True-amplitude transformation to zero offset of data from curved reflectors

Journal Article · Fri Jan 01 04:00:00 EST 1999 · Geophysics

DOI:https://doi.org/10.1190/1.1444509· OSTI ID:329236

Bleistein, N; Cohen, J ^[1]; Jaramillo, H ^[2]

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1. Colorado School of Mines, Golden, CO (United States). Center for Wave Phenomena
2. Western Atlas International, Houston, TX (United States)

Transformation to zero offset (TZO), alternatively known as migration to zero offset (MZO), or the combination of normal moveout and dip moveout (NMO/DMO), is a process that transforms data collected at finite offset between source and receiver to a pseudozero offset trace. The kinematic validity of NMO/DMO processing has been well established. The TZO integral operators proposed here differ from their NMO/DMO counterparts by a simple amplitude factor. (The form of the operator depends on how the input and output variables are chosen from among the combinations of mid-point or wavenumber with time or frequency.) With this modification in place, the dynamical validity for planar reflectors of the proposed TZO operators of this paper have been established in earlier studies. This means that the traveltime and geometrical spreading terms of the finite offset data are transformed to their counterparts for zero offset data, while the finite offset reflection coefficient is preserved. The main purpose of this study is to show that dynamical validity of the TZO operator extends to the case of curved reflectors in the 2.5-D limit. Furthermore, in this paper, the authors show how processing of the input data with a second TZO operator allows for the extraction of the cosine of the preserved specular angle, a necessary piece of information for amplitude versus angle (AVA) analysis. They then discuss the possibility of using the output of the processing formalism at multiple offsets to create a table of angularly dependent reflection coefficients and attendant incidence angles as a function of offset. Finally, the authors describe the modifications of Hale DMO and Gardner/Forel DMO to obtain true amplitude output equivalent to their`s and also how to extract the cosine of the specular angle for these forms of DMO.

• Sponsoring Organization: Los Alamos National Lab., NM (United States)
• OSTI ID: 329236
• Journal Information: Geophysics, Journal Name: Geophysics Journal Issue: 1 Vol. 64; ISSN GPYSA7; ISSN 0016-8033
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
AMPLITUDES
CALCULATION METHODS
DATA ANALYSIS
SEISMIC SURVEYS
SEISMIC WAVES