing a target area model including an abnormal body model and performing grid division on the target area model including the abnormal body model; A third module for setting the magnetic susceptibility of each grid unit in each layer of the abnormal body model in the target area model after grid division and calculating the magnetization intensity of each grid unit; A fourth module for calculating the contribution kernel function coefficients of each grid unit in each layer of the abnormal body model to the magnetic field at the observation height by using a compressed storage strategy, and further obtaining the kernel function coefficient matrix of each layer of the abnormal body model; A fifth module for performing fast convolution of the kernel function coefficient matrix and the magnetization intensity by using fast Fourier transform to obtain the abnormal magnetic field values at the observation height.

[0034] Next, the method of the present invention is verified through specific simulation examples.

[0035] In this example: The target area has a two-dimensional body model with a regular rectangular cross-section. The calculation area range is: x In the x direction from -1000 m to 1000 m, in the z direction from 0 m to 1000 m (the positive direction of the z-axis is vertically downward), the horizontal grid interval is 10 m, the vertical grid interval is 5 m, the number of horizontal and vertical grids is 200×200, and the distribution range of the abnormal body with a rectangular cross-section is: x In the x direction from -500 m to 500 m, in the z direction from 100 m to 400 m, the magnetic susceptibility of the abnormal area is 0.03, and the background magnetic susceptibility is 0; Given that the normal magnetic field intensity of the earth is 56000 nT, the magnetic inclination is 30°, and the magnetic declination is 0°, the horizontal and vertical components of the magnetic gradient tensor on the entire two-dimensional section are calculated by the method of the present invention.

[0036] The method of the present invention is implemented by programming in Fortran language. The configuration of the personal computer used to run the program is: CPU - Inter Core i7 - 8700, the main frequency is 3.2 GHz, and the running memory is 8.00 GB. Refer to Figures 2 to 7 , Figure 2 is the result diagram of the horizontal component of the ground magnetic field calculated by the magnetic anomaly acceleration calculation method proposed based on the present invention; Figure 3 is the result diagram of the horizontal component of the ground magnetic field calculated directly based on the analytical solution; Figure 4The figure shows the relative error results of the horizontal magnetic field component calculated based on the magnetic anomaly acceleration calculation method proposed in the present invention and the analytical solution; Figure 5 The figure shows the vertical component results of the ground magnetic field calculated by the magnetic anomaly acceleration calculation method proposed in the present invention; Figure 6 The figure shows the vertical component results of the ground magnetic field directly calculated based on the analytical solution; Figure 7 The figure shows the relative error results of the vertical magnetic field component calculated based on the magnetic anomaly acceleration calculation method proposed in the present invention and the analytical solution.

[0037] Among them, the calculation formulas for the horizontal magnetic field component and the vertical magnetic field component calculated based on the analytical solution are as follows: ; ; In the formula, and represent the horizontal magnetic field value and the vertical anomalous magnetic field value of the target area at the observation height, represents the vacuum permeability, ( x , z ) represents the coordinates of the observation point, represents the coordinates of each rectangular grid unit of the anomalous body model. and represent the horizontal and vertical magnetization intensities respectively.

[0038] Referring to Figure 2 and Figure 3 , from the morphological point of view, the coincidence degree of the two is very high. Referring to Figure 4 , it can be seen that the relative errors are all less than 7.0×10 -7 . Referring to Figure 5 and Figure 6 , it can be seen from the two figures that the morphological coincidence is very good. Referring to Figure 7 , it can be seen that the relative errors of the entire observation points are all less than 3.5×10 -7 . Generally speaking, it can be seen that the accuracy of the anomalous magnetic field value at the observation height obtained by the magnetic anomaly acceleration calculation method proposed in the present invention is very high.

[0039] On the other hand, the present invention provides a computer device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, the steps of the magnetic anomaly acceleration calculation method provided in any of the above embodiments are implemented. The computer device may be a server. 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 sample data. The network interface of the computer device is used to communicate with an external terminal through a network connection.

[0040] On the other hand, the present invention provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the magnetic anomaly acceleration calculation method provided in any of the above embodiments are implemented.

[0041] Those of ordinary skill in the art can understand that all or part of the processes of implementing the methods in the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it may include the processes of the embodiments of the above methods. Among them, any reference to a memory, storage, database, or other medium used in the various embodiments provided in the present application may include non-volatile and / or volatile memories. 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 an external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), 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.

[0042] Matters not described in detail in the present invention are well-known technologies.

[0043] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, 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, it should be considered as the scope described in this specification.

[0044] The above-described embodiments merely represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

[0045] The above is only the preferred embodiment of the present invention and is not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A magnetic anomaly acceleration calculation method, characterized in that, Including the following steps: Determine the target area of magnetic method geological exploration and the observation height of the target area, where the target area contains abnormal bodies; Construct a target area model including an abnormal body model, and perform grid division on the target area model including the abnormal body model; For the abnormal body model in the target area model after grid division, set the magnetic susceptibility of each grid cell in each layer of the abnormal body model, and calculate the magnetization intensity of each grid cell; Adopt a compressed storage strategy to calculate the contribution kernel function coefficients of each grid cell in each layer of the abnormal body model to the magnetic field at the observation height, and then obtain the kernel function coefficient matrix of each layer of the abnormal body model; Use the fast Fourier transform to realize the fast convolution of the kernel function coefficient matrix and the magnetization intensity, and obtain the abnormal magnetic field value at the observation height.

2. The magnetic anomaly acceleration calculation method according to claim 1, characterized in that The target area model containing the anomaly model is meshed using a rectangular grid, and the target area and the anomaly model within the target area are discretized into multiple rectangular grid cells; among them, the numbers of rectangular grid cells discretized along the x and z directions of the target area are respectively and respectively, and the numbers of rectangular grid cells discretized along the x and z directions of the anomaly model are respectively and respectively.

3. The magnetic anomaly acceleration calculation method according to claim 2, characterized in that Setting the magnetic susceptibility of each grid cell in each layer of the abnormal body model includes: setting the magnetic susceptibility value of each rectangular grid cell according to the geometric shape and magnetic susceptibility distribution of the abnormal body model, and the magnetic susceptibility of each rectangular grid cell is a constant value, and the magnetic susceptibility values of different rectangular grid cells are different, so as to describe a complex abnormal body model with any geometric shape and any magnetic susceptibility distribution.

4. The magnetic anomaly acceleration calculation method according to claim 2 or 3, characterized in that For the abnormal body model in the target area model after grid division, setting the magnetic susceptibility of each grid cell in each layer of the abnormal body model and calculating the magnetization intensity of each grid cell includes: According to the main geomagnetic field model of the earth, calculate the main geomagnetic field of each rectangular grid cell in each layer of the abnormal body model; Calculate the magnetization intensity of each rectangular grid cell according to the main geomagnetic field of each rectangular grid cell and the magnetic susceptibility of each rectangular grid cell.

5. The magnetic anomaly acceleration calculation method according to claim 4, wherein Adopting a compressed storage strategy to calculate the contribution kernel function coefficients of each grid cell in each layer of the abnormal body model to the magnetic field at the observation height, and then obtaining the kernel function coefficient matrix of each layer of the abnormal body model includes: For the set observation height , the contribution kernel function coefficients of each grid cell in the -layer anomaly body model to the magnetic field at the observation height are calculated by the following formula: ； ； Among them, and represent the horizontal and vertical direction contribution kernel function coefficients of the th grid cell in the th layer abnormal body model to the magnetic field at the observation height; , , , , represent the coordinates of the rectangular grid cell numbered ; ; ; ; represents the vacuum permeability, Δ x , Δ z respectively represent the intervals between the centers of the rectangular grid cells in the horizontal and vertical directions; Obtain the kernel function coefficient matrix of each layer of the abnormal body model based on the contribution kernel function coefficients of each grid cell in each layer of the abnormal body model to the magnetic field at the observation height.

6. The magnetic anomaly acceleration calculation method according to claim 5, characterized in that Using the fast Fourier transform to realize the fast convolution of the kernel function coefficient matrix and the magnetization intensity, and obtaining the abnormal magnetic field value at the observation height: ； ； In the formula, and represent the horizontal magnetic field value and the abnormal magnetic field value in the vertical direction of the target area at the observation height, and represent the Fourier transform pair, and respectively represent the horizontal and vertical kernel function coefficient matrices of the abnormal body model in the th layer, and respectively represent the horizontal magnetization intensity matrix composed of the horizontal magnetization intensities of each rectangular grid unit of the abnormal body model in the th layer and the vertical magnetization intensity matrix composed of the vertical magnetization intensities of each rectangular grid unit of the abnormal body model in the th layer; represents extracting the first elements of the matrix, that is, the abnormal magnetic field value at the observation height.

7. Magnetic anomaly acceleration calculation device, characterized in that, Including: The first module is used to determine the target area of magnetic method geological exploration and the observation height of the target area, where the target area contains abnormal bodies; The second module is used to construct a target area model including an abnormal body model, and perform grid division on the target area model including the abnormal body model; The third module is used to, for the abnormal body model in the target area model after grid division, set the magnetic susceptibility of each grid cell in each layer of the abnormal body model, and calculate the magnetization intensity of each grid cell; The fourth module is used to adopt a compressed storage strategy to calculate the contribution kernel function coefficients of each grid cell in each layer of the abnormal body model to the magnetic field at the observation height, and then obtain the kernel function coefficient matrix of each layer of the abnormal body model; The fifth module is used to use the fast Fourier transform to realize the fast convolution of the kernel function coefficient matrix and the magnetization intensity, and obtain the abnormal magnetic field value at the observation height.

8. The magnetic anomaly acceleration calculation device according to claim 7, wherein In the fourth module, a compressed storage strategy is adopted to calculate the contribution kernel function coefficients of each grid unit in the abnormal body models of each layer to the magnetic field at the observation height, and then the kernel function coefficient matrix of the abnormal body models of each layer is obtained, including: For the set observation height , the contribution kernel function coefficients of each grid cell in the -th layer anomaly body model to the magnetic field at the observation height are calculated by the following formula: ； ； Among them, the number of rectangular grid cells in which the target area is discretized along the x and z directions are respectively , ; the number of rectangular grid cells in which the anomaly body model is discretized along the x and z directions are respectively , ; and represent the horizontal direction contribution kernel function coefficient and the vertical direction contribution kernel function coefficient of the th grid cell in the th layer anomaly body model to the magnetic field at the observation height; , , , , represent the coordinates of the rectangular grid cell numbered ; represents the observation height at the rectangular grid cell coordinates numbered in the x direction; ; ; ; represents the vacuum permeability, Δ x , Δ z respectively represent the intervals between the centers of the rectangular grid cells in the horizontal direction and the vertical direction; The kernel function coefficient matrix of the abnormal body models of each layer is obtained based on the contribution kernel function coefficients of each grid unit in the abnormal body models of each layer to the magnetic field at the observation height.

9. A computer device, comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, the steps of the magnetic anomaly acceleration calculation method as described in claim 1 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, the steps of the magnetic anomaly acceleration calculation method as described in claim 1 are implemented.

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