446 results about "Transient electromagnetics" patented technology

According to the goaf detection method based on transient electromagnetic and seismic wave field joint inversion, data acquisition and joint inversion are carried out on the goaf through the combination of the transient electromagnetic detection system and the reflection seismic detection system, the complementary advantages of the two detection methods are played, the bottlenecks of a single method in the aspects of resolution and signal-to-noise ratio are broken through, and the goaf detection method based on transient electromagnetic and seismic wave field joint inversion is realized. Fine characterization of the structure, the physical property and the stability of the goaf is realized; a machine learning classification algorithm is introduced to analyze a goaf multi-attribute feature data set, and intelligent discrimination of the type, scale and stability of the goaf under complex geological conditions is realized; establishing a quantitative response relationship between goaf physical property parameters and goaf electrical and elastic difference characteristic parameters, constructing a goaf transient electromagnetic and seismic wave field joint forward modeling numerical model, and constructing an electromagnetic-seismic joint inversion objective function; and calculating and solving to obtain goaf resistivity, seismic wave velocity three-dimensional distribution and uncertainty quantitative evaluation results, and reducing blind areas of goaf judgment.

The invention discloses a transient electromagnetic three-dimensional dike leakage hidden danger detection method based on unmanned aerial vehicle carrying, and the method comprises the steps: S1, scanning a detection region range, obtaining dike terrain remote sensing image and point cloud image data, and setting a flight path of an unmanned aerial vehicle according to a preset detection region range; s2, performing task flight, and transmitting transient electromagnetic pulse signals with different frequencies to the underground of the dike through a transmitting coil according to a transmitting current frequency range; s3, a receiving coil is used for synchronously collecting secondary electromagnetic response signals generated by underground medium induction, discretization sampling is conducted on the collected signals according to the sampling time interval, and a sampling data sequence is obtained; s4, constructing a three-dimensional resistivity model of the dike underground medium through a three-dimensional inversion algorithm; and S5, through the constructed three-dimensional resistivity model, multi-dimensional features of the leakage hidden danger are extracted, and an area with the leakage hidden danger in the dike is identified. The leakage hidden danger area can be rapidly identified, and the detection efficiency and precision are improved.

The invention discloses a multi-source collaborative advanced geological exploration method based on TBM construction, and belongs to the technical field of tunnel engineering geological exploration. A three-dimensional geological model is constructed through multi-scale collaborative operation of directional long exploration drilling, branch short exploration drilling and in-hole transient electromagnetic detection; the directional long exploration adopts a secondary drilling structure and a screw motor directional drilling technology to realize accurate control of a deep stratum, the branch short exploration realizes dynamic and rapid verification through a TBM integrated drilling machine, meanwhile, in-hole transient electromagnetic exploration adopts three-component measurement and an intelligent inversion algorithm to fill the blank of geological information between drill holes, and by means of mutual data correction of the three methods, the detection accuracy is improved. A three-in-one detection system of drilling, geophysical prospecting and intelligent analysis is formed, and then accurate advanced prediction is achieved, so that the problems that a traditional single detection technology is low in precision and insufficient in coverage range are effectively solved, the water inrush risk is remarkably reduced, construction safety is guaranteed, and the method is effectively suitable for deep tunnel TBM safety construction.

The present disclosure belongs to the field of geophysical exploration, and discloses a method, a system, a medium, a device and a terminal for predicting the probing depth of transient electromagnetic. Based on the existing published resistivity model database, the transient electromagnetic field in layered medium is calculated, and the probing depth is calculated based on Jacobian matrix to establish a training data set. The simulated induced electromotive force is used as the input of the neural network, and the calculated probing depth is used as the output of the network. A rapid mapping between observation data and probing depth is established by using residual neural network.

The invention belongs to the technical field of geophysical exploration. The invention provides an inversion method and system based on transient electromagnetic and ground penetrating radar data collaborative correction, and the method comprises the steps: converting the preprocessed ground penetrating radar data into a format of transient electromagnetic detection data, or converting the preprocessed transient electromagnetic detection data into the format of the ground penetrating radar data; performing weighted summation on the ground penetrating radar data and the transient electromagnetic detection data after format conversion to obtain fusion data; performing three-dimensional joint inversion according to the fused data to obtain a final three-dimensional joint inversion result; according to the method, collaborative detection of different depths of the detection area is realized, a brand new underground structure detection interpretation scheme is provided through intelligent data preprocessing, intelligent correction and three-dimensional joint inversion technologies, and comprehensive, efficient and high-precision interpretation of the underground structure is realized.

The invention is suitable for the technical field of geophysical exploration, and provides a ground-air transient electromagnetic airborne receiving coil motion noise extraction method, which comprises the following steps: designing a receiving device carrying an IMU (Inertial Measurement Unit) sensor, the receiving device comprising a receiving coil, the IMU sensor and a synchronous clock; measuring a vector geomagnetic field in a transient electromagnetic detection area based on attitude angle data of the receiving device; and extracting the motion noise of the airborne transient electromagnetic coil based on the vector geomagnetic field and the attitude angle data. The invention designs a ground-air transient electromagnetic receiving device, and provides a method for extracting motion noise of an airborne receiving coil based on the ground-air transient electromagnetic receiving device, so that the problem that the motion noise is generated due to the fact that the coil cuts a geomagnetic field is effectively solved. Compared with a mode of directly separating the motion noise from the induced electromotive force signal, the method provided by the invention can directly extract the motion noise from the generation mechanism level of the motion noise, and effectively avoids the problem of incomplete noise extraction or target signal loss.

The invention relates to the technical field of coal mine goaf exploration, in particular to a goaf combined detection and identification method fusing gravity, earthquake and transient electromagnetism, which comprises the following steps of: (1) arranging an earthquake, transient electromagnetism and gravity method combined observation system according to a detection geological task and a field condition of a coal goaf; (2) seismic data, transient electromagnetic data and gravity data are collected through the combined observation system; (3) performing independent inversion on the gravity data, the transient electromagnetic data and the seismic data to obtain density distribution, resistivity distribution and wave velocity distribution of the goaf; (4) carrying out a joint inversion method based on improved cross gradient seismic data, transient electromagnetic data and gravity data; (5) obtaining a joint inversion resistivity profile map, a joint inversion wave velocity profile map and a joint inversion density profile map of the goaf through joint inversion of the seismic data, the transient electromagnetic data and the gravity data of the goaf; and identifying development characteristics of the goaf.

The invention belongs to the technical field of geophysical exploration. The invention provides a transient electromagnetic data three-dimensional inversion method, a transient electromagnetic data three-dimensional inversion system, a medium, a product and transient electromagnetic data three-dimensional inversion equipment. Three-dimensional regularization inversion is carried out by taking a minimum sum of a product of a model constraint term and a regularization parameter and a data fitting term as an objective function. The step of obtaining the sensitivity matrix in the gradient of the target function comprises the steps of solving a three-dimensional forward modeling electromagnetic field full-discrete equation to obtain a forward modeling field, constructing an adjoint forward modeling electromagnetic field full-discrete equation with a coefficient matrix being a low-order three-diagonal matrix, solving the adjoint forward modeling electromagnetic field full-discrete equation to obtain a calculated adjoint field, and calculating the sensitivity matrix in the gradient of the target function. And obtaining a sensitivity matrix according to the forward modeling field and the adjoint field. According to the method, the coupling electromagnetic field is decomposed by using a direct splitting strategy, and the large sparse matrix is reconstructed into a series of low-order tridiagonal matrixes, so that only the low-order tridiagonal matrixes need to be solved in a forward modeling process or sensitivity calculation, and the three-dimensional inversion speed is remarkably increased.

The invention relates to the technical field of geophysical exploration, and particularly provides a three-dimensional finite element transient electromagnetic forward modeling calculation method based on an iterative solution method.The method comprises the steps that tetrahedron space discretization is carried out based on a vector finite element method, and an electric field is given to six edges of a space tetrahedron; constructing a back-pushing Euler finite element equation set, and assembling a linear system formed by a large sparse matrix based on the equation set; performing iterative solution on the linear system based on an FGMRES algorithm to obtain an electric field value corresponding to a spatial tetrahedron unit edge; optimizing a spatial tetrahedral mesh based on a quadratic nesting method, and optimizing a time step length based on a third-order backward Euler difference format; a grid pre-encryption method is adopted, the calculation error of iterative solution is reduced, a region decomposition method is used for achieving parallel calculation, and the calculation efficiency is greatly improved. According to the method, the requirements of high precision and high efficiency in three-dimensional transient electromagnetic forward modeling calculation can be met, and an advanced calculation tool is provided for resource exploration in a complex geological environment.

The invention discloses an underground anti-seepage structure leakage monitoring method and system based on discrete time, and relates to leakage detection. The method comprises the following steps: collecting transient electromagnetic response data generated by an excitation signal; according to the initial conductivity parameter and the electrode position parameter of the monitoring area, establishing a three-dimensional geophysical model of the monitoring area through a full waveform inversion algorithm; obtaining electromagnetic abnormal data by using a finite element forward modeling algorithm; according to the temperature data, a distributed temperature field analysis method is adopted to calculate the space gradient and the time change rate of the temperature, and temperature abnormal data are obtained; according to the pressure data and time sequence change characteristics of the pressure data, determining pressure abnormal data; fusing the electromagnetic abnormal data, the temperature abnormal data and the pressure abnormal data by using a Bayesian algorithm to obtain fused data; and inputting the fusion data into a pre-trained machine learning model to obtain a leakage detection result. Aiming at the low dynamic leakage monitoring precision of the underground anti-seepage structure, the dynamic monitoring precision is improved.

The invention discloses a sea water area karst cave group transient electromagnetic collaborative investigation data processing method and system, and the method comprises the steps: transmitting a wide frequency spectrum excitation signal to the seabed through a shipborne transient electromagnetic transmitting system, and synchronously collecting a secondary field attenuation signal responded by a seabed medium through a pull-type receiving array, meanwhile, a distributed sensor network is arranged at a preset seabed node to collect background noise base data; performing motion attitude compensation on the secondary field attenuation signal to generate transient electromagnetic response data; constructing an adaptive filter based on the background noise base data, performing noise suppression processing on the transient electromagnetic response data, and outputting noise suppression data; and performing space-time alignment on the noise suppression data of the towed array and the seabed node data to form a three-dimensional space sampling data set. According to the method, high-precision fusion of deep and shallow detection data and quantitative evaluation of the stability of the karst cave are realized, and the detection reliability and the engineering risk early warning capability of the complex ocean karst area are remarkably improved.

The invention discloses a tunnel advanced geological forecast monitoring method and related equipment, and relates to the technical field of intelligent monitoring, and the method comprises the steps: obtaining the time domain response of a transient electromagnetic signal; processing the time domain response of the transient electromagnetic signal by using an adaptive filtering algorithm to obtain processing data; generating a three-dimensional geologic model according to the processing data by using a three-dimensional imaging algorithm; and predicting the geological condition based on an abnormal density function, a pattern recognition algorithm and the three-dimensional geological model.

The invention discloses an underground space time-shifting transient electromagnetic unmanned monitoring device and method. The underground space time-shifting transient electromagnetic unmanned monitoring device comprises a mobile platform, a multifunctional transient electromagnetic detection device and a ground remote control terminal, the multifunctional transient electromagnetic detection device can actively adjust the distance between a transmitting coil and a receiving coil so as to realize a mutual inductance eliminating 8-shaped coil structure, and through cooperation with a calibration algorithm of a control center, the automation level and reliability of detection are remarkably improved, and it is ensured that the 8-shaped coil is in a mutual inductance eliminating state. In addition, the transient electromagnetic monitoring device can perform structure switching between deep layer detection and shallow layer detection, so that a high-efficiency detection mode that one circle has two purposes is realized, and the efficiency and the flexibility of detection operation are remarkably improved. In the actual detection process, the advantages that the 8-shaped coil is small in shallow blind area and large in overlapped loop detection depth are fully played, advantage complementation of two coil modes is achieved, and comprehensiveness and accuracy of a detection result are remarkably improved through a data fusion mode.

The invention discloses a transient electromagnetic and magnetic method data joint inversion method. The method comprises the following steps: acquiring transient electromagnetic observation data and magnetic method observation data; converting the transient electromagnetic observation data into transient electromagnetic moment data; based on the transient electromagnetic moment data and the magnetic method observation data, a joint inversion objective function is constructed, and the joint inversion objective function comprises a data fitting residual term and a model constraint term; performing parameter coupling on the model constraint term by using a multivariate Gaussian mixture model to obtain a coupled model constraint term; and combining the data fitting residual term and the coupled model constraint term into a final objective function, and minimizing the final objective function through an optimization algorithm to obtain an electrical parameter and a magnetic parameter of the underground medium. According to the method, transient electromagnetic and magnetic method data joint inversion is realized, the problem of low three-dimensional inversion calculation efficiency is solved by introducing transient electromagnetic moment, and electrical and magnetic parameters are coupled by utilizing rock physics constraint, so that the inversion result is more accurate, and the structure is more consistent.

The invention belongs to the technical field of geological engineering monitoring and multi-physics field intelligent sensing, and discloses a separation grouting slurry migration monitoring method and system, and the method comprises the steps: constructing an acoustics-optics-electricity-electromagnetism multi-physics field coupling monitoring system; a grouting hole and a monitoring drilling hole array are arranged in a target stratum, a distributed optical fiber sensor, a drilling hole ultrasonic imager, a resistivity measuring device and a transient electromagnetic detection device are installed, and a three-dimensional monitoring network is formed; synchronously acquiring sound field, light field, electric field and magnetic field data; four-field monitoring data and overlying strata multi-parameter observation data are fused, a coal seam mining three-dimensional overlying strata separation model is constructed, and a slurry diffusion three-dimensional visualization model is generated through numerical simulation; and based on the four-field monitoring response difference of the separation space before and after grouting, in combination with a monitoring frequency domain correction model of multiple indexes of grout diffusion, the diffusion range, compactness and filling effect of the grouting grout are evaluated, and abnormal early warning is triggered.

The invention provides a drill hole joint detection method and system capable of reducing the number of advance drill holes in a tunnel roadway, and relates to the field of roadway engineering detection, and the method comprises the steps: obtaining the depth of a measurement point and the radar data and transient electromagnetic data of a target region, and enabling the radar data and the transient electromagnetic data to be collected through an integrated detection device in a drill hole; performing feature extraction on the radar data and the transient electromagnetic data, and fusing the extracted features based on contribution weights of the radar and the transient electromagnetism to obtain a fused feature vector; based on the depth of the measuring point and the fused feature vector, utilizing the trained physical information neural network to invert the dielectric constant and the resistivity; according to the dielectric constant and the resistivity, the geological anomalous body of the target area is identified; according to the invention, the drilling radar and the drilling transient electromagnetism are combined, so that the number of advanced drilling holes is reduced, the detection cost is reduced, and the full-area coverage of the forepoling of the roadway is ensured.

The invention mainly relates to the related technical field of earth and rockfill dam leakage detection, in particular to an earth and rockfill dam leakage detection method based on combination of a transient electromagnetic method and a single-hole dilution method. A leakage hidden danger area is rapidly scanned and positioned through a transient electromagnetic method, a single-hole dilution method is guided to conduct drilling in a key area, and invalid drilling is reduced; on the basis of a traditional dilution curve model, a drilling radius correction factor and a non-Darcy effect correction term are introduced, and the output precision of a vertical seepage profile is remarkably improved; a quantitative mapping model of the resistivity inversion image and the seepage velocity is established, and quantitative conversion from physical detection data to hydraulic parameters is achieved; leakage channel space distribution is automatically extracted based on the image recognition technology, and rapid calculation of the total dam leakage amount is achieved.

The invention provides a resistivity value energy ray estimation method for a termite ant cave position of a reservoir dam, and the method comprises the steps: calibrating different types of reservoir dams, and taking a corresponding determined termite ant cave of the reservoir dam as a calibration position; detecting all calibration positions by using a transient electromagnetic detector to obtain sampling data, and taking the sampling data as a background value; detecting the whole dam body of the target reservoir dam by using a high-resolution transient electromagnetic detector, and calculating the net block-shaped apparent resistivity value of the whole dam body; and determining the termite cave position of the target reservoir dam according to the net block apparent resistivity value and the background value. After the specific reservoir dam is calibrated, the termite cave position of the corresponding dam can be determined based on the sampling data and the background value of the high-resolution transient electromagnetic detector of the reservoir dam, so that the precision and the efficiency of detecting the termite cave position of the reservoir dam can be improved under the condition that the reservoir dam is not damaged.

The invention relates to the technical field of geophysical exploration equipment, and particularly discloses a double-top umbrella type multi-angle adjustable transient electromagnetic transmitting coil array detection device which comprises a main supporting system, a framework supporting system, a coil system, a multi-angle adjusting mechanism and a rapid storage system. The device has the beneficial effects that accurate adjustment in a continuous angle range is realized, and the adaptability of the device to different exploration environments is improved; a double-coil system design is adopted, so that two typical working modes are realized; in structural design, a double-top umbrella type folding structure is combined with a light-weight material, so that the weight of equipment is reduced. According to the device, conversion of multiple detection modes is achieved, traditional multiple fixed angle devices are replaced, the equipment investment cost is reduced, and the equipment operation efficiency is improved.

The invention discloses a radius-adjustable compensation anti-magnetic flux transient electromagnetic measurement device and method, and relates to the field of transient electromagnetic exploration, and the device comprises a transmitter, a receiver, a transmitting coil, a compensation coil and a receiving coil. The transmitting coil and the compensating coil are connected in series and are connected with two poles of the transmitter, and the receiver is connected with two ends of the receiving coil; the compensating coil is arranged on the outer side of the receiving coil; the transmitting coil is arranged on the outer side of the compensating coil; an adjustable buckle is arranged on the compensation coil; the adjustable buckle is used for adjusting the radius of the compensation coil. The reverse magnetic flux is adjusted by adjusting the radius of the compensation coil, so that primary field influences such as self-inductance and mutual inductance are effectively eliminated, more accurate secondary field response signals are obtained, and more reliable transient electromagnetic exploration data can be obtained.

The invention is suitable for the technical field of grounding grid defect evaluation, and provides a transient electromagnetism-based grounding grid corrosion defect evaluation method and system, and the method comprises the steps: placing a sensor of a transient electromagnetic detection device above a to-be-detected region of a grounding grid, injecting a pulse current excitation signal into a conical focusing excitation coil, and carrying out the detection of the to-be-detected region of the grounding grid; acquiring an induced voltage time sequence signal through a receiving coil; extracting at least one characteristic parameter from the induced voltage time sequence signal, wherein the characteristic parameter comprises a signal peak value, peak value time, an attenuation rate or a signal integral quantity; inputting the characteristic parameters into a preset corrosion evaluation model, and performing inversion to obtain a residual thickness value or a corrosion depth value of the grounding grid in the to-be-detected area; generating and outputting a quantitative evaluation result containing the residual thickness value or the corrosion depth value; the method can be implemented in a non-stop state of the grounding grid, and an efficient and reliable decision basis is provided for safe operation and state maintenance of a power system.

The invention relates to a transient electromagnetic and seismic wave multi-mode joint inversion imaging method based on physical information Transform, and belongs to the crossing field of geophysical exploration and artificial intelligence. Comprising the following steps: carrying out anomaly detection, interpolation, filtering and normalization preprocessing on transient electromagnetic and seismic wave original data; extracting features representing electrical property, elasticity and cross physical significance; serializing the spatial data through a gridding and alternating fusion strategy, and constructing an enhanced code fusing absolute and relative positions and physical attributes; a physically constrained encoder-decoder architecture is designed to carry out multi-scale forward modeling-inversion; and quantizing the uncertainty of an inversion result by adopting a Bayesian Monte Carlo method, and generating a confidence map. According to the method, through physical rule driving and multi-modal depth complementary fusion, the fine recognition capability and interpretation reliability of hidden disaster-causing geologic bodies such as underground goaf and collapse columns are effectively improved while the physical consistency of data is kept.

The invention belongs to the technical field of geophysical exploration, and particularly discloses a differential transient electromagnetic method device and an unexploded ordnance detection method thereof.The differential transient electromagnetic method device is characterized in that a transmitter injects emission current into an emission loop, and the emission loop generates a primary field excitation signal; the underground anomalous body target generates a secondary field excitation signal under the action of the primary field excitation signal; the receiving coil assembly is based on the structure of a differential coil, synchronously counteracts a primary field excitation signal and a uniform background signal in an induced voltage, and expands a local asymmetric differential signal generated by an underground anomalous body target; and the receiver carries out time sequence analysis on the local asymmetric differential signals and extracts differential signal features so as to realize positioning and identification of an underground anomalous body target. The device is suitable for detection of shallow-buried small bodies such as UXO, the overall arrangement range of the device is small, and rapid arrangement and mobile observation in the field are facilitated.

The invention discloses an underground space unmanned sensing detection system and method. An unmanned detection carrier platform obtains underground space surface data through a sensing radar holder and an unmanned aerial vehicle; then determining a detection target area according to the acquired data and planning a driving path; meanwhile, ad-hoc network relay nodes are placed at different positions on the unmanned detection carrier platform through a mechanical arm in combination with signal strength, an ad-hoc network is finally formed, and normal communication of the unmanned detection carrier platform and the unmanned aerial vehicle in the underground space is guaranteed; when the unmanned detection carrier platform travels to a target area, a seismic observation system is formed by arranging node type detectors, and an active seismic source and a transient electromagnetic detection device are respectively started, so that seismic wave data and transient electromagnetic data of the target area are obtained; according to the method, perception modeling of the underground space can be realized in an unmanned mode, and the overall detection data of the underground space can be accurately acquired, so that subsequent analysis and processing of the underground space data are facilitated.

The invention relates to the technical field of geophysical prospecting, in particular to a transient electromagnetic instrument detection unit and method, and the detection unit is powered by a detachable power supply nipple, is connected with a drill rod, and is pushed by the drill rod to measure in a drill hole. The detection unit comprises a shell and a detection framework, the detection framework comprises a detection support, a threaded nest, a detection control module, a transmitting antenna, a receiving antenna and an attitude measurement module, the receiving antenna is used for measuring three-component magnetic field change information, and the attitude measurement module is used for measuring working attitude information of the detection unit. The system has a high integration level, can realize integration of drilling track measurement and transient electromagnetic three-component measurement, can complete long drilling hole detection, does not need to be connected with a communication cable, and effectively reduces the system cost.

The invention discloses a multi-channel transient electromagnetic detection method and device for a tunnel face, and relates to the technical field of geophysical information, and the method comprises the steps: planning horizontal measuring lines for the tunnel face at equal intervals, and planning measuring points on each measuring line at equal intervals; building a multi-channel detection array composed of a transient electromagnetic receiving coil and a transient electromagnetic transmitting coil, and carrying out primary field zero magnetic flux point adjustment; the method comprises the following steps: setting emission parameters according to detection depth and resolution requirements, then emitting bipolar square waves, carrying out measurement point-by-measurement observation by using an adjusted multi-channel detection array, constructing a geometric network which takes measurement lines, measurement points and channel numbers as indexes according to observation data, and carrying out multi-channel combined three-dimensional imaging. By constructing a multi-channel detection array, the data volume of a measuring point is increased, and the fineness of three-dimensional imaging is improved; through primary field zero magnetic flux point adjustment, the influence of a primary magnetic field is counteracted, and the signal-to-noise ratio of data is improved.

The invention provides a karst cave group detection method and device in shield construction, and the method achieves the comprehensive detection of karst caves through a transient electromagnetic and sound wave array composite wave field detection mode, and improves the detection accuracy and detection efficiency of the karst cave group. And feature extraction is performed on the composite wave field detection data through a cross-physical coupling model, a karst cave probability model is established, and quantitative evaluation of a karst cave detection result is realized. When the karst cave possibly exists in the construction direction of the shield tunneling machine, the distribution prediction direction of the karst cave is further determined, and the shield tunneling machine is prevented from entering the karst cave area blindly in the tunneling process. Through the multi-source sensing array carried on the shield tunneling machine, equipment parameters during operation of the shield tunneling machine are collected in real time, potential construction anomalies can be found easily, and the accuracy and timeliness of karst cave detection are improved. Combined analysis is carried out on the composite wave field detection data and the operation parameters of the shield tunneling machine through the risk assessment model, a karst cave risk prediction value is determined, and the accuracy of karst cave risk assessment is improved.

The invention discloses a fast air-ground transient electromagnetic inversion method based on FiLM-U-net, and belongs to the field of electromagnetic signal data processing, and the method comprises the steps: obtaining geological data and air-ground transient electromagnetic detection data, carrying out the preprocessing, and constructing a data set; dividing a training set, a verification set and a test set; the method comprises the following steps: constructing a FiLM-U-net network model in combination with a FiLM structure and a U-net structure; adopting the training set to select a proper training strategy to train the FiLM-U-net network model, and adopting the test set to evaluate the inversion effect of the model; and the trained FiLM-U-net network model is used to carry out inversion on ground-air transient electromagnetic measured data, transmit-receive positions and ground-air transient electromagnetic response are inputted, and an underground model resistivity value is outputted. According to the invention, the space information can be effectively utilized to carry out efficient and rapid inversion on the ground-air transient electromagnetic signal.

The invention discloses a method for rapidly and efficiently extracting coal mine gas in a broken and soft coal seam, and belongs to the technical field of coal seam gas development and coal mine gas prevention and control. According to the method, geological features of a coal mining planning area are determined, a ground U-shaped well and underground bottom-pumped rock drift layer-crossing drilling combined treatment system is deployed, and regional large-scale treatment is achieved in a well factory mode; the fracturing transformation range and the fracturing fluid distribution characteristics are detected by using a ground and underground combined micro-seismic monitoring and underground transient electromagnetic method, and the arrangement of layer-crossing drill holes is optimized; dividing the cross-layer drill holes into drainage holes and air exhaust holes, and formulating a collaborative extraction system in combination with different drainage and extraction stages; the method solves the problems that broken soft coal seam gas extraction is low in efficiency and long in period, and treatment blind areas exist, treatment time is remarkably shortened, cost is reduced, and safe and efficient production of a coal mine is guaranteed.

The invention discloses a semi-aviation transient electromagnetic signal adaptive gain method and system, and relates to the technical field of geophysical exploration, and the method comprises the steps: obtaining a differential signal of a receiving coil, and carrying out the chopping self-stabilization zero amplification processing of the differential signal; the method comprises the following steps: dividing a total time window of a differential signal into a plurality of time channels under a set time reference, adjusting the length of each time channel according to a signal attenuation characteristic, calculating the time length and data point number of each time channel according to a sampling rate and the total time window, and calculating the time length and data point number of each time channel; the data points are distributed to an early time channel, a middle time channel and a late time channel, so that different gain multiples are switched, and adaptive gain amplification is carried out; and the differential signal subjected to adaptive gain amplification is transmitted to a receiver after being collected by an ADC (Analog to Digital Converter). By dynamically adjusting the gain coefficient in different time channels, the technical problems of large dynamic range of transient electromagnetic signals and low signal-to-noise ratio of weak signals are solved, and high-fidelity acquisition of full-time-domain signals is realized.