A three-dimensional geophysical prospecting method and system for underground space

Abstract

The application discloses a kind of underground space three-dimensional geophysical prospecting detection methods and systems, belong to underground space three-dimensional geophysical prospecting field, a kind of underground space three-dimensional geophysical prospecting detection method includes selecting reference site, with multiple reference detection units Reference three-dimensional geophysical prospecting array is laid out, the whole domain mutual interference calibration is carried out to the reference three-dimensional geophysical prospecting array, obtains the mutual interference coefficient of different adjacent reference detection unit combination, constructs mutual interference coefficient matrix;According to the site to be measured, with multiple actual detection units Actual three-dimensional geophysical prospecting array is laid out, and the original data of actual three-dimensional geophysical prospecting array is collected;According to the mutual interference coefficient matrix, the near-field mutual interference compensation processing of original data is carried out gradually, to eliminate the interference in the actual three-dimensional geophysical prospecting array;According to the compensation data after near-field mutual interference compensation, three-dimensional inversion imaging is carried out, and the three-dimensional model of underground space is constructed.The technical effect of the application is that it is easy to prevent strong near-field mutual interference between adjacent detection units.

Description

Technical Field

[0001] This invention relates to three-dimensional geophysical exploration in underground space, and more particularly to a method and system for three-dimensional geophysical exploration in underground space. Background Technology

[0002] Three-dimensional geophysical exploration of underground space is a comprehensive technology that uses physical means to accurately determine the geological structure and overall appearance of objects at a certain depth underground without damaging the surface.

[0003] To enhance the comprehensiveness of exploration, 3D geophysical exploration of underground spaces typically requires the use of multiple exploration units. Chinese invention patent CN121415010A, published on January 27, 2026, discloses a refined 3D geological modeling method based on 3D forward and inverse geophysical algorithms, belonging to the field of geological exploration. The method includes: acquiring multi-source data and constructing an initial model; using a joint constrained 3D inversion algorithm to obtain a 3D physical property model; creating a lithology classifier and generating a 3D lithology probability volume based on the 3D physical property model, followed by geological structure boundary enhancement and geological classification based on the probability volume; extracting isosurfaces from the 3D lithology probability volume, generating preliminary geological interfaces, performing structural processing, and then coupling attribute models to output the final model. This invention directly constructs a spatially continuous model through 3D joint inversion, avoiding interpolation errors between survey lines; forced matching of borehole data combined with trend control of geophysical data balances local accuracy and global rationality; the entire process from inversion to lithology classification is algorithm-driven, reducing manual intervention; and it is suitable for high-precision scenarios such as urban underground space, mineral exploration, and geological hazard assessment.

[0004] The shortcoming of this invention is that there is strong near-field interference between adjacent detection units of its multi-source data, which can easily lead to data distortion and signal-to-noise ratio reduction in the center and edge regions of the array. Small-scale anomalies (such as microcavities and non-metallic tubes) are easily masked or form false anomalies. Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to provide a three-dimensional geophysical exploration method for underground space, which facilitates the prevention of strong near-field interference between adjacent exploration units; another purpose of this invention is to provide a three-dimensional geophysical exploration system for underground space.

[0006] Technical solution:

[0007] A three-dimensional geophysical exploration method for underground space includes:

[0008] A reference site is selected, and a reference three-dimensional geophysical array is deployed with multiple reference detection units. The reference three-dimensional geophysical array is subjected to global mutual interference calibration to obtain the mutual interference coefficients of different adjacent combinations of the reference detection units and construct a mutual interference coefficient matrix.

[0009] Based on the site to be tested, an actual three-dimensional geophysical array is deployed with multiple actual detection units, and the raw data of the actual three-dimensional geophysical array is collected.

[0010] Based on the mutual interference coefficient matrix, the original data is subjected to near-field mutual interference compensation processing at each measurement point and at each level to eliminate interference within the actual three-dimensional geophysical array;

[0011] Based on the compensation data after near-field mutual interference compensation, three-dimensional inversion imaging is performed to construct a three-dimensional model of the underground space.

[0012] Specifically, the present invention provides a method for three-dimensional geophysical exploration in underground space. First, a benchmark detection array is deployed to complete the global mutual interference calibration. The mutual interference coefficients of different combinations of benchmark detection units are statistically analyzed and a mutual interference coefficient matrix is ​​constructed. Then, the original data of the actual three-dimensional geophysical array is collected. Based on the mutual interference coefficient matrix, near-field mutual interference compensation processing is carried out on the original data point by point and layer by layer. This effectively eliminates strong near-field mutual interference between actual detection units, thereby preventing data distortion and signal-to-noise ratio reduction in the center and edge areas of the actual three-dimensional geophysical array. Small-scale anomalies (such as microcavities and non-metallic tubes) are easily masked or form false anomalies.

[0013] Optionally, the global mutual interference calibration adopts a data acquisition mode in which each of the reference detection units transmits independently in sequence and the remaining reference detection units receive synchronously. The response data of each reference detection unit is recorded one by one, and the mutual interference correlation between any two groups of adjacent reference detection units is statistically analyzed to obtain the mutual interference coefficient of different combinations of adjacent reference detection units.

[0014] Optionally, the reference detection unit and the actual detection unit are of the same type.

[0015] Optionally, the step of performing global mutual interference calibration on the reference three-dimensional geophysical array, obtaining the mutual interference coefficients of different adjacent combinations of the reference detection units, and constructing a mutual interference coefficient matrix includes: dividing the reference three-dimensional geophysical array into three calibration regions: the array center region, the array edge region, and the array corner region; collecting the unit mutual interference coefficients of each calibration region respectively; and generating a partition-independent mutual interference coefficient unit matrix.

[0016] Optionally, it also includes dynamic correction of the mutual interference coefficient, which includes: correcting the pre-calibrated mutual interference coefficient according to the field medium environment of the site to be tested, so as to adapt to the interference deviation caused by the field medium environment.

[0017] Optionally, the near-field mutual interference compensation processing of the original data point by point and layer by layer includes:

[0018] Horizontal interference between adjacent actual detection units is eliminated;

[0019] Interference between adjacent longitudinal detection units is eliminated.

[0020] Vertical interference between adjacent detection units in the interlayer is eliminated.

[0021] Optionally, before performing near-field mutual interference compensation processing on the original data point by point and level by level, the following steps are included: pre-identifying strong anomalous feature signals in the original data and marking and locking effective anomalous signals to avoid the effective anomalous signals being mistakenly removed during the compensation process.

[0022] A three-dimensional geophysical exploration system for underground space includes:

[0023] The array calibration and matrix construction module is used to select a reference site, deploy a reference three-dimensional geophysical array with multiple reference detection units, perform global mutual interference calibration on the reference three-dimensional geophysical array, obtain the mutual interference coefficient of different adjacent combinations of the reference detection units, and construct a mutual interference coefficient matrix.

[0024] The actual array deployment and data acquisition module is used to deploy an actual three-dimensional geophysical array with multiple actual detection units according to the site to be tested, and to acquire the raw data of the actual three-dimensional geophysical array.

[0025] The hierarchical mutual interference compensation processing module is used to perform near-field mutual interference compensation processing on the original data point by point and layer by layer according to the mutual interference coefficient matrix, so as to eliminate interference within the actual three-dimensional geophysical array.

[0026] The three-dimensional inversion imaging and model building module is used to perform three-dimensional inversion imaging based on the compensation data after near-field mutual interference compensation, and to build a three-dimensional model of the underground space.

[0027] An electronic device, comprising:

[0028] Memory, used to store programs;

[0029] A processor is used to run a program stored in the memory to execute a three-dimensional geophysical exploration method for underground space.

[0030] A computer-readable storage medium having stored thereon computer program instructions, which, when executed by a processor, implement a three-dimensional geophysical exploration method for underground space.

[0031] Beneficial effects: The present invention provides a three-dimensional geophysical exploration method for underground space. First, a benchmark detection array is deployed to complete the global mutual interference calibration. The mutual interference coefficients of different benchmark detection unit combinations are statistically analyzed and a mutual interference coefficient matrix is ​​constructed. Then, the original data of the actual three-dimensional geophysical array is collected. Based on the mutual interference coefficient matrix, near-field mutual interference compensation processing is carried out on the original data point by point and layer by layer. This effectively eliminates strong near-field mutual interference between actual detection units, thereby preventing data distortion and signal-to-noise ratio reduction in the center and edge areas of the actual three-dimensional geophysical array. Small-scale anomalies (such as microcavities and non-metallic tubes) are easily masked or form false anomalies. Attached Figure Description

[0032] Figure 1 This is a flowchart of a three-dimensional geophysical exploration method for underground space according to the present invention;

[0033] Figure 2 This is a structural diagram of the reference three-dimensional geophysical array of the present invention;

[0034] Figure 3 It is a traditional three-dimensional geophysical imaging image;

[0035] Figure 4 This is a three-dimensional geophysical imaging image after near-field interference compensation processing according to the present invention;

[0036] Figure 5 This is a comparison chart of coefficient corrections under humidity-resistivity coupling according to the present invention. Detailed Implementation

[0037] To make the technical solution of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings. The terms "first," "second," etc., used in this invention are for the convenience of describing the technical solutions of the invention and have no specific limiting effect; they are all general terms and do not constitute a limitation on the technical solutions of the invention. It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other. In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, not to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Multiple technical solutions in the same embodiment, as well as multiple technical solutions in different embodiments, can be arranged and combined to form new technical solutions that do not contradict or conflict, all of which are within the scope of protection claimed by this invention.

[0039] Example 1

[0040] like Figure 1 This embodiment provides a method for three-dimensional geophysical exploration of underground space, including:

[0041] Step S1: Select a reference site, deploy a reference three-dimensional geophysical array with multiple reference detection units, perform global mutual interference calibration on the reference three-dimensional geophysical array, obtain the mutual interference coefficient of different combinations of adjacent reference detection units, and construct the mutual interference coefficient matrix.

[0042] Specifically, when selecting a benchmark site, priority should be given to areas with uniform surface soil, no underground structures, no external electromagnetic radiation interference, and a terrain undulation of no more than 3°. This ensures high environmental consistency of the benchmark site, making it easier for the mutual interference coefficient obtained from the global mutual interference calibration to be unaffected by terrain or external objects, thus enhancing the benchmark reliability of the mutual interference coefficient. The benchmark detection unit serves as the calibration carrier, simulating the signal transmission and reception characteristics of the actual detection unit. The type of benchmark detection unit can be ground-penetrating radar or transient electromagnetic radar, etc. The number of benchmark detection units is not limited; it can be 16, 18, etc., preferably 16, arranged in 4 rows and 4 columns in a double-layer three-dimensional arrangement to construct a benchmark three-dimensional geophysical array. The spacing of the benchmark three-dimensional geophysical array (including left and right, front and back, and top and bottom) is preferably 0.2m.

[0043] Step S2: Based on the site to be tested, deploy an actual three-dimensional geophysical array with multiple actual detection units and collect the raw data of the actual three-dimensional geophysical array.

[0044] Specifically, based on the topographic contour, detection range, and survey task requirements of the site to be measured, and referring to the layout specifications of the benchmark 3D geophysical array, multiple actual detection units are deployed on-site to form a complete actual 3D geophysical array. The layout specifications, unit spacing, and layering structure of the actual 3D geophysical array need to be consistent with those of the benchmark 3D geophysical array. Furthermore, the benchmark detection units and actual detection units are of the same type, such as ground-penetrating radar or transient electromagnetic arrays, to ensure that the mutual interference coefficients obtained from calibration are accurately adapted to the on-site conditions and to improve the accuracy of near-field mutual interference compensation.

[0045] Step S3: Based on the mutual interference coefficient matrix, perform near-field mutual interference compensation processing on the original data point by point and layer by layer to eliminate interference within the actual three-dimensional geophysical array.

[0046] Specifically, in this invention, it is necessary to eliminate interference from adjacent horizontal actual detection units, eliminate interference from adjacent vertical actual detection units, and eliminate vertical coupling interference from adjacent interlayer detection units.

[0047] Step S4: Perform three-dimensional inversion imaging based on the compensation data after near-field mutual interference compensation to construct a three-dimensional model of the underground space.

[0048] Specifically, firstly, the compensated data is preprocessed to remove noise, normalize, and unify coordinates, eliminating residual interference and outliers to ensure accuracy and spatial consistency. Secondly, based on the geological conditions and accuracy requirements of the site, 3D inversion parameters and a mesh model are set, and the preprocessed compensated data is imported for 3D inversion calculations to obtain 3D imaging results of the underground medium's physical properties. Finally, the 3D imaging results are corrected, destigmatized, and optimized based on prior geological information. The underground spatial structure is then reconstructed based on the optimized 3D imaging results, generating a 3D model that accurately reflects the underground strata, anomalies, and spatial distribution, thus achieving a three-dimensional and visual representation of the underground spatial structure.

[0049] In summary, the three-dimensional geophysical exploration method for underground space of the present invention first deploys a benchmark detection array to complete the global mutual interference calibration, statistically analyzes the mutual interference coefficients of different benchmark detection unit combinations and constructs a mutual interference coefficient matrix, then collects the original data of the actual three-dimensional geophysical array, and performs near-field mutual interference compensation processing on the original data point by point and layer by layer according to the mutual interference coefficient matrix, thereby effectively eliminating strong near-field mutual interference between actual detection units, thereby preventing data distortion and signal-to-noise ratio reduction in the center and edge areas of the actual three-dimensional geophysical array, and preventing small-scale anomalies (such as microcavities and non-metallic tubes) from being easily masked or forming false anomalies.

[0050] Through simulation analysis, such as Figure 3 As shown, the raw data is affected by near-field interference from the probe array, resulting in a large amount of background noise and free fragments. Abnormal target contours are distorted, have low recognition accuracy, and the imaging quality is poor. Figure 4 As shown, after near-field mutual interference compensation and correction using the three-dimensional geophysical exploration method for underground space of the present invention, most of the interference noise is effectively filtered out, leaving only a very small number of weak residual noise points. The underground anomaly targets have complete shapes and clear outlines, and the imaging accuracy and overall regularity are significantly improved, effectively solving the imaging distortion problem caused by near-field mutual interference in traditional detection methods.

[0051] Example 2

[0052] like Figure 1 A three-dimensional geophysical exploration method for underground space, based on Example 1, in step S1, the global mutual interference calibration adopts an acquisition mode in which a single reference detection unit transmits independently in sequence and the remaining reference detection units receive synchronously, and the response data of each reference detection unit is recorded one by one, and the mutual interference correlation between any two groups of adjacent reference detection units is fully statistically analyzed.

[0053] Furthermore, the mutual interference coefficient matrix is ​​constructed, including: constructing the mutual interference coefficient matrix based on the mutual interference correlation between any two sets of adjacent reference detection units.

[0054] Specifically, the baseline 3D geophysical array is arranged as follows: rows and columns numbered 1-4, and the baseline detection unit is identified as A. ij Where i is the row number and j is the column number, there are a total of 16 elements. The arrangement of the reference detection elements is shown in the table below.

[0055] ,

[0056] First, the coefficient values ​​are determined as follows: (1) No self-interference of the self-reference detection unit: the diagonal element value is 0; (2) Directly adjacent: the mutual interference coefficient is 0.15-0.45; (3) Obliquely adjacent: the mutual interference coefficient is 0.03-0.12; (4) No contact reference detection unit between intervals: the mutual interference coefficient approaches 0.

[0057] Secondly, let's take the example of a 4th-order cross-interference coefficient matrix, with row element A. 11 To A 44 Using row and column bases in sequence, a 16×16 interference coefficient matrix is ​​formed. A core 4×4 schematic matrix is ​​extracted for easier understanding:

[0058] ,

[0059] Wherein, K within the matrix mn This represents the mutual interference coefficient generated by the m-th reference probe unit to the n-th reference probe unit, for example, K. 12 =0.32, which means that the mutual interference coefficient generated by the first reference detection unit to the second reference detection unit is 0.32.

[0060] Finally, (1) the reference detection unit A is triggered separately. 11 The detector signal is transmitted, and the remaining 15 reference detector units receive the interference signal, which is then converted to obtain A. 11 For the mutual interference coefficients of the remaining 15 reference detection units, fill them into the first row of the mutual interference coefficient matrix; (2) Trigger A individually in sequence. 11 A 12 ...A 44 Repeat the signal transmission and reception test for each reference detection unit; (3) After all units have been traversed and tested, fill in the corresponding values ​​according to the row and column positions to generate a complete 16×16 mutual interference coefficient matrix.

[0061] Example 3

[0062] like Figure 1A three-dimensional geophysical exploration method for underground space, based on Example 1, in step S1, performs global mutual interference calibration on the benchmark three-dimensional geophysical array, obtains the mutual interference coefficient of different adjacent benchmark detection unit combinations, and constructs a mutual interference coefficient matrix, including: dividing the benchmark three-dimensional geophysical array into three calibration areas: array center area, array edge area, and array corner area, collecting the unit mutual interference coefficient of each calibration area respectively, and generating a partition-independent mutual interference coefficient unit matrix.

[0063] Specifically, the baseline 3D geophysical array has a 4×4 arrangement structure, with a total of 16 baseline detection units. The specific steps are as follows:

[0064] First, the 4×4 three-dimensional geophysical array of 16 reference detection units is divided into regions. Considering the array's layout, edge effects, and spatial interference differences, the array is uniformly divided into a central region (containing 4 reference detection units, e.g., ...). Figure 2 (square structure in the array), array edge region (8 reference detection units, such as...) Figure 2 The circular structure in the array), the corner region of the array (4 reference detection units, such as...) Figure 2 The three calibration areas (triangular structure in the middle) enable the classification of 16 reference detection units in a comprehensive and non-overlapping manner without any omissions or overlaps.

[0065] Secondly, for the three defined calibration areas, independent mutual interference calibration tests were conducted. Individual reference detectors within each calibration area were activated sequentially, and response data from all adjacent reference detectors were simultaneously collected. The combined operating conditions of different adjacent reference detectors were matched one by one, and the mutual interference impact values ​​corresponding to each combination of reference detectors were collected. The mutual interference coefficients of the array center area, array edge area, and array corner area were obtained separately. This effectively distinguished the mutual interference intensity deviations caused by differences in boundary and spatial positions in different calibration areas, avoiding coefficient errors caused by uniform calibration across the entire area.

[0066] Finally, based on the inter-interference coefficients of the units collected in each calibration area, independent inter-interference coefficient unit matrices are constructed for the array center area, array edge area, and array corner area respectively. Then, all independent inter-interference coefficient unit matrices are integrated to complete the construction of the inter-interference coefficient matrix of the entire domain of the 4×4 reference three-dimensional geophysical array.

[0067] In summary, this partition calibration method can specifically correct the near-field mutual interference deviation at the edge and corner positions of the benchmark three-dimensional geophysical array, accurately characterize the mutual interference pattern among the 16 benchmark detection units, and provide accurate and corresponding coefficient support for subsequent near-field mutual interference data compensation.

[0068] Example 4

[0069] like Figure 1A three-dimensional geophysical exploration method for underground space, based on Example 1, further includes dynamic correction of the mutual interference coefficient in step S2. The dynamic correction of the mutual interference coefficient includes: correcting the pre-calibrated mutual interference coefficient according to the on-site medium environment of the site to be tested, so as to adapt to the interference deviation caused by the on-site medium environment.

[0070] Specifically, this method dynamically corrects for interference deviations caused by differences in soil and humidity at different sites. After the cross-interference coefficient is determined at the benchmark site, the test site is a wet asphalt pavement after rain, and the soil dielectric constant and conductivity differ significantly from the dry benchmark site. The three-dimensional geophysical exploration method for underground space of this invention corresponds to a three-dimensional geophysical exploration system for underground space that collects the surface humidity and soil resistivity parameters of the test site in real time. The cross-interference coefficient is fine-tuned according to a preset correction formula to increase the interference compensation amplitude under humid conditions. Compared to fixed coefficient compensation, this method is adaptable to complex site environments and effectively solves the compensation failure problem caused by changes in the test site's operating conditions. The preset correction formula is as follows:

[0071] ,

[0072] In the formula, K is the corrected real-time mutual interference coefficient; K0 is the initial mutual interference coefficient of the reference site pre-calibration; α is the environmental correction weight constant; H is the real-time surface humidity of the site to be tested; H0 is the surface humidity of the reference site; β is the environmental correction weight constant; ρ is the real-time soil resistivity of the site to be tested; and ρ0 is the soil resistivity of the reference site.

[0073] like Figure 5 The horizontal axis represents the surface humidity of the test site (percentage relative to the reference site, unit: %), and the vertical axis represents the mutual interference coefficient (dimensionless). The black dashed line represents the traditional fixed coefficient compensation scheme, where the compensation intensity is always the initial mutual interference coefficient K0 pre-calibrated at the reference site. The red solid line represents the dynamic correction scheme of this invention, whose compensation coefficient can be adjusted in real time according to the coupling changes of on-site humidity and soil resistivity. Under the reference condition (blue dot), the dynamic correction coefficient is completely consistent with the fixed coefficient, verifying the continuity of the method. When humidity increases and soil resistivity decreases, the compensation coefficient automatically increases, effectively solving the problem of compensation failure caused by enhanced interference in humid environments. When humidity decreases, the compensation coefficient adaptively decreases, avoiding overcompensation distortion. This comparison intuitively demonstrates the adaptive compensation advantage of this invention in complex media environments.

[0074] Example 5

[0075] like Figure 1 A three-dimensional geophysical exploration method for underground space, based on Example 1, includes step S3, which involves performing near-field interference compensation processing on the raw data point-by-point and at different levels, including:

[0076] Horizontal interference between adjacent actual detection units is eliminated;

[0077] Interference between adjacent longitudinal detection units is eliminated.

[0078] Vertical interference between adjacent detection units in the interlayer is eliminated.

[0079] Specifically, the raw data undergoes point-by-point and level-by-level near-field interference compensation processing, and the self-interference signals of the actual three-dimensional geophysical array are simultaneously stripped away from the horizontal, vertical and other aspects to achieve accurate noise reduction and fidelity preservation.

[0080] Among them, the interference between adjacent actual detection units in the lateral direction is eliminated. In response to the lateral mutual interference and electromagnetic coupling interference caused by the dense arrangement of the left and right probes of the actual three-dimensional geophysical array in the same row, the near-field interference components of the adjacent actual detection units are calculated and removed with the target measurement point as the center, combined with the lateral mutual interference coefficient, to correct the lateral waveform distortion, eliminate the band-shaped false anomaly, and ensure that the anomaly boundary of the lateral detection profile is clear.

[0081] Interference between adjacent longitudinal detection units is eliminated. To address the signal superposition and time delay interference between actual detection units in the direction of travel, the signal trailing and superposition distortion caused by actual detection units in the direction of travel are filtered out based on the longitudinal mutual interference coefficient. This corrects the problems of longitudinal stretching and blurring of geological anomalies and restores the true longitudinal morphology of the strata.

[0082] Vertical coupling interference between adjacent detection units in the vertical layers is eliminated. In actual 3D geophysical arrays, electromagnetic penetration coupling, vertical signal interference and near-field superposition interference generated by actual detection units that are directly opposite or adjacent in the vertical space are eliminated. Based on the vertical interference coefficient, the vertical interference component between layers is calculated and stripped, vertical waveform distortion and signal tailing are corrected, and problems such as false anomalies in the depth direction, blurred stratum outlines and longitudinal stretching of anomalies caused by interlayer coupling are eliminated. The true burial depth and 3D shape of the underground target are restored, ensuring the accuracy and boundary clarity of the 3D inversion imaging in the depth direction.

[0083] Through the above-mentioned horizontal, vertical, and longitudinal collaborative point-by-point compensation, the near-field self-disruption of the actual three-dimensional geophysical array can be completely removed. While retaining the effective weak signals of underground pipelines, cavities, and geological defects, the signal-to-noise ratio of the original data can be significantly improved, providing a data foundation for high-precision three-dimensional inversion imaging.

[0084] Example 6

[0085] like Figure 1 A three-dimensional geophysical exploration method for underground space, based on Example 1, includes the following steps in step S3: before performing near-field mutual interference compensation processing on the original data point by point and layer by layer, identifying strong anomalous feature signals in the original data in advance, and marking and locking effective anomalous signals to avoid the effective anomalous signals being mistakenly removed during the compensation process.

[0086] Specifically, this embodiment adds an effective anomaly signal preservation mechanism to avoid the problem of effective anomaly signals being mistakenly deleted during the compensation process. Before performing near-field mutual interference compensation, the underground space three-dimensional geophysical exploration system of this invention uses feature recognition algorithms such as wavelet transform algorithm and extreme value threshold feature detection algorithm to identify waveform abrupt changes and amplitude anomaly-type feature signals in the original data, and marks and locks the effective anomaly signal areas corresponding to underground cavities, pipelines, and stratum voids. Subsequently, only background noise and array mutual interference signals without anomalies are removed, leaving weak effective anomaly signals corresponding to underground defects, completely improving the shortcomings of the traditional one-size-fits-all noise reduction compensation and significantly improving the accuracy of small-scale underground anomaly identification.

[0087] Example 7

[0088] like Figure 1 A three-dimensional geophysical exploration system for underground space, comprising:

[0089] The array calibration and matrix construction module is used to select a reference site, deploy a reference three-dimensional geophysical array with multiple reference detection units, perform global mutual interference calibration on the reference three-dimensional geophysical array, obtain the mutual interference coefficient of different combinations of adjacent reference detection units, and construct the mutual interference coefficient matrix.

[0090] The actual array deployment and data acquisition module is used to deploy an actual three-dimensional geophysical array with multiple actual detection units according to the site to be tested, and to acquire the raw data of the actual three-dimensional geophysical array.

[0091] The layered mutual interference compensation processing module is used to perform near-field mutual interference compensation processing on the original data point by point and layer by layer according to the mutual interference coefficient matrix, so as to eliminate interference in the actual three-dimensional geophysical array.

[0092] The 3D inversion imaging and model building module is used to perform 3D inversion imaging based on the compensated data after near-field mutual interference compensation, and to build a 3D model of the underground space.

[0093] Example 8

[0094] An electronic device, comprising:

[0095] Memory, used to store programs;

[0096] A processor for running programs stored in memory to execute a three-dimensional geophysical exploration method for underground space according to any one of embodiments 1-6.

[0097] Example 9

[0098] A computer-readable storage medium having stored thereon computer program instructions, which, when executed by a processor, implement a three-dimensional geophysical exploration method for underground space according to any one of embodiments 1-6.

[0099] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A three-dimensional geophysical exploration method for underground space, characterized in that, include: A reference site is selected, and a reference three-dimensional geophysical array is deployed with multiple reference detection units. The reference three-dimensional geophysical array is subjected to global mutual interference calibration to obtain the mutual interference coefficients of different adjacent combinations of the reference detection units and construct a mutual interference coefficient matrix. Based on the site to be tested, an actual three-dimensional geophysical array is deployed with multiple actual detection units, and the raw data of the actual three-dimensional geophysical array is collected. Based on the mutual interference coefficient matrix, the original data is subjected to near-field mutual interference compensation processing at each measurement point and at each level to eliminate interference within the actual three-dimensional geophysical array; Based on the compensation data after near-field mutual interference compensation, three-dimensional inversion imaging is performed to construct a three-dimensional model of the underground space; It also includes dynamic correction of the mutual interference coefficient, which includes: correcting the pre-calibrated mutual interference coefficient according to the field medium environment of the site to be tested, so as to adapt to the interference deviation caused by the field medium environment; The preset correction formula is as follows: ， In the formula, K is the corrected real-time mutual interference coefficient; K0 is the initial mutual interference coefficient of the reference site pre-calibration; α is the environmental correction weight constant; H is the real-time surface humidity of the site to be tested; H0 is the surface humidity of the reference site; β is the environmental correction weight constant; ρ is the real-time soil resistivity of the site to be tested; and ρ0 is the soil resistivity of the reference site.

2. The method for three-dimensional geophysical exploration of underground space according to claim 1, characterized in that, The global mutual interference calibration adopts a data acquisition mode in which each of the reference detection units transmits independently in sequence and the remaining reference detection units receive synchronously. The response data of each reference detection unit is recorded one by one, and the mutual interference correlation between any two groups of adjacent reference detection units is statistically analyzed to obtain the mutual interference coefficient of different combinations of adjacent reference detection units.

3. The method for three-dimensional geophysical exploration of underground space according to claim 2, characterized in that, The reference detection unit and the actual detection unit are of the same type.

4. The method for three-dimensional geophysical exploration of underground space according to claim 1, characterized in that, The step of performing global mutual interference calibration on the reference three-dimensional geophysical array, obtaining the mutual interference coefficients of different adjacent combinations of the reference detection units, and constructing a mutual interference coefficient matrix includes: dividing the reference three-dimensional geophysical array into three calibration regions: the array center region, the array edge region, and the array corner region; collecting the unit mutual interference coefficients of each calibration region; and generating a partition-independent mutual interference coefficient unit matrix.

5. The method for three-dimensional geophysical exploration of underground space according to claim 1, characterized in that, The near-field mutual interference compensation processing of the original data, performed point-by-point and at different levels, includes: Interference between adjacent horizontal detection units is eliminated. Interference between adjacent longitudinal detection units is eliminated. Vertical interference between adjacent detection units in the interlayer is eliminated.

6. The method for three-dimensional geophysical exploration of underground space according to claim 1, characterized in that, Before performing near-field mutual interference compensation processing on the original data point by point and level by level, the process includes: pre-identifying strong abnormal feature signals in the original data, marking and locking effective abnormal signals to avoid the effective abnormal signals being mistakenly removed during the compensation process.

7. A three-dimensional geophysical exploration system for underground space, characterized in that, A method for implementing a three-dimensional geophysical exploration method for underground space as described in any one of claims 1-6, comprising: The array calibration and matrix construction module is used to select a reference site, deploy a reference three-dimensional geophysical array with multiple reference detection units, perform global mutual interference calibration on the reference three-dimensional geophysical array, obtain the mutual interference coefficient of different adjacent combinations of the reference detection units, and construct a mutual interference coefficient matrix. The actual array deployment and data acquisition module is used to deploy an actual three-dimensional geophysical array with multiple actual detection units according to the site to be tested, and to acquire the raw data of the actual three-dimensional geophysical array. The hierarchical mutual interference compensation processing module is used to perform near-field mutual interference compensation processing on the original data point by point and layer by layer according to the mutual interference coefficient matrix, so as to eliminate interference within the actual three-dimensional geophysical array. The three-dimensional inversion imaging and model building module is used to perform three-dimensional inversion imaging based on the compensation data after near-field mutual interference compensation, and to build a three-dimensional model of the underground space.

8. An electronic device, characterized in that, include: Memory, used to store programs; A processor is configured to run a program stored in the memory to execute a three-dimensional geophysical exploration method for underground space according to any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, It stores computer program instructions, which, when executed by a processor, implement the three-dimensional geophysical exploration method for underground space according to any one of claims 1-6.

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