Obtaining high-resolution velocity spectra using weighted semblance
| Autor: | Amin Roshandel Kahoo, Saleh Ebrahimi, Ali Nejati Kalateh, Milton J. Porsani |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Physics
010504 meteorology & atmospheric sciences Normal moveout Mathematical analysis High resolution Mineralogy Geology 010502 geochemistry & geophysics 01 natural sciences Spectral line Weighting Singular value Geophysics Wavelet Singular value decomposition Coherence (signal processing) 0105 earth and related environmental sciences |
| Zdroj: | Exploration Geophysics. 48:210-218 |
| ISSN: | 1834-7533 0812-3985 |
| DOI: | 10.1071/eg15100 |
| Popis: | Velocity analysis employs coherency measurement along a hyperbolic or non-hyperbolic trajectory time window to build velocity spectra. Accuracy and resolution are strictly related to the method of coherency measurements. Semblance, the most common coherence measure, has poor resolution velocity which affects one's ability to distinguish and pick distinct peaks. Increase the resolution of the semblance velocity spectra causes the accuracy of estimated velocity for normal moveout correction and stacking is improved. The low resolution of semblance spectra depends on its low sensitivity to velocity changes. In this paper, we present a new weighted semblance method that ensures high-resolution velocity spectra. To increase the resolution of semblance spectra, we introduce two weighting functions based on the first to second singular values ratio of the time window and the position of the seismic wavelet in the time window to the semblance equation. We test the method on both synthetic and real field data to c... |
| Databáze: | OpenAIRE |
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