CN-122018011-A - Magnetic susceptibility random distribution ferromagnetic body aviation magnetic field iteration method and exploration system

CN122018011ACN 122018011 ACN122018011 ACN 122018011ACN-122018011-A

Abstract

The application relates to a method for iterating a ferromagnetic aviation magnetic field with arbitrarily distributed magnetic susceptibility and an exploration system. The method comprises the steps of respectively constructing a field source grid, an underground observation grid and an aviation observation grid, constructing an arctangent function and a logarithmic function related to cuboid units of the field source and the underground observation points according to the field source grid and the underground observation grid, determining a kernel function coefficient of each cuboid of the underground observation grid according to the arctangent function and the logarithmic function and a three-dimensional difference operator, constructing a kernel function coefficient compression matrix through three-dimensional discrete convolution to rapidly calculate an underground observation grid magnetic field, and constructing a two-dimensional compression kernel matrix to rapidly calculate three components of the aviation observation grid magnetic field in a vertical two-dimensional convolution accumulation mode. The method has the advantages of high flexibility, high calculation precision and high efficiency, solves the problem of low iteration efficiency of the existing ferromagnetic body model method, and can meet the requirements of ferromagnetic body aviation exploration.

Inventors

WANG XULONG
CHENG MING
MAN KAIFENG
Ren Wangqi
REN KE
LI NA

Assignees

空天信息大学(筹)

Dates

Publication Date: 20260512
Application Date: 20251217

Claims (10)

1. An iteration method of a ferromagnetic body aeromagnetic field with arbitrarily distributed magnetic susceptibility is characterized by comprising the following steps: Acquiring exploration target area information and ferromagnetic geologic body distribution information, uniformly dispersing a field source area and an underground observation area into a plurality of cuboid units along the directions of x, y and z respectively, and correspondingly obtaining a field source grid and an underground observation grid; acquiring aviation observation height information, uniformly dispersing an aviation observation area with a corresponding height into a plurality of rectangular units along the x-y direction, and obtaining an aviation observation grid; Assigning the magnetic susceptibility of each cuboid unit of the field source grid, establishing a complex ferromagnetic body model with any magnetic susceptibility distribution, and obtaining initial effective magnetization information according to the complex ferromagnetic body model; Constructing an arctangent function and a logarithmic function related to field source cuboid units and underground observation point cuboid units according to the field source grids and the underground observation grids, and determining a kernel function coefficient of each cuboid of the underground observation grids according to the arctangent function, the logarithmic function and a three-dimensional difference operator, wherein the value of the kernel function coefficient can be determined by the number of the field source cuboid units, the number of the underground observation grid cuboid units and the grid size; Obtaining an expression of three components of an underground observation grid magnetic field through three-dimensional discrete convolution, respectively constructing a three-dimensional compression core matrix and a three-dimensional effective magnetization matrix according to the core function coefficient and the initial effective magnetization information, further rapidly calculating the three components of the underground observation grid magnetic field to obtain underground magnetic field information, carrying out iterative judgment, and further obtaining effective magnetization information of the last iteration; and obtaining an expression of three components of the aviation observation grid magnetic field in a vertical two-dimensional convolution accumulation mode, respectively constructing a two-dimensional compression nuclear matrix and a two-dimensional effective magnetization matrix according to the nuclear function coefficient and the effective magnetization information of the last iteration, further rapidly calculating the three components of the aviation observation grid magnetic field, and outputting aviation magnetic field information.
2. The method of claim 1, wherein constructing an arctangent function and a logarithmic function associated with field source and subsurface observation point cuboid cells from the field source grid and the subsurface observation grid comprises: constructing an arctangent function related to a field source and an underground observation point cuboid unit according to the field source grid and the underground observation grid, wherein the arctangent function is as follows: the construction of a logarithmic function related to a field source and a cuboid unit of an underground observation point is as follows: Wherein, the 、、 The constructed arctangent function is represented as such, Representing an arctangent operation; 、、 the constructed logarithmic function is represented by a graph, Representing a logarithmic operation; , , , , , , , ; the representation number is The center coordinates of the rectangular parallelepiped elements of the subsurface observation grid, , , , 、、 A grid number in x, y and z directions for the subsurface observation grid; the representation number is The center coordinates of the field source grid cuboid cells, , , , 、、 The grid number of the field source grid in the x, y and z directions; , And The dimensions of the discrete cuboid units in the x, y and z directions are indicated, respectively.
3. The method of claim 2, wherein determining the kernel function coefficients for each cuboid of the subsurface observation grid from the arctangent function and the logarithmic function, and a three-dimensional difference operator, comprises: and determining the kernel function coefficient of each cuboid of the underground observation grid according to the arctangent function, the logarithmic function and the three-dimensional difference operator as follows: Wherein, the 、、、、、 The kernel function coefficients representing each of the subsurface observation grid cuboid cells, Representing a three-dimensional difference operator, The circumference ratio is indicated.
4. A method according to claim 3, wherein the expression of three components of the magnetic field of the underground observation grid is obtained by three-dimensional discrete convolution, a three-dimensional compressed core matrix and a three-dimensional effective magnetization matrix are respectively constructed according to the kernel function coefficient and the initial effective magnetization information, and further the three components of the magnetic field of the underground observation grid are rapidly calculated, and the method comprises the following steps: The expression for obtaining the three components of the underground observation grid magnetic field through three-dimensional discrete convolution is as follows: Wherein, the 、、 Is numbered as Is used for observing abnormal magnetic field of cuboid unit of grid underground Is used for the three-component(s) of (c), 、、 Is the effective magnetization three component; according to the kernel function coefficient the three-dimensional compression core matrix is constructed as follows: Wherein, the The upper mark represents the field source cuboid unit number, and the lower mark represents the underground observation point cuboid unit number; Constructing a three-dimensional effective magnetization matrix according to the initial effective magnetization information, wherein the three-dimensional effective magnetization matrix comprises the following steps: Wherein, the The superscript indicates the field source cuboid unit number; And rapidly calculating three components of the underground observation grid magnetic field: Wherein, the And Respectively representing the three-dimensional positive and negative Fourier transforms, Representing the front of the extraction matrix The elements.
5. The method of claim 4, wherein obtaining the information of the subsurface magnetic field and performing iterative determination to obtain the effective magnetization information of the last iteration comprises: obtaining underground magnetic field information and carrying out iteration judgment, wherein the iteration formula is as follows: Wherein, the As the value of the background magnetic field, Is the first The magnetic outlier of the second forward run, Is iterated by a tight operator The total magnetic field value of the second forward pass, Is an iteration The total magnetic field value of the second forward pass, Is the magnetic susceptibility of the magnetic body, 、 Is an intermediate variable; the termination conditions for the iteration convergence are: If it is Reaching the convergence condition, the effective magnetization of the last iteration is output Otherwise the effective magnetization is updated to be recycled.
6. The method of claim 5, wherein the obtaining the expression of the three components of the aviation observation grid magnetic field by means of vertical two-dimensional convolution accumulation, respectively constructing a two-dimensional compressed kernel matrix and a two-dimensional effective magnetization matrix according to the kernel function coefficient and the effective magnetization information of the last iteration, and further performing fast calculation on the three components of the aviation observation grid magnetic field, comprises: the expression for obtaining three components of the aviation observation grid magnetic field through a vertical two-dimensional convolution accumulation mode is as follows: Wherein, the The representation being numbered as altitude Numbered above as Central coordinates of rectangular cells of the aeronautical observation grid; 、、 is of aviation altitude Numbered above as Rectangular cell anomaly magnetic field of aeronautical observation grid Three components of (3); according to the kernel function coefficient the two-dimensional compression kernel matrix is constructed as follows: Wherein, the The upper marks of matrix elements represent field source cuboid unit numbers, and the lower marks represent underground observation point cuboid unit numbers; constructing a two-dimensional effective magnetization matrix according to the effective magnetization information of the last iteration, wherein the two-dimensional effective magnetization matrix comprises the following steps: Wherein, the 、、 Respectively represent the dimension as 、、 Is a two-dimensional zero matrix of (2); The three components of the aviation observation grid magnetic field are rapidly calculated to obtain the number of layers of a given field source Is a magnetic field of an aeronautical observation grid: Wherein, the And Respectively representing the two-dimensional positive and negative fourier transforms, Representing the front of the extraction matrix Line sum Column elements.
7. The method of claim 6, wherein the three components of the aviation observation grid magnetic field are rapidly calculated to obtain a given field source layer number After the aeronautical observation grid magnetic field, further comprising: obtaining the aviation observation total magnetic field at a given observation height in an accumulation mode: Will be As output aero magnetic field information.
8. A magnetic susceptibility random distribution ferromagnetic aero-magnetic field prospecting system, the system comprising: The system comprises a grid setting module, a field source grid, an underground observation grid, an aviation observation height information acquisition module, a grid setting module and a control module, wherein the grid setting module is used for acquiring exploration target area information and ferromagnetic geologic body distribution information, uniformly dispersing a field source area and an underground observation area into a plurality of cuboid units along the x, y and z directions respectively, and correspondingly acquiring a field source grid and an underground observation grid; The complex ferromagnetic body model construction module is used for assigning the magnetic susceptibility of each cuboid unit of the field source grid, establishing a complex ferromagnetic body model with any magnetic susceptibility distribution, and obtaining initial effective magnetization information according to the complex ferromagnetic body model; The kernel function coefficient determining module is used for constructing an arctangent function and a logarithmic function related to cuboid units of the field source and the underground observation point according to the field source grid and the underground observation grid, and determining the kernel function coefficient of each cuboid of the underground observation grid according to the arctangent function and the logarithmic function and a three-dimensional difference operator; the value of the kernel function coefficient can be determined by the grid cuboid unit number of the field source, the grid cuboid unit number of the underground observation grid and the grid size; The three-dimensional convolution module is used for obtaining an expression of three components of the underground observation grid magnetic field through three-dimensional discrete convolution, respectively constructing a three-dimensional compression core matrix and a three-dimensional effective magnetization matrix according to the core function coefficient and the initial effective magnetization information, further rapidly calculating the three components of the underground observation grid magnetic field to obtain underground magnetic field information, carrying out iterative judgment, and further obtaining effective magnetization information of the last iteration; The two-dimensional convolution module is used for obtaining an expression of three components of the aviation observation grid magnetic field in a vertical two-dimensional convolution accumulation mode, respectively constructing a two-dimensional compression kernel matrix and a two-dimensional effective magnetization intensity matrix according to the kernel function coefficient and the effective magnetization intensity information of the last iteration, further rapidly calculating the three components of the aviation observation grid magnetic field and outputting aviation magnetic field information.
9. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor implements the steps of the method of any of claims 1 to 7 when the computer program is executed.
10. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the steps of the method of any of claims 1 to 7.

Description

Magnetic susceptibility random distribution ferromagnetic body aviation magnetic field iteration method and exploration system Technical Field The application relates to the technical field of aviation geophysical exploration, in particular to an iteration method and an exploration system for a ferromagnetic aviation magnetic field with arbitrarily distributed magnetic susceptibility. Background The magnetic method exploration is a geophysical exploration means with the most mature development, particularly, with the development of instrument technology, the aviation magnetic measurement instrument is mature gradually, and compared with the ground magnetic measurement, the aviation magnetic measurement has the remarkable characteristics of high efficiency, low cost, no need of approaching an exploration area by ground personnel and the like, and is very suitable for mineral resource exploration in vast western regions of China. At the same time, the need to develop fast forward methods and inversion imaging software that match large scale aerial magnetometer data is becoming increasingly urgent. Furthermore, in magnetic prospecting, the effect of demagnetizing is usually ignored, the magnetization direction is considered to be parallel to the local geomagnetic field direction, and the effective magnetization is the product of the local geomagnetic field and the magnetic susceptibility, which assumption is effective at a magnetic susceptibility of less than 0.1 SI. However, when the magnetic susceptibility increases, not only the external magnetic field causes magnetization of the magnetic body but also the magnetic field generated inside the magnetic body and other magnetic bodies around the magnetic body, a phenomenon commonly called "demagnetizing effect". The demagnetizing effect can change the amplitude and direction of the external geomagnetic field, resulting in distortion of the magnetic anomaly. Especially when the magnetic susceptibility is greater than 1.0 SI, the influence of demagnetization and no demagnetization effect is considered to be 30%, which presents a great challenge for magnetic data processing and interpretation work. The existing numerical simulation method based on the strong magnetic body aviation magnetic anomaly exploration has the problems of large occupied memory, low efficiency and the like. Disclosure of Invention Accordingly, in order to solve the above-mentioned problems, it is necessary to provide a method, a system, a computer device, and a storage medium for performing an iteration of a ferromagnetic-based aeromagnetic field with arbitrary distribution of magnetic susceptibility, which can reduce the occupation of a numerically-simulated memory and improve the calculation efficiency. An iterative method for a ferromagnetic body aeromagnetic field with arbitrarily distributed magnetic susceptibility, the method comprising: Acquiring exploration target area information and ferromagnetic geologic body distribution information, uniformly dispersing a field source area and an underground observation area into a plurality of cuboid units along the directions of x, y and z respectively, and correspondingly obtaining a field source grid and an underground observation grid; acquiring aviation observation height information, uniformly dispersing an aviation observation area with a corresponding height into a plurality of rectangular units along the x-y direction, and obtaining an aviation observation grid; Assigning the magnetic susceptibility of each cuboid unit of the field source grid, establishing a complex ferromagnetic body model with any magnetic susceptibility distribution, and obtaining initial effective magnetization information according to the complex ferromagnetic body model; Constructing an arctangent function and a logarithmic function related to field source cuboid units and underground observation point cuboid units according to the field source grids and the underground observation grids, and determining a kernel function coefficient of each cuboid of the underground observation grids according to the arctangent function, the logarithmic function and a three-dimensional difference operator, wherein the value of the kernel function coefficient can be determined by the number of the field source cuboid units, the number of the underground observation grid cuboid units and the grid size; Obtaining an expression of three components of an underground observation grid magnetic field through three-dimensional discrete convolution, respectively constructing a three-dimensional compression core matrix and a three-dimensional effective magnetization matrix according to the core function coefficient and the initial effective magnetization information, further rapidly calculating the three components of the underground observation grid magnetic field to obtain underground magnetic field information, carrying out iterative judgment, and further obtaining effective magnetizat