A5100442215- Seismic Imaging and Inversion Techniques
- Seismic Waves and Analysis
- Geophysical and Geoelectrical Methods
- Hydrocarbon exploration and reservoir analysis
- Drilling and Well Engineering
- Seismology and Earthquake Studies
- Methane Hydrates and Related Phenomena
- Geophysics and Gravity Measurements
- Geological and Geophysical Studies
- earthquake and tectonic studies
- Geophysical Methods and Applications
- Image and Signal Denoising Methods
- Hydraulic Fracturing and Reservoir Analysis
- Medical Imaging Techniques and Applications
- Electromagnetic Scattering and Analysis
- Soil Moisture and Remote Sensing
- Advanced Numerical Analysis Techniques
- Advanced MRI Techniques and Applications
- Geological formations and processes
- Electromagnetic Simulation and Numerical Methods
- NMR spectroscopy and applications
- Machine Fault Diagnosis Techniques
- Computer Graphics and Visualization Techniques
- Advanced X-ray Imaging Techniques
- Magnetic Properties and Applications
Ocean University of China
2013-2024
Qingdao National Laboratory for Marine Science and Technology
2017-2023
Mineral Resources
2019
Ministry of Education of the People's Republic of China
2014-2017
Xiamen University of Technology
2011
The synchrosqueezing transform (SST) is a novel approach for time-frequency (T-F) representation of non-stationary signals. By and reassigning the T-F spectrum wavelet (WT) or short time Fourier (STFT) signal, SST can obtain high-resolution spectrum. In light superiority S-transform (ST) over WT STFT, especially, in representing high-frequency weak-amplitude signal on its spectrum, we propose (SSST) which realized by ST. formulas SSST inverse are derived. Synthetic examples show that has...
A step-by-step spectral inversion algorithm is proposed in this paper to estimate the thickness, depth, permittivity, and conductivity of layered media from ground-penetrating radar (GPR) signals. Due distinct GPR responses parameters, different attributes spectra are used estimate, separately, one or several parameters within each step. Such estimated then as starting values a nonlinear optimization problem for all simultaneously whole data. The cost function defined difference between...
SUMMARY Microseismic monitoring is crucial for risk assessment in mining, fracturing and excavation. In practice, microseismic records are often contaminated by undesired noise, which an obstacle to high-precision seismic locating imaging. this study, we develop a new denoising method improve the signal-to-noise ratio (SNR) of signals combining wavelet coefficient thresholding pixel connectivity thresholding. First, pure background noise range record estimated using variance (ROV) method....
We propose a new ray tracing technique in 3-D heterogeneous isotropic media based on bilinear traveltime interpolation and the wave front group marching. In this technique, is discretized into series of rectangular cells. There are two steps to be carried out: one forward step where expansion evolved from sources whole computational domain subsequent backward paths calculated for any source–receiver configuration as desired. step, we derive closed-form expression calculate at an arbitrary...
Abstract The Synchrosqueezing S‐transform (SSST) is a novel approach for time‐frequency (T‐F) representation of non‐stationary signals. By “squeezing” T‐F spectrum the (ST) signal, SSST can obtain high‐resolution spectrum. However, when phase signal varies non‐linearly with time, instantaneous frequency (IF) calculated by would be inaccurate, causing reduction resolution In order to improve its performance in imaging such signals, we modify formula IF help second‐order partial derivatives...
Abstract The linear traveltime interpolation has been a routine method to compute first arrivals of seismic waves and trace rays in complex media. assumes that traveltimes follow distribution on each boundary cells. linearity assumption facilitates the numerical implementation but its violation may result large computational errors. In this paper, we propose new way mitigate potential shortcoming hidden interpolation. We use vertex calculated cell introduce an equivalent homogeneous medium...
SUMMARY Attention is paid to joint inversion of multiple geophysical data because its advantages on weakening the non-uniqueness and further enhancing comprehensive interpretation. Due good correlation between rock velocity density, seismic gravity have been widely used in inversion. However, pre-stack reflection remains underdeveloped at exploration scale. Without a quantitive relation we develop structure-based using traveltimes, slopes Bouguer anomaly simultaneously for building both...
SUMMARY Accurate near-surface velocity models are necessary for land seismic imaging. First-arrival traveltime tomography (FTT) routinely used estimating may fail in geological complex areas. Supervised deep learning (SDL) is capable of building accurate models, based on tens thousands model-shot gathers training pairs. It takes lots time and memory space, which be unaffordable practical applications. We propose integrating the FTT SDL to build models. During neural network training,...
ABSTRACT Acoustic impedance is one of the best attributes for seismic interpretation and reservoir characterisation. We present an approach estimating acoustic accurately from a band‐limited noisy data. The composed two stages: inverting reflectivity data then inverted in first stage. For stage, we achieve two‐step spectral inversion that locates positions reflection coefficients step determines amplitudes second under constraints located step. construct iterative estimation algorithm based...
Abstract High signal-to-noise ratio (SNR) seismic waveform data are conductive to various studies in seismology. Seismic denoising aims enhance SNR by eliminating additive noise through signal processing while preserving important features of the signal. Conventional parametric methods often require selecting appropriate parameters achieve optimal results, which may be limiting when dealing with types and scales data. Here, we develop an adaptive parameter-free method combining general...
Microseismic events play a crucial role in mapping fault and fracture distributions natural induced earthquakes. Detecting localizing microseismic is challenging due to low signal-to-noise ratios (SNR). Waveform stacking (WS) imaging location practical approach for automatically detecting events, assuming that the traveltime-corrected seismic waveforms will stack enhance coherently. However, coherent enhancement susceptible polarity reversal caused by non-explosive components of source...
Reverse-time migration (RTM) of the towed-streamer seismic data is widely used for imaging sub-seabed layers. In areas with high-velocity shielding layers, RTM images deep layers may be severely damaged by coherent noises. The pressure component ocean bottom nodes (OBN) contains abundant reflection waves from deep-layers and can as supplementary to data. Joint these two kinds has potential acquire better images. However, using traditional cross-correlation condition, joint low...
SUMMARY A non-iterative first-arrival traveltime inversion method (NFTI) is proposed for building smooth velocity models using seismic diving waves observed on irregular surface. The new ray and equations of propagating in media with undulant observation surface are deduced. According to the equations, an analytical formula determining location diving-wave turning points then derived. Taking influence rough topography traveltimes into account, calculating velocities at established. Based...