Denoising becomes a non-trivial task when noise and signal overlap in multiple domains such as ti... more Denoising becomes a non-trivial task when noise and signal overlap in multiple domains such as time, frequency, and velocity. Fortunately, signal and noise waveforms in general tend to remain morphologically different. This paper shows how morphological differences can be used to separate body-wave signals from other waveforms such as ground roll and cultural noise. The key was finding a wavelet that was a close approximation of the true source signature (SS) and remained uncontaminated by the Greens function in any significant manner. An inverse filter designed using such a wavelet selectively compressed the body waves which was then extracted using median and low-pass filters. The overall phenomenon is explained with a synthetic example. The idea is also tested on a land dataset that was generated using a large weight drop source where a wavelet recorded ∼3 m from the source location fulfilled the criteria set in the proposed method. Results suggest that the incremental effort of...
Istanbul 2012 - International Geophysical Conference and Oil & Gas Exhibition, 2012
One of the most important aims of seismic data processing is to increase signal-to-noise ratio (S... more One of the most important aims of seismic data processing is to increase signal-to-noise ratio (SNR) via suppression of coherent and random noises. We introduce a Redundant Lifting-based Adaptive Wiener Filter with Thresholding for suppression of both coherent and incoherent noises of field records. The purposed method at the first step applies a one dimensional wavelet transform using Redundant Lifting Scheme (RLS) in a trace by trace manner. After eliminating of appropriate sub-bands, performs a two-dimensional Adaptive Wiener Filter (AWF) on thresholded sub-band gathers. The filtered records are obtained by inverse transforming of data into the time-space domain. We tested the performance of the purposed method on real seismic data.
One of the most important steps in seismic data processing to increase S/N is suppression of cohe... more One of the most important steps in seismic data processing to increase S/N is suppression of coherent and incoherent noises. In the this thesis we used three methods first, Seislet transform; second, adaptive wiener filter with thresholding in redundant-lifting wavelet domain; third, Laplacian of Gaussian filter in redundant-lifting wavelet domain that all of them are based on lifting scheme which is an alternative approach for computation of discrete wavelet transform (DWT). We applied the methods to suppress random noises in shot gathers. We indicate that adaptive wiener filter with thresholding in redundant-lifting wavelet domain and Laplacian of Gaussian filter in redundant-lifting wavelet domain are novel methods in seismic data processing that designed during this thesis and they can suppress both random and coherent noises in same time.
One-page abstract deadline: Oct. 31, 2019
Full chapter deadline: Jan. 31, 2020
We cordially invi... more One-page abstract deadline: Oct. 31, 2019 Full chapter deadline: Jan. 31, 2020
We cordially invite you and your relevant colleagues to join us in a new Open Access book project. In collaboration with Knowledge Unlatched, IntechOpen will publish an open access book "Applied Computational Near-surface Geophysics – From Integral and Derivative Formulas to MATLAB codes " (ISBN: 978-1-83962-229-8) with me appointed as the editor.
IMPORTANT: If your peer-reviewed submission is accepted, the open-access publishing fee will be covered by the publisher in collaboration with KU, so there will be no fee for your chapter.
The book will cover the following chapters: Chapter 1. Reviewing required mathematics with MATLAB · Matrices · MATLAB syntax · Import-export files · Finite difference method · Fourier analysis · Inverse method Chapter 2. Refraction seismology Chapter 3. Reflection Chapter 4. Cross/Down/up-hole seismic methods Chapter 5. Multi-channel surface wave analysis (MSWA) Chapter 6. Gravity Chapter 7. Resistivity Chapter 8. Electrical resistivity tomography Chapter 9. Magnetic Chapter 10. Electro-magnetic Chapter 11. Ground-penetrating radar (GPR) Or other chapters that you think can fit under the mentioned title.
The first step is to register on the following link:
and submit a short chapter proposal (Maximum one page i.e. an abstract consists of your point of view, strategy, etc., and keywords) by October 31, 2019, so that we can get an idea of what you would focus on in the full chapter.
The full chapter the deadline will not be until January 31, 2020, so there is plenty of time for you to prepare it. Once you have registered, you will have an IntechOpen Author service manager at your disposal who will lead you through the process, while we review proposals and later full chapters.
Please reply to my email (aghayan@okstate.edu) and inform me of your participation in the following week, if possible, so that I can make plans for the book. If you should have any questions, I will be happy to assist. Best wishes,
Denoising becomes a non-trivial task when noise and signal overlap in multiple domains such as ti... more Denoising becomes a non-trivial task when noise and signal overlap in multiple domains such as time, frequency, and velocity. Fortunately, signal and noise waveforms in general tend to remain morphologically different. This paper shows how morphological differences can be used to separate body-wave signals from other waveforms such as ground roll and cultural noise. The key was finding a wavelet that was a close approximation of the true source signature (SS) and remained uncontaminated by the Greens function in any significant manner. An inverse filter designed using such a wavelet selectively compressed the body waves which was then extracted using median and low-pass filters. The overall phenomenon is explained with a synthetic example. The idea is also tested on a land dataset that was generated using a large weight drop source where a wavelet recorded ∼3 m from the source location fulfilled the criteria set in the proposed method. Results suggest that the incremental effort of...
Istanbul 2012 - International Geophysical Conference and Oil & Gas Exhibition, 2012
One of the most important aims of seismic data processing is to increase signal-to-noise ratio (S... more One of the most important aims of seismic data processing is to increase signal-to-noise ratio (SNR) via suppression of coherent and random noises. We introduce a Redundant Lifting-based Adaptive Wiener Filter with Thresholding for suppression of both coherent and incoherent noises of field records. The purposed method at the first step applies a one dimensional wavelet transform using Redundant Lifting Scheme (RLS) in a trace by trace manner. After eliminating of appropriate sub-bands, performs a two-dimensional Adaptive Wiener Filter (AWF) on thresholded sub-band gathers. The filtered records are obtained by inverse transforming of data into the time-space domain. We tested the performance of the purposed method on real seismic data.
One of the most important steps in seismic data processing to increase S/N is suppression of cohe... more One of the most important steps in seismic data processing to increase S/N is suppression of coherent and incoherent noises. In the this thesis we used three methods first, Seislet transform; second, adaptive wiener filter with thresholding in redundant-lifting wavelet domain; third, Laplacian of Gaussian filter in redundant-lifting wavelet domain that all of them are based on lifting scheme which is an alternative approach for computation of discrete wavelet transform (DWT). We applied the methods to suppress random noises in shot gathers. We indicate that adaptive wiener filter with thresholding in redundant-lifting wavelet domain and Laplacian of Gaussian filter in redundant-lifting wavelet domain are novel methods in seismic data processing that designed during this thesis and they can suppress both random and coherent noises in same time.
One-page abstract deadline: Oct. 31, 2019
Full chapter deadline: Jan. 31, 2020
We cordially invi... more One-page abstract deadline: Oct. 31, 2019 Full chapter deadline: Jan. 31, 2020
We cordially invite you and your relevant colleagues to join us in a new Open Access book project. In collaboration with Knowledge Unlatched, IntechOpen will publish an open access book "Applied Computational Near-surface Geophysics – From Integral and Derivative Formulas to MATLAB codes " (ISBN: 978-1-83962-229-8) with me appointed as the editor.
IMPORTANT: If your peer-reviewed submission is accepted, the open-access publishing fee will be covered by the publisher in collaboration with KU, so there will be no fee for your chapter.
The book will cover the following chapters: Chapter 1. Reviewing required mathematics with MATLAB · Matrices · MATLAB syntax · Import-export files · Finite difference method · Fourier analysis · Inverse method Chapter 2. Refraction seismology Chapter 3. Reflection Chapter 4. Cross/Down/up-hole seismic methods Chapter 5. Multi-channel surface wave analysis (MSWA) Chapter 6. Gravity Chapter 7. Resistivity Chapter 8. Electrical resistivity tomography Chapter 9. Magnetic Chapter 10. Electro-magnetic Chapter 11. Ground-penetrating radar (GPR) Or other chapters that you think can fit under the mentioned title.
The first step is to register on the following link:
and submit a short chapter proposal (Maximum one page i.e. an abstract consists of your point of view, strategy, etc., and keywords) by October 31, 2019, so that we can get an idea of what you would focus on in the full chapter.
The full chapter the deadline will not be until January 31, 2020, so there is plenty of time for you to prepare it. Once you have registered, you will have an IntechOpen Author service manager at your disposal who will lead you through the process, while we review proposals and later full chapters.
Please reply to my email (aghayan@okstate.edu) and inform me of your participation in the following week, if possible, so that I can make plans for the book. If you should have any questions, I will be happy to assist. Best wishes,
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Papers by Afshin Aghayan
Books by Afshin Aghayan
Full chapter deadline: Jan. 31, 2020
We cordially invite you and your relevant colleagues to join us in a new Open Access book project. In collaboration with Knowledge Unlatched, IntechOpen will publish an open access book "Applied Computational Near-surface Geophysics – From Integral and Derivative Formulas to MATLAB codes " (ISBN: 978-1-83962-229-8) with me appointed as the editor.
IMPORTANT: If your peer-reviewed submission is accepted, the open-access publishing fee will be covered by the publisher in collaboration with KU, so there will be no fee for your chapter.
The book will cover the following chapters:
Chapter 1. Reviewing required mathematics with MATLAB
· Matrices
· MATLAB syntax
· Import-export files
· Finite difference method
· Fourier analysis
· Inverse method
Chapter 2. Refraction seismology
Chapter 3. Reflection
Chapter 4. Cross/Down/up-hole seismic methods
Chapter 5. Multi-channel surface wave analysis (MSWA)
Chapter 6. Gravity
Chapter 7. Resistivity
Chapter 8. Electrical resistivity tomography
Chapter 9. Magnetic
Chapter 10. Electro-magnetic
Chapter 11. Ground-penetrating radar (GPR)
Or other chapters that you think can fit under the mentioned title.
The first step is to register on the following link:
https://mts.intechopen.com/welcome/38cdbbb671df620b36ee96af1d9a3a90/
and submit a short chapter proposal (Maximum one page i.e. an abstract consists of your point of view, strategy, etc., and keywords) by October 31, 2019, so that we can get an idea of what you would focus on in the full chapter.
The full chapter the deadline will not be until January 31, 2020, so there is plenty of time for you to prepare it.
Once you have registered, you will have an IntechOpen Author service manager at your disposal who will lead you through the process, while we review proposals and later full chapters.
Please reply to my email (aghayan@okstate.edu) and inform me of your participation in the following week, if possible, so that I can make plans for the book. If you should have any questions, I will be happy to assist.
Best wishes,
Full chapter deadline: Jan. 31, 2020
We cordially invite you and your relevant colleagues to join us in a new Open Access book project. In collaboration with Knowledge Unlatched, IntechOpen will publish an open access book "Applied Computational Near-surface Geophysics – From Integral and Derivative Formulas to MATLAB codes " (ISBN: 978-1-83962-229-8) with me appointed as the editor.
IMPORTANT: If your peer-reviewed submission is accepted, the open-access publishing fee will be covered by the publisher in collaboration with KU, so there will be no fee for your chapter.
The book will cover the following chapters:
Chapter 1. Reviewing required mathematics with MATLAB
· Matrices
· MATLAB syntax
· Import-export files
· Finite difference method
· Fourier analysis
· Inverse method
Chapter 2. Refraction seismology
Chapter 3. Reflection
Chapter 4. Cross/Down/up-hole seismic methods
Chapter 5. Multi-channel surface wave analysis (MSWA)
Chapter 6. Gravity
Chapter 7. Resistivity
Chapter 8. Electrical resistivity tomography
Chapter 9. Magnetic
Chapter 10. Electro-magnetic
Chapter 11. Ground-penetrating radar (GPR)
Or other chapters that you think can fit under the mentioned title.
The first step is to register on the following link:
https://mts.intechopen.com/welcome/38cdbbb671df620b36ee96af1d9a3a90/
and submit a short chapter proposal (Maximum one page i.e. an abstract consists of your point of view, strategy, etc., and keywords) by October 31, 2019, so that we can get an idea of what you would focus on in the full chapter.
The full chapter the deadline will not be until January 31, 2020, so there is plenty of time for you to prepare it.
Once you have registered, you will have an IntechOpen Author service manager at your disposal who will lead you through the process, while we review proposals and later full chapters.
Please reply to my email (aghayan@okstate.edu) and inform me of your participation in the following week, if possible, so that I can make plans for the book. If you should have any questions, I will be happy to assist.
Best wishes,