scholarly journals R-EPSI and Marchenko equation-based workflow for multiple suppression in the case of a shallow water layer and a complex overburden: a 2D case study in the Arabian Gulf

Geophysics ◽  
2020 ◽  
pp. 1-62
Author(s):  
Myrna Staring ◽  
Marcin Dukalski ◽  
Mikhail Belonosov ◽  
Rolf Baardman ◽  
Jewoo Yoo ◽  
...  
Keyword(s):  
Shallow Water ◽  
Adaptive Filters ◽  
A Priori ◽  
Arabian Gulf ◽  
Water Layer ◽  
Prediction Errors ◽  
Marchenko Equation ◽  
Sparse Inversion ◽  
Internal Multiples ◽  
Multiple Prediction

Suppression of surface-related and internal multiples is an outstanding challenge in seismic data processing. The former is particularly difficult in shallow water, whereas the latter is problematic for targets buried under complex, highly scattering overburdens. We propose a two-step, amplitude- and phase-preserving, inversion-based workflow, which addresses these problems. We apply Robust Estimation of Primaries by Sparse Inversion (R-EPSI) to suppress the surface-related multiples and solve for the source wavelet. A significant advantage of the inversion approach of the R-EPSI method is that it does not rely on an adaptive subtraction step that typically limits other de-multiple methods such as SRME. The resulting Green's function is used as input to a Marchenko equation-based approach to predict the complex interference pattern of all overburden-generated internal multiples at once, without a priori subsurface information. In theory, the interbed multiples can be predicted with correct amplitude and phase and, again, no adaptive filters are required. We illustrate this workflow by applying it on an Arabian Gulf field data example. It is crucial that all pre-processing steps are performed in an amplitude preserving way to restrict any impact on the accuracy of the multiple prediction. In practice, some minor inaccuracies in the processing flow may end up as prediction errors that need to be corrected for. Hence, we decided that the use of conservative adaptive filters is necessary to obtain the best results after interbed multiple removal. The obtained results show promising suppression of both surface-related and interbed multiples.

Shallow water multiple prediction and attenuation, case study on data from the Arabian Gulf

2002 ◽  
Author(s):  
Riaz Alá'i ◽  
Dirk Jacob Verschuur ◽  
Jock Drummond ◽  
Stan Morris ◽  
Gerard Haughey
Keyword(s):  
Shallow Water ◽  
Arabian Gulf ◽  
Multiple Prediction

scholarly journals Internal multiple elimination: Can we trust an acoustic approximation?

Geophysics ◽  
2021 ◽  
pp. 1-44
Author(s):  
Christian Reinicke ◽  
Marcin Dukalski ◽  
Kees Wapenaar
Keyword(s):  
Field Data ◽  
A Priori ◽  
Elastic Field ◽  
Substantial Impact ◽  
Marchenko Equation ◽  
Acoustic Media ◽  
Particle Velocities ◽  
Internal Multiples ◽  
Multiple Elimination ◽  
Acoustic Approximation

Correct handling of strong elastic, internal, multiples remains a challenge for seismic imaging. Methods aimed at eliminating them are currently limited by monotonicity violations, a lack of a-priori knowledge about mode conversions, or unavailability of multi-component sources and receivers for not only particle velocities but also the traction vector. Most of these challenges vanish in acoustic media such that Marchenko-equation-based methods are able in theory to remove multiples exactly (within a certain wavenumber-frequency band). In practice, however, when applied to (elastic) field data, mode conversions are unaccounted for. Aiming to support a recently published marine field data study, we build a representative synthetic model. For this setting, we demonstrate that mode conversions can have a substantial impact on the recovered multiple-free reflection response. Nevertheless, the images are significantly improved by acoustic multiple elimination. Moreover, after migration the imprint of elastic effects is considerably weaker and unlikely to alter the seismic interpretation.

scholarly journals THE WAYS OF TECHNICAL REALIZATION OF ADAPTIVE ALGORITHM OF COMPENSATION OF NON-LINEAR DISTORTIONS OF RADIO DEVICES

2018 ◽  
Vol 6 (52) ◽  
pp. 140-143
Author(s):  
О. Shefer ◽  
N. Ichanska ◽  
B. Topikha ◽  
V. Shefer
Keyword(s):  
Adaptive Systems ◽  
Adaptive Filters ◽  
A Priori ◽  
Weather Conditions ◽  
Adaptive Method ◽  
Theory And Practice ◽  
Modern Theory ◽  
Additional Advantage ◽  
Local Systems ◽  
Non Linear

The practical realization of potential opportunities of onboard radio local systems of radio local systems (OBRLS) that are currently considerably higher than their real approachable technical characteristics is one of the main tasks of modern theory and practice of electronic and telecommunication. The authors of the article proposed some specific technical offers and ways of physical realization of scientifically grounded algorithm of adaptive compensation of non linear distortions (ACNLD). The insertion of artificial main and supportive entrances into the scheme of non-linear adaptive compensators allowed using the general theory of adaptive systems for their synthesis. The practical usage of synthesized following such a principle ACNLD according to the created recommendations allows to significantly increase the indices of quality of OBRLS in the real conditions of their functioning, comparing with the already known ones. An additional advantage of proposed adaptive method of expansion of linear dynamic diapason (LDD) is an improvement of all-weather of OBRLS and increasing of probability of identification of radio local maps of locality captured in different weather conditions without any additional changeovers. Except for this, a flexible reserve for the noise immunity of OBRLS is being fulfilled that allows taking into consideration the possible improvements of means of radio electronic struggle. Synthesized ACNLD are considerably free from many drawbacks of linear determined means of expansion of dynamic diapason of radio receiving devices (RRD) and also they have simpler apparatus realization. Except, in a process of projection of ACNLD a considerably less volume of a priori information about the parameters of LDD is needed for the calculation of already known schemes of depression of non-linear distortions. The transferring functions of adaptive filters of ACNLD are quite quickly gather at the non-linear transferring function of radio device (RD) provided that an effective convergence can be seen only with the presence of the inner noises at least unless they exceed the non-linear distortions by the level.

scholarly journals Relating source-receiver interferometry to an inverse-scattering series to derive a new method to estimate internal multiples

Geophysics ◽  
2016 ◽  
Vol 81 (3) ◽  
pp. Q27-Q40 ◽  
Author(s):  
Katrin Löer ◽  
Andrew Curtis ◽  
Giovanni Angelo Meles
Keyword(s):  
Inverse Scattering ◽  
Computational Cost ◽  
Synthetic Data ◽  
Data Set ◽  
Inverse Scattering Series ◽  
Internal Multiples ◽  
Multiple Prediction ◽  
New Formula ◽  
3D Applications ◽  
Insight Into

We have evaluated an explicit relationship between the representations of internal multiples by source-receiver interferometry and an inverse-scattering series. This provides a new insight into the interaction of different terms in each of these internal multiple prediction equations and explains why amplitudes of estimated multiples are typically incorrect. A downside of the existing representations is that their computational cost is extremely high, which can be a precluding factor especially in 3D applications. Using our insight from source-receiver interferometry, we have developed an alternative, computationally more efficient way to predict internal multiples. The new formula is based on crosscorrelation and convolution: two operations that are computationally cheap and routinely used in interferometric methods. We have compared the results of the standard and the alternative formulas qualitatively in terms of the constructed wavefields and quantitatively in terms of the computational cost using examples from a synthetic data set.

Information Processing Systems in UAV Based on Bayesian Filtering in Conditions of Uncertainty

2020 ◽  
Vol 12 (4) ◽  
pp. 42-59
Author(s):  
Rinat Galiautdinov
Keyword(s):  
Information Processing ◽  
Degrees Of Freedom ◽  
Adaptive Filters ◽  
A Priori ◽  
Practical Implementation ◽  
Bayesian Filtering ◽  
Math Model ◽  
Digital Implementation ◽  
Estimation Algorithms ◽  
A Priori Uncertainty

In this article, the author considers the possibility of applying modern IT technologies to implement information processing algorithms in UAV motion control system. Filtration of coordinates and motion parameters of objects under a priori uncertainty is carried out using nonlinear adaptive filters: Kalman and Bayesian filters. The author considers numerical methods for digital implementation of nonlinear filters based on the convolution of functions, the possibilities of neural networks and fuzzy logic for solving the problems of tracking UAV objects (or missiles), the math model of dynamics, the features of the practical implementation of state estimation algorithms in the frame of added additional degrees of freedom. The considered algorithms are oriented on solving the problems in real time using parallel and cloud computing.

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