An exemplary inventive optimization model delineates a three-dimensional geometric environment for situation therein of electromagnetic sources and an electromagnetic sensor array used for measuring electric and magnetic fields emanating from the electromagnetic sources. Based on measurements and computations relating to electrical, magnetic, and structural physical properties, the geometric environment is stratified into air, sea, and seafloor regions as well as into electromagnetically distinct zones. The design of the electromagnetic sensor array is optimized through an iterative process involving successive determinations as to how well the electric and magnetic fields emanating from the electromagnetic sources may be calculated based on measurements taken in the geometric environment by the electromagnetic sensor array. Every instance of the electromagnetic sensor array in the iterative process is uniquely located and/or uniquely configured vis-à-vis every other instance. Design optimization can be performed with respect to various frequencies or frequency ranges.

Provided is a metal detector capable of quickly and accurately ascertaining a noise generating situation. A metal detector generates a magnetic field in an inspection region and detects a change in the magnetic field in the inspection region to detect a foreign substance in an inspection object passing through the inspection region. The metal detector measures the change in the magnetic field of the inspection region while changing an inspection frequency, performs frequency analysis of the measurement result, and displays an obtained frequency distribution diagram on the display unit as a noise diagnosis result. In the frequency distribution diagram, target foreign substance reference lines are displayed.

A method for separating and quantifying gamma ray induced and neutron induced responses in a radiation detector includes detecting radiation in a radiation field comprising neutrons and gamma rays. The detected events are converted into a detector pulse amplitude spectrum. The pulse amplitude spectrum is decomposed into contributions from detected gamma rays and detected neutrons using gamma ray standard spectra and neutron standard spectra and a spectral fitting procedure which results in a best fit between a weighted sum of the contributions and the detector pulse amplitude spectrum. The fitting procedure includes determining fitting parameters for each of the standard spectra wherein at least one of the fitting parameters is different for the gamma ray standard spectra and the neutron standard spectra. In one embodiment, the fitting parameter is spectral gain.

A vertical bipole source in a borehole generates a vertical bipole flow. The vertical bipole flow generates mutually orthogonal time-domain B-field data. Magnetic receivers at a surface location receive the time-domain B-field data and determine elements of a hydrocarbon reservoir using a 3D EM inversion technique. The vertical bipole source may extend into the borehole or be a virtual bipole source located at a surface location above a reservoir.

An electrical prospecting signal transmission device capable of suppressing electromagnetic coupling interference, including a rectangular wave signal source, an output circuit for supplying power to the ground and a plurality of transmission channels. Each of the plurality of transmission channels includes an isolated driving circuit, a low-pass filter circuit and a power amplification circuit connected sequentially in series. The rectangular wave signal source is configured to generate a rectangular wave or a composite rectangular wave. A signal output terminal of the rectangular wave signal source is connected to an input terminal of the isolated driving circuit, and an output terminal of the power amplification circuit is connected to the output circuit to supply power to the ground.

A method can include selecting a type of geophysical data; selecting a type of algorithm; generating synthetic geophysical data based at least in part on the algorithm; training a deep learning framework based at least in part on the synthetic geophysical data to generate a trained deep learning framework; receiving acquired geophysical data for a geologic environment; implementing the trained deep learning framework to generate interpretation results for the acquired geophysical data; and outputting the interpretation results.

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.

A method for collecting and processing the tensor artificial-source electromagnetic signal data and a device thereof; the method comprising the steps of: step S1: determining an electric field polarization direction in a measuring area, and arranging electromagnetic field sensors according to the electric field polarization direction in the measuring area, step S2: respectively collecting artificial-source electromagnetic field signals and natural-field-source electromagnetic field signals, step S3: respectively Fourier-transforming the collected electromagnetic field signals, thereby obtaining the electromagnetic field values corresponding to the artificial source, and the collected electromagnetic field signals corresponding to n groups of natural sources, step S4: calculating to obtain the underground tensor impedances according to the electromagnetic field values corresponding to the artificial source and the electromagnetic field signals corresponding to n groups of natural sources that are obtained based on the least square method, step S5.

A system and method of evaluating and correcting for the effects of a near-surface anomaly on surface-to-borehole (STB) measurement data in a geological halfspace includes transmitting electromagnetic radiation from an EM source located on a ground surface which is positioned over the near-surface anomaly, measuring EM fields at a plurality of remote EM receivers located on the surface at a far distance from the EM source, obtaining vertical STB measurement data downhole, determining an orientation and moment of a secondary source equivalent dipole associated with the near-surface anomaly excited by the radiation transmitted by the EM source based on measurements of the EM fields at the plurality of remote receivers, determining a correction factor for the secondary source equivalent dipole on the EM field measurements at the plurality of remote receivers, and removing the effects of the near surface anomaly on the vertical STB measurement data using the correction factor.

Inversion of enhanced-sensitivity controlled source electromagnetic data can include combining measured controlled source electromagnetic (CSEM) data onto a common set of virtual receiver positions for each of a plurality of positions of a source along a survey path, determining a steering vector that enhances a sensitivity of the measured CSEM data to a subsurface resistivity variation, and performing an inversion using the measured CSEM data and modeled CSEM data, each having the steering vector applied thereto as a data weight, to better identify the subsurface resistivity variation.