22 results about "Subsurface imaging" patented technology

The invention belongs to the technical field of earth exploration, and relates to an underground imaging method based on a reformed Marchenko method, which comprises the following steps: removing direct waves from seismic data, and carrying out seismic deconvolution to obtain preprocessed seismic data; selecting an underground imaging point, setting the underground imaging point as an underground focus point, and estimating a direct wave Green function from the underground focus point to a ground surface receiving point according to a background speed model; the direct wave Green function is reversed on a time axis to serve as an initial downlink focusing function, and an initial uplink focusing function is set to be zero; and performing iterative calculation according to the initial downlink focusing function and the initial uplink focusing function to obtain a downlink focusing function and an uplink focusing function after iteration, calculating a downlink green function and an uplink green function according to the uplink focusing function and the downlink focusing function, and imaging the underground imaging point. According to the method, iteration absolute convergence can be ensured by mediating convergence parameters, and finally an underground imaging result which is not influenced by multiple waves is obtained.

The invention discloses a discrete imaging method and device for a ground penetrating radar system, terminal equipment and a storage medium, and relates to the technical field of detection radar imaging, and the method comprises the steps: obtaining a plurality of antennas of a common midpoint antenna array, and carrying out the integration and superposition of initial signals collected at different collection points in a detection region, generating a discrete signal of each antenna pair on each acquisition point, and determining the two-way travel time and the inclination factor of a detection target detected by each antenna pair at each acquisition point according to the discrete signal, and carrying out migration integration according to the coordinate position of each acquisition point, the discrete signal of each antenna pair, the two-way travel time of the corresponding detection target and the inclination factor, generating a two-dimensional imaging result of the depth profile of each acquisition point, and finally splicing the two-dimensional imaging results of the acquisition points to obtain the depth profile of the detection target. And generating an underground three-dimensional model of the detection area. Therefore, the problem that the underground imaging result of the existing handheld radar ground penetrating system is not ideal can be effectively solved.

A system and method for generating synthetic high-frequency seismic data for subsurface imaging comprises injecting a first seismic shot having a low frequency into a surface region and receiving reflected waves at a plurality of seismic receivers. Seismic traces are recorded and processed to generate a low-frequency seismic shot gather. A second seismic shot having a high frequency is injected, and a sparse number of high-frequency traces are recorded. A computing device resamples the low-frequency traces to match the sparse high-frequency dataset and applies a one-dimensional (1D) local matching filter to transform the low-frequency traces into simulated high-frequency traces. The transformed dataset is used to generate a high-resolution subsurface image of geological interfaces. The system enables computationally efficient high-frequency seismic data synthesis, optimizing seismic inversion accuracy while reducing acquisition costs and computational overhead.

The invention discloses a high-speed rail seismic source seismic data wave field separation method and system using random Cadzow filtering, and belongs to the technical field of exploration geophysics. The method comprises the following steps: acquiring seismic data when a high-speed rail passes; estimating the seismic wave propagation speed through Radon transformation; performing time difference correction on the same-direction wave field event to obtain aligned data; blocking the aligned data and randomly rearranging the aligned data; fourier transform is carried out on the rearranged data, and a Hankel matrix is constructed; carrying out SVD (Singular Value Decomposition) decomposition and low-rank reconstruction on the Hankel matrix; reconstructing a frequency domain data block through an anti-Hankel operation; inverse Fourier transform is carried out, and a trace sequence is recovered; and extracting and averaging a central channel to obtain unidirectional wave field data. The system comprises modules with corresponding functions. The method can effectively separate the high-speed rail seismic source mixed wave field, improves the signal-to-noise ratio of data, and provides a reliable data basis for underground imaging.

The application discloses a complex ground surface ground penetrating radar amplitude-preserving imaging method based on an orthogonal skin mesh, and comprises the following steps: 1) constructing a ground surface model according to ground fluctuation data; constructing an electromagnetic wave underground propagation speed model according to geological exploration data; 2) generating an orthogonal skin mesh by using a Ryskin-Leal method; 3) discretizing the orthogonal skin mesh by using a finite difference time domain method; 4) performing reverse extrapolation on the received ground penetrating radar signal, and reversely propagating the electromagnetic wave field to an initial time; in the reverse extrapolation process, the spatial position of a reflection interface is calculated through a cross-correlation imaging condition, and an underground imaging profile is obtained; 5) calculating a target function gradient, and solving an inversion problem by using a conjugate gradient method to iteratively update the electromagnetic wave underground propagation speed model; and 6) generating an imaging profile of an underground structure according to the iteratively converged electromagnetic wave underground propagation speed model. The application significantly improves the precision, stability and anti-noise performance of underground imaging.

A computer-implemented method and system for optimizing shallow subsurface imaging includes applying super-virtual interferometric redatuming (SVIR) to seismic wave data, and applying wave-equation travel-time inversion (WTI) to the redatumed seismic wave data.

To simulate a 3D image of a subsurface below a surface, the system having a memory device for storing an instruction, a processor in communication with the memory device configured to execute the instruction, and a subsurface image capture module in communication with the processor, the subsurface image capture module having one or more wave generating device and one or more sensor affixed to a vehicle to capture a series of digital image datasets of the subsurface with a coordinate reference data, wherein the processor executes an instruction to generate a digital model of the series of digital image datasets of the subsurface while maintaining the coordinate reference data, wherein the processor executes an instruction to determine a depth map of the digital model, and wherein the processor executes an instruction to identify a key subject point in the digital model, where subsurface includes an internal biology, below ground, underwater.

Embodiments of the present disclosure relate to fast scanning acoustic microscopy for subsurface imaging and inspection. For example, a system may include at least one processing device configured to perform operations including initiating imaging of a sample using an acoustic microscope, and causing the sample to be scanned at a radial distance relative to a center position of the sample to perform the imaging of the sample. The sample is located on a stage, and the stage rotates at a rotational speed determined based on the radial distance.

The invention relates to an underground imaging device (100) with a walking stick view. In particular, the invention relates to an extension (101) comprising sensors used for underground scanning and extending towards the ground plane and approaching the ground plane during scanning; a handle (102) in contact with said extension (101) and located at the farthest point from the ground plane during use, designed for the user to hold said device (100); a display (10) located at the top of said handle (102) and displaying parameters and underground scan results in three dimensions; a mechanical or optical rotary encoder (11) that measures the angular position, speed and direction of a rotary shaft and converts these data into digital signals, said mechanical or optical rotary encoder (11) comprising a control ring (12) that monitors the speed and direction of the rotary movement, which, working together with said mechanical or optical rotary encoder (11), increases the accuracy and precision of the rotary movement.

The application belongs to the technical field of exploring the earth and is an adaptive offset aperture Marchenko imaging method for large-scale underground areas, comprising: calculating the travel time field information of preprocessed seismic data; performing longitudinal difference calculation according to the calculated travel time field information to obtain a longitudinal travel time difference field; completing the offset aperture size corresponding to all underground imaging points; calculating the background velocity model gradient to obtain the normal direction of the underground structure interface, making an extension line along the normal method to the surface to obtain an intersection point as the offset aperture center position corresponding to the underground imaging point; calculating the final offset aperture range; screening a local reflection data body; calculating the local focusing function and the local Green function corresponding to the underground imaging point; and performing imaging operation on the underground imaging point according to the imaging condition and the local focusing function and the local Green function.

Techniques for generating a subsurface image include analyzing a region to be sensed to determine a plurality of reflector locations; and performing a survey. Performing the survey includes irradiating a plurality of reflectors positioned in the plurality of determined reflector locations with coherent electromagnetic energy; identifying one or more vibrations of the plurality of reflectors based on reflected electromagnetic energy from the plurality of reflectors; and generating survey data associated with the identified vibrations for at least one reflector of the plurality of reflectors. The techniques include providing the survey data as input to a machine learning algorithm; and generating, using the machine learning algorithm, a subsurface image associated with the region to be sensed.

This application belongs to the field of exploration earth technology and is a subsurface imaging method based on the renormalized Marchenko method. The method includes: removing direct waves from seismic data and performing seismic deconvolution to obtain preprocessed seismic data; selecting subsurface imaging points and setting them as subsurface focal points; estimating the direct wave Green's function from the subsurface focal point to the surface receiver point based on a background velocity model; reversing the direct wave Green's function on the time axis to obtain the initial downlink focusing function, and setting the initial uplink focusing function to zero; iteratively calculating the initial downlink and uplink focusing functions to obtain the iterated downlink and uplink focusing functions; calculating the downlink and uplink Green's functions based on the uplink and downlink focusing functions; and imaging the subsurface imaging points. This method ensures absolute convergence of the iteration by adjusting the convergence parameters, ultimately obtaining subsurface imaging results unaffected by multiple waves.

The invention belongs to the technical field of earth exploration, and relates to a large-scale underground region-oriented adaptive migration aperture Marchenko imaging method, which comprises the following steps of: calculating travel time field information of preprocessed seismic data; performing longitudinal difference calculation according to the calculated travel time field information to obtain a longitudinal travel time difference field; offset aperture sizes corresponding to all underground imaging points are completed; calculating the gradient of the background velocity model to obtain the normal direction of an underground structure interface, and making an extension line towards the ground surface along a normal method to obtain an intersection point as the center position of a migration aperture corresponding to an underground imaging point; calculating a final offset aperture range; screening a local reflection data body; calculating a local focusing function and a local Green function corresponding to the underground imaging point; according to the local focusing function and the local Green function, imaging operation is carried out on the underground imaging points by using imaging conditions; according to the invention, by setting the variable migration aperture, the imaging interference caused by far migration data is reduced, and the imaging resolution is improved.

A correlated sparse nodes and mini-streamers system for collecting seismic data includes plural nodes distributed on the ocean bottom, and a mini-streamer spread that includes plural mini-streamers. The plural nodes and the mini-streamer spread are configured to simultaneously collect seismic data from a surveyed subsurface, and wherein a length of the mini-streamers is equal to or less than three times an inline distance between adjacent nodes of the plural nodes.

An example image registration system (100) identifies subsurface structures (502, 504) at a surgical site (306) based on subsurface imaging data from a subsurface image scan at the surgical site. The image registration system (100) uses the subsurface structures (502, 504) identified at the surgical site to register endoscopic imaging data (304-1) from an endoscopic imaging modality (302-1) with additional imaging data from an additional imaging modality (304-2). Corresponding systems and methods are also disclosed.

Systems and methods for determining Green's function between known receiver positions based upon seismic data from an unknown source, the unknown source having unknown source positions and unknown source characteristics. The systems and methods include estimating an up-going component and a down-going component of the seismic data at receivers of the seismic data by combining particle motion characteristics of the seismic data, assigning geometry to the unknown source by computing a point spread function (PSF) based on a conjugate transpose of the down-going component at the receivers and the down-going component at the receivers, and computing a cross-correlation function (CF) based on the conjugate transpose of the down-going component and the up-going component at the receivers, interpolating the PSF and the CF across the receivers, estimating a Green's function based on the interpolated CF and the interpolated PSF, and taking an action based on the Green's function.

The application discloses a high-speed rail seismic data wave field separation method and system using random Cadzow filtering, and belongs to the technical field of exploration geophysics. The method comprises the following steps: collecting seismic data of high-speed rail passing time; estimating seismic wave propagation velocity through Radon transformation; correcting the time difference of the same direction wave field event to obtain aligned data; dividing the aligned data into blocks and randomly rearranging; performing Fourier transformation on the rearranged data and constructing a Hankel matrix; performing SVD decomposition and low-rank reconstruction on the Hankel matrix; reconstructing the frequency domain data block through inverse Hankel operation; performing inverse Fourier transformation and recovering the channel sequence; and extracting and averaging the central channel to obtain unidirectional wave field data. The system comprises corresponding functional modules. The application can effectively separate the mixed wave field of the high-speed rail seismic source, improve the data signal-to-noise ratio, and provide a reliable data basis for underground imaging.

The invention discloses a complex earth surface ground penetrating radar amplitude-preserving imaging method based on an orthogonal body-fitted grid, and the method comprises the following steps: 1), constructing an earth surface model according to the ground fluctuation data; constructing an electromagnetic wave underground propagation velocity model according to geological exploration data; (2) an orthogonal body-fitted grid is generated by means of a Ryskin-Leal method; 3) discretizing the orthogonal body-fitted mesh by using a finite difference time domain method; 4) performing reverse extrapolation on the received ground penetrating radar signal, and reversely propagating an electromagnetic wave field to an initial moment; in the reverse extrapolation process, the spatial position of a reflection interface is calculated through cross-correlation imaging conditions, and an underground imaging profile is obtained; 5) calculating the gradient of a target function, solving an inversion problem by adopting a conjugate gradient method, and iteratively updating the electromagnetic wave underground propagation velocity model; and 6) generating an imaging profile of the underground structure according to the electromagnetic wave underground propagation velocity model after iterative convergence. According to the invention, the precision, the stability and the anti-noise performance of underground imaging are obviously improved.

An active electromagnetic sensor for underground imaging and object detection systems that enables the detection of all magnetic or non-magnetic objects, characterized in that; it includes a signal regulator board (1), which generates the signal required for the formation of an electromagnetic field on the coil (2), processes the electromagnetic field generated by the object to be detected on the coil (2) and generates an output signal, a coil (2), which converts the signal generated by the signal regulator board (1) into an electromagnetic field and induces electricity in the object, induces voltage by the electromagnetic field generated in the object and thus enables detection.

The present invention provides a fast Marchenko imaging method for undulating surface conditions, comprising the following steps: S1: inputting seismic shot records of a fixed surface and an undulating offset surface in the depth domain, and correcting the seismic shot records to the offset surface by a static correction method. S2: inputting a seismic velocity model in the depth domain, and constructing an initial downward focusing function from the imaging point of the underground target area to the offset surface of the undulating surface by a ray tracing algorithm. S3: using the shot records and the initial downward focusing function on the undulating offset surface as input, and calculating the upward and downward Green's functions from the underground imaging point to the ground by an iterative method. S4: applying the energy normalized cross-correlation imaging condition to the reconstructed upward and downward Green's functions to obtain the Marchenko imaging result. The present invention solves the problem that conventional Marchenko imaging has low computational efficiency and cannot handle undulating surface conditions, and ensures the quality of Marchenko imaging under undulating surface conditions while improving computational efficiency.

The application discloses an angle domain adaptive local optimization reverse time migration method, an electronic device and a medium. The method can comprise: extrapolating a shot point and a receiver point reverse time wave field, constructing an energy target functional under gradient constraint on each time slice; iteratively solving a shot point end and a receiver point end wave field vector direction at a current time; constructing an adaptive threshold value through global amplitude scanning, screening to generate an effective point table at the current time, and calculating reflection opening angles or azimuth angles of effective points in the table; performing interpolation calculation of the reflection opening angles or the azimuth angles within a set range of each effective point in the table; and applying an azimuth angle domain cross-correlation imaging condition to determine a gather at an underground imaging point. The application solves the precision problem of the angle domain reverse time migration common imaging point gather, makes the angle domain reverse time migration common imaging point gather result more accurate and reliable, and is beneficial to subsequent interpretation processing.

A multimodal subsurface imaging unit includes a wideband transceiver with a wide band radio frequency signal generator operable to generate radio frequency signals within a wide band. The multimodal subsurface imaging unit includes a plurality of sets of imaging antennas, including a high frequency set, a low frequency set, and a time domain set. The multimodal subsurface imaging unit includes a switching network communicatively coupled to the wideband radio transceiver and to each of the plurality of antennas, and a control unit. The control unit is operable to control operations of the wideband radio transceiver and the switching network and receive echo signals from the plurality of sets of radio imaging antennas based on echoes of the radio frequency signals and provide the echo signals to a storage device, wherein the echo signals are suitable for analysis for feature extraction.