Seismic Source Dithering for Robust Coherent Signal Separation
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Solution Overview
Problem
Seismic data acquisition and processing in complex water areas with challenging geological structures face difficulties due to noise attenuation inefficiencies in existing dithering techniques, which reduce the effectiveness of identifying coherent signals amidst interference noise.
Innovation Solution
Implementing a method and system that designs dithers with a predetermined distribution within a range, optimizing source positions and activating sources with randomized dither times to enhance noise attenuation and improve signal localization in seismic data analysis, utilizing a sparsity promoting domain for source separation processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If dithering techniques are used to improve noise attenuation in seismic data analysis, then the ability to identify coherent signals is improved, but the efficiency of noise attenuation processing deteriorates
Solution Approach 1:
The patent applies preliminary action by pre-designing dither values with specific statistical properties (uniform distribution, controlled range) before the seismic survey. This pre-planned dithering strategy ensures that noise randomization is optimized in advance, allowing efficient processing during data acquisition without compromising signal identification accuracy.
Solution Approach 2:
The patent changes parameters by optimizing the dither range and distribution characteristics. Specifically, it controls the dither amplitude to be within a predetermined range and uses uniform distribution to maximize noise randomization. These parameter optimizations enable both high signal identification accuracy and processing efficiency by finding the optimal balance between dither strength and computational burden.
2Object-generated harmful factors
If dithers are added to nominal source positions to randomize source locations, then interference noise is maximally randomized, but the complexity of survey design and source positioning increases
Solution Approach 1:
The patent applies local quality by applying dither offsets specifically to source positions while keeping receiver positions fixed on a regular grid. This localized randomization approach maximizes interference noise randomization where it is most needed (at the source) without requiring complete redesign of the entire survey geometry, thus controlling design complexity.
Solution Approach 2:
The patent uses preliminary action by pre-calculating and storing the dithered source positions before the survey begins. The dither values are generated in advance with known statistical properties, allowing the actual survey execution to follow a predetermined pattern. This reduces real-time decision complexity while maintaining optimal noise randomization.
Data Source
AI summary
System and method for designing dithers having a pre-determined distribution within a dithers range, wherein the dithers range is chosen for the seismic survey, wherein a lower boundary of the dithers range is 4 seconds or +2 seconds dithers distribution relative to nominal shotting times of sources of seismic waves in the seismic survey, and wherein an upper boundary of the dithers range is a largest value compatible with constraints of the seismic survey.