Multidimensional linearized inversion and seismic migration

Geophysics ◽  
1984 ◽  
Vol 49 (11) ◽  
pp. 1881-1895 ◽  
Author(s):  
A. J. Berkhout
Keyword(s):  
Wave Field ◽  
Inverse Scattering ◽  
Scattering Problem ◽  
Inverse Scattering Problem ◽  
Measured Data ◽  
Inversion Method ◽  
Inversion Process ◽  
Elastic Parameters ◽  
Seismic Migration ◽  
Reference Medium

This paper discusses the close relationship between seismic migration and multidimensional inversion according to the linearized inverse scattering theory. The linearized inverse scattering approach represents a mixed modeling‐inversion procedure. Unlike seismic migration, the actual inversion process is carried out on the difference between a modeled reference response and the actually measured data. The output is generally presented in terms of the elastic parameters of the medium. Seismic migration represents a direct inversion method: the downward extrapolation process is carried out directly on the measured data. Output is presented in terms of reflectivity. If the reference medium has been chosen in such a way that (1) the total wave field in the reference medium can be split into a downward traveling source wave field and an upward traveling response (the propagation of both wave fields being defined by the one‐way wave equation) and that, (2) the upward traveling response in the reference medium can be neglected with respect to the upward traveling response in the actual medium, then seismic migration and linearized inversion define identical inversion processes. Typically, the above conditions are fulfilled in a homogeneous reference medium. In iteractive multidimensional inversion, the full inverse scattering problem is approached by a number of linearized inversion steps. I show that each linear step consists of a prestack migration process and a prestack modeling process, the modeling output being used to remove the contribution of multiple scattering. Finally, I argue that for a proper inversion process, information on the elastic parameters outside the seismic frequency bandwidth (temporally and spatially) should be accounted for in the reference medium.

scholarly journals A Non-Iterative Method Combined with Neural Network Embedded in Physical Model to Solve the Imaging of Electromagnetic Inverse Scattering Problem

Electronics ◽  
2021 ◽  
Vol 10 (24) ◽  
pp. 3104
Author(s):  
Hongsheng Wu ◽  
Xuhu Ren ◽  
Liang Guo ◽  
Zhengzhe Li
Keyword(s):  
Inverse Scattering ◽  
Scattering Problem ◽  
Computational Cost ◽  
Inverse Scattering Problem ◽  
Forward Model ◽  
Inversion Method ◽  
Generative Adversarial Network ◽  
Simple Method ◽  
Adversarial Network ◽  
Electromagnetic Inverse Scattering

The main purpose of this paper is to solve the electromagnetic inverse scattering problem (ISP). Compared with conventional tomography technology, it considers the interaction between the internal structure of the scene and the electromagnetic wave in a more realistic manner. However, due to the nonlinearity of ISP, the conventional calculation scheme usually has some problems, such as the unsatisfactory imaging effect and high computational cost. To solve these problems and improve the imaging quality, this paper presents a simple method named the diagonal matrix inversion method (DMI) to estimate the distribution of scatterer contrast (DSC) and a Generative Adversarial Network (GAN) which could optimize the DSC obtained by DMI and make it closer to the real distribution of scatterer contrast. In order to make the distribution of scatterer contrast generated by GAN more accurate, the forward model is embedded in the GAN. Moreover, because of the existence of the forward model, not only is the DSC generated by the generator similar to the original distribution of the scatterer contrast in the numerical distribution, but the numerical of each point is also approximate to the original.

Direct nonlinear Q-compensation of seismic primaries reflecting from a stratified, two-parameter absorptive medium

Geophysics ◽  
2010 ◽  
Vol 75 (2) ◽  
pp. V13-V23 ◽  
Author(s):  
Kristopher A. Innanen ◽  
Jose E. Lira
Keyword(s):  
Inverse Scattering ◽  
Scattering Problem ◽  
Inverse Scattering Problem ◽  
Text Structure ◽  
Nonlinear Inversion ◽  
Reflection Data ◽  
Born Series ◽  
Highly Nonlinear ◽  
Reference Medium ◽  
Absorptive Medium

[Formula: see text]-compensation of seismic primaries that have reflected from a stratified, absorptive-dispersive medium may be posed as a direct, nonlinear inverse scattering problem. If the reference medium is chosen to be nonattenuating and homogeneous, an inverse-scattering [Formula: see text]-compensation procedure may be derived that is highly nonlinear in the data, but which operates in the absence of prior knowledge of the properties of the subsurface, including its [Formula: see text] structure. It is arrived at by (1) performing an order-by-order inversion of a subset of the Born series, (2) isolating and extracting a component of the resulting nonlinear inversion equations argued to enact [Formula: see text]- compensation, and (3) mapping the result back to data space. Once derived, the procedure can be understood in terms of nonlinear interaction of the input primary reflection data: the attenuation of deeper primaries is corrected by an operator built (automatically) using the angle- and frequency variations of all shallower primaries. A simple synthetic example demonstrates the viability of the procedure in the presence of densely sampled, broadband reflection data.

scholarly journals Imaging of bi-anisotropic periodic structures from electromagnetic near-field data

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Dinh-Liem Nguyen ◽  
Trung Truong
Keyword(s):  
Inverse Scattering ◽  
Maxwell Equations ◽  
Field Data ◽  
Periodic Structures ◽  
Near Field ◽  
Scattering Problem ◽  
Three Dimensional ◽  
Inverse Scattering Problem ◽  
Factorization Method ◽  
Unique Determination

AbstractThis paper is concerned with the inverse scattering problem for the three-dimensional Maxwell equations in bi-anisotropic periodic structures. The inverse scattering problem aims to determine the shape of bi-anisotropic periodic scatterers from electromagnetic near-field data at a fixed frequency. The factorization method is studied as an analytical and numerical tool for solving the inverse problem. We provide a rigorous justification of the factorization method which results in the unique determination and a fast imaging algorithm for the periodic scatterer. Numerical examples for imaging three-dimensional periodic structures are presented to examine the efficiency of the method.

scholarly journals Evaluating Performance of Microwave Image Reconstruction Algorithms: Extracting Tissue Types with Segmentation Using Machine Learning

2021 ◽  
Vol 7 (1) ◽  
pp. 5
Author(s):  
Douglas Kurrant ◽  
Muhammad Omer ◽  
Nasim Abdollahi ◽  
Pedram Mojabi ◽  
Elise Fear ◽  
...  
Keyword(s):  
Machine Learning ◽  
Dielectric Properties ◽  
Image Quality ◽  
Inverse Scattering ◽  
Quantitative Assessment ◽  
Scattering Problem ◽  
Inverse Scattering Problem ◽  
Malignant Tissue ◽  
Segmentation Technique ◽  
Specific Tissue

Evaluating the quality of reconstructed images requires consistent approaches to extracting information and applying metrics. Partitioning medical images into tissue types permits the quantitative assessment of regions that contain a specific tissue. The assessment facilitates the evaluation of an imaging algorithm in terms of its ability to reconstruct the properties of various tissue types and identify anomalies. Microwave tomography is an imaging modality that is model-based and reconstructs an approximation of the actual internal spatial distribution of the dielectric properties of a breast over a reconstruction model consisting of discrete elements. The breast tissue types are characterized by their dielectric properties, so the complex permittivity profile that is reconstructed may be used to distinguish different tissue types. This manuscript presents a robust and flexible medical image segmentation technique to partition microwave breast images into tissue types in order to facilitate the evaluation of image quality. The approach combines an unsupervised machine learning method with statistical techniques. The key advantage for using the algorithm over other approaches, such as a threshold-based segmentation method, is that it supports this quantitative analysis without prior assumptions such as knowledge of the expected dielectric property values that characterize each tissue type. Moreover, it can be used for scenarios where there is a scarcity of data available for supervised learning. Microwave images are formed by solving an inverse scattering problem that is severely ill-posed, which has a significant impact on image quality. A number of strategies have been developed to alleviate the ill-posedness of the inverse scattering problem. The degree of success of each strategy varies, leading to reconstructions that have a wide range of image quality. A requirement for the segmentation technique is the ability to partition tissue types over a range of image qualities, which is demonstrated in the first part of the paper. The segmentation of images into regions of interest corresponding to various tissue types leads to the decomposition of the breast interior into disjoint tissue masks. An array of region and distance-based metrics are applied to compare masks extracted from reconstructed images and ground truth models. The quantitative results reveal the accuracy with which the geometric and dielectric properties are reconstructed. The incorporation of the segmentation that results in a framework that effectively furnishes the quantitative assessment of regions that contain a specific tissue is also demonstrated. The algorithm is applied to reconstructed microwave images derived from breasts with various densities and tissue distributions to demonstrate the flexibility of the algorithm and that it is not data-specific. The potential for using the algorithm to assist in diagnosis is exhibited with a tumor tracking example. This example also establishes the usefulness of the approach in evaluating the performance of the reconstruction algorithm in terms of its sensitivity and specificity to malignant tissue and its ability to accurately reconstruct malignant tissue.

scholarly journals Adaptive B -spline scheme for solving an inverse scattering problem

2004 ◽  
Vol 20 (2) ◽  
pp. 347-365 ◽  
Author(s):  
Alexandre Baussard ◽  
Eric L Miller ◽  
Denis Prémel
Keyword(s):  
Inverse Scattering ◽  
Scattering Problem ◽  
Inverse Scattering Problem ◽  
B Spline

Inverse scattering problem with isobars

1977 ◽  
Vol 16 (2) ◽  
pp. 721-725 ◽  
Author(s):  
J. T. Londergan ◽  
E. J. Moniz
Keyword(s):  
Inverse Scattering ◽  
Scattering Problem ◽  
Inverse Scattering Problem
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