arXiv subjects

Tiago A. Coimbra

Publications and source records attributed to Tiago A. Coimbra.

3 recordsLinked to original sources

arXiv2026

Offset-continuation-trajectory stacking based on common-reflection-point kinematics for five-dimensional prestack dataset regularization and enhancement

Prestack seismic data regularization and enhancement are critical steps for reliable imaging and inversion, particularly in five-dimensional (5D) dataset geometries affected by irregular sampling, noise contamination, and incomplete spatial coverage. These limitations often degrade event continuity and compromise the physical consistency of conventional interpolation methods. This study introduces a physics-informed framework for 5D prestack dataset reconstruction based on a multi-parameter common-reflection-point (CRP) traveltime stacking operator. The proposed offset-continuation-trajectory (OCT) operator derives coherent stacking trajectories from wavefront propagation, isochronous surface geometry, specular reflection, and diffraction kinematics. All kinematic parameters are estimated directly from the data through a global coevolutionary optimization strategy. The method reconstructs missing traces and enhances spatial continuity by stacking seismic events along physically consistent traveltime surfaces, preserving both reflection and diffraction kinematics. Applications to synthetic and field datasets demonstrate improved signal-to-noise ratio, enhanced structural continuity, and reliable recovery of unrecorded amplitudes without introducing artificial events. The results indicate that incorporating physically constrained traveltime models into the regularization process provides a robust, geologically consistent alternative to purely mathematical interpolation techniques, thereby improving data fidelity for subsequent imaging and quantitative interpretation.

physics.geo-ph↗

arXiv2023

Ultra-fast traveltime parameters search by a coevolutionary optimization approach using graphics processing units

The search for traveltime parameters is a global optimization problem. Several metaheuristics have been proposed to locate the global optima to compute the least amount of their objective functions. However, the theoretical limitations imposed by the no-free-lunch theorem restrict the optimality of such metaheuristics. To escape those limitations, we propose a coevolutionary approach called evolution by neighborhood similarity, which is outside the scope of the restrictions of this theorem and allows us to speed up the search convergence. The technique's effectiveness is based on the approach to exchanging the best individuals found between suitable domains during a differential evolution metaheuristic execution. Moreover, we further expand our technique to graphics processing units, allowing us to explore the performance and memory aspects of the method. Ultimately, our complete coevolutionary algorithm can speed up the parameter search by more than five times and reduce the energy consumption by more than thirty-three times compared to a regular metaheuristic implementation. Although some overheads are still problematic in the technique, we present a first approach that effectively explores the data redundancy hidden in the estimation process, allowing us to provide qualitative, performance, and scalable improvements.

physics.geo-ph↗

arXiv2023

Exploring velocity-spreading factor and consequences through dynamic ray-tracing in general anisotropic media: A comprehensive tutorial

In seismic imaging, understanding the relationship between wavefront-propagation velocity and time-interval velocity is crucial for achieving optimal resolution. However, this task becomes even more challenging when considering anisotropic situations. To accurately account for the influence of anisotropy on wavefronts, it is essential to have a solid grasp of the underlying physics. Unfortunately, the anisotropy model that best describes the medium is often unknown. To address this issue, we utilize paraxial-ray theory in a ray-centered coordinate system to study the wavefront phenomenon. This approach allows us to develop explicit expressions that describe the physics of the problem. Using this theoretical framework, we can accurately generalize the relationship between time-migration rays and Dix velocity by incorporating the velocity-spreading factor for general anisotropic media. This factor lets us determine the type of anisotropy present in the medium. Moreover, the velocity-spreading factor provides valuable information for various applications, including model building, time-imaging, and time-to-depth conversion. Overall, the presented theoretical framework offers a comprehensive understanding of wavefront propagation in anisotropic media, which can aid in improving the knowledge of the phenomena that form seismic images.

physics.geo-ph↗