Frequency-Dependent Ray Tracing at Sub-Surface Interfaces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional ray tracing methods break down at interfaces with high contrast or complex structures, such as those with salt and rugose boundaries, and finite-difference methods are computationally demanding, necessitating more effective data processing techniques for sub-surface region imaging.
Innovation Solution
The method involves performing conventional ray tracing before and after the interface, and at the interface, computing a frequency-dependent outgoing ray direction based on the incoming ray direction, surface normals, and a computed boundary integral that incorporates a frequency parameter, allowing for improved wave propagation modeling through the use of boundary integrals and Fresnel volumes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional ray tracing is used, then computational efficiency is improved, but accuracy breaks down at interfaces with high contrast or complex structures
Solution Approach 1:
The patent applies different ray tracing approaches in different spatial locations: conventional ray tracing is used in regions away from interfaces where it is efficient, while frequency-dependent ray tracing with boundary integrals is applied specifically at interfaces with high contrast or complex structures where accuracy is compromised. This localized application of different methods optimizes both computational efficiency and accuracy.
2Measurement precision
If finite-difference methods are used, then wave propagation accuracy is improved, but computational demand increases significantly
Solution Approach 1:
The patent segments the computational domain into regions where different methods are applied: finite-difference accuracy is captured through frequency-dependent boundary integrals only at interfaces, while conventional ray tracing handles the bulk regions. This segmentation avoids the prohibitive computational cost of applying finite-difference methods throughout the entire domain while preserving their accuracy benefits where needed.
Solution Approach 2:
The patent introduces frequency-dependent boundary integrals as an intermediary approach that bridges conventional ray tracing and full finite-difference methods. These boundary integrals capture the band-limited wave propagation effects of finite-difference methods at interfaces without requiring the full computational apparatus of finite-difference schemes, thus providing finite-difference accuracy at ray-tracing computational cost.
3Stability of the object's composition
If model smoothing is applied, then geometric ray stability is improved, but interface complexity and contrast are reduced
Solution Approach 1:
The patent uses frequency-dependent boundary integrals that incorporate the actual interface geometry and velocity contrasts without modification. These integrals compute the wavefield effects by integrating over the true interface structure, thus preserving interface complexity and contrast fidelity while providing stable results without requiring model smoothing.
4Measurement precision
If frequency-dependent ray tracing with boundary integrals is used, then accuracy at interfaces is improved, but computational complexity increases
Solution Approach 1:
The patent implements frequency-dependent boundary integrals that capture the essential band-limited wave propagation effects at interfaces without computing the full spectrum of possible wave interactions. By focusing on the dominant frequency-dependent effects rather than all possible wave phenomena, the method achieves sufficient accuracy for seismic imaging while keeping computational complexity manageable.
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
Computing systems and methods for improving processing of collected data are disclosed. In one embodiment, while ray-tracing through a sub-surface region, a frequency-dependent outgoing ray direction is computed from a point on an interface disposed in the sub-surface region when the ray tracing is at the interface.