Abstract: A short-offset transient electromagnetic transmission system, including: an electromagnetic transmitter with transmission power supplies P1, P2, P3, P4, grounding electrodes A, B, C, D, F, and transmission wires LA, LB1, LB2, LC1, LC2, LD1, LD2, LE. The electrodes A and B are connected to the transmission power supply P1 via the wires LA and LB1. The electrodes B and C are connected to the transmission power supply P2 via the wires LB2 and LC1. The electrodes C and D are connected to the transmission power supply P3 via the wires LC2 and LD1. The electrodes D and E are connected to the transmission power supply P4 via the wires LD2 and LE. The wires LA and LB1 are pulled from the electromagnetic transmitter to the electrode B and the wires LD2 and LE are pulled from the electromagnetic transmitter to the electrode D in a twisted-pair manner.

Abstract: The present application proposes an airborne electromagnetic signal observation device and a system carried by an unmanned aerial vehicle (UAV). The device includes an inner frame, an outer frame and a flexible support that are connected to each other. The device and the system can enhance the stability of the sensor in flight and greatly suppress motion noise.

Abstract: This application provides an adaptive damping magnetic field sensor, including: a receiving coil, an adaptive damping matching resistance circuit, and an amplifying circuit; where the receiving coil is used for receiving an earth response signal generated by the earth under excitation of an emission source, and generating an induced voltage; the adaptive damping matching resistance circuit is used for receiving the induced voltage generated by the receiving coil and automatically matching a damping resistance value to obtain a near-source broadband observation signal; and the amplifying circuit is used for amplifying the observation signal with a constant gain and outputting a sensor output signal. This application carries out automatic matching control on the damping resistance value through the adaptive damping matching resistance circuit, thereby ensuring that the sensor can stably and reliably implement fine observation of an earth response under near-source, broadband and complex scene conditions.

Abstract: The present application proposes a method and apparatus for transfer learning-based localization of igneous carbonate-hosted rare earth mineralization. The technology relates to electromagnetic exploration and includes obtaining exploration data for electric, magnetic, seismic, and gravity methods in the target area. Transfer learning-based localization is applied to the electric, magnetic, seismic, and gravity exploration data to determine the cross-sectional map corresponding to the anomalous position of igneous carbonate-hosted rare earth mineralization in the target area. Feature decomposition dimensionality reduction, feature enhancement, and weighted fusion processing are applied to the cross-sectional map, followed by segmentation of the igneous carbonate-hosted rare earth mineralization geological body in the fused image to obtain the spatial distribution of the detection target.

Abstract: The application provides an estimation method of detecting elevation by a semi-airborne electromagnetic method, including the following steps: S1, judging original elevation data to obtain wrong point data and normal data; S2, filtering the wrong point data by an improved Kalman filtering method, and filtering the normal data by a conventional Kalman filtering method; S3, fusing a filtering result of the wrong point data and a filtering result of the normal data, and taking a fused result as a measured value sequence used in a next working process; and S4, repeating the S1-S3 until the fused result meets preset requirements.

Abstract: The present disclosure provides an apparent resistivity-depth section generating method for short-offset electromagnetic exploration, including: determining, in field zones divided quantitatively based on the induction number, positions of a recording point for each of observation points and frequencies or a time window thereof, and taking determined positions of the recording point as the assignment point for the observation point and the frequencies or the time window thereof, where one survey line of an axial configuration generates one apparent resistivity-depth section along the survey line; and one survey line of an equatorial configuration typically generates one apparent resistivity-depth section along the survey line, and apparent resistivity-depth sections along connecting lines from the observation points to the source which are the same as observation points in the number.

Abstract: Disclosed are a multi-line source ground-borehole transient electromagnetic detection method and a multi-line source ground-borehole transient electromagnetic detection device. The method includes following steps: S1, constructing a multi-line source ground-borehole transient electromagnetic forward model; S2, obtaining multi-line source ground-borehole transient electromagnetic responses of an underground target layer by the multi-line source ground-borehole transient electromagnetic forward model; and S3, recognizing the underground target layer according to electromagnetic diffusion characteristics of the multi-line source ground-borehole transient electromagnetic responses. A resolution and a detection capability of the underground target by a ground-borehole transient electromagnetic method is greatly improved by adopting technical schemes.

Abstract: The embodiment of the invention provides a ground-air TEM transverse magnetic polarization field detection method and system, and a forward modeling method and device.

Abstract: The present application proposes an airborne electromagnetic signal observation device and a system carried by an unmanned aerial vehicle (UAV). The device includes an inner frame, an outer frame and a flexible support that are connected to each other. The device and the system can enhance the stability of the sensor in flight and greatly suppress motion noise.

Abstract: Disclosed is a method for extracting IP information in a TEM response of a grounded-wire source, comprising the following steps: 1) obtaining subsurface resistivity through inversion of a vertical magnetic field less influenced by an IP effect; 2) obtaining an electric field response not influenced by the IP effect based on forward modeling of the obtained underground electrical structure; 3) removing the influence of the IP effect on an observed response to obtain a pure IP response; and 4) inverting the obtained IP response to obtain IP information of polarizability, a frequency dependence, and a time constant. The method of the present invention provides a new idea for further extracting IP information in a TEM response.

Abstract: Embodiments of a method for measurement of electromagnetic field strength at a point of interest in a coverage area of a 2-dimensional (2D) active antenna system (AAS). The 2D AAS transmits with a load factor of 100 percent. The 2D AAS sweeps a predefined range of azimuth and elevation angles, and azimuth and elevation directions which yield highest EMF at the point of interest are determined. First beamforming weights are determined based on the azimuth and elevation directions and the 2D AAS caused to apply the first beamforming weights. The 2D AAS sweeps a co-phasing angle from 0 to 360 degrees, and a co-phasing angle which yields highest EMF is determined. Second beamforming weights are determined based on azimuth and elevation directions and the co-phasing angle, and the 2D AAS caused to apply the second beamforming weights. The EMF strength at the point of interest is measured.

Abstract: Provided are a geological target identification method and apparatus based on image information fusion.

Abstract: The present disclosure provides an apparent resistivity-depth section generating method for short-offset electromagnetic exploration, including: determining, in field zones divided quantitatively based on the induction number, positions of a recording point for each of observation points and frequencies or a time window thereof; and taking determined positions of the recording point as the assignment point for the observation point and the frequencies or the time window thereof, where one survey line of an axial configuration generates one apparent resistivity-depth section along the survey line; and one survey line of an equatorial configuration typically generates one apparent resistivity-depth section along the survey line, and apparent resistivity-depth sections along connecting lines from the observation points to the source which are the same as observation points in the number.

Abstract: Disclosed is an exploration method and system for pegmatite veins. The exploration method includes: three grounding electrodes are arranged at each observation point in a target area where pegmatite veins are located, and collecting electric field differences between two groups of grounding electrodes; drawing a multi-channel map, based on positions of the grounding electrodes, according to the electric field differences; obtaining resistivity variation characteristics of pegmatite veins according to the transverse variation of multi-channel map, and determining locations and lithologic characteristics of pegmatite veins according to the resistivity variation characteristics. Through functional modules with different functions, an exploration system is formed to realize the exploration method mentioned in the application.

Abstract: Disclosed is an exploration method and system for pegmatite veins. The exploration method includes: three grounding electrodes are arranged at each observation point in a target area where pegmatite veins are located, and collecting electric field differences between two groups of grounding electrodes; drawing a multi-channel map, based on positions of the grounding electrodes, according to the electric field differences; obtaining resistivity variation characteristics of pegmatite veins according to the transverse variation of multi-channel map, and determining locations and lithologic characteristics of pegmatite veins according to the resistivity variation characteristics. Through functional modules with different functions, an exploration system is formed to realize the exploration method mentioned in the application.

Abstract: This application provides an adaptive damping magnetic field sensor, including: a receiving coil, an adaptive damping matching resistance circuit, and an amplifying circuit; where the receiving coil is used for receiving an earth response signal generated by the earth under excitation of an emission source, and generating an induced voltage; the adaptive damping matching resistance circuit is used for receiving the induced voltage generated by the receiving coil and automatically matching a damping resistance value to obtain a near-source broadband observation signal; and the amplifying circuit is used for amplifying the observation signal with a constant gain and outputting a sensor output signal. This application carries out automatic matching control on the damping resistance value through the adaptive damping matching resistance circuit, thereby ensuring that the sensor can stably and reliably implement fine observation of an earth response under near-source, broadband and complex scene conditions.

Abstract: Disclosed are a multi-line source ground-borehole transient electromagnetic detection method and a multi-line source ground-borehole transient electromagnetic detection device. The method includes following steps: S1, constructing a multi-line source ground-borehole transient electromagnetic forward model; S2, obtaining multi-line source ground-borehole transient electromagnetic responses of an underground target layer by the multi-line source ground-borehole transient electromagnetic forward model; and S3, recognizing the underground target layer according to electromagnetic diffusion characteristics of the multi-line source ground-borehole transient electromagnetic responses. A resolution and a detection capability of the underground target by a ground-borehole transient electromagnetic method is greatly improved by adopting technical schemes.

Abstract: Embodiments of a method for measurement of electromagnetic field strength at a point of interest in a coverage area of a 2-dimensional (2D) active antenna system (AAS). The 2D AAS transmits with a load factor of 100 percent. The 2D AAS sweeps a predefined range of azimuth and elevation angles, and azimuth and elevation directions which yield highest EMF at the point of interest are determined. First beamforming weights are determined based on the azimuth and elevation directions and the 2D AAS caused to apply the first beamforming weights. The 2D AAS sweeps a co-phasing angle from 0 to 360 degrees, and a co-phasing angle which yields highest EMF is determined. Second beamforming weights are determined based on azimuth and elevation directions and the co-phasing angle, and the 2D AAS caused to apply the second beamforming weights. The EMF strength at the point of interest is measured.

Abstract: A method of solving closed form exact solution for the field generated by a finite-length harmonic linear current source in a whole space. The vector magnetic potential formula of the finite-length harmonic linear current source containing a source point position vector is listed, the uniform current is subjected to cosine processing, and the current in the vector magnetic potential formula of the harmonic linear current source is expressed by a cosine function. The vector magnetic potential formula can be subjected to quadrature by an elementary function to obtain the closed form exact solution for the field generated by the finite-length harmonic linear current source in whole space. The cosine expression of the linear current source can better reflect the fundamental attributes of the electric dipole and harmonic current of linear current source in the conductive whole space. The obtained closed form exact solution is applicable in the all zone.

Abstract: A method and system for electromagnetic method (EM) signal detection based on an onshore sparker source, the method including: arranging an EM signal detection system near a sparker source; releasing, by the sparker source, an electromagnetic pulse concomitantly in a discharge and mechanical energy output process; observing an electromagnetic response generated by the earth under the excitation of the electromagnetic pulse by means of the EM signal detection system for extracting distribution information of geo-electrical parameters; when the sparker source moves, moving the electromagnetic method signal detection system to a new position along with the sparker source while keeping their positions relative to each other unchanged; and repeating the above process after the movement is completed. According to the technical solution of the present invention, fine electromagnetic detection results can be obtained while seismic detection is carried out.