The inverse scattering series for tasks associated with primaries: depth imaging and direct non‐linear inversion of 1D variable velocity and density acoustic media

2005 ◽  
Author(s):  
Haiyan Zhang ◽  
Arthur B. Weglein
Keyword(s):  
Inverse Scattering ◽  
Variable Velocity ◽  
Linear Inversion ◽  
Depth Imaging ◽  
Non Linear ◽  
Inverse Scattering Series ◽  
Acoustic Media

Removing free-surface multiples from teleseismic transmission and constructed reflection responses using reciprocity and the inverse scattering series

Geophysics ◽  
2006 ◽  
Vol 71 (4) ◽  
pp. SI71-SI78 ◽  
Author(s):  
Chengliang Fan ◽  
Gary L. Pavlis ◽  
Arthur B. Weglein ◽  
Bogdan G. Nita
Keyword(s):  
Free Surface ◽  
Inverse Scattering ◽  
Synthetic Data ◽  
P Wave ◽  
Transmission Data ◽  
Before And After ◽  
Small Incidence ◽  
Inverse Scattering Series ◽  
Acoustic Media ◽  
The Difference

We develop a new way to remove free-surface multiples from teleseismic P- transmission and constructed reflection responses. We consider two types of teleseismic waves with the presence of the free surface: One is the recorded waves under the real transmission geometry; the other is the constructed waves under a virtual reflection geometry. The theory presented is limited to 1D plane wave acoustic media, but this approximation is reasonable for the teleseismic P-wave problem resulting from the steep emergence angle of the wavefield. Using one-way wavefield reciprocity, we show how the teleseismic reflection responses can be reconstructed from the teleseismic transmission responses. We use the inverse scattering series to remove free-surface multiples from the original transmission data and from the reconstructed reflection response. We derive an alternative algorithm for reconstructing the reflection response from the transmission data that is obtained by taking the difference between the teleseismic transmission waves before and after free-surface multiple removal. Numerical tests with 1D acoustic layered earth models demonstrate the validity of the theory we develop. Noise test shows that the algorithm can work with S/N ratio as low as 5 compared to actual data with S/N ratio from 30 to 50. Testing with elastic synthetic data indicates that the acoustic algorithm is still effective for small incidence angles of typical teleseismic wavefields.

First field data examples of inverse scattering series direct depth imaging without the velocity model

2012 ◽  
Author(s):  
Arthur B. Weglein ◽  
Fang Liu ◽  
Xu Li ◽  
Paolo Terenghi ◽  
Ed Kragh ◽  
...  
Keyword(s):  
Inverse Scattering ◽  
Field Data ◽  
Velocity Model ◽  
Depth Imaging ◽  
Inverse Scattering Series

Direct nonlinear inversion of 1D acoustic media using inverse scattering subseries

Geophysics ◽  
2009 ◽  
Vol 74 (6) ◽  
pp. WCD29-WCD39 ◽  
Author(s):  
Haiyan Zhang ◽  
Arthur B. Weglein
Keyword(s):  
Inverse Scattering ◽  
Target Identification ◽  
Numerical Test ◽  
Added Value ◽  
Acoustic Medium ◽  
Nonlinear Inversion ◽  
Model Matching ◽  
Inverse Scattering Series ◽  
Acoustic Media ◽  
Property Changes

A task-specific, multiparameter (more than one mechanical property changes across a reflector), direct nonlinear inversion subseries of the inverse-scattering series is derived and tested for an acoustic medium in which velocity and density vary vertically. Task-specific means that terms in the distinct subseries corresponding to tasks for imaging only and inversion only are identified and separated. Direct means there are formulas that solve explicitly for and output the physical properties, without, e.g., search algorithms, model matching and optimization schemes, and proxies that typically characterize indirect methods. Numerical test results with analytic data indicate that one term beyond linear provides added value beyond standard linear techniques, and the improved estimates are valid over a larger range of angles. The direct acoustic inversion is nonlinear. It serves as an important step for new concepts and methods to guide the much more complicated and minimally realistic elastic inverse for exploration seismology target identification purposes.

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