Ground-to-air transient electromagnetic multi-height data measurement and multi-parameter reconstruction method and system
By collecting ground-space transient electromagnetic data at different flight altitudes and optimizing geoelectric parameters using particle swarm and genetic algorithms, the singularity and multi-solvency problems of multi-parameter model reconstruction in transient electromagnetic method are solved, and the detection accuracy is improved And control work costs.
Patent Information
- Application Number
- CN202411487206.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-24
- Publication Date
- 2025-02-18
- Estimated Expiration
- 2044-10-24
AI Technical Summary
The existing transient electromagnetic method has problems of singularity and multi-solvency in multi-parameter model reconstruction, which leads to inaccurate reconstruction results, and increasing the amount of data acquisition to constrain the reconstruction process will greatly increase the work cost.
Using ground-space transient electromagnetic multi-altitude data measurement method, through data acquisition at different flight altitudes, combined with particle swarm algorithms and genetic algorithms, the objective function of ground-electric parameters is constructed and optimized, reducing the singularity and multi-solution of multi-parameter reconstruction .
It effectively reduces the multi-solvency problem of multi-parameter reconstruction, improves the accuracy of transient electromagnetic multi-parameter detection, and maintains a low working cost while increasing work cost.
Smart Images
Figure CN119001880B_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of electromagnetic detection technology, and in particular to a method and system for ground-to-air transient electromagnetic multi-height data measurement and multi-parameter reconstruction. Background Art
[0002] Transient electromagnetic method (TEM) is a geophysical exploration technology that detects the electrical properties of underground media by exciting transient electromagnetic fields and measuring their attenuation characteristics. The method generates a primary electromagnetic field by injecting a short current pulse, inducing underground currents. The current decays to generate a secondary magnetic field, which is related to the conductivity of the underground medium. Data acquisition and analysis are mainly carried out in the time domain, including curve analysis and apparent resistivity calculation. TEM has the advantages of large exploration depth, high resolution, and sensitivity to low-resistance layers. It is widely used in hydrogeology, environmental engineering and other fields. The earth medium has the characteristics of induced polarization, which produces effects under the excitation of transient electromagnetic fields, affecting the transient electromagnetic response, which needs to be considered. In order to analyze and interpret transient electromagnetic response data and infer underground geological structures, a multi-parameter model is often used to describe the earth, including resistivity, polarizability, time constant, and frequency-related factors. Through inversion modeling technology, the multi-parameter model is reconstructed according to the transient electromagnetic response.
[0003] However, the reconstruction of multi-parameter models requires the recovery of multiple geoelectric parameters based on limited transient electromagnetic data, which results in numerical singularities. The measured transient electromagnetic data are often insufficient to effectively constrain the reconstruction process, resulting in multiple solutions to the inversion and reconstruction results. This singularity can be weakened by collecting transient electromagnetic data at different locations or using different observation parameters for multiple data collections to increase the amount of effective data and jointly constrain the reconstruction process. However, in practical applications, especially in ground transient electromagnetic methods, increasing the amount of collected data often significantly increases the cost of work and creates difficulties in use. Summary of the invention
[0004] The purpose of this application is to provide a method and system for ground-to-air transient electromagnetic multi-height data measurement and multi-parameter reconstruction, which can improve the accuracy of transient electromagnetic multi-parameter detection.
[0005] To achieve the above objectives, this application provides the following solutions:
[0006] In a first aspect, the present application provides a method for ground-to-air transient electromagnetic multi-height data measurement and multi-parameter reconstruction, comprising:
[0007] Deploy emission sources in the target area.
[0008] According to the work design, ground-to-air transient electromagnetic measurements are carried out at different flight altitudes to obtain a total set of transient electromagnetic data; the total set of transient electromagnetic data includes transient electromagnetic data sets at different flight altitudes; the transient electromagnetic data set includes a number of transient electromagnetic data.
[0009] According to the transient electromagnetic data, a particle swarm algorithm is used to construct an objective function of geoelectric parameters.
[0010] The objective function of the geoelectric parameters is optimized, and when the convergence error is greater than the termination threshold, the optimal particle is used as an individual of the genetic algorithm population to perform genetic algorithm inversion to obtain a multi-parameter geoelectric model.
[0011] In a second aspect, the present application provides a ground-to-air transient electromagnetic multi-height data measurement and multi-parameter reconstruction system, comprising:
[0012] The deployment module is used to deploy the emission source in the target area.
[0013] The acquisition module is used to carry out ground-to-air transient electromagnetic measurements at different flight altitudes according to the work design to obtain a total set of transient electromagnetic data; the total set of transient electromagnetic data includes transient electromagnetic data sets at different flight altitudes; the transient electromagnetic data set includes a plurality of transient electromagnetic data.
[0014] The function construction module is used to construct the objective function of geoelectric parameters according to the transient electromagnetic data by using a particle swarm algorithm.
[0015] The model building module is used to optimize the objective function of the geoelectric parameters. When the convergence error is greater than the termination threshold, the optimal particle is used as an individual of the genetic algorithm population to perform genetic algorithm inversion to obtain a multi-parameter geoelectric model.
[0016] According to the specific embodiments provided in this application, this application discloses the following technical effects:
[0017] The present application provides a method and system for measuring multi-altitude data and reconstructing multi-parameters of ground-to-air transient electromagnetic data. The method adopts a ground-to-air transient electromagnetic measurement method to quickly obtain transient electromagnetic response data at different flight altitudes in the air, and uses the data at different flight altitudes in combination to perform multi-parameter reconstruction of the earth model, thereby weakening the singularity problem of multi-parameter reconstruction, solving the multi-solution problem of inversion and reconstruction results, and improving the accuracy of transient electromagnetic multi-parameter detection. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0019] Figure 1A flowchart of a method for ground-to-air transient electromagnetic multi-height data measurement and multi-parameter reconstruction provided in one embodiment of the present application.
[0020] Figure 2 A schematic diagram of measuring the flying height H1 provided in an embodiment of the present application.
[0021] Figure 3 A schematic diagram of measuring the flying height H2 provided in an embodiment of the present application.
[0022] Figure 4 A schematic structural diagram of a ground-to-air transient electromagnetic multi-height data measurement and multi-parameter reconstruction system provided in one embodiment of the present application. DETAILED DESCRIPTION
[0023] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0024] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.
[0025] Embodiment 1
[0026] like Figure 1 As shown, this embodiment provides a method for ground-to-air transient electromagnetic multi-height data measurement and multi-parameter reconstruction, including:
[0027] Step 101: Deploy emission sources in the target area.
[0028] Step 102: According to the work design, ground-to-air transient electromagnetic measurements are carried out at different flight altitudes to obtain a total set of transient electromagnetic data; the total set of transient electromagnetic data includes transient electromagnetic data sets at different flight altitudes; the transient electromagnetic data set includes a plurality of transient electromagnetic data.
[0029] Step 103: constructing an objective function of geoelectric parameters using a particle swarm algorithm based on the transient electromagnetic data.
[0030] Step 104: Optimize the objective function of the geoelectric parameters. When the convergence error is greater than the termination threshold, use the optimal particle as an individual of the genetic algorithm population to perform genetic algorithm inversion to obtain a multi-parameter geoelectric model.
[0031] After executing step 102, the method further includes:
[0032] Data preprocessing is performed on each transient electromagnetic data in the transient electromagnetic data collection.
[0033] Specifically, data preprocessing is performed on each transient electromagnetic data in the transient electromagnetic data set, specifically including:
[0034] Noise filtering is performed on each transient electromagnetic data.
[0035] The transient electromagnetic data after noise filtering is normalized.
[0036] Perform time series analysis on the normalized data to identify and remove outliers.
[0037] The processed data are integrated to obtain the total set of transient electromagnetic data after data processing.
[0038] In some embodiments, when executing step 103, it specifically includes:
[0039] Based on known geological information and electromagnetic theory, an initial model of geoelectric parameters is established.
[0040] The initial model is iteratively optimized using the particle swarm algorithm to obtain the optimized geoelectric parameter model.
[0041] The optimized geoelectric parameter model is used as the initial population of the particle swarm algorithm, and a genetic algorithm inversion is performed to obtain the objective function of the geoelectric parameter.
[0042] Specifically, the objective function is:
[0043] .
[0044] in, is the objective function, r is the residual vector, , d is transient electromagnetic data, the superscript obs and fit represent the measured data of transient electromagnetic data and the fitted data of transient electromagnetic data, respectively. i Representative corresponding to i A transient electromagnetic dataset of heights, C m is the weight matrix of transient electromagnetic data, m is the inversion model, D is the regularization matrix, the transient electromagnetic response theoretical value , ρ is the resistivity, η is the polarizability, is the time constant, c is the frequency-dependent factor.
[0045] Among them, when executing step 104, it can be specifically as follows: if the convergence error is greater than the termination threshold, it is determined that the reconstruction process converges prematurely to the local minimum point. At this time, the optimal particle is used as an individual of the genetic algorithm population, and the genetic algorithm inversion is performed to obtain a reconstructed multi-parameter geoelectric model.
[0046] The present application is further described in detail below with reference to a specific embodiment.
[0047] S1. Set up the transmitting source T1 and carry out ground-to-air transient electromagnetic measurement at the flight altitude H1 according to the work design to obtain the transient electromagnetic data set corresponding to the first flight altitude (see Appendix Figure 2 ).
[0048] S2. Change the flight altitude and carry out ground-to-air transient electromagnetic measurements at the flight altitude H2 to obtain the transient electromagnetic data set corresponding to the second flight altitude (see Appendix Figure 3 ).
[0049] S3. Stop collecting and organize the data.
[0050] S4. Use particle swarm algorithm to reconstruct geoelectric parameters, and the optimization objective function is:
[0051] .
[0052] in, d is transient electromagnetic data, with superscript obs and fit represent measured data and fitted data, respectively. Subscripts 1 and 2 represent transient electromagnetic data sets corresponding to the first and second heights, respectively. C m is the weight matrix of the data, m is the inversion model, D is the regularization matrix, generally a smoothness or roughness matrix, and the transient electromagnetic response theoretical value ,in ρ is the resistivity, η is the polarizability, is the time constant, c is the frequency related factor.
[0053] S5. Set the iteration termination threshold to 15%. If the convergence error is greater than 15%, it is determined that the reconstruction process converges prematurely to the local minimum. At this time, the optimal particle is used as an individual in the genetic algorithm population to perform genetic algorithm inversion to obtain a reconstructed multi-parameter geoelectric model.
[0054] Embodiment 2
[0055] like Figure 4As shown, this embodiment provides a ground-to-air transient electromagnetic multi-height data measurement and multi-parameter reconstruction system, including:
[0056] The deployment module 401 is used to deploy the emission sources in the target area.
[0057] The acquisition module 402 is used to carry out ground-to-air transient electromagnetic measurements at different flight altitudes according to the work design to obtain a total set of transient electromagnetic data; the total set of transient electromagnetic data includes transient electromagnetic data sets at different flight altitudes; the transient electromagnetic data set includes a plurality of transient electromagnetic data.
[0058] The function construction module 403 is used to construct the objective function of the geoelectric parameters according to the transient electromagnetic data by using the particle swarm algorithm.
[0059] The model building module 404 is used to optimize the objective function of the geoelectric parameters. When the convergence error is greater than the termination threshold, the optimal particle is used as an individual of the genetic algorithm population to perform genetic algorithm inversion to obtain a multi-parameter geoelectric model.
[0060] The data preprocessing module is used to perform data preprocessing on each transient electromagnetic data in the transient electromagnetic data set.
[0061] Wherein, the data preprocessing module includes:
[0062] The noise filtering submodule is used to filter the noise of each transient electromagnetic data.
[0063] The normalization processing submodule is used to perform normalization processing on the transient electromagnetic data after noise is filtered out.
[0064] The outlier submodule is used to perform time series analysis on the normalized data and identify and remove outliers.
[0065] The integration submodule is used to integrate the processed data to obtain the total set of transient electromagnetic data after data processing.
[0066] Wherein, the function building module includes:
[0067] The first construction submodule is used to establish an initial model of geoelectric parameters based on known geological information and electromagnetic theory.
[0068] The iterative optimization submodule is used to iteratively optimize the initial model using the particle swarm algorithm to obtain an optimized geoelectric parameter model.
[0069] The second construction submodule is used to use the optimized geoelectric parameter model as the initial population of the particle swarm algorithm, perform genetic algorithm inversion, and obtain the objective function of the geoelectric parameter.
[0070] In summary, this application has the following technical effects:
[0071] (1) This application increases the amount of effective data and strengthens the constraints of data on the reconstruction process by collecting ground-to-air transient electromagnetic data at different flight altitudes, which can effectively reduce the multi-solution problem of multi-parameter reconstruction.
[0072] (2) This application only needs to collect ground-to-air transient electromagnetic data at different flight altitudes, without the need to redeploy the launch system. The additional work cost is relatively low, and it has good practicality and scalability.
[0073] (3) This application is based on the ground-to-air transient electromagnetic method, carries out transient electromagnetic data collection at different altitudes under the same source emission, combines transient electromagnetic data sets at different altitudes, adopts a specific objective function, and uses particle swarm algorithm and genetic algorithm to carry out multi-parameter reconstruction. On the basis of only increasing a very small amount of work cost, it solves the singularity problem of multi-parameter reconstruction and improves the accuracy of transient electromagnetic detection.
[0074] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0075] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.
Claims
1. A method for measuring ground-to-air transient electromagnetic multi-height data and reconstructing multi-parameters, characterized in that: include: Deploy emission sources in the target area; According to the work design, ground-to-air transient electromagnetic measurements are carried out at different flight altitudes to obtain a total transient electromagnetic data set; the total transient electromagnetic data set includes transient electromagnetic data sets at different flight altitudes; the transient electromagnetic data set includes a plurality of transient electromagnetic data; Based on the transient electromagnetic data, a particle swarm algorithm is used to construct an objective function of geoelectric parameters; The objective function of the geoelectric parameters is optimized, and when the convergence error is greater than the termination threshold, the optimal particle is used as an individual of the genetic algorithm population to perform genetic algorithm inversion to obtain a multi-parameter geoelectric model; According to the transient electromagnetic data, a particle swarm algorithm is used to construct an objective function of geoelectric parameters, which specifically includes: Based on known geological information and electromagnetic theory, an initial model of geoelectric parameters is established; The initial model is iteratively optimized using the particle swarm algorithm to obtain the optimized geoelectric parameter model; The optimized geoelectric parameter model is used as the initial population of the particle swarm algorithm, and a genetic algorithm inversion is performed to obtain the objective function of the geoelectric parameter; The objective function is: ； in, is the objective function, r is the residual vector, , d is transient electromagnetic data, with superscript obs and fit represent the measured data of transient electromagnetic data and the fitted data of transient electromagnetic data, respectively. i Representative corresponding to i A transient electromagnetic dataset of heights, C m is the weight matrix of transient electromagnetic data, m is the inversion model, D is the regularization matrix, the transient electromagnetic response theoretical value , ρ is the resistivity, η is the polarizability, is the time constant, c is the frequency-dependent factor.
2. A method for ground-to-air transient electromagnetic multi-height data measurement and multi-parameter reconstruction according to claim 1, characterized in that: After carrying out ground-to-air transient electromagnetic measurements at different flight altitudes according to the work design and obtaining the total set of transient electromagnetic data, it also includes: Data preprocessing is performed on each transient electromagnetic data in the transient electromagnetic data collection.
3. A method for ground-to-air transient electromagnetic multi-height data measurement and multi-parameter reconstruction according to claim 2, characterized in that: Performing data preprocessing on each transient electromagnetic data in the transient electromagnetic data set specifically includes: Perform noise filtering on each transient electromagnetic data; Normalize the transient electromagnetic data after noise is filtered out; Perform time series analysis on the normalized data to identify and remove outliers; The processed data are integrated to obtain the total set of transient electromagnetic data after data processing.
4. The method for ground-to-air transient electromagnetic multi-height data measurement and multi-parameter reconstruction according to claim 1, characterized in that: The termination threshold is set to 15%.
5. A ground-to-air transient electromagnetic multi-height data measurement and multi-parameter reconstruction system based on a ground-to-air transient electromagnetic multi-height data measurement and multi-parameter reconstruction method according to any one of claims 1 to 4, characterized in that: include: A deployment module, used for deploying the emission source in the target area; The acquisition module is used to carry out ground-to-air transient electromagnetic measurement at different flight altitudes according to the work design to obtain a total set of transient electromagnetic data; the total set of transient electromagnetic data includes transient electromagnetic data sets at different flight altitudes; the transient electromagnetic data set includes a plurality of transient electromagnetic data; A function construction module, used to construct an objective function of geoelectric parameters using a particle swarm algorithm according to the transient electromagnetic data; The model building module is used to optimize the objective function of the geoelectric parameters. When the convergence error is greater than the termination threshold, the optimal particle is used as an individual of the genetic algorithm population to perform genetic algorithm inversion to obtain a multi-parameter geoelectric model.
6. A ground-to-air transient electromagnetic multi-height data measurement and multi-parameter reconstruction system according to claim 5, characterized in that: The data preprocessing module is used to perform data preprocessing on each transient electromagnetic data in the transient electromagnetic data set.
7. A ground-to-air transient electromagnetic multi-height data measurement and multi-parameter reconstruction system according to claim 6, characterized in that: The data preprocessing module comprises: A noise filtering submodule is used to filter noise from each transient electromagnetic data; A normalization processing submodule is used to perform normalization processing on the transient electromagnetic data after noise is filtered out; The outlier submodule is used to perform time series analysis on the normalized data and identify and remove outliers; The integration submodule is used to integrate the processed data to obtain the total set of transient electromagnetic data after data processing.
8. The ground-to-air transient electromagnetic multi-height data measurement and multi-parameter reconstruction system according to claim 7, characterized in that: The function building block includes: The first construction submodule is used to establish an initial model of geoelectric parameters based on known geological information and electromagnetic theory; Iterative optimization submodule, used to iteratively optimize the initial model using particle swarm algorithm to obtain an optimized geoelectric parameter model; The second construction submodule is used to use the optimized geoelectric parameter model as the initial population of the particle swarm algorithm, perform genetic algorithm inversion, and obtain the objective function of the geoelectric parameter.