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 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 comprises 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.

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:

Disclosed are methods and systems for producing bipole source modeling with reduced computational loads. A method may comprise receiving first electromagnetic data and second electromagnetic data from a first shotpoint and a second of a marine electromagnetic survey, modelling a first electromagnetic field and second electromagnetic field for one or more dipole sources of a bipole source and combining a plurality of data points to provide an approximation of an electromagnetic field for the bipole source. A system may comprise electromagnetic sensors, a bipole source, wherein the bipole source comprise a pair of electrodes that are separated by a distance, wherein the bipole source is configured to generate an electromagnetic field, and a data processing system configured to receive electromagnetic data from a plurality of shotpoints of the bipole source and model electromagnetic fields for one or more dipole sources of the bipole source from the electromagnetic data.

A method of processing controlled source electromagnetic (CSEM) data is provided for reducing the airwave contribution. CSEM data are acquired, for example using a conventional towed source (4) and receiver (5) arrangement. The recorded data are weighted in accordance with the geometrical spreading of the airwave component. The differences between pairs of weighted data records are then formed.

A method of estimating electromagnetic parameters of a geological structure, comprising: providing controlled source electromagnetic, CSEM, data of the structure, calculating a numerical model representing electromagnetic parameters of the structure and generating simulated CSEM data, discretising the numerical model based on prior knowledge of the structure, defining a functional for minimising the distance between said simulated CSEM data and said CSEM data, wherein the functional comprises a regularisation term which depends on prior knowledge of said structure.

A system for near-surface geophysical subsurface imaging for detecting and characterizing subsurface heterogeneities comprises an instrument that outputs probing electromagnetic signals through a ground surface that interact and are affected by scattered signals of acoustic waves that travel through the ground surface and further senses vibrational modes of a subsurface below the ground surface; an imaging device that dynamically generates a time sequence of images of properties of the acoustic waves and maps elastic wave fields of the acoustic waves; and a processor that analyzes dynamic multi-wave data of the images to quantify spatial variations in the mechanical and viscoelastic properties of the subsurface.

A method for efficient use of a computing system of parallel processors to perform inversion of geophysical data, or joint inversion of two or more data types. The method includes assigning at least one control processor to control sequence of operations and reduce load imbalance, assigning a group of one or more processors dedicated to updating one or more model parameters, and assigning another group of one or more processors dedicated to forward modeling simulated data.

A resistivity profile can be generated directly from measured electromagnetic field data from a marine survey. A series of transformations can be applied to remove a conductivity dependency from a boundary value problem such that an inversion method may no longer be required to generate the resistivity profile.

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.