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CN-122018012-A - High-efficiency calculation method for aeromagnetic anomaly of ferromagnetic body in consideration of demagnetization influence

CN122018012ACN 122018012 ACN122018012 ACN 122018012ACN-122018012-A

Abstract

The application relates to a high-efficiency calculation method, a device, computer equipment and a storage medium for aeromagnetic anomalies of a ferromagnetic body, which take demagnetization influence into consideration. The method comprises the steps of respectively establishing discrete grids of a field source region and an underground observation region to correspondingly obtain the field source grid and the observation grid. And constructing an arctangent function and a logarithmic function related to cuboid units of the field source and the observation point according to the field source grid and the observation grid, and determining a unit integral coefficient of each cuboid of the observation grid according to the arctangent function and the logarithmic function and the three-dimensional difference operator. And calculating three components of the abnormal magnetic field of the observation grid through two-dimensional compression discrete convolution, and then solving the abnormal value of the aeromagnetic of the ferromagnetic body through a cyclic iteration 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

Assignees

  • 空天信息大学(筹)

Dates

Publication Date
20260512
Application Date
20251217

Claims (10)

  1. 1. An efficient calculation method for aeromagnetic anomalies of a ferromagnetic body taking into account the influence of demagnetization, characterized in that it comprises: According to the information of the exploration target area and the distribution information of the ferromagnetic geologic body, a field source area and an underground observation area are respectively scattered into a plurality of cuboid units along the directions of x, y and z, and a field source grid and an observation grid are correspondingly obtained; assigning the magnetic susceptibility of each cuboid unit of the field source grid, and establishing a complex ferromagnetic body model with arbitrary magnetic susceptibility distribution; Constructing an arc tangent function and a logarithmic function related to field source and observation point cuboid units according to the field source grids and the observation grids, and determining a unit integral coefficient of each cuboid of the observation grids according to the arc tangent function, the logarithmic function and a three-dimensional difference operator, wherein the value of the unit integral coefficient can be determined by the number of the field source cuboid units, the number of the observation grid cuboid units and the grid size; Determining an expression of three components of an observed grid abnormal magnetic field in a mode of accumulating a plurality of vertical two-dimensional discrete convolutions according to the unit integral coefficient, given earth main magnetic field model information and the random susceptibility distribution complex ferromagnetic body model; and calculating three components of the abnormal magnetic field of the observation grid through two-dimensional compression discrete convolution, and further solving the abnormal value of the aeromagnetic of the ferromagnetic body through a cyclic iteration mode.
  2. 2. The method of claim 1, wherein constructing an arctangent function and a logarithmic function associated with field source and observation point cuboid units from the field source grid and the observation grid comprises: Constructing an arctangent function related to a field source and observation point cuboid unit according to the field source grid and the observation grid, wherein the arctangent function comprises the following steps: The logarithmic function related to the field source and observation point cuboid units is constructed 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 Cuboid of observation grid of (a) the center coordinates of the cell are used to determine, The representation number is The center coordinates of the field source grid cuboid cells, , And The dimensions of the discrete cuboid units in the x, y and z directions are respectively represented; , , , A grid number in x, y and z directions for the observation grid; , , , the grid number in x, y and z directions for the field source grid.
  3. 3. The method of claim 2, wherein determining the cell integral coefficients for each cuboid of the observation grid from the arctangent function and the logarithmic function, and a three-dimensional difference operator, comprises: And determining the unit integral coefficient of each cuboid of the observation grid according to the arctangent function, the logarithmic function and a three-dimensional difference operator as follows: Wherein, the 、 、 、 、 、 Representing the integral coefficient of each cuboid unit, Representing a three-dimensional difference operator, The circumference ratio is indicated.
  4. 4. A method according to claim 3, wherein determining the expression of three components of the observed grid anomaly magnetic field by means of a vertical plurality of two-dimensional discrete convolution summations based on the unit integral coefficients, given earth main magnetic field model information, and the arbitrary susceptibility distribution complex ferromagnetic body model comprises: According to the unit integral coefficient, given earth main magnetic field model information and the arbitrary susceptibility distribution complex ferromagnetic body model, determining the expression of three components of the observed grid abnormal magnetic field by a mode of accumulating a plurality of vertical two-dimensional discrete convolutions, wherein the expression is as follows: Wherein, the 、 、 Is numbered as Is used for observing abnormal magnetic field of grid cuboid unit Is used for the three-component(s) of (c), 、 、 The complex ferromagnetic body model with arbitrary magnetic susceptibility distribution is numbered Effective magnetization of the cuboid unit is three components.
  5. 5. The method of claim 4, wherein computing the three components of the observed grid anomaly magnetic field by two-dimensional compressed discrete convolution comprises: Constructing a compression matrix according to the unit integral coefficients as follows: Wherein, the upper marks of matrix elements represent field source cuboid numbers, and the lower marks represent observation point cuboid unit numbers; Constructing and compressing matrices Field source matrix of equal size The method comprises the following steps: Wherein, the Respectively represent the dimension as 、 、 Is a two-dimensional zero matrix of (2); Calculating three components of the abnormal magnetic field of the observation grid through two-dimensional compression discrete convolution: Wherein, the And Respectively representing the two-dimensional positive and negative fourier transforms, Representing the front of the extraction matrix Line sum Column elements.
  6. 6. The method of claim 5, wherein solving for ferromagnetic aeromagnetic anomalies by means of cyclic iteration comprises: Three components of the abnormal magnetic field according to the observation grid Any observed height magnetic field value is calculated by multi-layer accumulation: from the arbitrary observed height magnetic field value Iteration is carried out to obtain a total magnetic field value: 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 magnetic susceptibility; And stopping iteration after a preset iteration convergence condition is reached, and outputting the total magnetic field value as the ferromagnetic body aeromagnetic abnormal value of the target area.
  7. 7. The method according to any of claims 1 to 6, wherein the number of grids of the field source grid and the observation grid can be set to be the same or different.
  8. 8. A ferromagnetic aeromagnetic anomaly efficient computing device that accounts for demagnetization effects, the device comprising: The grid construction module is used for dispersing a field source region and an underground observation region into a plurality of cuboid units along the x, y and z directions respectively according to the exploration target region information and the ferromagnetic geologic body distribution information to correspondingly obtain a field source grid and an observation grid; the complex ferromagnetic body model building module is used for assigning the magnetic susceptibility of each cuboid unit of the field source grid and building a complex ferromagnetic body model with arbitrary magnetic susceptibility distribution; The unit integral coefficient determining module is used for constructing an arc tangent function and a logarithmic function related to cuboid units of a field source and an observation point according to the field source grid and the observation grid, and determining a unit integral coefficient of each cuboid of the observation grid according to the arc tangent function and the logarithmic function and a three-dimensional difference operator, wherein the value of the unit integral coefficient can be determined by the number of cuboid units of the field source grid, the number of cuboid units of the observation grid and the grid size; The discrete convolution module is used for determining an expression of three components of the abnormal magnetic field of the observation grid in a mode of accumulating a plurality of vertical two-dimensional discrete convolutions according to the unit integral coefficient, given earth main magnetic field model information and the random susceptibility distribution complex ferromagnetic body model; and the result output module is used for calculating three components of the abnormal magnetic field of the observation grid through two-dimensional compression discrete convolution, and further solving the aeromagnetic abnormal value of the ferromagnetic body through a cyclic iteration mode.
  9. 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. 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

High-efficiency calculation method for aeromagnetic anomaly of ferromagnetic body in consideration of demagnetization influence Technical Field The application relates to the technical field of aviation geophysical exploration, in particular to a high-efficiency calculation method, device, computer equipment and storage medium for ferromagnetic aviation magnetic anomalies in consideration of demagnetization influence. Background The magnetization state of an object depends not only on the excitation of an external magnetic field, but also on the combined influence of the magnetic field generated by itself and the magnetic fields of other objects around. This complex coupling phenomenon is commonly referred to as the "self-demagnetizing" effect. The intensity of the effect is closely related to the magnetic susceptibility of the object, and is usually negligible when the magnetic susceptibility is low, namely, the classical magnetic anisotropy interpretation method usually does not consider the influence of the demagnetizing effect, however, as the magnetic susceptibility is increased, the self-demagnetizing effect is obviously enhanced, and becomes a key factor influencing the magnetic field distribution. As an important feature of the magnetic field, the demagnetizing effect must be fully considered in the interpretation of the magnetic data. In particular, in the field of mineral exploration, the mineral is known to be in shortage gradually, and the difficulty of finding the mineral is also increased continuously. Iron ore is an important mineral resource in China, and the magnetic susceptibility of the iron ore is greatly different from that of surrounding rock, so that the iron ore can be directly used for prospecting by a magnetic method. The self-demagnetizing effect of the iron polymetallic ore is particularly remarkable, and if the factor is ignored in the modeling process, systematic deviation is caused on the inference of the spatial position, the geometric form and the magnetization intensity of the magnet, and the reliability of the exploration result is seriously affected. However, the accurate calculation of the self-demagnetizing effect involves complex nonlinear coupling relation, the calculation process is extremely resource-consuming, and extremely high requirements are put on the calculation memory and the performance of the processor. This computational bottleneck severely constrains the practical application of high-precision magnetic field modeling. Therefore, the existing three-dimensional ferromagnetic body numerical simulation technology has the problems of large occupied memory and low iteration efficiency. Disclosure of Invention In view of the foregoing, it is desirable to provide a method, an apparatus, a computer device, and a storage medium for efficiently calculating a ferromagnetic aeromagnetic anomaly in consideration of demagnetization effects, which can achieve both of calculation efficiency and modeling accuracy. A method for efficient computation of ferromagnetic aeromagnetic anomalies taking into account demagnetization effects, the method comprising: According to the information of the exploration target area and the distribution information of the ferromagnetic geologic body, a field source area and an underground observation area are respectively scattered into a plurality of cuboid units along the directions of x, y and z, and a field source grid and an observation grid are correspondingly obtained; assigning the magnetic susceptibility of each cuboid unit of the field source grid, and establishing a complex ferromagnetic body model with arbitrary magnetic susceptibility distribution; Constructing an arc tangent function and a logarithmic function related to field source and observation point cuboid units according to the field source grids and the observation grids, and determining a unit integral coefficient of each cuboid of the observation grids according to the arc tangent function, the logarithmic function and a three-dimensional difference operator, wherein the value of the unit integral coefficient can be determined by the number of the field source cuboid units, the number of the observation grid cuboid units and the grid size; Determining an expression of three components of an observed grid abnormal magnetic field in a mode of accumulating a plurality of vertical two-dimensional discrete convolutions according to the unit integral coefficient, given earth main magnetic field model information and the random susceptibility distribution complex ferromagnetic body model; and calculating three components of the abnormal magnetic field of the observation grid through two-dimensional compression discrete convolution, and further solving the abnormal value of the aeromagnetic of the ferromagnetic body through a cyclic iteration mode. In one embodiment, the method further comprises constructing an arctangent function related to the field source and observation p