Layer Stripping Solutions of Inverse Seismic Problems.
MASSACHUSETTS INST OF TECH CAMBRIDGE LAB FOR INFORMATION AND DECISION SYSTEMS
Pagination or Media Count:
The inverse scattering theory concept of layer stripping is applied to a variety of inverse seismic problems. This results in fast algorithms that solve these problems more simple and quickly than techniques used previously on these problems, and also admit physical insight into their operation. A layer stripping algorithm works by recursively identifying and stripping away differential layers of the medium. As the wave front of the excitation passes through a given depth z, the first non zero value of the medium response at depth z yields information about the medium at depth z. Then the excitation and response can be propagated through the known differential layer at depth z to depth z delta, where the process is repeated. The inverse seismic problems for which layer stripping fast algorithm solutions are obtained include the reconstruction of layered acoustic and elastic media from their reflection responses to impulsive plane waves at non-normal incidence the reconstruction of a layered acoustic medium from its reflection response to a point impulsive or harmonic source and the reconstruction of a two dimensionally inhomogeneous medium from its plane wave reflection response. None of these algorithms has appeared previously in the literature. Computer runs of some of these algorithms are included. Several procedures for improving their performance on noisy data are given. Some results on general inverse scattering theory, and relations between these fast algorithms and fast algorithms that exploit structure in matrices or the kernels of integral equations, are presented.