Magnetic anomaly acceleration calculation method, device, equipment and medium

Abstract

The present invention relates to the field of magnetic prospecting technology and proposes a magnetic anomaly acceleration calculation method, device, equipment, and medium. The method comprises determining a target area and an observation height of the target area; constructing a target area model including an anomaly model, and gridding the target area model including the anomaly model; for the anomaly model in the gridded target area model, setting the magnetic susceptibility of each grid cell in each layer of the anomaly model and calculating the magnetization intensity of each grid cell; using a compressed storage strategy to calculate the kernel function coefficient of each grid cell in each layer of the anomaly model to the magnetic field at the observation height, thereby obtaining a kernel function coefficient matrix for each layer of the anomaly model; and using a fast Fourier transform to achieve fast convolution of the kernel function coefficient matrix with the magnetization intensity to obtain the anomalous magnetic field value at the observation height. The present invention significantly improves the efficiency of magnetic anomaly forward modeling while ensuring calculation accuracy and reducing memory consumption.

Description

Technical Field

[0001] The present invention mainly relates to the field of magnetic prospecting technology, in particular to a magnetic anomaly acceleration calculation method, device, equipment and medium. Background Art

[0002] Magnetic prospecting has been widely used to solve various geological problems due to its low cost, high efficiency, environmental friendliness, and wide coverage. In actual field observations, geological volumes with strike dimensions significantly larger than those perpendicular to their strike are often approximated by a two-dimensional volume extending infinitely along their strike. This significantly reduces computational memory and time, making inversion easier to perform.

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

[0004] Existing traditional numerical simulations of magnetic anomalies suffer from poor applicability to complex geometries with arbitrary geometric shapes and magnetic susceptibility distributions, as well as low computational efficiency. Therefore, it is necessary to develop an efficient, well-suited, two-dimensional magnetic field numerical simulation method for arbitrarily complex geological bodies, and to address the shortcomings of traditional methods. Summary of the Invention

[0005] In response to the technical problems existing in the prior art, the present invention proposes a magnetic anomaly acceleration calculation method, device, equipment and medium, which are highly applicable to complex geological bodies of arbitrary geometric shapes and arbitrary magnetic susceptibility distributions, and can significantly improve the efficiency and accuracy of magnetic anomaly forward calculations while ensuring the calculation accuracy of the magnetic field values ​​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:

[0007] In one aspect, the present invention provides a method for calculating magnetic anomaly acceleration, comprising the following steps:

[0008] determining a target area for magnetic geological exploration and an observation height of the target area, wherein the target area contains an anomaly;

[0009] Constructing a target area model including the abnormal body model, and performing grid division on the target area model including the abnormal body model;

[0010] For the anomaly model in the target area model after grid division, the magnetic susceptibility of each grid cell in each layer of the anomaly model is set, and the magnetization intensity of each grid cell is calculated;

[0011] The kernel function coefficients of the contribution of each grid cell in each layer of the anomaly model to the observed height magnetic field are calculated using a compression storage strategy, and then the kernel function coefficient matrix of each layer of the anomaly model is obtained.

[0012] Fast Fourier transform is used to realize fast convolution of the kernel function coefficient matrix and the magnetization intensity, so as to obtain the abnormal magnetic field value at the observation height.

[0013] Furthermore, the target area model including the abnormal body model is divided into grids using rectangular grids, and the target area and the abnormal body model in the target area are discretized into multiple rectangular grid units; wherein, the number of rectangular grid units discretized in the target area along the x and z directions is respectively 、 The number of rectangular grid units of the anomaly model along the x and z directions are respectively 、 indivual.

[0014] Furthermore, the magnetic susceptibility of each grid unit in each layer of the anomaly model is set, including: setting the magnetic susceptibility value of each rectangular grid unit according to the geometric shape and magnetic susceptibility distribution of the anomaly 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 anomaly model with arbitrary geometric shape and arbitrary magnetic susceptibility distribution.

[0015] Furthermore, for the anomaly model in the target area model after grid division, the magnetic susceptibility of each grid unit in each layer of the anomaly model is set, and the magnetization intensity of each grid unit is calculated, including:

[0016] According to the Earth's main magnetic field model, calculate the Earth's main magnetic field of each rectangular grid unit in each layer of the anomaly model;

[0017] The magnetization intensity of each rectangular grid cell is calculated according to the main magnetic field of the earth and the magnetic susceptibility of each rectangular grid cell.

[0018] Furthermore, a compression storage strategy is used to calculate the kernel function coefficient of each grid cell in each layer of the anomaly model to the observed height magnetic field, and then the kernel function coefficient matrix of each layer of the anomaly model is obtained, including:

[0019] For the set observation height , No. The kernel function coefficient of the contribution of each grid cell in the layer anomaly model to the observed height magnetic field is calculated by the following formula:

[0020] ;

[0021] ;

[0022] in, and Indicates the The first layer of the anomaly model Each grid cell contributes to the horizontal and vertical kernel function coefficients of the observed height magnetic field; , , , , Indicates the number The coordinates of the rectangular grid cells, ; ; ; represents the vacuum permeability, Δ x , Δ z Respectively represent the intervals between the centers of rectangular grid cells in the horizontal and vertical directions;

[0023] The kernel function coefficient matrix of each layer of anomaly model is obtained based on the kernel function coefficient of each grid cell in each layer of anomaly model to the observed height magnetic field.

[0024] Furthermore, the fast Fourier transform is used to realize the fast convolution of the kernel function coefficient matrix and the magnetization intensity to obtain the abnormal magnetic field value at the observation height:

[0025] ;

[0026] ;

[0027] Where, and Indicates the horizontal magnetic field value and vertical abnormal magnetic field value of the target area at the observation height. and represents the Fourier transform pair, and Respectively represent The kernel function coefficient matrix of the horizontal and vertical directions of the layer anomaly model, and Respectively represented by The horizontal magnetic intensity matrix composed of the horizontal magnetic intensity of each rectangular grid unit of the layer anomaly model and the horizontal magnetic intensity matrix composed of the first The vertical direction magnetization intensity matrix composed of the vertical direction magnetization intensity of each rectangular grid unit of the layer anomaly model; Indicates the front of the extracted matrix elements, namely the abnormal magnetic field value at the observation height.

[0028] In another aspect, a magnetic anomaly acceleration calculation device is provided, comprising:

[0029] The first module is used to determine a target area for magnetic geological exploration and an observation height of the target area, wherein the target area contains an anomaly;

[0030] The second module is used to construct a target area model including the abnormal body model and perform grid division on the target area model including the abnormal body model;

[0031] The third module is used to set the magnetic susceptibility of each grid cell in each layer of the anomaly model in the target area model after grid division, and calculate the magnetization intensity of each grid cell;

[0032] The fourth module is used to calculate the kernel function coefficient of the contribution of each grid cell in each layer of the anomaly model to the observed height magnetic field using a compression storage strategy, and then obtain the kernel function coefficient matrix of each layer of the anomaly model;

[0033] The fifth module is used to implement fast convolution of the kernel function coefficient matrix and the magnetization intensity by using fast Fourier transform to obtain the abnormal magnetic field value at the observation height.

[0034] Furthermore, in the fourth module, a compression storage strategy is used to calculate the kernel function coefficient of each grid cell in each layer of the anomaly model to the observed height magnetic field, and then the kernel function coefficient matrix of each layer of the anomaly model is obtained, including:

[0035] For the set observation height , No. The kernel function coefficient of the contribution of each grid cell in the layer anomaly model to the observed height magnetic field is calculated by the following formula:

[0036] ;

[0037] ;

[0038] Among them, the number of discrete rectangular grid units in the target area along the x and z directions are 、 The number of rectangular grid units of the anomaly model along the x and z directions are respectively 、 indivual, and Indicates the The first layer of the anomaly model Each grid cell contributes to the horizontal and vertical kernel function coefficients of the observed height magnetic field; , , , , Indicates the number The coordinates of the rectangular grid cells, Indicates the observation altitude The numbers in the x direction are The coordinates of the rectangular grid cells, ; ; ; represents the vacuum permeability, Δ x , Δ z Respectively represent the intervals between the centers of rectangular grid cells in the horizontal and vertical directions;

[0039] The kernel function coefficient matrix of each layer of anomaly model is obtained based on the kernel function coefficient of each grid cell in each layer of anomaly model to the observed height magnetic field.

[0040] On the other hand, the present invention provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above-mentioned magnetic anomaly acceleration calculation method when executing the computer program.

[0041] On the other hand, the present invention provides a computer-readable storage medium having a computer program stored thereon, which implements the steps of the above-mentioned magnetic anomaly acceleration calculation method when executed by a processor.

[0042] On the other hand, the present invention provides a computer program product, which is stored on a computer-readable storage medium and includes computer instructions, which, when executed by a processor, enable a computer device to implement the steps of the above-mentioned magnetic anomaly acceleration calculation method.

[0043] Compared with the prior art, the technical effects of the present invention are:

[0044] This method uses an analytical method to calculate the kernel function coefficient matrix, which can effectively ensure the calculation accuracy.

[0045] This method employs a compressed storage strategy, requiring only the calculation of kernel coefficients associated with the grid cells in the anomaly model. This reduces the calculation and storage of kernel coefficient matrices for the corresponding layers, reducing memory requirements and computational complexity. This improves computational efficiency while maintaining the accuracy of the analytical formula, effectively increasing computational speed without sacrificing accuracy. This method is well-suited for calculating complex anomalies with arbitrary geometric shapes and magnetic susceptibility distributions. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0047] Figure 1 This is a flow chart of a magnetic anomaly acceleration calculation method proposed in one embodiment;

[0048] Figure 2 This is a result diagram of the horizontal component of the ground magnetic field calculated based on the magnetic anomaly acceleration calculation method proposed by the present invention in one embodiment;

[0049] Figure 3 This is a result diagram of the horizontal component of the ground magnetic field directly calculated based on the analytical solution in one embodiment;

[0050] Figure 4 A diagram showing the relative error between the horizontal component of the magnetic field obtained by the magnetic anomaly acceleration calculation method proposed by the present invention and the calculation based on the analytical solution in one embodiment;

[0051] Figure 5 This is a result diagram of the vertical component of the ground magnetic field calculated based on the magnetic anomaly acceleration calculation method proposed by the present invention in one embodiment;

[0052] Figure 6 This is a result diagram of the vertical component of the ground magnetic field obtained by directly calculating based on the analytical solution in one embodiment;

[0053] Figure 7 This is a diagram showing the relative error between the vertical component of the magnetic field obtained by the magnetic anomaly acceleration calculation method proposed by the present invention and the calculation based on the analytical solution in one embodiment. DETAILED DESCRIPTION

[0054] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0055] One embodiment provides a magnetic field acceleration forward modeling method, comprising:

[0056] determining a target area for magnetic geological exploration and an observation height of the target area, wherein the target area contains an anomaly;

[0057] Constructing a target area model including the abnormal body model, and performing grid division on the target area model including the abnormal body model;

[0058] For the anomaly model in the target area model after grid division, the magnetic susceptibility of each grid cell in each layer of the anomaly model is set, and the magnetization intensity of each grid cell is calculated;

[0059] The kernel function coefficients of the contribution of each grid cell in each layer of the anomaly model to the observed height magnetic field are calculated using a compression storage strategy, and then the kernel function coefficient matrix of each layer of the anomaly model is obtained.

[0060] Fast Fourier transform is used to realize fast convolution of the kernel function coefficient matrix and the magnetization intensity, so as to obtain the abnormal magnetic field value at the observation height.

[0061] The anomaly body described in the present invention can be a complex geological body with any geometric shape and any magnetic susceptibility distribution.

[0062] The target area containing the abnormal body model is constructed according to the size of the abnormal body, and the corresponding target area model containing the abnormal body model is constructed according to the target area and the size of the abnormal body. The target area model containing the abnormal body model is meshed using a rectangular grid, and the target area and the abnormal body model in the target area are discretized into multiple rectangular grid units, where the number of rectangular grid units discretized in the target area along the x and z directions is respectively 、 The number of rectangular grid units of the anomaly model along the x and z directions are respectively 、 indivual.

[0063] Next, the magnetic susceptibility of each grid cell in each layer of the anomaly model is set, including: setting the magnetic susceptibility value of each rectangular grid cell according to the geometric shape and magnetic susceptibility distribution of the anomaly 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 complex anomaly models with arbitrary geometric shapes and arbitrary magnetic susceptibility distributions.

[0064] The present invention sets the magnetic susceptibility of each grid unit in each layer of the abnormal body model for the abnormal body model in the target area model after grid division, and calculates the magnetization intensity of each grid unit according to the magnetic susceptibility of each grid unit in each layer of the abnormal body model, including the following steps:

[0065] According to the Earth's main magnetic field model, calculate the Earth's main magnetic field of each rectangular grid unit in each layer of the anomaly model ;

[0066] ;

[0067] Indicates the abnormal body model numbered The coordinates of the rectangular grid cells, Indicates the The number of the layer anomaly model is The Earth's main magnetic field in a rectangular grid cell. and Respectively represent The number of the layer anomaly model is The Earth's main magnetic field of the rectangular grid cell x (horizontally), z (vertical) component, Indicates the local magnetic inclination.

[0068] The magnetic intensity at each rectangular grid cell is calculated based on the Earth's main magnetic field and the magnetic susceptibility of each rectangular grid cell in each layer of the anomaly model. ;

[0069] ;

[0070] Where, Indicates the abnormal body model numbered The magnetic susceptibility value of the rectangular grid cell; 、 Respectively represent The number of the layer anomaly model is Rectangular grid cells The magnetization intensity x (horizontally), z (vertical) component.

[0071] No. The horizontal magnetic intensity matrix composed of the horizontal magnetic intensity of each rectangular grid unit in the layer anomaly model , No. The vertical direction magnetization intensity matrix composed of the vertical direction magnetization intensity of each rectangular grid unit in the layer anomaly model .

[0072] The present invention adopts a compression storage strategy to calculate the kernel function coefficient of each grid cell in each layer of the anomaly model to the observed height magnetic field, and then obtains the kernel function coefficient matrix of each layer of the anomaly model, including:

[0073] For the set observation height , No. The kernel function coefficient of the contribution of each grid cell in the layer anomaly model to the observed height magnetic field is calculated by the following formula:

[0074] ;

[0075] ;

[0076] in, and Respectively represent The first layer of the anomaly model Each grid cell contributes to the horizontal and vertical kernel function coefficients of the observed height magnetic field; , , , , Indicates the number The coordinates of the rectangular grid cells, Indicates the observation altitude The numbers in the x direction are The coordinates of the rectangular grid cells, ; ; ; represents the vacuum permeability, Δ x , Δ z The above formula reduces the calculation of the inverse tangent and cotangent functions, improving the computational efficiency while ensuring the accuracy of the analytical formula.

[0077] The kernel function coefficient matrix of each layer of anomaly model is obtained based on the kernel function coefficient of each grid cell in each layer of anomaly model to the observed height magnetic field.

[0078] The magnetic susceptibility of each discrete grid unit is a constant, so the integral of each grid unit can be used to derive its analytical formula, with high calculation accuracy. n When calculating the contribution value of the layer anomaly model to the observed height magnetic field, it is only necessary to calculate the contribution kernel function coefficient of each grid unit in the anomaly model to the observed height magnetic field. This means that the size of the kernel function coefficient matrix of each layer anomaly model can be the same or different, which is related to the discrete situation of the anomaly model. When a layer of anomaly model is divided into fewer grid units, it means that the contribution kernel function coefficient that needs to be calculated will also be reduced, which can effectively improve the calculation speed.

[0079] Finally, the fast Fourier transform is used to realize the fast convolution of the kernel function coefficient matrix and the magnetization intensity to obtain the abnormal magnetic field value at the observation height:

[0080] ;

[0081] ;

[0082] Where, and Indicates the horizontal magnetic field value and vertical abnormal magnetic field value of the target area at the observation height. and represents the Fourier transform pair, and Respectively represent The kernel function coefficient matrix of the horizontal and vertical directions of the layer anomaly model, and Respectively represented by The horizontal magnetic intensity matrix composed of the horizontal magnetic intensity of each rectangular grid unit of the layer anomaly model and the horizontal magnetic intensity matrix composed of the first The vertical direction magnetization intensity matrix composed of the vertical direction magnetization intensity of each rectangular grid unit of the layer anomaly model; Indicates the front of the extracted matrix elements, namely the abnormal magnetic field value at the observation height.

[0083] In one embodiment, a magnetic anomaly acceleration calculation device is provided, comprising:

[0084] The first module is used to determine a target area for magnetic geological exploration and an observation height of the target area, wherein the target area contains an anomaly;

[0085] The second module is used to construct a target area model including the abnormal body model and perform grid division on the target area model including the abnormal body model;

[0086] The third module is used to set the magnetic susceptibility of each grid cell in each layer of the anomaly model in the target area model after grid division, and calculate the magnetization intensity of each grid cell;

[0087] The fourth module is used to calculate the kernel function coefficient of the contribution of each grid cell in each layer of the anomaly model to the observed height magnetic field using a compression storage strategy, and then obtain the kernel function coefficient matrix of each layer of the anomaly model;

[0088] The fifth module is used to implement fast convolution of the kernel function coefficient matrix and the magnetization intensity by using fast Fourier transform to obtain the abnormal magnetic field value at the observation height.

[0089] The method of the present invention is verified by a specific simulation example below.

[0090] In this example, the target area has a two-dimensional model with a regular rectangular cross section, and the calculation area range is: x The direction is from -1000 m to 1000 m, the z direction is from 0 m to 1000 m (z axis is vertically downward and positive), 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 anomaly with a rectangular cross section is: x The direction is from -500m to 500m, the z direction is from 100m to 400m, 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 56000nT, 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 profile are calculated by the method of the present invention.

[0091] 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, main frequency is 3.2 GHz, and running memory is 8.00 GB. Figures 2 to 7 , Figure 2 This is a result diagram of the horizontal component of the ground magnetic field calculated based on the magnetic anomaly acceleration calculation method proposed in the present invention; Figure 3 This is the result diagram of the horizontal component of the ground magnetic field calculated directly based on the analytical solution; Figure 4 This is a diagram showing the relative error between the horizontal component of the magnetic field obtained by the magnetic anomaly acceleration calculation method proposed in the present invention and the calculation based on the analytical solution; Figure 5 This is a result diagram of the vertical component of the ground magnetic field calculated based on the magnetic anomaly acceleration calculation method proposed in the present invention; Figure 6 This is the result diagram of the vertical component of the ground magnetic field calculated directly based on the analytical solution; Figure 7 This is a diagram showing the relative error results of the vertical component of the magnetic field obtained by the magnetic anomaly acceleration calculation method proposed in this invention and the calculation based on the analytical solution.

[0092] The horizontal component and vertical component of the magnetic field calculated based on the analytical solution are calculated as follows:

[0093] ;

[0094] ;

[0095] Where, and Indicates the horizontal magnetic field value and vertical abnormal 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 anomaly model. and represent the horizontal and vertical magnetization intensities, respectively.

[0096] Reference Figure 2 and Figure 3 From the morphological point of view, the two are very consistent. Figure 4 , it can be seen that the relative errors are less than 7.0×10 -7 . Reference Figure 5 and Figure 6 , it can be seen from the two pictures that the morphology is well matched. Figure 7 , it can be seen that the relative error of the entire observation point is less than 3.5×10 -7 Overall, it can be seen that the accuracy of the abnormal magnetic field value at the observation height obtained by the magnetic anomaly acceleration calculation method proposed in the present invention is very high.

[0097] On the other hand, the present invention provides a computer device comprising a memory and a processor, wherein 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 comprises a processor, a memory, a network interface, and a database connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device comprises 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 via a network connection.

[0098] On the other hand, the present invention provides a computer-readable storage medium having a computer program stored thereon. 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.

[0099] Those skilled in the art will understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the 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 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 DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0100] Matters not covered by the present invention are known technologies.

[0101] The technical features of the above embodiments can be combined arbitrarily. In order 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.

[0102] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and such modifications and improvements are intended to fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

[0103] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A magnetic anomaly acceleration calculation method, characterized in that: The following steps are involved: determining a target area for magnetic geological exploration and an observation height of the target area, wherein the target area contains an anomaly; Constructing a target area model including the abnormal body model, and performing grid division on the target area model including the abnormal body model; For the anomaly model in the target area model after grid division, the magnetic susceptibility of each grid cell in each layer of the anomaly model is set, and the magnetization intensity of each grid cell is calculated; The kernel function coefficients of the contribution of each grid cell in each layer of the anomaly model to the observed height magnetic field are calculated using a compression storage strategy, and then the kernel function coefficient matrix of each layer of the anomaly model is obtained; including: For a given observation height z0, the kernel function coefficient of the contribution of each grid cell in the n-th layer anomaly model to the magnetic field at the observation height is calculated by the following formula: Among them, the number of discrete rectangular grid units in the target area along the x and z directions is N respectively. x 、N z The number of rectangular grid units of the anomaly model along the x and z directions is N′ respectively. x 、N z indivual, and represents the horizontal and vertical contribution kernel function coefficients of the ith grid cell in the nth layer anomaly model to the observed height magnetic field; X1 = x i -x′ l -0.5Δx,X2=x i -x' l +0.5Δx, Z1=z0-z′ n -0.5Δz, Z2=z0-z′ n +0.5Δz,(x′ l , z′ n ) represents the coordinates of the rectangular grid unit numbered (l, n), (x i , z0) represents the coordinates of the rectangular grid unit numbered (i) in the x direction at the observation height z0, i = 1, 2, ... N x ; l = 1, 2, ... N ' x ; n = 1, 2, ... N z ; μ0 represents the vacuum magnetic permeability, Δx and Δz represent the intervals between the centers of the rectangular grid units in the horizontal and vertical directions, respectively; Based on the kernel function coefficients of the contribution of each grid cell in each layer of the anomaly model to the observed height magnetic field, the kernel function coefficient matrix of each layer of the anomaly model is obtained; Fast Fourier transform is used to realize fast convolution of the kernel function coefficient matrix and the magnetization intensity, so as to 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 including the anomaly model is divided into grids using rectangular grids, and the target area and the anomaly model in the target area are discretized into multiple rectangular grid units; the number of rectangular grid units discretized in the target area along the x and z directions is N respectively. x 、N z The number of rectangular grid units of the anomaly model along the x and z directions is N′ respectively. x 、N z indivual.

3. The magnetic anomaly acceleration calculation method according to claim 2, characterized in that: The magnetic susceptibility of each grid cell in each layer of the anomaly model is set, including: setting the magnetic susceptibility value of each rectangular grid cell according to the geometric shape and magnetic susceptibility distribution of the anomaly 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 anomaly model with arbitrary geometric shape and arbitrary magnetic susceptibility distribution.

4. The magnetic anomaly acceleration calculation method according to claim 2 or 3, characterized in that: For the anomaly model in the target area model after grid division, set the magnetic susceptibility of each grid cell in each layer of the anomaly model and calculate the magnetization intensity of each grid cell, including: According to the Earth's main magnetic field model, calculate the Earth's main magnetic field of each rectangular grid unit in each layer of the anomaly model; The magnetization intensity of each rectangular grid cell is calculated according to the main magnetic field of the earth and the magnetic susceptibility of each rectangular grid cell.

5. The magnetic anomaly acceleration calculation method according to claim 1, characterized in that: Fast Fourier transform is used to realize the fast convolution of the kernel function coefficient matrix and the magnetization intensity to obtain the abnormal magnetic field value at the observation height: Where B x and B z Indicates the horizontal magnetic field value and vertical abnormal magnetic field value of the target area at the observation height, F and F -1 represents the Fourier transform pair, and Respectively represent the kernel function coefficient matrices in the horizontal and vertical directions of the n-th layer anomaly model, and They represent the horizontal magnetization matrix composed of the horizontal magnetization of each rectangular grid unit of the n-th layer anomaly model and the vertical magnetization matrix composed of the vertical magnetization of each rectangular grid unit of the n-th layer anomaly model respectively; Indicates extracting the first N of the matrix x elements, namely the abnormal magnetic field value at the observation height.

6. A magnetic anomaly acceleration calculation device, characterized in that: include: The first module is used to determine a target area for magnetic geological exploration and an observation height of the target area, wherein the target area contains an anomaly; The second module is used to construct a target area model including the abnormal body model and perform grid division on the target area model including the abnormal body model; The third module is used to set the magnetic susceptibility of each grid cell in each layer of the anomaly model in the target area model after grid division, and calculate the magnetization intensity of each grid cell; The fourth module is used to calculate the kernel function coefficient of each grid cell in each layer of the anomaly model to the observed height magnetic field using a compression storage strategy, and then obtain the kernel function coefficient matrix of each layer of the anomaly model; including: For a given observation height z0, the kernel function coefficient of the contribution of each grid cell in the n-th layer anomaly model to the magnetic field at the observation height is calculated by the following formula: Among them, the number of discrete rectangular grid units in the target area along the x and z directions is N respectively. x 、N z The number of rectangular grid units of the anomaly model along the x and z directions is N′ respectively. x 、N z indivual, and represents the horizontal and vertical contribution kernel function coefficients of the ith grid cell in the nth layer anomaly model to the observed height magnetic field; X1 = x i -x′ l -0.5Δx,X2=x i -x′ l +0.5Δx, Z1=z0-z′ n -0.5Δz, Z2=z0-z′ n +0.5Δz,(x′ l , z′ n ) represents the coordinates of the rectangular grid unit numbered (l, n), (x i , z0) represents the coordinates of the rectangular grid unit numbered (i) in the x direction at the observation height z0, i = 1, 2, ... N x ; l = 1, 2, ... N ' x ; n = 1, 2, ... N z ; μ0 represents the vacuum magnetic permeability, Δx and Δz represent the intervals between the centers of the rectangular grid units in the horizontal and vertical directions, respectively; Based on the kernel function coefficients of the contribution of each grid cell in each layer of the anomaly model to the observed height magnetic field, the kernel function coefficient matrix of each layer of the anomaly model is obtained; The fifth module is used to implement fast convolution of the kernel function coefficient matrix and the magnetization intensity by using fast Fourier transform to obtain the abnormal magnetic field value at the observation height.

7. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the magnetic anomaly acceleration calculation method as claimed in claim 1 are implemented.

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

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