PICETTI FRANCESCO | Cycle: XXXIV |
Section: Telecommunications
Advisor: TUBARO STEFANO
Tutor: MONTI-GUARNIERI ANDREA VIRGILIO
Major Research topic:
A Study on Deep Learning Methodologies Applied to Geophysical Inverse Problems
Abstract:
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
Exploration Geophysics aims at estimating accurate physical properties of the Earth subsurface from seismic data acquired close to the surface.
For physical reasons, data are band-limited and corrupted by a great variety of noises, disturbances, and other phenomena.
Therefore, the fundamental tasks of Geophysics are challenging inverse problems.
Moreover, the acquisition campaigns result in massive datasets, limiting the algorithms to be computationally feasible.
To tackle this challenge, I leverage recent Machine Learning techniques.
Seismic data show a great variety of statistically relevant and independent patterns.
I devise Deep Learning methods to solve several geophysical tasks by learning such patterns.
I first interpolate seismic data using Deep Priors, which are Convolutional Neural Networks (CNNs) that precondition the interpolation problem.
Then, I study how to use deep learning to solve imaging problems, i.e., computing images of the subsurface characteristics out of the data.
Specifically, I devise generative networks as a post-processing operator for refining images obtained with Reverse Time Migration (RTM) techniques.
Moreover, I recast the post-stack seismic inversion in a Bayesian framework that uses Deep Priors to quantify the uncertainty.
Finally, I demonstrate the features extraction ability of CNNs for two interpretation tasks: landmine detection and velocity model building.
The former aims at spotting buried threats (e.g., landmines) signatures in Ground Penetrating Radar (GPR) acquisitions.
The latter is an iterative process that estimates the subsurface P-wave velocity. When in presence of salt bodies, imaging becomes particularly challenging because such bodies are characterized by higher P-wave velocities.
By processing images migrated at different angles, CNNs can leverage this physical information to produce accurate segmentations of the bottom of salt.
Through numerical experiments on both synthetic and field data, I demonstrate the devised machine learning methods to be effective compared to the state of the art. The results suggest that improvements can be achieved by integrating pure data-driven algorithms within general inverse problems theory through a-priori information derived from domain knowledge.
;
For physical reasons, data are band-limited and corrupted by a great variety of noises, disturbances, and other phenomena.
Therefore, the fundamental tasks of Geophysics are challenging inverse problems.
Moreover, the acquisition campaigns result in massive datasets, limiting the algorithms to be computationally feasible.
To tackle this challenge, I leverage recent Machine Learning techniques.
Seismic data show a great variety of statistically relevant and independent patterns.
I devise Deep Learning methods to solve several geophysical tasks by learning such patterns.
I first interpolate seismic data using Deep Priors, which are Convolutional Neural Networks (CNNs) that precondition the interpolation problem.
Then, I study how to use deep learning to solve imaging problems, i.e., computing images of the subsurface characteristics out of the data.
Specifically, I devise generative networks as a post-processing operator for refining images obtained with Reverse Time Migration (RTM) techniques.
Moreover, I recast the post-stack seismic inversion in a Bayesian framework that uses Deep Priors to quantify the uncertainty.
Finally, I demonstrate the features extraction ability of CNNs for two interpretation tasks: landmine detection and velocity model building.
The former aims at spotting buried threats (e.g., landmines) signatures in Ground Penetrating Radar (GPR) acquisitions.
The latter is an iterative process that estimates the subsurface P-wave velocity. When in presence of salt bodies, imaging becomes particularly challenging because such bodies are characterized by higher P-wave velocities.
By processing images migrated at different angles, CNNs can leverage this physical information to produce accurate segmentations of the bottom of salt.
Through numerical experiments on both synthetic and field data, I demonstrate the devised machine learning methods to be effective compared to the state of the art. The results suggest that improvements can be achieved by integrating pure data-driven algorithms within general inverse problems theory through a-priori information derived from domain knowledge.
Cookies
We serve cookies. If you think that's ok, just click "Accept all". You can also choose what kind of cookies you want by clicking "Settings".
Read our cookie policy
Cookies
Choose what kind of cookies to accept. Your choice will be saved for one year.
Read our cookie policy
-
Necessary
These cookies are not optional. They are needed for the website to function. -
Statistics
In order for us to improve the website's functionality and structure, based on how the website is used. -
Experience
In order for our website to perform as well as possible during your visit. If you refuse these cookies, some functionality will disappear from the website. -
Marketing
By sharing your interests and behavior as you visit our site, you increase the chance of seeing personalized content and offers.