Geological body surveying method based on multi-dimensional electromagnetic method

Abstract

The invention discloses a geologic body surveying method based on a multi-dimensional electromagnetic method, which comprises the following steps: transmitting a multi-dimensional electromagnetic wave signal to an underground geologic body by using a multi-dimensional electromagnetic transmitting device, and determining an underground geologic structure; receiving an electromagnetic response signal generated by the geologic body, acquiring electromagnetic characteristic distribution parameters of the geologic body, and preprocessing the electromagnetic characteristic distribution parameters of the geologic body; carrying out inversion calculation on the preprocessed electromagnetic characteristic distribution parameters of the geologic body by adopting a multi-dimensional electromagnetic inversion method, and constructing a multi-dimensional electromagnetic parameter model of the geologic body; and comprehensively analyzing and explaining the geologic body according to the multi-dimensional electromagnetic parameter model, determining boundary, form, depth and component information of the geologic body, and realizing accurate exploration of the geologic body. According to the invention, high-precision and all-directional detection of a complex geologic body is realized, and important technical support is provided for exploration and development of geological resources.

Description

Technical Field

[0001] The present invention relates to the technical field of geological exploration, and particularly to a method for surveying geological bodies based on multi-dimensional electromagnetic method. Background Art

[0002] In the field of geological exploration, accurately surveying the structure, composition, and distribution of underground geological bodies is of crucial significance for mineral resource exploration, engineering construction site selection, groundwater detection, and geological disaster prevention. Traditional geological survey methods mainly include seismic exploration, gravity and magnetic exploration, and resistivity method, etc.

[0003] Seismic exploration mainly infers the structure of geological bodies by artificially exciting seismic waves and measuring the propagation time of seismic waves in underground media and the characteristics of reflected waves. However, this method has a high cost and poor detection effect on some geological bodies with low impedance differences. Gravity and magnetic exploration uses the changes in the gravitational field and magnetic field in the geophysical field to find geological body anomalies. However, gravity and magnetic anomalies are often affected by various factors, and the interpretation results have multiple solutions, making it difficult to directly determine the detailed parameters of geological bodies. The resistivity method detects geological bodies by measuring the resistivity differences of underground media, but it usually can only obtain one-dimensional or two-dimensional resistivity distribution information of geological bodies, and has limited ability to detect the three-dimensional structure and multi-physical properties of complex geological bodies.

[0004] With the development of technology, the application of electromagnetic method in geological exploration is becoming increasingly widespread. As a new electromagnetic exploration technology, multi-dimensional electromagnetic method has the advantages of large detection depth, high resolution, and the ability to obtain multi-parameter information. However, there are still some deficiencies in the existing multi-dimensional electromagnetic method geological survey methods. On the one hand, some methods are not rich enough in the emission and reception dimensions of electromagnetic wave signals, and fail to fully utilize multi-dimensional electromagnetic information to comprehensively excite and receive geological bodies, resulting in incomplete electromagnetic data acquisition and affecting the accurate detection and interpretation of geological bodies. On the other hand, in terms of electromagnetic data processing and inversion algorithms, the existing methods often have low calculation efficiency and low inversion accuracy. How to maximize the extraction of electromagnetic characteristic information of geological bodies under limited detection conditions and convert it into reliable geological interpretation results is the core problem that geological electromagnetic survey technology urgently needs to break through. Summary of the Invention

[0005] To solve the above technical problems existing in the prior art, the present invention proposes a method for surveying geological bodies based on multi-dimensional electromagnetic method, which improves the accuracy and efficiency of geological survey by accurately determining information such as the boundary, shape, depth, and composition of geological bodies.

[0006] To achieve the above object, the present invention provides a method for surveying geological bodies based on multi-dimensional electromagnetic method, including:

[0007] A multi - dimensional electromagnetic wave signal is transmitted to a subsurface geological body by a multi - dimensional electromagnetic emission device to determine the subsurface geological structure. The multi - dimensional electromagnetic wave signal includes a signal combination with different frequencies, polarization directions, and propagation directions.

[0008] The electromagnetic response signal generated by the geological body is received by a multi - dimensional electromagnetic receiving device, the distribution parameters of the electromagnetic characteristics of the geological body are obtained, and the distribution parameters of the electromagnetic characteristics of the geological body are pre - processed to obtain the pre - processed distribution parameters of the electromagnetic characteristics of the geological body.

[0009] A multi - dimensional electromagnetic inversion method is used to perform inversion calculations on the pre - processed distribution parameters of the electromagnetic characteristics of the geological body to construct a multi - dimensional electromagnetic parameter model of the geological body.

[0010] Based on the multi - dimensional electromagnetic parameter model, a comprehensive analysis and interpretation of the geological body are carried out to determine the boundary, shape, depth, and composition information of the geological body, realizing the precise exploration of the geological body.

[0011] Preferably, transmitting a multi - dimensional electromagnetic wave signal to a subsurface geological body by the multi - dimensional electromagnetic emission device to determine the subsurface geological structure includes:

[0012] An initial signal is obtained, the parameters of the initial signal are pre - processed by a signal processing method, and different frequency components are separated by Fourier transform to obtain the frequency distribution characteristics.

[0013] If the frequency distribution characteristics meet the preset frequency distribution threshold, a multi - dimensional signal model is constructed using the parameters of the polarization direction and the propagation direction to determine the multi - angle excitation mode.

[0014] According to the multi - angle excitation mode, a multi - dimensional electromagnetic wave signal is transmitted to the subsurface geological body, the electromagnetic response data generated by the geological body are obtained, the dimensionality reduction processing is performed on the electromagnetic response data by using the principal component analysis algorithm, the multi - parameter excitation characteristics are extracted to obtain a set of eigenvectors, and the electromagnetic response characteristics of the geological body are judged by matching the set of eigenvectors with a pre - established geological body model.

[0015] If the deviation of the electromagnetic response characteristics from the preset model is lower than the preset frequency distribution threshold, a multi - parameter distribution map of the geological body is generated according to the matching result to determine the subsurface geological structure.

[0016] Preferably, judging the electromagnetic response characteristics of the geological body includes:

[0017] The dimensionality reduction processing is performed on the electromagnetic response data by using the principal component analysis to extract multi - parameter features to obtain an initial set of eigenvectors.

[0018] Through the initial set of eigenvectors, a multi - dimensional feature matrix is constructed to determine the distribution characteristics of the multi - dimensional feature matrix.

[0019] Classify the multi-dimensional feature matrix using a clustering analysis algorithm to obtain a classification result. According to the classification result, extract the representative vectors of each type of feature matrix to generate a set of feature vectors.

[0020] Calculate the similarity between the set of feature vectors and the pre-established geological body response model to judge the matching degree of the geological body response. If the similarity calculation result is higher than the preset similarity threshold, generate geological body parameter distribution data according to the matching degree and determine the geological body characteristics.

[0021] Preferably, obtaining the distribution parameters of the electromagnetic characteristics of the geological body includes:

[0022] Obtain the electromagnetic response signals collected by the multi-dimensional electromagnetic receiving device, where the electromagnetic response signals include response components with different frequencies, polarization directions, and propagation directions, to obtain an initial electromagnetic response data set.

[0023] Process the initial electromagnetic response data set through signal processing techniques, and use fast Fourier transform to separate different frequency components to obtain a frequency response feature set.

[0024] If the distribution of the frequency response feature set meets the preset threshold, construct a multi-dimensional signal decomposition model according to the polarization direction parameters and propagation direction characteristics to determine a set of multi-dimensional response components.

[0025] Use the independent component analysis algorithm to perform dimensionality reduction processing on the set of multi-dimensional response components, extract the electromagnetic characteristic components, and obtain a dimensionality reduction feature vector set.

[0026] Judge the type of electromagnetic response of the geological body by performing similarity matching between the dimensionality reduction feature vector set and the pre-established geological body electromagnetic characteristic database.

[0027] If the similarity of the electromagnetic response type of the geological body to a certain category in the database is higher than the preset similarity threshold, generate the distribution parameters of the electromagnetic characteristics of the geological body according to the matching result.

[0028] Preferably, preprocess the distribution parameters of the electromagnetic characteristics of the geological body, including:

[0029] Use the mean filtering method to smooth the distribution parameters of the electromagnetic characteristics of the geological body, reduce the residual noise interference, obtain a set of smooth signals, and use the signal segmentation technology to divide the set of smooth signals into several sub-signal sets according to the time series characteristics to obtain a sequence of sub-signal sets.

[0030] Through the sequence of sub-signal sets, use the principal component analysis algorithm to extract the main components of the electromagnetic characteristics of each sub-signal set to generate a set of principal component features.

[0031] Use the interpolation algorithm to perform spatial mapping on the principal component feature set, generate the electromagnetic property distribution map of the geological body, obtain the distribution mapping data set, and use cluster analysis to perform regional division on the distribution mapping data set to obtain the electromagnetic property partition set of the geological body;

[0032] Through the electromagnetic property partition set of the geological body, use data compression technology to encode the partition set and generate the preprocessed electromagnetic property distribution parameters of the geological body.

[0033] Preferably, using the interpolation algorithm to perform spatial mapping on the principal component feature set to generate the electromagnetic property distribution map of the geological body includes:

[0034] Through the characteristic category label, use the grid division technology to perform regional segmentation on the sub-signal set sequence to generate the initial grid data set;

[0035] If the resolution of the initial grid data set meets the preset resolution threshold, use the spatial interpolation algorithm to fill in the features of the grid data set to generate the filled grid data set;

[0036] Based on the filled grid data set, use the feature extraction technology to obtain the spatial distribution pattern of the electromagnetic properties of the geological body and generate the electromagnetic property partition set;

[0037] Through the electromagnetic property partition set, use data compression technology to encode the partition set to generate the compressed partition data set, and use the decoding algorithm to restore the electromagnetic property distribution to generate the final distribution mapping data set;

[0038] If the integrity of the final distribution mapping data set meets the preset integrity distribution, generate the electromagnetic property distribution map of the geological body through visualization technology.

[0039] Preferably, constructing the multi-dimensional electromagnetic parameter model of the geological body includes:

[0040] Use data standardization technology to normalize the preprocessed electromagnetic property distribution parameters of the geological body to obtain the standardized signal data set, and use the regularization constraint technology to smooth the standardized signal data set to obtain the smoothed signal data set;

[0041] Use the multi-dimensional electromagnetic inversion algorithm to perform inversion calculation on the smoothed signal data set to obtain the preliminary electromagnetic parameter set. According to the preliminary electromagnetic parameter set, use the grid division method to divide the geological body space into several sub-regions to obtain the sub-region parameter set;

[0042] Through the sub-region parameter set, use the interpolation algorithm to perform spatial interpolation processing on the electromagnetic parameters of each sub-region to obtain the continuous electromagnetic parameter distribution set, and optimize the continuous electromagnetic parameter distribution set through the data fusion method to construct the multi-dimensional electromagnetic parameter model.

[0043] Preferably, the smoothed signal dataset is inversely calculated using a multi-dimensional electromagnetic inversion algorithm to obtain a preliminary electromagnetic parameter set, including:

[0044] The smoothed signal dataset is stratified using a signal stratification technique to obtain a stratified signal dataset, and the stratified signal dataset is inversely calculated using a multi-dimensional electromagnetic inversion algorithm to obtain a stratified electromagnetic parameter set;

[0045] Using the stratified electromagnetic parameter set, the geological body space is divided into several independent regions using a region segmentation technique to obtain a region parameter set;

[0046] According to the region parameter set, the electromagnetic parameters of each independent region are adjusted at the boundary using a boundary optimization technique to obtain the preliminary electromagnetic parameter set.

[0047] Compared with the prior art, the present invention has the following advantages and technical effects:

[0048] (1) The present invention emits multi-dimensional electromagnetic wave signals to the underground geological body to achieve multi-angle and multi-parameter excitation of the geological body. A multi-dimensional electromagnetic receiving device is used to receive the electromagnetic response signals generated by the geological body to obtain the distribution parameters of the electromagnetic characteristics of the geological body. After preprocessing and a multi-dimensional electromagnetic inversion algorithm, a multi-dimensional electromagnetic parameter model of the geological body is constructed, and then the geological body is comprehensively analyzed and interpreted;

[0049] (2) The present invention can accurately determine information such as the boundary, shape, depth, and composition of the geological body, effectively improving the accuracy and efficiency of geological exploration. Through multi-dimensional excitation and reception, combined with advanced data processing and inversion techniques, high-precision and all-round detection of complex geological bodies is achieved, providing important technical support for geological resource exploration and development. Description of the Drawings

[0050] The drawings forming a part of this application are used to provide a further understanding of this application. The schematic embodiments and descriptions of this application are used to explain this application and do not constitute an improper limitation of this application. In the drawings:

[0051] Figure 1 It is a flowchart of a geological body survey method based on multi-dimensional electromagnetic method according to an embodiment of the present invention. Detailed Embodiments

[0052] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The following will refer to the drawings and combine the embodiments to detail this application.

[0053] It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. And although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0054] The present invention proposes a geological body survey method based on multi-dimensional electromagnetic method, such as Figure 1 , including:

[0055] Using a multi-dimensional electromagnetic emission device to emit multi-dimensional electromagnetic wave signals to the underground geological body to determine the underground geological structure, and the multi-dimensional electromagnetic wave signals include a signal combination of different frequencies, polarization directions and propagation directions;

[0056] Receiving the electromagnetic response signals generated by the geological body through a multi-dimensional electromagnetic receiving device, obtaining the distribution parameters of the electromagnetic characteristics of the geological body, and preprocessing the distribution parameters of the electromagnetic characteristics of the geological body to obtain the preprocessed distribution parameters of the electromagnetic characteristics of the geological body;

[0057] Adopting a multi-dimensional electromagnetic inversion method to perform inversion calculation on the preprocessed distribution parameters of the electromagnetic characteristics of the geological body to construct a multi-dimensional electromagnetic parameter model of the geological body;

[0058] According to the multi-dimensional electromagnetic parameter model, comprehensively analyzing and interpreting the geological body to determine the boundary, shape, depth and composition information of the geological body, so as to realize the precise survey of the geological body.

[0059] In this embodiment, by emitting multi-dimensional electromagnetic wave signals to the underground geological body, multi-angle and multi-parameter excitation of the geological body is realized. Using a multi-dimensional electromagnetic receiving device to receive the electromagnetic response signals generated by the geological body, the distribution parameters of the electromagnetic characteristics of the geological body are obtained. Through preprocessing and a multi-dimensional electromagnetic inversion algorithm, a multi-dimensional electromagnetic parameter model of the geological body is constructed, and then the geological body is comprehensively analyzed and interpreted.

[0060] Further, using a multi-dimensional electromagnetic emission device to emit multi-dimensional electromagnetic wave signals to the underground geological body, determining the underground geological structure includes:

[0061] Obtaining an initial signal, preprocessing the initial signal parameters through a signal processing method, and separating different frequency components by Fourier transform to obtain a frequency distribution characteristic;

[0062] If the frequency distribution characteristic meets a preset frequency distribution threshold, then a multi-dimensional signal model is constructed using the parameters of the polarization direction and the propagation direction to determine a multi-angle excitation mode;

[0063] According to the multi-angle excitation mode, a multi-dimensional electromagnetic wave signal is transmitted to the underground geological body, electromagnetic response data generated by the geological body is obtained, the principal component analysis algorithm is used to perform dimensionality reduction processing on the electromagnetic response data, multi-parameter excitation characteristics are extracted to obtain a set of feature vectors, and the electromagnetic response characteristics of the geological body are judged by matching the set of feature vectors with a pre-established geological body model;

[0064] If the deviation of the electromagnetic response characteristics from the preset model is lower than the preset frequency distribution threshold, a multi-parameter distribution map of the geological body is generated according to the matching result to determine the underground geological structure.

[0065] Specifically, the electromagnetic wave signal emitted by the multi-dimensional electromagnetic emission device includes multiple frequencies, polarization directions and propagation directions, aiming to detect the underground geological structure. In this embodiment, the multi-dimensional electromagnetic emission device can emit electromagnetic waves with a frequency range of 1 Hz to 100 kHz, the polarization directions include horizontal and vertical polarizations, and the propagation directions cover multiple angles such as 0°, 45° and 90°. The acquisition of the initial signal parameters is completed by a high-precision receiving antenna, and the frequency, amplitude and phase of each signal are recorded.

[0066] In this embodiment, the excitation mode includes three groups of signals: low-frequency vertical polarization, medium-frequency horizontal polarization, and high-frequency mixed polarization, which are respectively aimed at geological bodies at different depths. After transmitting multi-dimensional electromagnetic waves to the underground, the geological body generates electromagnetic response data.

[0067] For example, the response data may show strong reflection in a certain area at the low-frequency band, indicating the existence of a highly conductive ore body. The principal component analysis algorithm reduces the dimension of the response data and extracts the key feature vectors. After dimensionality reduction, the first three principal components are retained, explaining 90% of the variance, and the feature vectors reflect the conductivity and dielectric constant distributions. This method significantly reduces the data complexity and improves the calculation efficiency.

[0068] Furthermore, judging the electromagnetic response characteristics of the geological body includes:

[0069] Performing dimensionality reduction processing on the electromagnetic response data by using principal component analysis, extracting multi-parameter features to obtain an initial set of feature vectors;

[0070] Constructing a multi-dimensional feature matrix through the initial set of feature vectors and determining the distribution characteristics of the multi-dimensional feature matrix;

[0071] Classifying the multi-dimensional feature matrix by using the clustering analysis algorithm to obtain a classification result, and according to the classification result, extracting the representative vectors of each type of feature matrix to generate a set of feature vectors;

[0072] Calculate the similarity between the feature vector set and the pre-established geological body response model to determine the matching degree of the geological body response. If the similarity calculation result is higher than the preset similarity threshold, generate geological body parameter distribution data according to the matching degree and determine the geological body characteristics.

[0073] Obtain the distribution parameters of the electromagnetic characteristics of the geological body, including:

[0074] Obtain the electromagnetic response signals collected by the multi-dimensional electromagnetic receiving device, where the electromagnetic response signals contain response components with different frequencies, polarization directions, and propagation directions, and obtain the initial electromagnetic response data set;

[0075] Process the initial electromagnetic response data set through signal processing techniques, and use fast Fourier transform to separate different frequency components to obtain the frequency response feature set;

[0076] If the distribution of the frequency response feature set meets the preset threshold, construct a multi-dimensional signal decomposition model according to the polarization direction parameters and propagation direction characteristics to determine the multi-dimensional response component set;

[0077] Use the independent component analysis algorithm to perform dimensionality reduction processing on the multi-dimensional response component set, extract the electromagnetic characteristic components, and obtain the dimensionality reduction feature vector set;

[0078] Judge the type of geological body electromagnetic response by performing similarity matching between the dimensionality reduction feature vector set and the pre-established geological body electromagnetic characteristic database;

[0079] If the similarity between the type of geological body electromagnetic response and a certain category in the database is higher than the preset similarity threshold, generate the distribution parameters of the electromagnetic characteristics of the geological body according to the matching result.

[0080] Specifically, when obtaining the electromagnetic response signals collected by the multi-dimensional electromagnetic receiving device, it can be realized through a high-sensitivity electromagnetic sensor array. The array is arranged on the ground or underground and covers different directions to capture multi-dimensional signals. The signals include electromagnetic waves with a frequency range from 0.1 Hz to 100 kHz, the polarization direction includes horizontal and vertical components, and the propagation direction covers radial and tangential directions. The initial electromagnetic response data set can be recorded through time series, for example, sampling 1000 times per second, generating a data matrix containing frequency, amplitude, and phase. Assume that 100 groups of time series data are obtained in a certain acquisition, and each group contains 5000 sampling points, forming the initial electromagnetic response data set.

[0081] When constructing a multi-dimensional signal decomposition model, the signal can be decomposed into components such as horizontally polarized radial and vertically polarized tangential according to the polarization direction and propagation direction parameters. The model is represented in matrix form, such as a 4×4 matrix, with each row corresponding to a polarization-propagation combination. The parameters are optimized by the least squares method to ensure the decomposition accuracy. Suppose after a certain signal is decomposed, the horizontally polarized radial component accounts for 40% and the vertically polarized tangential component accounts for 25%, forming a multi-dimensional response component set.

[0082] Furthermore, preprocess the distribution parameters of the electromagnetic properties of the geological body, including:

[0083] Use the mean filtering method to smooth the distribution parameters of the electromagnetic properties of the geological body, reduce the residual noise interference, obtain a smoothed signal set, and use the signal segmentation technology to divide the smoothed signal set into several sub-signal sets according to the time series characteristics to obtain a sub-signal set sequence;

[0084] Through the sub-signal set sequence, use the principal component analysis algorithm to extract the main components of the electromagnetic properties of each sub-signal set to generate a main component feature set;

[0085] Use the interpolation algorithm to perform spatial mapping on the main component feature set to generate a distribution map of the electromagnetic properties of the geological body, obtain a distribution mapping data set, and use cluster analysis to perform regional division on the distribution mapping data set to obtain a partition set of the electromagnetic properties of the geological body;

[0086] Through the partition set of the electromagnetic properties of the geological body, use data compression technology to encode the partition set to generate the preprocessed distribution parameters of the electromagnetic properties of the geological body.

[0087] Specifically, in the field of analysis of the electromagnetic properties of geological bodies, preprocessing the digital signal set is a key step to ensure data quality. The mean filtering technology can effectively reduce noise interference by smoothing the signal. For example, when processing the electromagnetic response signal of a certain mining area, assume that the original signal contains high-frequency noise. Use a mean filter with a window width of 5 to take the average value of every 5 sampling points to generate a smoothed signal set. It should be noted that the selection of the window width needs to be adjusted according to the signal frequency distribution to avoid losing key features due to over-smoothing. The signal-to-noise ratio of the smoothed signal set is significantly improved, providing a reliable data basis for subsequent analysis. For example, for a certain geological exploration task, divide the 1-second smoothed signal into 100-millisecond segments to generate 10 sub-signal sets. Each sub-signal set retains the local electromagnetic response characteristics, facilitating subsequent feature extraction. This segmentation method can reflect the electromagnetic properties of the geological body changing over time and improve the analysis accuracy.

[0088] The principal component analysis algorithm is used to extract the principal components of the electromagnetic characteristics of the sub-signal set. Perform principal component analysis on the above 10 sub-signal sets, extract the first 3 principal components, and generate a principal component feature set. These principal components usually represent the most significant electromagnetic change patterns in the signal, such as intensity or direction changes. Principal component analysis reduces data redundancy through dimensionality reduction while retaining key information, providing an efficient feature set for subsequent matching.

[0089] Run-length encoding is used to compress the same type of grid cells in the partition set. For example, encoding consecutive high-response area grids into a single identifier reduces the data volume. By compressing the partition data set, a decoding algorithm is used to restore the electromagnetic characteristic distribution and generate a final distribution mapping data set. The decoding algorithm ensures the accurate restoration of the compressed data.

[0090] In a possible implementation, based on run-length decoding, the grid distribution of the partition set is restored, such as restoring the spatial range of the high-response area. If the integrity of the final distribution mapping data set meets the preset threshold, for example, the data loss rate is less than 5%, then a geological body electromagnetic characteristic distribution map is generated through visualization technology to obtain the geological body electromagnetic characteristic partition set.

[0091] Furthermore, an interpolation algorithm is used to perform spatial mapping on the principal component feature set to generate a geological body electromagnetic characteristic distribution map, including:

[0092] Through the characteristic category label, the grid division technology is used to perform regional segmentation on the sub-signal set sequence to generate an initial grid data set;

[0093] If the resolution of the initial grid data set meets the preset resolution threshold, then a spatial interpolation algorithm is used to fill in the features of the grid data set to generate a filled grid data set;

[0094] Based on the filled grid data set, a feature extraction technology is used to obtain the spatial distribution pattern of the geological body electromagnetic characteristics to generate an electromagnetic characteristic partition set;

[0095] Through the electromagnetic characteristic partition set, a data compression technology is used to encode the partition set to generate a compressed partition data set, and a decoding algorithm is used to restore the electromagnetic characteristic distribution to generate a final distribution mapping data set;

[0096] If the integrity of the final distribution mapping data set meets the preset integrity distribution, then the geological body electromagnetic characteristic distribution map is generated through visualization technology.

[0097] Specifically, in this embodiment, spatial mapping is performed through characteristic category tags, and an interpolation algorithm is used to generate an electromagnetic characteristic distribution map. Using the Kriging interpolation method, a distribution map covering an area of 1000 square meters is generated based on the spatial coordinates of the sub-signal set. The distribution map intuitively shows the spatial variation of the electromagnetic characteristics of the geological body and provides a basis for geological zoning. It should be noted that the choice of interpolation algorithm needs to consider the data density to ensure the accuracy of the distribution map. In this embodiment, if the coverage rate of the distribution mapping data set reaches more than 90%, regional division can be carried out through cluster analysis. Using the K-means clustering algorithm, the distribution data set is divided into 3 regions, such as high electromagnetic response region, low electromagnetic response region, etc. This zoning method can clearly distinguish the characteristics of the geological body and facilitate subsequent exploration planning.

[0098] Furthermore, a multi-dimensional electromagnetic parameter model of the geological body is constructed, including:

[0099] The distribution parameters of the electromagnetic characteristics of the preprocessed geological body are normalized using data standardization technology to obtain a standardized signal data set, and the standardized signal data set is smoothed using regularization constraint technology to obtain a smoothed signal data set;

[0100] A multi-dimensional electromagnetic inversion algorithm is used to perform inversion calculations on the smoothed signal data set to obtain a preliminary electromagnetic parameter set. According to the preliminary electromagnetic parameter set, the geological body space is divided into several sub-regions using a grid division method to obtain a sub-region parameter set;

[0101] Through the sub-region parameter set, an interpolation algorithm is used to perform spatial interpolation on the electromagnetic parameters of each sub-region to obtain a continuous electromagnetic parameter distribution set, and the continuous electromagnetic parameter distribution set is optimized using a data fusion method to construct a multi-dimensional electromagnetic parameter model.

[0102] Furthermore, a multi-dimensional electromagnetic inversion algorithm is used to perform inversion calculations on the smoothed signal data set to obtain a preliminary electromagnetic parameter set, including:

[0103] The smoothed signal data set is stratified using signal stratification technology to obtain a stratified signal data set, and a multi-dimensional electromagnetic inversion algorithm is used to perform inversion calculations on the stratified signal data set to obtain a stratified electromagnetic parameter set;

[0104] Through the stratified electromagnetic parameter set, the geological body space is divided into several independent regions using region segmentation technology to obtain a region parameter set;

[0105] According to the region parameter set, boundary optimization technology is used to adjust the boundaries of the electromagnetic parameters of each independent region to obtain the preliminary electromagnetic parameter set.

[0106] Specifically, data normalization techniques are used to normalize electromagnetic response signal data, aiming to unify the data dimension for subsequent analysis. Min-max normalization or Z-score normalization is often adopted for normalization.

[0107] For example, the amplitude range of electromagnetic response signal data is from 0 to 1000 μV. Through min-max normalization, it is mapped to the range from 0 to 1. The specific method is to divide the difference between each data point minus the minimum value by the range difference. Suppose the amplitude of a signal point is 500 μV, and the normalized value is (500 - 0) / (1000 - 0) = 0.5. This method ensures the comparability of data with different dimensions and improves the adaptability of the algorithm.

[0108] In a possible implementation, the regularization constraint technique smooths the normalized signal data set to reduce abnormal fluctuations in the data. For the normalized signal data set, a regularization parameter λ = 0.01 is set, and a smoothing constraint is imposed on the points with large signal fluctuations. Suppose a certain segment of the signal shows a mutation in the time series. After regularization, the fluctuation amplitude decreases, and the signal curve becomes smoother. This method enhances the stability of the data and facilitates subsequent inversion calculations.

[0109] Specifically, the multi-dimensional electromagnetic inversion algorithm is used to deduce the electromagnetic parameters of geological bodies from the smoothed signal data set. The inversion algorithm is based on the electromagnetic field theory and optimizes the fitting of the observed data and the model prediction through iteration.

[0110] For example, for the smoothed signal data set, suppose the electromagnetic field intensity observed in a certain area is 200 nT. The inversion algorithm adjusts the conductivity and permeability parameters to make the model prediction value close to the observed value. Finally, a preliminary set of electromagnetic parameters with a conductivity of 0.1 S / m is obtained. This method can effectively restore the internal characteristics of geological bodies.

[0111] The grid division technique divides the geological body space into sub-regions for refined analysis. Suppose the geological body is a cube with dimensions of 1000 m × 1000 m × 500 m. Using uniform grid division, each side is divided into 10 units, resulting in 1000 sub-regions. The local electromagnetic parameters, such as conductivity or permeability, are recorded for each sub-region. This division method facilitates subsequent interpolation and regional analysis.

[0112] Furthermore, based on the multi-dimensional electromagnetic parameter model, a comprehensive analysis and interpretation of the geological body are carried out to determine the boundary, shape, depth, and composition information of the geological body, achieving precise exploration of the geological body.

[0113] Specifically, edge detection technology is used to extract the edges of the multi-dimensional electromagnetic parameter model to obtain the edge point set. Edge detection identifies the edge positions of geological bodies by calculating the electromagnetic parameter gradients. If the connectivity of the edge point set meets the preset connectivity threshold, surface fitting technology is used to process the edge point set to obtain the morphological description set. Connectivity judgment determines whether the fitting conditions are met by calculating the distance and continuity between edge points. Surface fitting fits the edge points by the least squares method to generate the surface morphology of the geological body. Through the morphological description set, stereo disparity technology is used to estimate the depth of the geological body to obtain the depth distribution set. Stereo disparity technology calculates the depth information of each part of the geological body by analyzing the geometric features in the morphological description set. According to the depth distribution set, component analysis technology is used to identify the substances of the geological body to obtain the component distribution set. Component analysis determines the substance composition of the geological body by comparing the depth distribution set with the preset database of electromagnetic characteristics of substances. If the coverage rate of the component distribution set meets the preset threshold, spatial interpolation technology is used to optimize the component distribution set to obtain the optimized component distribution set. Spatial interpolation interpolates the component distribution set by Kriging method to generate a continuous component distribution. Through the optimized component distribution set, stereomicroscopy technology is used to analyze the fine structure of the geological body to obtain the structure distribution set. Stereomicroscopy technology determines the internal structure of the geological body by analyzing the microscopic features in the optimized component distribution set. According to the structure distribution set, data fusion technology is used to comprehensively analyze the geological body to obtain the comprehensive distribution set. Data fusion integrates the morphological description set, depth distribution set, optimized component distribution set and structure distribution set by the weighted average method to generate the comprehensive parameter distribution of the geological body.

[0114] The above is only the preferred specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A geological body survey method based on multi-dimensional electromagnetic method, characterized in that, include: Using a multi-dimensional electromagnetic transmitting device to transmit a multi-dimensional electromagnetic wave signal to an underground geological body to determine the underground geological structure, the multi-dimensional electromagnetic wave signal includes a signal combination of different frequencies, polarization directions and propagation directions; Receiving the electromagnetic response signal generated by the geological body through a multi-dimensional electromagnetic receiving device, obtaining the electromagnetic characteristic distribution parameters of the geological body, and preprocessing the electromagnetic characteristic distribution parameters of the geological body to obtain the preprocessed electromagnetic characteristic distribution parameters of the geological body; Using a multi-dimensional electromagnetic inversion method to perform inversion calculation on the electromagnetic characteristic distribution parameters of the pre-processed geological body, and constructing a multi-dimensional electromagnetic parameter model of the geological body; The geological body is comprehensively analyzed and interpreted based on the multi-dimensional electromagnetic parameter model to determine the boundary, shape, depth, and composition information of the geological body, thereby achieving accurate survey of the geological body.

2. The geological body survey method based on multi-dimensional electromagnetic method according to claim 1, characterized in that, Utilizing the multi-dimensional electromagnetic transmitting device to transmit multi-dimensional electromagnetic wave signals to the underground geological body to determine the underground geological structure includes: Acquire an initial signal, pre-process the initial signal parameters by a signal processing method, separate different frequency components by Fourier transform, and obtain frequency distribution characteristics; If the frequency distribution characteristics meet the preset frequency distribution threshold, a multi-dimensional signal model is constructed using the parameters of the polarization direction and the propagation direction to determine the multi-angle excitation mode; According to the multi-angle excitation mode, a multi-dimensional electromagnetic wave signal is emitted to the underground geological body to obtain the electromagnetic response data generated by the geological body, and the electromagnetic response data is subjected to dimensionality reduction processing by using the principal component analysis algorithm to extract the multi-parameter excitation characteristics to obtain a feature vector set, and the feature vector set is matched with the pre-established geological body model to determine the electromagnetic response characteristics of the geological body; If the deviation between the electromagnetic response characteristics and the preset model is lower than the preset frequency distribution threshold, a multi-parameter distribution map of the geological body is generated according to the matching results to determine the underground geological structure.

3. The geological body survey method based on the multi-dimensional electromagnetic method according to claim 2, wherein Determining the electromagnetic response characteristics of the geological body includes: The principal component analysis is used to reduce the dimension of electromagnetic response data, extract multi-parameter features, and obtain the initial feature vector set; Constructing a multidimensional feature matrix through the initial feature vector set, and determining the distribution characteristics of the multidimensional feature matrix; A cluster analysis algorithm is used to classify the multidimensional feature matrix to obtain the classification results. According to the classification results, the representative vector of each type of feature matrix is extracted to generate a feature vector set. The similarity calculation is performed between the feature vector set and the pre-established geological body response model to determine the matching degree of the geological body response. If the similarity calculation result is higher than a preset similarity threshold, geological body parameter distribution data is generated according to the matching degree to determine the geological body characteristics.

4. The geological body survey method based on multi-dimensional electromagnetic method according to claim 1, characterized in that, Obtaining the electromagnetic characteristic distribution parameters of the geological body includes: Acquire an electromagnetic response signal collected by a multi-dimensional electromagnetic receiving device, wherein the electromagnetic response signal includes response components of different frequencies, polarization directions, and propagation directions, and obtain an initial electromagnetic response data set; The initial electromagnetic response data set is processed by signal processing technology, and different frequency components are separated by fast Fourier transform to obtain a frequency response feature set; If the distribution of the frequency response feature set meets a preset threshold, a multi-dimensional signal decomposition model is constructed based on the polarization direction parameter and the propagation direction characteristic to determine a multi-dimensional response component set; The independent component analysis algorithm is used to perform dimensionality reduction processing on the multi-dimensional response component set, extract electromagnetic characteristic components, and obtain a dimensionality reduction feature vector set; The similarity between the dimensionality reduction feature vector set and a pre-established geological body electromagnetic characteristic database is matched to determine the electromagnetic response type of the geological body; If the similarity between the electromagnetic response type of the geological body and a certain category in the database is higher than the preset similarity threshold, the electromagnetic characteristic distribution parameters of the geological body are generated according to the matching result.

5. The geological body survey method based on the multi-dimensional electromagnetic method according to claim 1, characterized in that, Preprocessing is performed on the electromagnetic characteristic distribution parameters of the geological body, including: The mean filtering method is used to smooth the electromagnetic characteristic distribution parameters of the geological body to reduce residual noise interference, and a smoothed signal set is obtained. The signal segmentation technology is used to divide the smoothed signal set into several sub-signal sets according to the time series characteristics to obtain a sub-signal set sequence; Through the sub-signal set sequence, the principal component analysis algorithm is used to extract the electromagnetic characteristic principal components of each sub-signal set to generate a principal component feature set; The interpolation algorithm is used to perform spatial mapping on the principal component feature set to generate a geological body electromagnetic characteristic distribution map, obtain a distribution mapping data set, and use clustering analysis to perform regional division on the distribution mapping data set to obtain a geological body electromagnetic characteristic partition set; Through the geological body electromagnetic characteristic partition set, the data compression technology is used to perform encoding processing on the partition set to generate the preprocessed electromagnetic characteristic distribution parameters of the geological body.

6. The geological body survey method based on the multi-dimensional electromagnetic method according to claim 5, characterized in that, The interpolation algorithm is used to perform spatial mapping on the principal component feature set to generate a geological body electromagnetic characteristic distribution map, including: Through the characteristic category label, the grid division technology is used to perform regional segmentation on the sub-signal set sequence to generate an initial grid data set; If the resolution of the initial grid data set meets the preset resolution threshold, the spatial interpolation algorithm is used to fill in the features of the grid data set to generate a filled grid data set; Based on the filled grid data set, the feature extraction technology is used to obtain the spatial distribution pattern of the geological body electromagnetic characteristics to generate an electromagnetic characteristic partition set; Through the electromagnetic characteristic partition set, the data compression technology is used to perform encoding processing on the partition set to generate a compressed partition data set, and the decoding algorithm is used to restore the electromagnetic characteristic distribution to generate a final distribution mapping data set; If the integrity of the final distribution mapping data set meets the preset integrity distribution, the geological body electromagnetic characteristic distribution map is generated through the visualization technology.

7. The geological body survey method based on the multi-dimensional electromagnetic method according to claim 1, characterized in that Construct the multi-dimensional electromagnetic parameter model of the geological body, including: The data standardization technology is used to normalize the preprocessed electromagnetic characteristic distribution parameters of the geological body to obtain a standardized signal data set, and the regularization constraint technology is used to smooth the standardized signal data set to obtain a smoothed signal data set; The multi-dimensional electromagnetic inversion algorithm is used to perform inversion calculation on the smoothed signal data set to obtain a preliminary electromagnetic parameter set. According to the preliminary electromagnetic parameter set, the grid division method is used to divide the geological body space into several sub-regions to obtain a sub-region parameter set; Through the sub-region parameter set, spatial interpolation processing is performed on the electromagnetic parameters of each sub-region by using an interpolation algorithm to obtain a continuous electromagnetic parameter distribution set, and the continuous electromagnetic parameter distribution set is optimized by a data fusion method to construct the multi-dimensional electromagnetic parameter model.

8. The geological body survey method based on the multi-dimensional electromagnetic method according to claim 7, characterized in that, The multi-dimensional electromagnetic inversion algorithm is used to perform inversion calculation on the smoothed signal data set to obtain a preliminary electromagnetic parameter set, including: The signal stratification technology is used to perform stratification processing on the smoothed signal data set to obtain a stratified signal data set, and the multi-dimensional electromagnetic inversion algorithm is used to perform inversion calculation on the stratified signal data set to obtain a stratified electromagnetic parameter set; Through the stratified electromagnetic parameter set, the geological body space is divided into several independent regions by using the region segmentation technology to obtain a region parameter set; According to the region parameter set, the boundary optimization technology is used to adjust the boundaries of the electromagnetic parameters of each independent region to obtain the preliminary electromagnetic parameter set.

Images