Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 53 for “"Full-waveform"”.
-
Full waveform acoustic logs in radially layered boreholes
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric and Planetary Sciences, 1984.
-
Effects of layer boundaries on full waveform acoustic logs
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric and Planetary Sciences, 1985.
-
Seismic velocity and attenuation from full waveform acoustic logs
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1983.
-
Determining the focal mechanisms of earthquakes by full waveform modeling
… of earthquakes. This objective is met using a full waveform modeling method in which we generate synthetic seismograms using a discrete wavenumber code to match the observed seismograms. We first calculate Green's functions given an initial estimate of the earthquake's hypocenter, the locations …
-
DTM Generation in Forested Areas from Full-Waveform Airborne LiDAR Data
… of Digital Terrain Model (DTM) extraction from full-waveform LiDAR data. Specifically, the primary goal was to develop a novel method to improve DTM extraction by utilizing low amplitude pulses that are generated by terrain under vegetation, but undetectable using traditional Gaussian …
-
Full waveform inversion combining rock physics for seismic reservoir characterization and monitoring
… based on amplitude variation with offset (AVO). Full waveform inversion (FWI) methods, although computationally more complex than AVO approaches, can produce more accurate elastic models by extracting the full information content in the seismogram. Progress has been reported in using elastic FWI …
-
Microseismic mapping and source characterization for hydrofracture monitoring : a full-waveform approach
… capability for hydrofracture monitoring by using full-waveform information and understand fracturing mechanisms via microsesimic source mechanism inversion. First, we develop an array-based correlation approach to improve the detection of small magnitude events with mechanisms and locations …
-
APPROXIMATE VS. PURELY NUMERICAL APPROACHES FOR FULL WAVEFORM MODELLING OF GLOBAL EARTH STRUCTURE
… seismic forward modelling of body and surface waveforms in realistic 3-D Earth models using approximate and purely numerical methods. Firstly, we investigate two techniques: (i) the Born approximation, which should be valid for media with weak heterogeneity; and, (ii) the full ray theory …
-
Machine learning methods modeling waveform, multi-parameter full waveform inversion, and uncertainty quantification
Full waveform inversion (FWI) is a potent technology capable of estimating subsurface parameters using seismic records. However, several challenges hinder its widespread application in large-scale field operations. In this thesis, I introduce strategies that leverage machine learning techniques to …
-
Distributed acoustic sensing: modelling, full waveform inversion, and its use in seismic monitoring
… wavefield modes that are crucial to support land full waveform inversion (FWI). The inherently different sampling that DAS fibers provide leads to a requirement for modeling strategies that differ from those used to simulate point sensor data. To maximize the potential of DAS which only samples …
-
Application of full waveform acoustic logging data to the estimation of reservoir permeability
Thesis: M.S., Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 1984
-
Fusion of Full Waveform LiDAR and Passive Remote Sensing for Improved Land-Cover Classification
… properties. With the introduction of full waveform LiDAR (FWL), the possibility of using LiDAR for target discrimination has been enhanced due to the additional structural information acquired. The geometrical information and backscattering properties measured by FWL is complementary …
-
Full-waveform inversion of time-lapse seismic data using physics-based and data-driven techniques
Time-lapse (4D) full-waveform inversion (FWI) is an advanced seismic technique that can enable accurate estimation of changes in the subsurface properties, such as fluid saturation or reservoir depletion, by utilizing amplitude and phase information in seismic data. However, most existing 4D FWI …
-
Acoustic full-waveform to elastic pre-stack seismic inversion of the Yakutat Terrane, Gulf of Alaska
… acoustic and isotropic time-domain full waveform inversion (FWI) of marine seismic reflection and refraction data from the STEEP project (ST. Elias Erosion/tectonics Project). FWI is a non-linear data-fitting algorithm that aims to recover subsurface parameters from the recorded …
-
Quantifying structural change in UK woodland canopies with a dual-wavelength full-waveform terrestrial laser scanner
… (SALCA), a research TLS with dual-wavelength full-waveform capabilities.There were three key objectives to this research: (1) the development of a radiometric calibration for the SALCA instrument to produce an apparent reflectance product, (2) the separation of SALCA point clouds into leaf and …
-
Viscoelastic full-waveform inversion: treating attenuation uncertainty, characterizing cross-talk, and quantifying confidence in inversion results
Full waveform inversion (FWI) is a powerful technique for estimating the subsurface properties which affect seismic wave propagation but it is often limited by simplistic treatment of wave propagation physics. In particular, attenuation and dispersion, which play major roles in most seismic …
-
Full waveform inversion of ultrasonic phased array data for the tomographic reconstruction of heterogeneous media for NDT
… work builds upon that work by creating a full waveform inversion framework to build a tomography method that reconstructs spatially heterogeneous wave speeds maps from simulated ultrasonic phased array data. This framework consists of: a Voronoi tessellation to spatially parametrise the …
-
Investigation of Source Extension Methods, the Discrepancy Algorithm, and Noise Estimation to Overcome Cycle Skipping in Full Waveform Inversion
Full waveform inversion (FWI) is a geophysical technique used to create highly detailed mod- els of the Earth’s subsurface which can be used to explore for hydrocarbons and to predict natural hazards such as earthquakes. Seismic waves are generated from controlled sources such as vibroseis trucks …
Page 1 of 3