A single-transmitter multi-receiver transient electromagnetic detection device and method

Abstract

The application relates to the technical field of geological exploration, and provides a single-transmitter multi-receiver transient electromagnetic detection device and method. The single-transmitter multi-receiver transient electromagnetic detection device comprises a transmitting system, a receiving system, a support frame, a synchronization assembly and a three-component directional device. The single-transmitter multi-receiver transient electromagnetic detection device can excite a bipolar square wave to the underground through a single transmitter and a transmitting coil, so as to generate an induced secondary field. Six groups of orthogonal receiving coils arranged around the transmitting coil are used to synchronously collect three-component transient electromagnetic response data of corresponding positions with the transmitter. The three-component directional device is used to record the directional data of three components in the measurement process, so as to complete the directional correction of the measurement data and achieve the purpose of simultaneously obtaining complete detection information of the underground target body at multiple positions. In addition, the application further provides a method applied to the single-transmitter multi-receiver transient electromagnetic detection device.

Description

Technical Field

[0001] This application relates to the technical field of geological exploration, and in particular to a single-transmitter, multi-receiver transient electromagnetic detection device and method. Background Technology

[0002] Transient electromagnetic methods (TEM) are an important geophysical exploration technique for detecting the electrical characteristics of underground geological bodies. Their detection devices and methods are a significant research area in the fields of geological exploration and underground target identification. This technology is crucial for landslide investigation, dam hazard detection, and the identification of shallow underground anomalies. Current research mainly focuses on transient electromagnetic detection devices and data acquisition methods, aiming to achieve effective identification and detection of shallow underground geological bodies and anomalous structures through technological means.

[0003] Currently, the mainstream technical solution for transient electromagnetic detection of underground targets adopts a single-transmitter, single-receiver device and measurement mode. This mode uses a single set of transmitting coils to excite a transient electromagnetic field underground, and a single set of receiving coils to receive the transient response of the secondary field generated by the underground target. By processing and inverting the collected response data, the electrical distribution characteristics of the underground strata are obtained, thereby identifying the abnormal geological bodies that exist underground.

[0004] However, existing conventional single-transmitter, single-receiver transient electromagnetic detection schemes employ a single-point, fixed-receiver operating mode. This makes it impossible to simultaneously acquire transient response data from multiple key locations under the same transmitter during a single detection process. Consequently, it is difficult to comprehensively obtain complete detection information about underground targets, thus limiting the effectiveness and accuracy of identifying underground anomalies. Furthermore, existing schemes have significant limitations in shallow geological exploration scenarios. They are unable to effectively reduce the blind zone of shallow detection, nor can they effectively suppress inherent interference factors during the detection process. Their ability to identify weak underground anomalies is insufficient, making them unsuitable for the practical application requirements of shallow, fine-grained geological exploration. Summary of the Invention

[0005] In view of this, this application aims to propose a single-transmitter, multi-receiver transient electromagnetic detection device and method to solve the above-mentioned technical problems.

[0006] To achieve the above objectives, the technical solution of this application is implemented as follows: In a first aspect, this application proposes a single-transmitter, multi-receiver transient electromagnetic detection device, comprising: The transmitting system is used to transmit bipolar square waves underground to excite the underground target to generate a secondary induction field; The receiving system is synchronously connected to the transmitting system and is used to simultaneously acquire transient electromagnetic response data of multiple locations and multiple orthogonal components around the transmitting coil; The support frame is a hexahedral structure, and its edges are used to support and fix the transmitting system and the receiving system. A synchronization component is electrically connected to the transmitting system and the receiving system respectively, and is used to realize the synchronization control of the transmitted signal and the received acquisition. A three-component orienter is fixed to the support frame, and its three components are arranged corresponding to the three orthogonal edges of the support frame. It is used to record the direction data of the three components during the measurement process and to provide a basis for direction correction of the measurement data.

[0007] Furthermore, the launching system includes: Transmitter, used to output bipolar square wave current with set parameters; The transmitting coil, made of one or more turns of copper wire with good conductivity, is fixed to the edge of the support frame. Its input end is electrically connected to the output end of the transmitter. It is used to generate a primary field underground under current excitation, thereby causing the underground target to generate a secondary induction field.

[0008] Furthermore, the receiving system includes a Z-component receiving unit, an X-component receiving unit, and a Y-component receiving unit; the Z-component receiving unit, the X-component receiving unit, and the Y-component receiving unit are arranged orthogonally in pairs and fixed at corresponding positions on the support frame.

[0009] Furthermore, the Z component receiving unit includes a Z1 receiving coil, a Z2 receiving coil, a Z1 receiver, and a Z2 receiver; The Z1 receiving coil is electrically connected to the Z1 receiver and is located at the lower part of the support frame. The Z2 receiving coil is electrically connected to the Z2 receiver and is located at the upper part of the support frame. Both are used to collect the vertical component transient response data of the underground secondary induction field.

[0010] Furthermore, the X component receiving unit includes an X1 receiving coil, an X2 receiving coil, an X1 receiver, and an X2 receiver; The X1 receiving coil is electrically connected to the X1 receiver and is located at the front of the support frame. The X2 receiving coil is electrically connected to the X2 receiver and is located at the rear of the support frame. Both are used to collect transient response data of the horizontal component of the underground secondary induction field in the X direction.

[0011] Furthermore, the Y component receiving unit includes a Y1 receiving coil, a Y2 receiving coil, a Y1 receiver, and a Y2 receiver; The Y1 receiving coil is electrically connected to the Y1 receiver and is located on the left side of the support frame. The Y2 receiving coil is electrically connected to the Y2 receiver and is located on the right side of the support frame. Both are used to collect transient response data of the horizontal component of the underground secondary induction field in the Y direction.

[0012] Compared with existing technologies, the transient electromagnetic detection device with single-transmitter and multi-receiver capability proposed in this application has the following advantages: (1) This application uses a transmitting system in conjunction with multiple sets of orthogonally deployed receiving systems to simultaneously collect transient electromagnetic response data of multiple locations and multiple orthogonal components under the condition of a single transmitting source. This achieves the effect of obtaining multi-dimensional complete detection information of underground targets in a single detection, effectively improving the accuracy of spatial location judgment of underground anomalies.

[0013] (2) By deploying multiple sets of receiving coils of the same component at different positions of the support frame, this application can perform differential processing on transient electromagnetic response data of the same component at different positions, thereby effectively suppressing mutual inductance interference between the transmitting and receiving coils, while also increasing the amplitude of abnormal signals of underground targets and enhancing the ability to identify weak underground anomalies.

[0014] (3) This application realizes the synchronous acquisition and control of the transmitting system and the receiving system through the synchronization component. Combined with the direction data collected by the three-component directional device fixed on the support frame, it achieves the effect of directional correction of the acquired transient electromagnetic response data, ensuring the reliability and consistency of the detection data, and can adapt to the application requirements of complex exploration scenarios.

[0015] Secondly, this application proposes a method for use in the aforementioned single-transmitter, multi-receiver transient electromagnetic detection device, comprising the following steps: S1, Complete the construction of the support frame, which adopts a cube structure or a cuboid structure; S2, The transmission system and the three-component directional device are deployed. A transmission coil is wound with copper wire with good conductivity according to the length of the edge of the support frame. The transmission coil is fixed on the support frame. At the same time, the three-component directional device is fixed on the support frame, ensuring that the three components of the three-component directional device are consistent with the three orthogonal edges of the support frame. The transmitter is electrically connected to the transmission coil. S3, the receiving system is deployed by winding multiple sets of receiving coils with copper enameled wire according to the dimensions of the support frame. Each set of receiving coils is fixed in an orthogonal state at the corresponding position of the support frame. Each set of receiving coils is connected to the corresponding receiver to form an independent receiving branch. Each receiving branch is connected to the transmitter through a synchronization component. At the same time, the three-component directional device is connected to each receiver. S4, Set acquisition parameters: A bipolar square wave current is passed through the transmitting coil by the transmitter, and the transmitting current parameters and acquisition parameters are set according to the detection requirements. S5, synchronous data acquisition: the 6 sets of receiving coils are synchronized with the transmitter, and simultaneously measure the transient electromagnetic response data at their respective positions and the direction data of the three-component directional device. The acquisition process is carried out during the off-time period of the transmitted waveform, and the acquisition rate is set to 1000KHz-250KHz. S6, Data processing and anomaly analysis: Based on the collected transient electromagnetic response data and direction data, the detection and feature analysis of underground anomalies are completed.

[0016] Furthermore, in step S6, the direction data collected by the three-component directional device is first used to correct the direction of each group of transient electromagnetic response data, and then the corrected 6 groups of transient electromagnetic response data are inverted and calculated separately to obtain the detection information of the underground anomalies at 6 corresponding locations.

[0017] Furthermore, in step S6, the corrected transient electromagnetic response data is grouped according to the three components X, Y, and Z, and the gradient change data of the three groups of data is calculated respectively. Based on the gradient change data, the electrical abrupt change region of the underground anomaly is located.

[0018] Furthermore, in step S6, the corrected 6 sets of transient electromagnetic response data are synthesized into vector data, and the spatial morphological parameters of the underground anomaly are obtained by tracing the vector data.

[0019] Compared with existing technologies, the method proposed in this application for the aforementioned single-transmitter, multi-receiver transient electromagnetic detection device has the following advantages: (1) This application sets up the transmitting system, the three-component directional device and the receiving system in sequence after the supporting frame is completed. Then, the transmitter sets the acquisition parameters and controls multiple sets of receiving coils to collect data synchronously. This achieves the effect of simultaneously acquiring multi-position multi-component transient electromagnetic response data in a single detection process, which simplifies the operation process of multi-position detection and improves the efficiency of detection work.

[0020] (2) This application uses the directional data collected by the three-component directional device to perform directional correction on the transient electromagnetic response data, and then performs gradient change calculation on the corrected same component data, thereby achieving the effect of effectively locating the electrical abrupt change area of ​​the underground anomaly and improving the recognition effect of the boundary and spatial distribution of the underground anomaly.

[0021] (3) This application achieves the effect of comprehensively acquiring multi-dimensional information of underground anomalies and clarifying their spatial morphological characteristics by performing separate inversion and vector synthesis processing on multiple sets of corrected transient electromagnetic response data, thereby further improving the comprehensive detection capability of underground complex anomalies. Attached Figure Description

[0022] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the structure of the single-transmitter, multi-receiver transient electromagnetic detection device described in the embodiments of this application; Figure 2 This is a schematic diagram of a single-transmitter, multi-receiver transient electromagnetic detection device as described in an embodiment of this application; Figure 3 This is a comparison diagram of wireframe data of the single-transmitter, multi-receiver transient electromagnetic detection device described in the embodiments of this application under different conditions; Figure 4 This is a comparison of two curves under the condition of no abnormal body for the single-transmitter, multi-receiver transient electromagnetic detection device described in the embodiments of this application. Figure 5 A comparison diagram of two curves under abnormal conditions for the single-transmitter, multi-receiver transient electromagnetic detection device described in this application embodiment; Figure 6 This is a diagram showing the data difference results between the left and right sides of the single-transmitter, multi-receiver transient electromagnetic detection device described in this application embodiment. Detailed Implementation

[0023] To make the technical solution and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0025] Furthermore, it should be noted that in the description of this application, if terms such as "upper," "lower," "inner," or "outer" appear, indicating orientation or positional relationship, these are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this application and simplifying the description, and do not 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 on this application. In addition, if terms such as "first" or "second" appear, they are also used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] Furthermore, in the description of this application, unless otherwise expressly defined, the terms "installation," "connection," "joining," and "connector" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection 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 application in light of the specific circumstances.

[0027] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0028] The present application will now be described in detail through exemplary embodiments. However, it should be understood that, without further description, elements, structures, and features in one embodiment may be advantageously incorporated into other embodiments.

[0029] This application provides a single-transmitter, multi-receiver transient electromagnetic detection device, applicable to the field of geological exploration, comprising a transmitting system, a receiving system, a support frame, a synchronization component, and a three-component direction finder. (Refer to...) Figure 1The support frame is a hexahedral structure made of insulated rigid material. Its edges provide a stable support foundation for the entire device. Both the transmitting and receiving systems are fixed to corresponding positions on the edges of the support frame, ensuring that the relative positions of each component remain fixed during detection and preventing data consistency issues caused by positional shifts. The transmitting system emits bipolar square waves into the ground, exciting the underground target to generate a secondary induction field. The output of the transmitting system is synchronously connected to the input of the receiving system via a synchronization component, ensuring that the acquisition actions of the receiving system are synchronized with the signal transmission actions of the transmitting system. The receiving system simultaneously acquires transient electromagnetic response data from multiple locations and multiple orthogonal components around the transmitting coil. It can acquire multiple sets of response data excited by the same source in a single detection, solving the problem that existing single-transmitter, single-receiver devices can only acquire data from a single point in a single detection. The synchronization component is electrically connected to both the transmitting and receiving systems, and consists of multiple sets of synchronization cables. It provides a unified timing reference for the transmitting and receiving systems, achieving synchronous control of the transmitted signal and the received data, ensuring that the data acquired by multiple receiving systems have a unified time reference, providing a foundation for subsequent data processing. The three-component directional device is fixed at the center of the support frame, and its three components are arranged corresponding to the three orthogonal edges of the support frame. A magnetic directional device or a gravity acceleration directional device is used to record the direction data of the three components during the measurement process, providing a basis for direction correction of the measurement data. If the device tilts or deviates in direction during the detection process, the response data can be corrected by the collected direction data to ensure the accuracy of the detection data.

[0030] exist Figure 1In the middle, Tx—transmitter, which emits a bipolar square wave in the transmitting coil to excite the underground target to generate a secondary field; Tx loop—transmitting coil, composed of a single-turn or multi-turn coil loop, forming the transmitting system with Tx, its side length is positively correlated with the detection depth; Coil Z1—Z component receiving coil (bottom), composed of multi-turn coils, receives the vertical component (Z component) of the secondary field; Coil Z2—Z component receiving coil (top), composed of multi-turn coils, receives the vertical component (Z component) of the secondary field; Coil X1—X component receiving coil (front), composed of multi-turn coils, receives the horizontal component (X component) of the secondary field; Coil X2—X component receiving coil (rear), composed of multi-turn coils, receives the horizontal component (X component) of the secondary field; Coil Y1—Y component receiving coil (left), composed of multi-turn coils, receives the horizontal component (Y component) of the secondary field; Coil Y2—Y component receiving coil (right), composed of multi-turn coils, receives the horizontal component (Y component) of the secondary field; RZ1—receiver, connected to Coil Z1; RZ2—Receiver, connected to Coil Z2; RX1—Receiver, connected to Coil X1; RX2—Receiver, connected to Coil X2; RY1—Receiver, connected to Coil Y1; RY2—Receiver, connected to Coil Y2; S—Frame, a hexahedral structure, its edges are used to support and fix each coil. C—Synchronization cable, the connecting line between the transmitter and receiver, to achieve signal synchronization. Director—Three-component director, using a magnetic director or a gravity acceleration director to record the direction data of the three components during the measurement process, which can be used for direction correction later.

[0031] To stably generate a primary field that meets the detection requirements underground, in this embodiment, the transmitting system includes a transmitter and a transmitting coil. The transmitter is a dedicated transient electromagnetic transmitting device, internally equipped with a power amplification module, a waveform generation module, and a synchronization control module. The waveform generation module generates a bipolar square wave signal with set parameters, which is amplified by the power amplification module and output to the transmitting coil. The synchronization control module is connected to a synchronization component and is used to output a synchronization timing signal to the receiving system. The transmitting coil is wound with one or more turns of highly conductive copper wire. The shape of the wound coil matches the end face shape of the support frame and is fixed to the edge of the support frame. Its input end is electrically connected to the output end of the transmitter via a waterproof cable. Under the excitation of the current output by the transmitter, the transmitting coil generates a primary field underground. The alternating primary field generates induced eddy currents in the underground strata, thereby causing the underground target to generate a secondary induced field, providing a field source basis for subsequent receiving and acquisition. The side length of the transmitting coil is positively correlated with the detection depth. The side length and number of turns of the transmitting coil can be adjusted according to the actual detection depth requirements to adapt to the exploration needs at different depths.

[0032] To achieve the goal of comprehensively acquiring field response data from the three orthogonal directions of the underground secondary induction field, this embodiment includes a Z-component receiving unit, an X-component receiving unit, and a Y-component receiving unit. These three units are arranged orthogonally in pairs and fixed to corresponding end faces of the support frame. The measurement directions of the three units are mutually perpendicular, corresponding to the three orthogonal directions of the spatial rectangular coordinate system. This allows for the complete acquisition of the underground secondary induction field components in the three orthogonal directions, avoiding the loss of field information caused by acquisition from a single direction. The three receiving units are positioned on different end faces of the support frame, enabling simultaneous acquisition of field response data from different spatial locations under the excitation of the same source, providing a data foundation for subsequent differential processing and gradient calculation.

[0033] To accurately acquire the transient response data of the vertical component of the underground secondary induction field, in this embodiment, the Z-component receiving unit includes a Z1 receiving coil, a Z2 receiving coil, a Z1 receiver, and a Z2 receiver. The Z1 receiving coil and the Z1 receiver are electrically connected via a shielded cable and are positioned at the lower part of the support frame, specifically fixed to the lower end face of the support frame, close to the detection ground. The Z2 receiving coil and the Z2 receiver are electrically connected via a shielded cable and are positioned at the upper part of the support frame, specifically fixed to the upper end face of the support frame, arranged vertically opposite to the Z1 receiving coil. The planes of the two coils are parallel to each other, and their central axes coincide. Both the Z1 and Z2 receiving coils are made of multi-turn copper enameled wire, with the coil plane parallel to the ground. They are used to collect the transient response data of the vertical component of the underground secondary induction field. In the two sets of vertical component data, the common-mode interference signal generated by the mutual inductance between the coils has similar amplitude and phase, while the effective response signal generated by the underground anomaly has positional differences. By differential processing of the two sets of data, the common-mode mutual inductance interference signal can be eliminated, highlighting the effective response signal generated by the underground anomaly.

[0034] To accurately acquire transient response data of the horizontal component of the underground secondary induction field in the X direction, this embodiment includes an X1 receiving coil, an X2 receiving coil, an X1 receiver, and an X2 receiver. The X1 receiving coil and the X1 receiver are electrically connected via a shielded cable and are positioned at the front of the support frame, specifically fixed to the front end face of the support frame. The X2 receiving coil and the X2 receiver are electrically connected via a shielded cable and are positioned at the rear of the support frame, specifically fixed to the rear end face of the support frame. They are arranged opposite to the X1 receiving coil, with their planes parallel and their central axes coinciding. Both the X1 and X2 receiving coils are wound with multi-turn copper enameled wire, and their coil planes are perpendicular to the ground. They are used to acquire transient response data of the horizontal component of the underground secondary induction field in the X direction. The two sets of horizontal component data in the X direction can be used to directly calculate the horizontal gradient, reflecting the electrical lateral variation characteristics of the underground strata in the X direction. Simultaneously, differential processing can eliminate common-mode interference and improve the recognition of abnormal signals.

[0035] To accurately acquire transient response data of the horizontal component of the underground secondary induction field in the Y direction, in this embodiment, the Y component receiving unit includes a Y1 receiving coil, a Y2 receiving coil, a Y1 receiver, and a Y2 receiver. The Y1 receiving coil and the Y1 receiver are electrically connected via a shielded cable and are positioned on the left side of the support frame, specifically fixed to the left end face of the support frame. The Y2 receiving coil and the Y2 receiver are electrically connected via a shielded cable and are positioned on the right side of the support frame, specifically fixed to the right end face of the support frame. They are arranged opposite to the Y1 receiving coil, with their planes parallel to each other and their central axes coinciding. Both the Y1 and Y2 receiving coils are made of multi-turn copper enameled wire. The coil plane is perpendicular to the ground and orthogonal to the coil plane of the X component receiving unit. They are used to collect transient response data of the horizontal component of the underground secondary induction field in the Y direction. The horizontal gradient can be directly obtained from the two sets of horizontal component data in the Y direction, reflecting the electrical transverse variation characteristics of the underground strata in the Y direction. Combined with the X component data, the horizontal electrical variation information of the underground strata can be completely obtained. At the same time, common-mode interference can be eliminated through differential processing, further improving the ability to identify underground anomalies.

[0036] Based on the goal of standardizing the single-transmitter multi-receiver transient electromagnetic detection process and ensuring the synchronous acquisition of multiple sets of data, in this embodiment, the single-transmitter multi-receiver transient electromagnetic detection method is applied to the aforementioned single-transmitter multi-receiver transient electromagnetic detection device, including the following steps. Step S1: Complete the construction of the support frame. The support frame adopts a cubic or cuboid structure. The size of the support frame is determined according to the actual detection requirements. Insulated rigid rods are spliced ​​to form a hexahedral support frame, ensuring that the edges of the frame are straight and that each adjacent edge is perpendicular to each other, providing a stable support foundation for the subsequent fixing of various components. Step S2: Deploy the transmitting system and the three-component directional device. Use highly conductive copper wire to wind the transmitting coil according to the length of the support frame edges. After winding, fix the transmitting coil on the corresponding edge of the support frame, ensuring that the shape of the transmitting coil is regular. At the same time, fix the three-component directional device at the center position of the support frame, adjust the deployment angle of the three-component directional device to ensure that the three components of the three-component directional device are consistent with the three orthogonal edges of the support frame, and then connect the transmitter and the transmitting coil through a waterproof cable to complete the deployment of the transmitting system and the three-component directional device. Step S3: Deployment of the receiving system. Multiple sets of receiving coils are wound using copper enameled wire according to the end face dimensions of the support frame. The number of coil turns is set from several to tens of turns based on actual detection requirements. Each set of receiving coils is fixed orthogonally to the corresponding end face position of the support frame, ensuring that the deployment planes of each set of receiving coils are mutually orthogonal. Each set of receiving coils is then connected to its corresponding receiver via shielded cables to form an independent receiving branch. Each receiving branch is connected to the transmitter via a synchronization component. Simultaneously, a three-component directional sensor is connected to each receiver, allowing the direction data collected by the three-component directional sensor to be synchronously transmitted to each receiver and stored synchronously with the transient electromagnetic response data. Step S4: Setting of acquisition parameters. A bipolar square wave current is passed through the transmitting coil via the transmitter. The transmitting current parameters and acquisition parameters are set according to the detection requirements. The transmitting current can be set from several amperes to tens of amperes. Parameters such as the frequency and off-time of the transmitted waveform, as well as the acquisition duration and storage format of the receiver, are also set. Step S5: Synchronous data acquisition. Six sets of receiving coils are synchronized with the transmitter, simultaneously measuring the transient electromagnetic response data and the direction data of the three-component directional probe at their respective locations. The acquisition process is performed during the off-time of the transmitted waveform to avoid strong primary field interference. The acquisition rate is set between 1000 kHz and 2500 kHz to ensure that the acquired data fully reflects the attenuation process of the transient field. Step S6: Data processing and anomaly analysis. Based on the acquired transient electromagnetic response and direction data, the detection and feature analysis of underground anomalies are completed. By processing multiple sets of synchronously acquired response data, the electrical distribution characteristics of the underground strata can be comprehensively obtained, identifying underground anomalies and analyzing their related features.

[0037] To eliminate the impact of device attitude changes on the data during detection and improve the reliability of single-point inversion results, in this embodiment, in step S6, the direction data collected by the three-component directional device is first used to correct the direction of each group of transient electromagnetic response data. Then, the corrected six groups of transient electromagnetic response data are inverted and calculated separately to obtain the detection information of underground anomalies at six corresponding locations. (Refer to...) Figure 2 To verify the detection effect of this method, a model of a blocky low-resistivity anomaly located below a uniform half-space was constructed. In the model, the bedrock conductivity was set to 0.001, the anomaly conductivity was set to 0.1, and the emission frame size was 1m x 1m. The frame closer to the anomaly was designated as the left frame, and the frame farther from the anomaly as the right frame. (Refer to...) Figure 3 The image shows a comparison of wireframe data under different conditions. When there are no underground anomalies, the X-direction component data collected by the left wireframe overlaps with the data collected by the right wireframe. When there are underground anomalies, the X-direction component data collected by the left wireframe is clearly separated from the data collected by the right wireframe. The data closer to the anomaly shows obvious anomalies in the later stages. By inverting the data from six different locations separately, the underground stratigraphic information corresponding to different locations can be obtained, and the data can be compared and verified to improve the accuracy of anomaly location judgment.

[0038] To accurately locate the boundaries and electrical abrupt change regions of underground anomalies, in this embodiment, step S6 involves grouping the corrected transient electromagnetic response data into three components (X, Y, and Z), calculating the gradient change data for each of the three groups, and then locating the electrical abrupt change regions of the underground anomalies based on the gradient change data. (Refer to...) Figure 4 This is a comparison of the curves on both sides under the condition of no anomalies. When there are no anomalies underground, the X-direction component field values ​​at different times of the left and right frame positions are symmetrically distributed and opposite in value. (Refer to...) Figure 5 The image shows a comparison of curves on both sides under the condition of an anomaly. When an anomaly is present underground, the field value diffusion is slower and the field value distribution range is smaller at the boundary of the anomaly. The field value diffusion is faster and the distribution range is larger at the boundary of the anomaly. By obtaining gradient change data from two sets of data with the same component, the difference in field value caused by the anomaly can be effectively highlighted, the electrical abrupt change region of the underground anomaly can be located, and the boundary range of the anomaly can be clarified.

[0039] To fully reconstruct the spatial morphological characteristics of underground anomalies and improve the precision of detection, in this embodiment, step S6 involves synthesizing the corrected six sets of transient electromagnetic response data into vector data. The spatial morphological parameters of the underground anomaly are then calculated using vector data tracing. (Refer to...) Figure 6The image shows the difference results of the data on the left and right sides. By performing differential calculations on two sets of data with the same component, common-mode interference signals can be effectively eliminated, highlighting the effective response generated by the anomaly. The differential results can intuitively reflect the spatial distribution of the anomaly boundary. By synthesizing the response data of 6 sets of different locations and different components into vector data, the spatial distribution characteristics of the underground secondary induction field can be fully reflected. Through the source tracing calculation of the vector data, the spatial morphological parameters of the underground anomaly can be accurately obtained, realizing the fine detection of the underground anomaly.

[0040] The above descriptions are merely some embodiments of this application and are not intended to limit this application. The technical features or structures in the foregoing different embodiments can be arbitrarily combined to form other specific technical solutions as needed. For those skilled in the art, this application can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of the claims of this application.

Claims

1. A transient electromagnetic detection device with single-transmitter and multiple-receiver capability, characterized in that, include: The transmitting system is used to transmit bipolar square waves underground to excite the underground target to generate a secondary induction field; The receiving system is synchronously connected to the transmitting system and is used to simultaneously acquire transient electromagnetic response data of multiple locations and multiple orthogonal components around the transmitting coil; The support frame is a hexahedral structure, and its edges are used to support and fix the transmitting system and the receiving system. A synchronization component is electrically connected to the transmitting system and the receiving system respectively, and is used to realize the synchronization control of the transmitted signal and the received acquisition. A three-component orienter is fixed to the support frame, and its three components are arranged corresponding to the three orthogonal edges of the support frame. It is used to record the direction data of the three components during the measurement process and to provide a basis for direction correction of the measurement data.

2. The transient electromagnetic detection device with single-transmitter and multi-receiver capability according to claim 1, characterized in that, The launching system includes: Transmitter, used to output bipolar square wave current with set parameters; The transmitting coil, made of one or more turns of copper wire with good conductivity, is fixed to the edge of the support frame. Its input end is electrically connected to the output end of the transmitter. It is used to generate a primary field underground under current excitation, thereby causing the underground target to generate a secondary induction field.

3. The transient electromagnetic detection device with single-transmitter and multi-receiver capability according to claim 1, characterized in that, The receiving system includes a Z-component receiving unit, an X-component receiving unit, and a Y-component receiving unit; the Z-component receiving unit, the X-component receiving unit, and the Y-component receiving unit are arranged orthogonally in pairs and fixed at corresponding positions on the support frame.

4. A single-transmitter, multi-receiver transient electromagnetic detection device according to claim 3, characterized in that, The Z-component receiving unit includes a Z1 receiving coil, a Z2 receiving coil, a Z1 receiver, and a Z2 receiver; The Z1 receiving coil is electrically connected to the Z1 receiver and is located at the lower part of the support frame. The Z2 receiving coil is electrically connected to the Z2 receiver and is located at the upper part of the support frame. Both are used to collect the vertical component transient response data of the underground secondary induction field.

5. A single-transmitter, multi-receiver transient electromagnetic detection device according to claim 3, characterized in that, The X component receiving unit includes an X1 receiving coil, an X2 receiving coil, an X1 receiver, and an X2 receiver; The X1 receiving coil is electrically connected to the X1 receiver and is located at the front of the support frame. The X2 receiving coil is electrically connected to the X2 receiver and is located at the rear of the support frame. Both are used to collect transient response data of the horizontal component of the underground secondary induction field in the X direction.

6. A single-transmitter, multi-receiver transient electromagnetic detection device according to claim 3, characterized in that, The Y component receiving unit includes a Y1 receiving coil, a Y2 receiving coil, a Y1 receiver, and a Y2 receiver; The Y1 receiving coil is electrically connected to the Y1 receiver and is located on the left side of the support frame. The Y2 receiving coil is electrically connected to the Y2 receiver and is located on the right side of the support frame. Both are used to collect transient response data of the horizontal component of the underground secondary induction field in the Y direction.

7. A method for detecting transient electromagnetic signals with single-transmission and multiple-receiver capability, applied to the transient electromagnetic detection device with single-transmission and multiple-receiver capability as described in any one of claims 1 to 6, characterized in that, Includes the following steps: S1, Complete the construction of the support frame, which adopts a cube structure or a cuboid structure; S2, The transmission system and the three-component directional device are deployed. A transmission coil is wound with copper wire with good conductivity according to the length of the edge of the support frame. The transmission coil is fixed on the support frame. At the same time, the three-component directional device is fixed on the support frame, ensuring that the three components of the three-component directional device are consistent with the three orthogonal edges of the support frame. The transmitter is electrically connected to the transmission coil. S3, the receiving system is deployed by winding multiple sets of receiving coils with copper enameled wire according to the dimensions of the support frame. Each set of receiving coils is fixed in an orthogonal state at the corresponding position of the support frame. Each set of receiving coils is connected to the corresponding receiver to form an independent receiving branch. Each receiving branch is connected to the transmitter through a synchronization component. At the same time, the three-component directional device is connected to each receiver. S4, Set acquisition parameters: A bipolar square wave current is passed through the transmitting coil by the transmitter, and the transmitting current parameters and acquisition parameters are set according to the detection requirements; S5, synchronous data acquisition: the 6 sets of receiving coils are synchronized with the transmitter, and simultaneously measure the transient electromagnetic response data at their respective positions and the direction data of the three-component directional device. The acquisition process is carried out during the off-time period of the transmitted waveform, and the acquisition rate is set to 1000KHz-250KHz. S6, Data processing and anomaly analysis: Based on the collected transient electromagnetic response data and direction data, the detection and feature analysis of underground anomalies are completed.

8. The transient electromagnetic detection method with single transmission and multiple reception according to claim 7, characterized in that, In step S6, the direction data collected by the three-component directional device is first used to correct the direction of each group of transient electromagnetic response data. Then, the corrected 6 groups of transient electromagnetic response data are inverted and calculated separately to obtain the detection information of the underground anomalies at the 6 corresponding locations.

9. A single-transmitter, multi-receiver transient electromagnetic detection method according to claim 7, characterized in that, In step S6, the corrected transient electromagnetic response data is grouped into three components: X, Y, and Z. The gradient change data of the three groups of data is calculated respectively, and the electrical abrupt change region of the underground anomaly is located based on the gradient change data.

10. A single-transmitter, multi-receiver transient electromagnetic detection method according to claim 7, characterized in that, In step S6, the corrected 6 sets of transient electromagnetic response data are combined into vector data, and the spatial morphological parameters of the underground anomaly are obtained by tracing the source of the vector data.

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