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Modeling of Seismic Data in the Downward Continuation Approach [PDF]

SIAM Journal on Applied Mathematics, 2005
Summary: Seismic data are commonly modeled by a high-frequency single scattering approximation. This amounts to a linearization in the medium coefficient about a smooth background. The discontinuities are contained in the medium perturbation. The high-frequency part of the wavefield in the background medium is described by a geometrical optics ...
Christiaan C. Stolk, Maarten V. de Hoop
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An improved and stable downward continuation of potential field data: The truncated Taylor series iterative downward continuation method

Geophysics, 2013
ABSTRACT We present a stable downward continuation strategy based on combining the ideas of the Taylor series expansion and the iterative downward continuation methods in a single method with better downward continuation and/or computer time/memory performance for potential field data containing noise.
Henglei Zhang, Dhananjay Ravat, Xiangyun Hu   +2 more
exaly   +2 more sources

Stable downward continuation of the total-field magnetic anomaly derived by using equivalent sources

Journal of Applied Geophysics, 2021
The stable downward continuation is an important and difficult problem in magnetic data processing and interpretation. The downward continuation of the magnetic field is an unstable process, wherein high-frequency signals will be rapidly amplified and ...
Zhikui Guo
exaly   +2 more sources

Downward continuation of Helmert's gravity

Journal of Geodesy, 1996
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Vaníček, P., Sun, W., Ong, P., Martinec, Z., Najafi, M., Vajda, P., ter Horst, B.   +6 more
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Wavelet transforms and downward continuation

1994
Applications of wavelet theory [5, 6] to the numerical solution of partial differential equations and integral operators is a rapidly developing topic of research [1]. For a large class of integral operators, with smooth slowly decaying kernels, the matrices approximating these operators which are dense in the natural basis become sparser for the same ...
Ronan Bras, George Mellman
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The downward continuation of the tilt angle

Near Surface Geophysics, 2016
ABSTRACTThe tilt angle filter can be used both to enhance images of aeromagnetic data and as the basis of semi‐automatic interpretation methods. For vertically magnetised and vertically dipping contacts, rescaling by factor is equivalent to computing from sources with all depths decreased by a factor .
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Wavelet transform method for downward continuation

SEG Technical Program Expanded Abstracts 1992, 1992
Wavelet transforms allow efficient analysis of signals in one or more dimensions. The signals may be expressed at different scales of resolution. This provides schemes for compression of informations in image and speech processing. The mathematical framework of wavelet analysis is novel and well grounded in theoretical works and the computation of ...
Ronan LeBras, George Mellman, M. Peters
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Downward continuation within the quasiharmonic region

EGM 2010 International Workshop, 2010
Downward continuation is a useful transformation, mainly used to enhance the measured field. Known limitations regard its instability and are theoretical, because the continuation level should not be deeper than the source depth. Despite of this downward continuation was used in several papers to recover source parameters with different methods here ...
M. Fedi, G. Florio
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A note on downward continuation of gravity

Geophysics, 1954
Abstract Comparing calculated and exact values in an ideal example, it is shown that Peters' proposed method of downward continuation of gravity is far less suitable than a combination of Peters' procedure for upward continuation and a finite differences method for downward continuation.
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Downward continuation of Mars SHARAD data

SEG Technical Program Expanded Abstracts 2014, 2014
Shallow Subsurface Radar (SHARAD) data from the Mars Reconnaissance Orbiter are acquired approximately 300 kilometers above the Martian polar icecap. In this report we detail how to adapt seismic 3D poststack downward continuation to allow construction of the data that would have been recorded a short distance above the Martian surface, thereby saving ...
Stewart A. Levin*, Fritz Foss
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