東華大學圖書館 |

語系: 繁體中文

說明(常見問題)

回圖書館首頁

手機版館藏查詢

登入

回首頁

切換: 標籤 | MARC模式 | ISBD

Velocity analysis in the presence of...

Dussaud, Eric Albert.

FindBook

Google Book

Amazon

博客來

Velocity analysis in the presence of uncertainty.

紀錄類型:	書目-語言資料,印刷品 : Monograph/item
正題名/作者:	Velocity analysis in the presence of uncertainty./
作者:	Dussaud, Eric Albert.
面頁冊數:	199 p.
附註:	Adviser: William W. Symes.
Contained By:	Dissertation Abstracts International67-05B.
標題:	Geophysics. -
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3216700
ISBN:	9780542679971

Velocity analysis in the presence of uncertainty.
Dussaud, Eric Albert.

Velocity analysis in the presence of uncertainty. - 199 p.

Adviser: William W. Symes.

Thesis (Ph.D.)--Rice University, 2005.

Velocity analysis resolves relatively long scales of earth structure, on the order of 1 km. Migration produces images with length scales (wavelengths) on the order of 10's of m. In between these two scale regimes lies another, corresponding roughly to structures between 60 to 300m in extent, in which the resolution of velocity analysis is uncertain and the energy of images is small to non-existent. This thesis aims at assessing the impact on velocity analysis of uncertainty at these intermediate length scales, using ideas on time reversal and imaging in randomly inhomogeneous media developed by Borcea and colleagues, in combination with velocity estimation methods of differential semblance type. The main result of this thesis is that the noise in seismic reflection data associated with the middle scales in velocity heterogeneity does not strongly affect the estimates of the long-scale component of velocity, if these estimates are obtained using a statistically stable formulation of differential semblance optimization. Hence the nonlinear influence of uncertainty in the middle scales does not propagate down the length scale. This is in contrast with the results of Borcea and colleagues, who have shown that prestack images are strongly affected, implying that the uncertainty in the middle scales does certainly propagate up the length scale. Random perturbations associated with the middle scales of velocity heterogeneity yield measurable phase shifts in the reflection data. However, it is known that cross-correlations of neighboring seismic traces are stable against these perturbations, under some circumstances. The main theoretical achievement of this thesis, presented in Chapter 3, is to extend this stability result to laterally homogeneous background velocity models, and to cross-correlations containing slowly-varying weights. Chapter 4 shows that differential semblance functionals, specialized to layered modeling, can be written entirely in terms of weighted cross-correlations, and therefore argues that the velocity analysis algorithm and the associated velocity estimates inherit the statistical stability property. A quantitative verification of the stability claims is provided in Chapter 5.

ISBN: 9780542679971Subjects--Topical Terms:

535228
Geophysics.

Velocity analysis in the presence of uncertainty.
LDR:03079nam 2200277 a 45 001 971873
005 20110927
008 110927s2005 eng d
020 $a 9780542679971
035 $a (UnM)AAI3216700
035 $a AAI3216700
040 $a UnM $c UnM
100 1 $a Dussaud, Eric Albert. $3 1295902
245 1 0 $a Velocity analysis in the presence of uncertainty.
300 $a 199 p.
500 $a Adviser: William W. Symes.
500 $a Source: Dissertation Abstracts International, Volume: 67-05, Section: B, page: 2586.
502 $a Thesis (Ph.D.)--Rice University, 2005.
520 $a Velocity analysis resolves relatively long scales of earth structure, on the order of 1 km. Migration produces images with length scales (wavelengths) on the order of 10's of m. In between these two scale regimes lies another, corresponding roughly to structures between 60 to 300m in extent, in which the resolution of velocity analysis is uncertain and the energy of images is small to non-existent. This thesis aims at assessing the impact on velocity analysis of uncertainty at these intermediate length scales, using ideas on time reversal and imaging in randomly inhomogeneous media developed by Borcea and colleagues, in combination with velocity estimation methods of differential semblance type. The main result of this thesis is that the noise in seismic reflection data associated with the middle scales in velocity heterogeneity does not strongly affect the estimates of the long-scale component of velocity, if these estimates are obtained using a statistically stable formulation of differential semblance optimization. Hence the nonlinear influence of uncertainty in the middle scales does not propagate down the length scale. This is in contrast with the results of Borcea and colleagues, who have shown that prestack images are strongly affected, implying that the uncertainty in the middle scales does certainly propagate up the length scale. Random perturbations associated with the middle scales of velocity heterogeneity yield measurable phase shifts in the reflection data. However, it is known that cross-correlations of neighboring seismic traces are stable against these perturbations, under some circumstances. The main theoretical achievement of this thesis, presented in Chapter 3, is to extend this stability result to laterally homogeneous background velocity models, and to cross-correlations containing slowly-varying weights. Chapter 4 shows that differential semblance functionals, specialized to layered modeling, can be written entirely in terms of weighted cross-correlations, and therefore argues that the velocity analysis algorithm and the associated velocity estimates inherit the statistical stability property. A quantitative verification of the stability claims is provided in Chapter 5.
590 $a School code: 0187.
650 4 $a Geophysics. $3 535228
650 4 $a Mathematics. $3 515831
690 $a 0373
690 $a 0405
710 2 0 $a Rice University. $3 960124
773 0 $t Dissertation Abstracts International $g 67-05B.
790 $a 0187
790 1 0 $a Symes, William W., $e advisor
791 $a Ph.D.
792 $a 2005
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3216700